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Insecticide resistance across sub-Saharan Africa may impact the continued effectiveness of malaria vector control.,We investigated the association between carbamate and pyrethroid resistance with Anopheles gambiae s.l. parity, Plasmodium falciparum infection, and molecular insecticide resistance mechanisms in Guinea.,Pyrethroid resistance was intense, with field populations surviving ten times the insecticidal concentration required to kill susceptible individuals.,The L1014F kdr-N1575Y haplotype and I1527T mutation were significantly associated with mosquito survival following permethrin exposure (Prevalence Ratio; PR = 1.92, CI = 1.09-3.37 and PR = 2.80, CI = 1.03-7.64, respectively).,Partial restoration of pyrethroid susceptibility following synergist pre-exposure suggests a role for mixed-function oxidases.,Carbamate resistance was lower and significantly associated with the G119S Ace-1 mutation.,Oocyst rates were 6.8% and 4.2% among resistant and susceptible mosquitoes, respectively; survivors of bendiocarb exposure were significantly more likely to be infected.,Pyrethroid resistant mosquitoes had significantly lower parity rates than their susceptible counterparts (PR = 1.15, CI = 1.10-1.21).,Our findings emphasize the need for additional studies directly assessing the influence of insecticide resistance on mosquito fitness.

Large-scale implementation of Indoor Residual Spraying and Insecticide Treated Nets has been implemented in Plateau Department, Benin between 2011 and 2014.,The purpose of this study was to monitor the frequency and mechanisms of pyrethroid resistance in malaria vectors following the implementation of vector control tools for malaria prevention.,Anopheles larvae were collected in 13 villages twice a year from 2012 to 2014.,WHO tube tests were used to assess the phenotypic resistance of each population to 0.05 % deltamethrin.,Sibling species within Anopheles gambiae complex were identified by PCR techniques.,Taqman and biochemical assays were performed to identify the presence of kdr mutations in individual mosquitoes and to detect any increase in the activity of enzymes putatively involved in insecticide metabolism (oxidases, esterase and glutathione-S-transferases).,Quantitative real time PCR was used to measure the expression of three metabolic genes involved in pyrethroid resistance (CYP6P3, CYP6M2 and GSTD3).,Anopheles populations showed < 90 % mortality to deltamethrin in all villages and at all time points.,The 1014 F kdr allele frequency was close to fixation (> 0.9) over the sampling periods in both An. gambiae and An. coluzzii.,Biochemical assays showed higher activities of alpha esterase and GST in field malaria vector populations compared to susceptible mosquitoes. qPCR assays showed a significant increase of CYP6P3, CYP6M2 GSTD3 expression in An. gambiae after a three-year implementation of LLINs.,The study confirmed that deltamethrin resistance is widespread in malaria vectors in Southern Benin.,We suspect that the increase in deltamethrin resistance between 2012 and 2014 resulted from an increased expression of metabolic detoxification genes (CYP6M2 and CYP6P3) rather than from kdr mutations.,It is urgent to evaluate further the impact of metabolic resistance on the efficacy of vector control interventions using pyrethroid insecticides.

Electroencephalography at hospital presentation may offer important insights regarding prognosis that can inform understanding of cerebral malaria (CM) pathophysiology and potentially guide patient selection and risk stratification for future clinical trials.,Electroencephalogram (EEG) findings in children with CM in Uganda and Malawi were compared and associations between admission EEG findings and outcome across this diverse population were assessed.,Demographic, clinical and admission EEG data from Ugandan and Malawian children admitted from 2009 to 2012 with CM were gathered, and survivors assessed for neurological abnormalities at discharge.,281 children were enrolled (Uganda n = 122, Malawi n = 159).,The Malawian population was comprised only of retinopathy positive children (versus 72.5% retinopathy positive in Uganda) and were older (4.2 versus 3.7 years; p = 0.046), had a higher HIV prevalence (9.0 versus 2.8%; p = 0.042), and worse hyperlactataemia (7.4 versus 5.2 mmol/L; p < 0.001) on admission compared to the Ugandan children.,EEG findings differed between the two groups in terms of average voltage and frequencies, reactivity, asymmetry, and the presence/absence of sleep architecture.,In univariate analyses pooling EEG and outcomes data for both sites, higher average and maximum voltages, faster dominant frequencies, and retained reactivity were associated with survival (all p < 0.05).,Focal slowing was associated with death (OR 2.93; 95% CI 1.77-7.30) and a lower average voltage was associated with neurological morbidity in survivors (p = 0.0032).,Despite substantial demographic and clinical heterogeneity between subjects in Malawi and Uganda as well as different EEG readers at each site, EEG findings on admission predicted mortality and morbidity.,For CM clinical trials aimed at decreasing mortality or morbidity, EEG may be valuable for risk stratification and/or subject selection.

Arjen Dondorp and colleagues investigate whether the plasma level of Plasmodium falciparum histidine-rich protein 2 can be used to distinguish between severe malaria and other severe febrile illness in African children with malaria.,In African children, distinguishing severe falciparum malaria from other severe febrile illnesses with coincidental Plasmodium falciparum parasitaemia is a major challenge.,P. falciparum histidine-rich protein 2 (PfHRP2) is released by mature sequestered parasites and can be used to estimate the total parasite burden.,We investigated the prognostic significance of plasma PfHRP2 and used it to estimate the malaria-attributable fraction in African children diagnosed with severe malaria.,Admission plasma PfHRP2 was measured prospectively in African children (from Mozambique, The Gambia, Kenya, Tanzania, Uganda, Rwanda, and the Democratic Republic of the Congo) aged 1 month to 15 years with severe febrile illness and a positive P. falciparum lactate dehydrogenase (pLDH)-based rapid test in a clinical trial comparing parenteral artesunate versus quinine (the AQUAMAT trial, ISRCTN 50258054).,In 3,826 severely ill children, Plasmadium falciparum PfHRP2 was higher in patients with coma (p = 0.0209), acidosis (p<0.0001), and severe anaemia (p<0.0001).,Admission geometric mean (95%CI) plasma PfHRP2 was 1,611 (1,350-1,922) ng/mL in fatal cases (n = 381) versus 1,046 (991-1,104) ng/mL in survivors (n = 3,445, p<0.0001), without differences in parasitaemia as assessed by microscopy.,There was a U-shaped association between log10 plasma PfHRP2 and risk of death.,Mortality increased 20% per log10 increase in PfHRP2 above 174 ng/mL (adjusted odds ratio [AOR] 1.21, 95%CI 1.05-1.39, p = 0.009).,A mechanistic model assuming a PfHRP2-independent risk of death in non-malaria illness closely fitted the observed data and showed malaria-attributable mortality less than 50% with plasma PfHRP2≤174 ng/mL.,The odds ratio (OR) for death in artesunate versus quinine-treated patients was 0.61 (95%CI 0.44-0.83, p = 0.0018) in the highest PfHRP2 tertile, whereas there was no difference in the lowest tertile (OR 1.05; 95%CI 0.69-1.61; p = 0.82).,A limitation of the study is that some conclusions are drawn from a mechanistic model, which is inherently dependent on certain assumptions.,However, a sensitivity analysis of the model indicated that the results were robust to a plausible range of parameter estimates.,Further studies are needed to validate our findings.,Plasma PfHRP2 has prognostic significance in African children with severe falciparum malaria and provides a tool to stratify the risk of “true” severe malaria-attributable disease as opposed to other severe illnesses in parasitaemic African children.,Please see later in the article for the Editors' Summary.,Malaria is a life-threatening disease caused by parasites that are transmitted to people through the bites of infected mosquitoes.,In 2010, malaria caused an estimated 655,000 deaths worldwide, mostly in Africa, where according to the World Health Organization, one African child dies every minute from the disease.,There are four Plasmodium parasite species that cause malaria in humans, with one species, Plasmodium falciparum, causing the most severe disease.,However, diagnosing severe falciparum malaria in children living in endemic areas is problematic, as many semi-immune children may have the malaria parasites in their blood (described as being parasitaemic) but do not have clinical disease.,Therefore, a positive malaria blood smear may be coincidental and not be diagnostic of severe malaria, and unfortunately, neither are the clinical symptoms of severe malaria, such as shock, acidosis, or coma, which can also be caused by other childhood infections.,For these reasons, the misdiagnosis of falciparum malaria in severely ill children is an important problem in sub-Saharan Africa, and may result in unnecessary child deaths.,Previous studies have suggested that a parasite protein-P. falciparum histidine-rich protein-2 (PfHRP2)-is a measure of the total number of parasites in the patient.,Unlike the circulating parasites detected on a blood film, which do not represent the parasites that get stuck in vital organs, PfHRP2 is distributed equally through the total blood plasma volume, and so can be considered a measure of the total parasite burden in the previous 48 hours.,So in this study, the researchers assessed the prognostic value of plasma PfHRP2 in African children with severe malaria and whether this protein could distinguish children who really do have severe malaria from those who have severe febrile illness but coincidental parasitaemia, who may have another infection.,The researchers assessed levels of plasma PfHRP2 in 3,826 out of a possible 5,425 African children who participated in a large multinational trial (in Mozambique, The Gambia, Rwanda, Tanzania, Kenya, Uganda, and the Democratic Republic of Congo) that compared the anti-malarial drugs quinine and artesunate for the treatment of severe malaria.,All children had a clinical diagnosis of severe malaria confirmed by a rapid diagnostic test, and the researchers used clinical signs to define the severity of malaria.,The researchers assessed the relationship between plasma PfHRP2 concentrations and risk of death taking other well established predictors of death, such as coma, convulsions, hypoglycaemia, respiratory distress, and shock, into account.,The researchers found that PfHRP2 was detectable in 3,800/3,826 (99%) children with severe malaria and that the average plasma PfHRP2 levels was significantly higher in the 381 children who died from malaria than in children who survived (1,611 ng/mL versus 1,046 ng/mL).,Plasma PfHRP2 was also significantly higher in children with severe malaria signs and symptoms such as coma, acidosis, and severe anaemia.,Importantly, the researchers found that high death rates were associated with either very low or very high values of plasma PfHRP2: the odds (chance) of death were 20% higher per unit increase in PfHRP2 above a specific threshold (174 ng/ml), but below this concentration, the risk of death increased with decreasing levels, probably because at lower levels disease was caused by a severe febrile disease other than malaria, like septicemia.,Finally, the researchers found that in children within the highest PfHRP2 tertile, the chance of death when treated with the antimalarial drug artesunate versus quinine was 0.61 but that there was no difference in death rates in the lowest tertile, which supports that patients with very low plasma PfHRP2 have a different severe febrile illness than malaria.,The researchers use mathematical modeling to provide cut-off values for plasma PfHRP2 denoting the proportion of patients with a diagnosis other than severe malaria.,These findings suggest that in areas of moderate or high malaria transmission where a high proportion of children are parasitaemic, plasma PfHRP2 levels taken on admission to hospital can differentiate children at highest risk of death from severe falciparum malaria from those likely to have alternative causes of severe febrile illness.,Therefore, plasma PfHRP2 could be considered a valuable additional diagnostic tool and prognostic indicator in African children with severe falciparum malaria.,This finding is important for clinicians treating children with severe febrile illnesses in malaria-endemic countries: while high levels of plasma PfHRP2 is indicative of severe malaria which needs urgent antimalarial treatment, low levels suggest that another severe infective disease should be considered, warranting additional investigations and urgent treatment with antibiotics.,Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001297.,A previous small study in PLOS ONE explores the relationship between plasma PfHRP2 and severe malaria in Tanzanian children,The WHO website and the website of Malaria No More have comprehensive information about malaria

Trichinella spiralis is a parasitic helminth that can infect almost all mammals, including humans.,Trichinella spiralis infection elicits a typical type 2 immune responses, while suppresses type 1 immune responses, which is in favour of their parasitism.,DNA vaccines have been shown to be capable of eliciting balanced CD4+ and CD8+ T cell responses as well as humoral immune responses in small-animal models, which will be advantage to induce protective immune response against helminth infection.,In this study, serine protease (Ts-NBLsp) was encoded by a cDNA fragment of new-born T. spiralis larvae, and was inserted after CMV promoter to construct a DNA vaccine [pcDNA3·1(+)-Ts-NBLsp].,Ts-NBLsp expression was demonstrated by immunofluorescence.,Sera samples were obtained from vaccinated mice, and they showed strong anti-Ts-NBLsp-specific IgG response.,Mice immunized with the pcDNA3·1(+)-Ts-NBLsp DNA vaccine showed a 77·93% reduction in muscle larvae (ML) following challenge with T. spiralis ML.,Our results demonstrate that the vaccination with pcDNA3·1(+)-Ts-NBLsp plasmid promoted the balance of type 1 and 2 immune responses and produced a significant protection against T. spiralis infection in mice.

Our previous studies showed that Trichinella spiralis paramyosin (TsPmy) is an immunomodulatory protein that inhibits complement C1q and C8/C9 to evade host complement attack.,Vaccination with recombinant TsPmy protein induced protective immunity against T. spiralis larval challenge.,Due to the difficulty in producing TsPmy as a soluble recombinant protein, we prepared a DNA vaccine as an alternative approach in order to elicit a robust immunity against Trichinella infection.,The full-length TsPmy coding DNA was cloned into the eukaryotic expression plasmid pVAX1, and the recombinant pVAX1/TsPmy was transformed into attenuated Salmonella typhimurium strain SL7207.,Oral vaccination of mice with this attenuated Salmonella-delivered TsPmy DNA vaccine elicited a significant mucosal sIgA response in the intestine and a systemic IgG antibody response with IgG2a as the predominant subclass.,Cytokine analysis also showed a significant increase in the Th1 (IFN-γ, IL-2) and Th2 (IL-4, 5, 6, 10) responses in lymphocytes from the spleen and MLNs of immunized mice upon stimulation with TsPmy protein.,The expression of the homing receptors CCR9/CCR10 on antibody secreting B cells may be related to the translocation of IgA-secreted B cells to local intestinal mucosa.,The mice immunized with Salmonella-delivered TsPmy DNA vaccine produced a significant 44.8% reduction in adult worm and a 46.6% reduction in muscle larvae after challenge with T. spiralis larvae.,Our results demonstrated that oral vaccination with TsPmy DNA delivered by live attenuated S. typhimurium elicited a significant local IgA response and a mixed Th1/Th2 immune response that elicited a significant protection against T. spiralis infection in mice.

Active case detection (ACD) significantly contributes to early detection and treatment of visceral leishmaniasis (VL) and post kala-azar dermal leishmaniasis (PKDL) cases and is cost effective.,This paper evaluates the performance and feasibility of adapting ACD strategies into national programs for VL elimination in Bangladesh, India and Nepal.,The camp search and index case search strategies were piloted in 2010-11 by national programs in high and moderate endemic districts / sub-districts respectively.,Researchers independently assessed the performance and feasibility of these strategies through direct observation of activities and review of records.,Program costs were estimated using an ingredients costing method.,Altogether 48 camps (Bangladesh-27, India-19, Nepal-2) and 81 index case searches (India-36, Nepal-45) were conducted by the health services across 50 health center areas (Bangladesh-4 Upazillas, India-9 PHCs, Nepal-37 VDCs).,The mean number of new case detected per camp was 1.3 and it varied from 0.32 in India to 2.0 in Bangladesh.,The cost (excluding training costs) of detecting one new VL case per camp varied from USD 22 in Bangladesh, USD 199 in Nepal to USD 320 in India.,The camp search strategy detected a substantive number of new PKDL cases.,The major challenges faced by the programs were inadequate preparation, time and resources spent on promoting camp awareness through IEC activities in the community.,Incorrectly diagnosed splenic enlargement at camps probably due to poor clinical examination skills resulted in a high proportion of patients being subjected to rK39 testing.,National programs can adapt ACD strategies for detection of new VL/PKDL cases.,However adequate time and resources are required for training, planning and strengthening referral services to overcome challenges faced by the programs in conducting ACD.

Incidence of Leishmania donovani infection and Visceral Leishmaniasis (VL) was assessed in a prospective study in Indian and Nepalese high-endemic villages.,DAT-seroconversion was used as marker of incident infection in 3 yearly surveys.,The study population was followed up to month 30 to identify incident clinical cases.,In a cohort of 9034 DAT-negative individuals with neither active signs nor history of VL at baseline, 42 VL cases and 375 asymptomatic seroconversions were recorded in the first year, giving an infection∶disease ratio of 8.9 to 1.,In the 18 months' follow-up, 7 extra cases of VL were observed in the seroconverters group (N = 375), against 14 VL cases among the individuals who had not seroconverted in the first year (N = 8570) (RR = 11.5(4.5<RR<28.3)).,Incident asymptomatic L. donovani infection in VL high-endemic foci in India and Nepal is nine times more frequent than incident VL disease.,About 1 in 50 of these new but latent infections led to VL within the next 18 months.

Acquired immunity in vertebrates maintains polymorphisms in endemic pathogens, leading to identifiable signatures of balancing selection.,To comprehensively survey for genes under such selection in the human malaria parasite Plasmodium falciparum, we generated paired-end short-read sequences of parasites in clinical isolates from an endemic Gambian population, which were mapped to the 3D7 strain reference genome to yield high-quality genome-wide coding sequence data for 65 isolates.,A minority of genes did not map reliably, including the hypervariable var, rifin, and stevor families, but 5,056 genes (90.9% of all in the genome) had >70% sequence coverage with minimum read depth of 5 for at least 50 isolates, of which 2,853 genes contained 3 or more single nucleotide polymorphisms (SNPs) for analysis of polymorphic site frequency spectra.,Against an overall background of negatively skewed frequencies, as expected from historical population expansion combined with purifying selection, the outlying minority of genes with signatures indicating exceptionally intermediate frequencies were identified.,Comparing genes with different stage-specificity, such signatures were most common in those with peak expression at the merozoite stage that invades erythrocytes.,Members of clag, PfMC-2TM, surfin, and msp3-like gene families were highly represented, the strongest signature being in the msp3-like gene PF10_0355.,Analysis of msp3-like transcripts in 45 clinical and 11 laboratory adapted isolates grown to merozoite-containing schizont stages revealed surprisingly low expression of PF10_0355.,In diverse clonal parasite lines the protein product was expressed in a minority of mature schizonts (<1% in most lines and ∼10% in clone HB3), and eight sub-clones of HB3 cultured separately had an intermediate spectrum of positive frequencies (0.9 to 7.5%), indicating phase variable expression of this polymorphic antigen.,This and other identified targets of balancing selection are now prioritized for functional study.

Chlorproguanil-dapsone (Lapdap), developed as a low-cost antimalarial, was withdrawn in 2008 after concerns about safety in G6PD deficient patients.,This trial was conducted in 2004 to evaluate the safety and effectiveness of CD and comparison with artemether-lumefantrine (AL) under conditions of routine use in G6PD normal and G6PD deficient patients with uncomplicated malaria in The Gambia.,We also examined the effects of a common genetic variant that affects chlorproguanil metabolism on risk of treatment failure.,1238 children aged 6 months to 10 years with uncomplicated malaria were randomized to receive CD or artemether-lumefantrine (AL) and followed for 28 days.,The first dose was supervised, subsequent doses given unsupervised at home.,G6PD genotype was determined to assess the interaction between treatment and G6PD status in their effects on anaemia.,The main endpoints were clinical treatment failure by day 28, incidence of severe anaemia (Hb<5 g/dL), and haemoglobin concentration on day 3.,One third of patients treated with AL, and 6% of patients treated with CD, did not complete their course of medication. 18% (109/595) of children treated with CD and 6.1% (36/587) with AL required rescue medication within 4 weeks, risk difference 12% (95%CI 8.9%-16%). 23 children developed severe anaemia (17 (2.9%) treated with CD and 6 (1.0%) with AL, risk difference 1.8%, 95%CI 0.3%-3.4%, P = 0.02).,Haemoglobin concentration on day 3 was lower among children treated with CD than AL (difference 0.43 g/dL, 95% CI 0.24 to 0.62), and within the CD group was lower among those children who had higher parasite density at enrolment.,Only 17 out of 1069 children who were typed were G6PD A- deficient, of these 2/9 treated with CD and 1/8 treated with AL developed severe anaemia. 5/9 treated with CD had a fall of 2 g/dL or more in haemoglobin concentration by day 3.,AL was well tolerated and highly effective and when given under operational conditions despite poor adherence to the six-dose regimen.,There were more cases of severe malaria and anaemia after CD treatment although G6PD deficiency was uncommon.,Clinicaltrials.gov NCT00118794

Growing concerns about the waning efficacy of IPTp-SP warrants continuous monitoring and evaluation.,This study determined coverage of IPTp-SP and compared the effectiveness of the 3-dose to 2-dose regimen on placental malaria (PM) infection and low birth weight (LBW) in the Mount Cameroon area.,Consenting pregnant women were enrolled consecutively through a cross-sectional survey at delivery at four antenatal clinics, two each from semi-rural and semi-urban settings from November 2016 to December 2017.,Reported IPTp-SP use, demographic and antenatal clinic (ANC) data of the mothers and neonate birth weights were documented.,Maternal haemoglobin concentration was measured using a haemoglobinometer and PM infection diagnosed by placental blood microscopy.,Logistic regression analysis was used to model study outcomes.,Among the 465 parturient women enrolled, 47.0% (203), 34.7% (150), 18.3% (79) and 7.1% (33) reported uptake of ≥ 3, 2.1 dose(s) and no SP, respectively.,Uptake of ≥ 3 doses varied significantly (p < 0.001) according to type of medical facility, timing of ANC initiation and number of ANC visits.,The prevalence of PM was 18.5% where uptake of ≥ 3 SP doses (AOR = 2.36: 95% CI 1.41-4.87), primiparity (AOR = 2.13: 95% CI 1.19-3.81), semi-rural setting (AOR = 1.85: 95% CI 1.12-3.04) increased odds of infection.,Also, three or more dosing was associated (p < 0.001) with increased PM density notably among women from semi-urban areas.,Compared with third trimester, ANC initiation in the second trimester (AOR: 0.39: 95% CI 0.20-0.74) lower odds of infection.,The prevalence of LBW infants was 7.3% and were generally those of anaemic (AOR: 4.6: 95% CI 1.03-20.57) and semi-rural (AOR: 5.29: 95% CI 1.73-16.15) women.,Although ≥ 3 (AOR: 0.31: 95% CI 0.11-0.87) and 2 (AOR: 0.32: 95% CI 0.11-0.93) doses of SP was associated with lower odds of LBW, ≥ 3 doses were not associated with additional increase in birth weight nor maternal haemoglobin levels when compared with 2 doses.,In the Mount Cameroon area, reported uptake of IPTp with ≥ 3 SP doses did not provide observable prophylactic benefits.,SP resistance efficacy studies are necessary.

Malaria in pregnancy is a major public health challenge, but its risk factors remain poorly understood in some settings.,This study assessed the association between household and maternal characteristics and malaria among pregnant women in a high transmission area of Uganda.,A nested prospective study was conducted between 6th September 2016 and 5th December 2017 in Busia district.,782 HIV uninfected women were enrolled in the parent study with convenience sampling.,Socioeconomic and house construction data were collected via a household survey after enrolment.,Homes were classified as modern (plaster or cement walls, metal or wooden roof and closed eaves) or traditional (all other homes).,Maternal and household risk factors were evaluated for three outcomes: (1) malaria parasitaemia at enrolment, measured by thick blood smear and qPCR, (2) malaria parasitaemia during pregnancy following initiation of IPTp, measured by thick blood smear and qPCR and (3) placental malaria measured by histopathology.,A total of 753 of 782 women were included in the analysis.,Most women had no or primary education (75%) and lived in traditional houses (77%).,At enrolment, microscopic or sub-microscopic parasitaemia was associated with house type (traditional versus modern: adjusted risk ratio (aRR) 1.29, 95% confidence intervals 1.15-1.45, p < 0.001), level of education (primary or no education versus O-level or beyond: aRR 1.13, 95% confidence interval 1.02-1.24, p = 0.02), and gravidity (primigravida versus multigravida: aRR 1.10, 95% confidence interval 1.02-1.18, p = 0.009).,After initiation of IPTp, microscopic or sub-microscopic parasitaemia was associated with wealth index (poorest versus least poor: aRR 1.24, 95% CI 1.10-1.39, p < 0.001), house type (aRR 1.14, 95% CI 1.01-1.28, p = 0.03), education level (aRR 1.19, 95% CI 1.06-1.34, p = 0.002) and gravidity (aRR 1.32, 95% CI 1.20-1.45, p < 0.001).,Placental malaria was associated with gravidity (aRR 2.87, 95% CI 2.39-3.45, p < 0.001), but not with household characteristics.,In an area of high malaria transmission, primigravid women and those belonging to the poorest households, living in traditional homes and with the least education had the greatest risk of malaria during pregnancy.

The ability to undertake controlled human malaria infection (CHMI) studies for preliminary evaluation of malaria vaccine candidates and anti-malaria drug efficacy has been limited by the need for access to sporozoite infected mosquitoes, aseptic, purified, cryopreserved sporozoites or blood-stage malaria parasites derived ex vivo from malaria infected individuals.,Three different strategies are described for the manufacture of clinical grade cultured malaria cell banks suitable for use in CHMI studies.,Good Manufacturing Practices (GMP)-grade Plasmodium falciparum NF54, clinically isolated 3D7, and research-grade P. falciparum 7G8 blood-stage malaria parasites were cultured separately in GMP-compliant facilities using screened blood components and then cryopreserved to produce three P. falciparum blood-stage malaria cell banks.,These cell banks were evaluated according to specific criteria (parasitaemia, identity, viability, sterility, presence of endotoxin, presence of mycoplasma or other viral agents and in vitro anti-malarial drug sensitivity of the cell bank malaria parasites) to ensure they met the criteria to permit product release according to GMP requirements.,The P. falciparum NF54, 3D7 and 7G8 cell banks consisted of >78% ring stage parasites with a ring stage parasitaemia of >1.4%.,Parasites were viable in vitro following thawing.,The cell banks were free from contamination with bacteria, mycoplasma and a broad panel of viruses.,The P. falciparum NF54, 3D7 and 7G8 parasites exhibited differential anti-malarial drug susceptibilities.,The P. falciparum NF54 and 3D7 parasites were susceptible to all anti-malaria compounds tested, whereas the P. falciparum 7G8 parasites were resistant/had decreased susceptibility to four compounds.,Following testing, all defined release criteria were met and the P. falciparum cell banks were deemed suitable for release.,Ethical approval has been obtained for administration to human volunteers.,The production of cultured P. falciparum blood-stage malaria cell banks represents a suitable approach for the generation of material suitable for CHMI studies.,A key feature of this culture-based approach is the ability to take research-grade material through to a product suitable for administration in clinical trials.,The online version of this article (doi:10.1186/s12936-015-0663-x) contains supplementary material, which is available to authorized users.

In 2006, the first-line anti-malarial drug treatment in Tanzania was changed from sulphadoxine-pyrimethamine (SP) to artemether-lumefantrine (ALu), an artemisinin-based combination (ACT), since when the use of SP has been restricted for intermittent preventive treatment in pregnancy (IPTp).,A number of Plasmodium falciparum mutations are known to be associated with resistance to SP, but it is not known if the prevalence of these mutations is increasing or decreasing under the conditions of reduced levels of SP use.,This study reports on the current SP resistant quintuple Pfdhfr-Pfdhps mutations in six regions of Tanzania.,Finger-prick blood on filter paper and rapid diagnostic test strips from P. falciparum-positive individuals of all age groups attending health facilities in six regions of Tanzania between June 2010 and August 2011 were obtained.,Using chelex-100 extracted DNA, genotyping was done for mutations on codons 51, 59 and 108 of Pfdhfr and 437 and 540 of Pfdhps genes using PCR-RFLP technique.,A total of 802 malaria-positive samples were screened and genotyped.,The prevalence of Pfdhfr 51I, Pfdhps 437G and 540E varied between the regions (p < 0.001) whereas Pfdhfr 59R (FE 10.79, p = 0.225) and 108 N (FE 10.61, p = 0.239) did not vary between the regions.,The Pfdhfr triple mutant was above 84% and close to fixation levels in all regions, whereas the Pfdhps double mutation ranged from 43.8 to 97% between the regions.,The quintuple mutant (IRNGE) was the most prevalent in all regions and it varied significantly from 37.5 to 90.2% (χ2 = 1.11, p <0.001).,There is evidence of persistent high levels of SP resistance markers in Tanzania with evidence of quintuple mutations that are likely to become fixed in the population.,This threatens the future of SP not only in IPTp programmes, but as a combination drug for ACT.,Continuous monitoring of SP-IPTp efficacy should be encouraged subsequent to searching for alternative drugs for IPTp in East Africa.

Gamma-aminobutyric acid (GABA) serves diverse biological functions in prokaryotes and eukaryotes, including neurotransmission in vertebrates.,Yet, the role of GABA in the immune system has remained elusive.,Here, a comprehensive characterization of human and murine myeloid mononuclear phagocytes revealed the presence of a conserved and tightly regulated GABAergic machinery with expression of GABA metabolic enzymes and transporters, GABA-A receptors and regulators, and voltage-dependent calcium channels.,Infection challenge with the common coccidian parasites Toxoplasma gondii and Neospora caninum activated GABAergic signaling in phagocytes.,Using gene silencing and pharmacological modulators in vitro and in vivo in mice, we identify the functional determinants of GABAergic signaling in parasitized phagocytes and demonstrate a link to calcium responses and migratory activation.,The findings reveal a regulatory role for a GABAergic signaling machinery in the host-pathogen interplay between phagocytes and invasive coccidian parasites.,The co-option of GABA underlies colonization of the host by a Trojan horse mechanism.

During acute infection in human and animal hosts, the obligate intracellular protozoan Toxoplasma gondii infects a variety of cell types, including leukocytes.,Poised to respond to invading pathogens, dendritic cells (DC) may also be exploited by T. gondii for spread in the infected host.,Here, we report that human and mouse myeloid DC possess functional γ-aminobutyric acid (GABA) receptors and the machinery for GABA biosynthesis and secretion.,Shortly after T. gondii infection (genotypes I, II and III), DC responded with enhanced GABA secretion in vitro.,We demonstrate that GABA activates GABAA receptor-mediated currents in T. gondii-infected DC, which exhibit a hypermigratory phenotype.,Inhibition of GABA synthesis, transportation or GABAA receptor blockade in T. gondii-infected DC resulted in impaired transmigration capacity, motility and chemotactic response to CCL19 in vitro.,Moreover, exogenous GABA or supernatant from infected DC restored the migration of infected DC in vitro.,In a mouse model of toxoplasmosis, adoptive transfer of infected DC pre-treated with GABAergic inhibitors reduced parasite dissemination and parasite loads in target organs, e.g. the central nervous system.,Altogether, we provide evidence that GABAergic signaling modulates the migratory properties of DC and that T. gondii likely makes use of this pathway for dissemination.,The findings unveil that GABA, the principal inhibitory neurotransmitter in the brain, has activation functions in the immune system that may be hijacked by intracellular pathogens.

Most malaria-endemic countries have struggled in the past decade to establish effective national-scale continuous distribution mechanisms for long-lasting insecticidal nets (LLINs).,Since the implementation of the Tanzania National Voucher Scheme in 2004 and mass-distribution campaigns in 2009-2011 and 2015-2016, Tanzania has been committed to finding new and innovative ways of achieving and maintaining universal bed net coverage.,Planning for the School Net Programme (SNP) began in 2011 and in 2013, the country piloted a SNP in three regions.,Nets were distributed annually to children attending schools in selected primary and secondary grades.,Intra-family re-distribution was assumed, and hence the family as a whole, rather than just the children themselves, were the targeted beneficiaries.,The programme has since expanded to 14 regions and has seen six rounds of annual distribution.,In its fifth year, 3 million nets were distributed at a cost of USD 3.64 per net and USD 0.60 per person-year of protection (including the net).,ITN access and use were maintained at a high level (~ 50-75%) over the first 4 years of distribution within selected evaluation areas, even in the absence of a mass distribution event.,Net distribution through primary schools has proven to be a feasible and effective strategy for maintaining consistently high coverage in Tanzania.

School-age children have attracted relatively little attention as a group in need of special measures to protect them against malaria.,However, increasing success in lowering the level of malaria transmission in many previously highly endemic areas will result in children acquiring immunity to malaria later in life than has been the case in the past.,Thus, it can be anticipated that in the coming years there will be an increase in the incidence of both uncomplicated and severe malaria in school-age children in many previously highly endemic areas.,In this review, which focuses primarily on Africa, recent data on the prevalence of malaria parasitaemia and on the incidence of clinical malaria in African school-age children are presented and evidence that malaria adversely effects school performance is reviewed.,Long-lasting insecticide treated bednets (LLIN) are an effective method of malaria control but several studies have shown that school-age children use LLINs less frequently than other population groups.,Antimalarial drugs are being used in different ways to control malaria in school-age children including screening and treatment and intermittent preventive treatment.,Some studies of chemoprevention in school-age children have shown reductions in anaemia and improved school performance but this has not been the case in all trials and more research is needed to identify the situations in which chemoprevention is likely to be most effective and, in these situations, which type of intervention should be used.,In the longer term, malaria vaccines may have an important role in protecting this important section of the community from malaria.,Regardless of the control approach selected, it is important this is incorporated into the overall programme of measures being undertaken to enhance the health of African school-age children.

Malaria remains a public health concern worldwide, including Indonesia.,Purworejo is a district in which endemic of malaria, they have re-setup to entering malaria elimination in 2021.,Accordingly, actions must be taken to accelerate and guaranty that the goal will reach based on an understanding of the risk factors for malaria.,Thus, we analysed malaria risk factors based on human and housing conditions in Kaligesing, Purworejo, Indonesia.,A case-control study was carried out in Kaligesing subdistrict, Purworejo, Indonesia in July to August 2017.,A structured questionnaire and checklist were used to collect data from 96 participants, who consisted of 48 controls and 48 cases.,Univariate, bivariate, and multivariate analyses were performed.,Bivariate analysis found that education level, the presence of a cattle cage within 100 m of the house, not sleeping under a bednet the previous night, and not closing the doors and windows from 6 p.m. to 5 a.m. were significantly (p≤0.25) associated with malaria.,Of these factors, only not sleeping under a bednet the previous night and not closing the doors and windows from 6 p.m. to 5 a.m. were significantly associated with malaria.,The findings of this study demonstrate that potential risk factor for Malaria should be paid of attention all the time, particularly for an area which is targeting Malaria elimination.

Malaria is one of the leading public health problems in most of sub-Saharan Africa, particularly in Ethiopia.,Almost all demographic groups are at risk of malaria because of seasonal and unstable transmission of the disease.,Therefore, there is a need to develop malaria early-warning systems to enhance public health decision making for control and prevention of malaria epidemics.,Data from orbiting earth-observing sensors can monitor environmental risk factors that trigger malaria epidemics.,Remotely sensed environmental indicators were used to examine the influences of climatic and environmental variability on temporal patterns of malaria cases in the Amhara region of Ethiopia.,In this study seasonal autoregressive integrated moving average (SARIMA) models were used to quantify the relationship between malaria cases and remotely sensed environmental variables, including rainfall, land-surface temperature (LST), vegetation indices (NDVI and EVI), and actual evapotranspiration (ETa) with lags ranging from one to three months.,Predictions from the best model with environmental variables were compared to the actual observations from the last 12 months of the time series.,Malaria cases exhibited positive associations with LST at a lag of one month and positive associations with indicators of moisture (rainfall, EVI and ETa) at lags from one to three months.,SARIMA models that included these environmental covariates had better fits and more accurate predictions, as evidenced by lower AIC and RMSE values, than models without environmental covariates.,Malaria risk indicators such as satellite-based rainfall estimates, LST, EVI, and ETa exhibited significant lagged associations with malaria cases in the Amhara region and improved model fit and prediction accuracy.,These variables can be monitored frequently and extensively across large geographic areas using data from earth-observing sensors to support public health decisions.

To colonize phagocytes, Leishmania subverts microbicidal processes through components of its surface coat that include lipophosphoglycan and the GP63 metalloprotease.,How these virulence glycoconjugates are shed, exit the parasitophorous vacuole (PV), and traffic within host cells is poorly understood.,Here, we show that lipophosphoglycan and GP63 are released from the parasite surface following phagocytosis and redistribute to the endoplasmic reticulum (ER) of macrophages.,Pharmacological disruption of the trafficking between the ER and the Golgi hindered the exit of these molecules from the PV and dampened the cleavage of host proteins by GP63.,Silencing by RNA interference of the soluble N-ethylmaleimide-sensitive-factor attachment protein receptors Sec22b and syntaxin-5, which regulate ER-Golgi trafficking, identified these host proteins as components of the machinery that mediates the spreading of Leishmania effectors within host cells.,Our findings unveil a mechanism whereby a vacuolar pathogen takes advantage of the host cell's secretory pathway to promote egress of virulence factors beyond the PV.

Herein, we review evidence supporting a role for Leishmania exosomes during early infection.,We suggest a model in which Leishmania secreted microvesicles released into the extracellular milieu deliver effector cargo to host target cells.,This cargo mediates immunosuppression and functionally primes host cells for Leishmania invasion.,Leishmania ssp. release microvesicles and the amount of vesicle release and the specific protein cargo of the vesicles is sensitive to changes in environmental conditions that mimic infection.,Leishmania exosomes influence the phenotype of treated immune cells.,For example, wild-type (WT) exosomes attenuate interferon-γ-induced pro-inflammatory cytokine production (TNF-α) by Leishmania-infected monocytes while conversely enhancing production of the anti-inflammatory cytokine IL-10.,The Leishmania proteins GP63 and elongation factor-1α (EF-1α) are found in secreted vesicles and are likely important effectors responsible for these changes in phenotype.,GP63 and EF-1α access host cell cytosol and activate multiple host protein-tyrosine phosphatases (PTPs).,Activation of these PTPs negatively regulates interferon-γ signaling and this prevents effective expression of the macrophage microbicidal arsenal, including TNF-α and nitric oxide.,In addition to changing macrophage phenotype, WT vesicles dampen the immune response of monocyte-derived dendritic cells and CD4+ T lymphocytes.,This capacity is lost when the protein cargo of the vesicles is modified, specifically when the amount of GP63 and EF-1α in the vesicles is reduced.,It appears that exosome delivery of effector proteins results in activation of host PTPs and the negative regulatory effects of the latter creates a pro-parasitic environment.,The data suggest that Leishmania exosomes secreted upon initial infection are capable of delivering effector cargo to naïve target cells wherein the cargo primes host cells for infection by interfering with host cell signaling pathways.

Use of insecticide treated nets is widely recognized as one of the main interventions to prevent malaria and high use rates are a central goal of malaria programs.,The gap between household ownership of at least one ITN and population use of ITN has in the past been seen as evidence for failure to achieve appropriate net use.,However, past studies compared net use with ownership of at least one net, not access to sufficient nets within households.,This study recalculates the net use gap in recent large household surveys using the comparison indicator of ‘access to nets within the household’ as now recommended by Roll Back Malaria and the World Health Organization.,Data from 41 Demographic Health Surveys (DHS) and Malaria Indicator Surveys (MIS) (2005-2012) in sub-Saharan Africa were used.,For each dataset three indicators were calculated: population access to ITN, population use of ITN, and household ownership of at least one ITN.,The ITN use gap was expressed as the difference between one and the ratio of use to access.,The median proportion of users compared to those with access was high, at 82.1%.,Even at population access levels below 50%, a median 80.6% used an ITN given they had access, and this rate increased to 91.2% for access rates above 50%.,Linear regression of use against access showed that 89.0% of household members with access to nets used them the night before.,These results clearly show that previous interpretations of the net use gap as a failure of behavioral change communication interventions were not justified and that the gap was instead primarily driven by lack of intra-household access.,They also demonstrate the usefulness of the newly recommended ITN indicators; access to an ITN within the household provides a much more accurate comparison of ITN use than ownership.

The use of larval source management is not prioritized by contemporary malaria control programs in sub-Saharan Africa despite historical success.,Larviciding, in particular, could be effective in urban areas where transmission is focal and accessibility to Anopheles breeding habitats is generally easier than in rural settings.,The objective of this study is to assess the effectiveness of a community-based microbial larviciding intervention to reduce the prevalence of malaria infection in Dar es Salaam, United Republic of Tanzania.,Larviciding was implemented in 3 out of 15 targeted wards of Dar es Salaam in 2006 after two years of baseline data collection.,This intervention was subsequently scaled up to 9 wards a year later, and to all 15 targeted wards in 2008.,Continuous randomized cluster sampling of malaria prevalence and socio-demographic characteristics was carried out during 6 survey rounds (2004-2008), which included both cross-sectional and longitudinal data (N = 64,537).,Bayesian random effects logistic regression models were used to quantify the effect of the intervention on malaria prevalence at the individual level.,Effect size estimates suggest a significant protective effect of the larviciding intervention.,After adjustment for confounders, the odds of individuals living in areas treated with larviciding being infected with malaria were 21% lower (Odds Ratio = 0.79; 95% Credible Intervals: 0.66-0.93) than those who lived in areas not treated.,The larviciding intervention was most effective during dry seasons and had synergistic effects with other protective measures such as use of insecticide-treated bed nets and house proofing (i.e., complete ceiling or window screens).,A large-scale community-based larviciding intervention significantly reduced the prevalence of malaria infection in urban Dar es Salaam.

Artemether-lumefantrine (AL) is the recommended first-line artemisinin-based combination therapy (ACT) for the treatment of uncomplicated falciparum malaria in most of the malaria-endemic countries, including Tanzania.,Recently, dihydroartemisinin-piperaquine (DP) has been recommended as the alternative anti-malarial to ensure effective case management in Tanzania.,This study assessed the parasite clearance rate and efficacy of AL and DP among patients aged 6 months to 10 years with uncomplicated falciparum malaria in two sites with different malaria transmission intensity.,This was an open-label, randomized trial that was conducted at two sites of Muheza Designated District Hospital and Ujiji Health Centre in Tanga and Kigoma regions, respectively.,Patients meeting inclusion criteria were enrolled, treated with either AL or DP and followed up for 28 (extended to 42) and 42 (63) days for AL and DP, respectively.,Parasite clearance time was monitored in the first 72 h post treatment and the clearance rate constant and half-life were calculated using an established parasite clearance estimator.,The primary outcome was parasitological cure on days 28 and 42 for AL and DP, respectively, while secondary outcome was extended parasitological cure on days 42 and 63 for AL and DP, respectively.,Of the 509 children enrolled (192 at Muheza and 317 at Ujiji), there was no early treatment failure and PCR uncorrected cure rates on day 28 in the AL group were 77.2 and 71.2% at Muheza and Ujiji, respectively.,In the DP arm, the PCR uncorrected cure rate on day 42 was 73.6% at Muheza and 72.5% at Ujiji.,With extended follow-up (to day 42 for AL and 63 for DP) cure rates were lower at Ujiji compared to Muheza (AL: 60.2 and 46.1%, p = 0.063; DP: 57.6 and 40.3% in Muheza and Ujiji, respectively, p = 0.021).,The PCR corrected cure rate ranged from 94.6 to 100% for all the treatment groups at both sites.,Parasite clearance rate constant was similar in the two groups and at both sites (< 0.28/h); the slope half-life was < 3.0 h and all but only one patient cleared parasites by 72 h.,These findings confirm high efficacy of the first- and the newly recommended alternative ACT for treatments for uncomplicated falciparum malaria in Tanzania.,The high parasite clearance rate suggests absence of suspected artemisinin resistance, defined as delayed parasite clearance.,Trial registration This trial is registered at ClinicalTrials.gov under registration number NCT02590627

Studies in Southeast Asia reported a strong relationship between polymorphisms at the propeller domain of the Kelch 13 (K13) protein encoded by the Plasmodiumfalciparumk13(pfk13) gene and delayed parasite clearance after artemisinin treatment.,In Africa, P. falciparum remains susceptible and combination therapy regimens which include an artemisinin component display good efficacy.,Using quantitative real-time PCR (qPCR), sub-microscopic persistence of P. falciparum has previously been reported in one-third of children treated with artemisinin combination therapy (ACT) in western Kenya.,In this study, further investigation was made to evaluate whether these sub-microscopic residual parasites also harbour mutations at the propeller region of pfk13 and whether the mutations, if any, affect treatment outcome.,The pfk13 propeller domain was genotyped in DNA samples obtained in 2009 from Kenyan children treated with artemether-lumefantrine (AL) and dihydroartemisinin-piperaquine (DP).,Paired samples at pre-treatment (day 0) and day of treatment failure (day 28 or 42) for 32 patients with documented recurrent parasitaemia were available for genotyping.,Additional day 3 DNA samples were available for 10 patients.,No mutation associated with artemisinin resistance in Southeast Asia was observed.,Only one DP-treated patient harboured a non-synonymous mutation at codon 578 (A578S) of pfk13-propeller gene in the day 0 sample, but this allele was replaced by the wild-type (A578) form on day 3 and on the day of recurrent parasitaemia.,The mutation at amino acid codon 578 showed no association with any phenotype.,Polymorphisms in pfk13 were not responsible for parasite persistence and gametocyte carriage in the children treated with ACT.,This study contributes to the ongoing surveillance of suspected artemisinin resistance parasites in Africa by providing baseline prevalence of k13-propeller mutations in western Kenya with samples collected from a longitudinal study.,Clinical Trials Registration NCT00868465.

The RTS,S/AS01E vaccine provides partial protection against malaria in African children, but immune responses have only been partially characterized and do not reliably predict protective efficacy.,We aimed to evaluate comprehensively the immunogenicity of the vaccine at peak response, the factors affecting it, and the antibodies associated with protection against clinical malaria in young African children participating in the multicenter phase 3 trial for licensure.,We measured total IgM, IgG, and IgG1-4 subclass antibodies to three constructs of the Plasmodium falciparum circumsporozoite protein (CSP) and hepatitis B surface antigen (HBsAg) that are part of the RTS,S vaccine, by quantitative suspension array technology.,Plasma and serum samples were analyzed in 195 infants and children from two sites in Ghana (Kintampo) and Mozambique (Manhiça) with different transmission intensities using a case-control study design.,We applied regression models and machine learning techniques to analyze immunogenicity, correlates of protection, and factors affecting them.,RTS,S/AS01E induced IgM and IgG, predominantly IgG1 and IgG3, but also IgG2 and IgG4, subclass responses.,Age, site, previous malaria episodes, and baseline characteristics including antibodies to CSP and other antigens reflecting malaria exposure and maternal IgGs, nutritional status, and hemoglobin concentration, significantly affected vaccine immunogenicity.,We identified distinct signatures of malaria protection and risk in RTS,S/AS01E but not in comparator vaccinees.,IgG2 and IgG4 responses to RTS,S antigens post-vaccination, and anti-CSP and anti-P. falciparum antibody levels pre-vaccination, were associated with malaria risk over 1-year follow-up.,In contrast, antibody responses to HBsAg (all isotypes, subclasses, and timepoints) and post-vaccination IgG1 and IgG3 to CSP C-terminus and NANP were associated with protection.,Age and site affected the relative contribution of responses in the correlates identified.,Cytophilic IgG responses to the C-terminal and NANP repeat regions of CSP and anti-HBsAg antibodies induced by RTS,S/AS01E vaccination were associated with malaria protection.,In contrast, higher malaria exposure at baseline and non-cytophilic IgG responses to CSP were associated with disease risk.,Data provide new correlates of vaccine success and failure in African children and reveal key insights into the mode of action that can guide development of more efficacious next-generation vaccines.,The online version of this article (10.1186/s12916-018-1186-4) contains supplementary material, which is available to authorized users.

Leishmania donovani, the causative agent of Indian visceral leishmaniasis has to face several barriers of the immune system inside the mammalian host for its survival.,The complement system is one of the first barriers and consists of a well-balanced network of proteases including S1A family serine proteases (SPs).,Inhibitor of serine peptidases (ISPs) is considered as inhibitor of S1A family serine peptidases and is reported to be present in trypanosomes, including Leishmania.,In our previous study, we have deciphered the role of ISPs [LdISP1 and L. donovani inhibitor of serine peptidases 2 (LdISP2)] in the survival of L. donovani inside the sandfly midgut.,However, the role of theses ISPs in the survival of L. donovani inside mammalian host still remains elusive.,In the present study, we have deciphered the inhibitory effect of LdISPs on the host complement S1A serine peptidases, such as C1r/C1s and MASP1/MASP2.,Our study suggested that although both rLdISP1 and rLdISP2 inferred strong interaction with C1complex and MBL-associated serine proteases (MASPs) but rLdISP2 showed the stronger inhibitory effect on MASP2 than rLdISP1.,Moreover, we found that rLdISP2 significantly reduces the formation of C3, C5 convertase, and membrane attacking complex (MAC) by lectin pathway (LP) resulting in significant reduction in serum mediated lysis of the parasites.,The role of LdISP2 on neutrophil elastase-mediated C5aR signaling was also evaluated.,Notably, our results showed that infection of macrophages with ISP2-overexpressed Leishmania parasites significantly induces the expression of C5aR both at the transcript and translational level.,Simultaneously, infection with ISP2KD parasites results in downregulation of host PI3K/AKT phosphorylation and increased in IL-12 production.,Taken together, our findings clearly suggest that LdISP2 promotes parasite survival inside host by inhibiting MAC formation and complement-mediated lysis via LP and by upregulation of C5aR signaling.

A very large biomass of intact asexual-stage malaria parasites accumulates in the spleen of asymptomatic human individuals infected with Plasmodium vivax.,The mechanisms underlying this intense tropism are not clear.,We hypothesised that immature reticulocytes, in which P. vivax develops, may display high densities in the spleen, thereby providing a niche for parasite survival.,We examined spleen tissue in 22 mostly untreated individuals naturally exposed to P. vivax and Plasmodium falciparum undergoing splenectomy for any clinical indication in malaria-endemic Papua, Indonesia (2015 to 2017).,Infection, parasite and immature reticulocyte density, and splenic distribution were analysed by optical microscopy, flow cytometry, and molecular assays.,Nine non-endemic control spleens from individuals undergoing spleno-pancreatectomy in France (2017 to 2020) were also examined for reticulocyte densities.,There were no exclusion criteria or sample size considerations in both patient cohorts for this demanding approach.,In Indonesia, 95.5% (21/22) of splenectomy patients had asymptomatic splenic Plasmodium infection (7 P. vivax, 13 P. falciparum, and 1 mixed infection).,Significant splenic accumulation of immature CD71 intermediate- and high-expressing reticulocytes was seen, with concentrations 11 times greater than in peripheral blood.,Accordingly, in France, reticulocyte concentrations in the splenic effluent were higher than in peripheral blood.,Greater rigidity of reticulocytes in splenic than in peripheral blood, and their higher densities in splenic cords both suggest a mechanical retention process.,Asexual-stage P. vivax-infected erythrocytes of all developmental stages accumulated in the spleen, with non-phagocytosed parasite densities 3,590 times (IQR: 2,600 to 4,130) higher than in circulating blood, and median total splenic parasite loads 81 (IQR: 14 to 205) times greater, accounting for 98.7% (IQR: 95.1% to 98.9%) of the estimated total-body P. vivax biomass.,More reticulocytes were in contact with sinus lumen endothelial cells in P. vivax- than in P. falciparum-infected spleens.,Histological analyses revealed 96% of P. vivax rings/trophozoites and 46% of schizonts colocalised with 92% of immature reticulocytes in the cords and sinus lumens of the red pulp.,Larger splenic cohort studies and similar investigations in untreated symptomatic malaria are warranted.,Immature CD71+ reticulocytes and splenic P. vivax-infected erythrocytes of all asexual stages accumulate in the same splenic compartments, suggesting the existence of a cryptic endosplenic lifecycle in chronic P. vivax infection.,Findings provide insight into P. vivax-specific adaptions that have evolved to maximise survival and replication in the spleen.,Dr.,Anstey and co-authors found that P. vivax-infected immature reticulocytes and erythrocytes accumulate in the same splenic compartments, suggesting existence of a cryptic endosplenic lifecycle in chronic P. vivax infection that maximizes survival and replication in the spleen.

Multiplexed bead-based assays that use Luminex® xMAP® technology have become popular for measuring antibodies against proteins of interest in many fields, including malaria and more recently SARS-CoV-2/COVID-19.,There are currently two formats that are widely used: non-magnetic beads or magnetic beads.,Data are lacking regarding the comparability of results obtained using these two types of beads, and for assays run on different instruments.,Whilst non-magnetic beads can only be run on flow-based instruments (such as the Luminex® 100/200™ or Bio-Plex® 200), magnetic beads can be run on both these and the newer MAGPIX® instruments.,In this study we utilized a panel of purified recombinant Plasmodium vivax proteins and samples from malaria-endemic areas to measure P. vivax-specific IgG responses using different combinations of beads and instruments.,We directly compared: i) non-magnetic versus magnetic beads run on a Bio-Plex® 200, ii) magnetic beads run on the Bio-Plex® 200 versus MAGPIX® and iii) non-magnetic beads run on a Bio-Plex® 200 versus magnetic beads run on the MAGPIX®.,We also performed an external comparison of our optimized assay.,We observed that IgG antibody responses, measured against our panel of P. vivax proteins, were moderately-strongly correlated in all three of our comparisons (pearson r>0.5 for 18/19 proteins), however higher amounts of protein were required for coupling to magnetic beads.,Our external comparison indicated that results generated in different laboratories using the same coupled beads are also highly comparable (pearson r>0.7), particularly if a reference standard curve is used.

Many human genetic associations with resistance to malaria have been reported but few have been reliably replicated.,We collected data on 11,890 cases of severe malaria due to Plasmodium falciparum and 17,441 controls from 12 locations in Africa, Asia and Oceania.,There was strong evidence of association with the HBB, ABO, ATP2B4, G6PD and CD40LG loci but previously reported associations at 22 other loci did not replicate in the multi-centre analysis.,The large sample size made it possible to identify authentic genetic effects that are heterogeneous across populations or phenotypes, a striking example being the main African form of G6PD deficiency, which reduced the risk of cerebral malaria but increased the risk of severe malarial anaemia.,The finding that G6PD deficiency has opposing effects on different fatal complications of P. falciparum infection indicates that the evolutionary origins of this common human genetic disorder are more complex than previously supposed.

Following fertilization, the early proteomes of metazoans are defined by the translation of stored but repressed transcripts; further embryonic development relies on de novo transcription of the zygotic genome.,During sexual development of Plasmodium berghei, a rodent model for human malaria species including P. falciparum, the stability of repressed mRNAs requires the translational repressors DOZI and CITH.,When these repressors are absent, Plasmodium zygote development and transmission to the mosquito vector is halted, as hundreds of transcripts become destabilized.,However, which mRNAs are direct targets of these RNA binding proteins, and thus subject to translational repression, is unknown.,We identify the maternal mRNA contribution to post-fertilization development of P. berghei using RNA immunoprecipitation and microarray analysis.,We find that 731 mRNAs, approximately 50% of the transcriptome, are associated with DOZI and CITH, allowing zygote development to proceed in the absence of RNA polymerase II transcription.,Using GFP-tagging, we validate the repression phenotype of selected genes and identify mRNAs relying on the 5′ untranslated region for translational control.,Gene deletion reveals a novel protein located in the ookinete crystalloid with an essential function for sporozoite development.,Our study details for the first time the P. berghei maternal repressome.,This mRNA population provides the developing ookinete with coding potential for key molecules required for life-cycle progression, and that are likely to be critical for the transmission of the malaria parasite from the rodent and the human host to the mosquito vector.,The online version of this article (doi:10.1186/s13059-014-0493-0) contains supplementary material, which is available to authorized users.

Many school children living in Africa are infected with plasmodia and helminth species and are consequently at risk of coinfection.,However, the epidemiology of such coinfection and the implications of coinfection for children’s health remain poorly understood.,This study describes the epidemiology of Ascaris lumbricoides-Plasmodium and hookworm-Plasmodium coinfection among school children living in western Kenya and investigates the associated risk factors.,As part of a randomized trial, a baseline cross-sectional survey was conducted among school children aged 5-18 years in 23 schools in Bumula District.,Single stool samples were collected to screen for helminth infections using the Kato-Katz technique and malaria parasitaemia was determined from a finger prick blood sample.,Demographic and anthropometric data were also collected.,Overall, 46.4 % of the children were infected with Plasmodium falciparum while 27.6 % of the children were infected with at least one soil transmitted helminth (STH) species, with hookworm being the most common (16.8 %) followed by A. lumbricoides (15.3 %).,Overall 14.3 % of the children had STH-Plasmodium coinfection, with hookworm-Plasmodium (9.0 %) coinfection being the most common.,Geographical variation in the prevalence of coinfection occurred between schools.,In multivariable logistic regression analysis, hookworm was positively associated with P. falciparum infection.,In stratified analysis, hookworm infection was associated with increased odds of P. falciparum infection among both boys (P < 0.001) and girls (P = 0.01), whereas there was no association between A. lumbricoides and P. falciparum.,These findings demonstrate STH infections are still prevalent, despite the ongoing national deworming programme in Kenya, and that malaria parasitaemia is widespread, such that coinfection occurs among a proportion of children.,A subsequent trial will allow us to investigate the implications of coinfection for the risk of clinical malaria.,The online version of this article (doi:10.1186/s13071-015-0891-5) contains supplementary material, which is available to authorized users.

The suppression of indoor malaria transmission requires additional interventions that complement the use of insecticide treated nets (ITNs) and indoor residual spraying (IRS).,Previous studies have examined the impact of house structure on malaria transmission in areas of low transmission.,This study was conducted in a high transmission setting and presents further evidence about the association between specific house characteristics and the abundance of endophilic malaria vectors.,Mosquitoes were sampled using CDC light traps from 72 randomly selected houses in two villages on a monthly basis from 2008 to 2011 in rural Southern Tanzania.,Generalized linear models using Poisson distributions were used to analyze the association of house characteristics (eave gaps, wall types, roof types, number of windows, rooms and doors, window screens, house size), number of occupants and ITN usage with mean catches of malaria vectors (An.gambiae s.l. and An. funestus).,A total of 36490 female An. gambiae s.l. were collected in Namwawala village and 21266 in Idete village.,As for An. funestus females, 2268 were collected in Namwawala and 3398 in Idete.,Individually, each house factor had a statistically significant impact (p < 0.05) on the mean catches for An. gambiae s.l. but not An. funestus.,A multivariate analysis indicated that the combined absence or presence of eaves, treated or untreated bed-nets, the number of house occupants, house size, netting over windows, and roof type were significantly related (p < 0.05) to An.gambiae s.l. and An. funestus house entry in both villages.,Despite significant reductions in vector density and malaria transmission caused by high coverage of ITNs, high numbers of host-seeking malaria vectors are still found indoors due to house designs that favour mosquito entry.,In addition to ITNs and IRS, significant efforts should focus on improving house design to prevent mosquito entry and eliminate indoor malaria transmission.

The Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) is a variant surface antigen expressed on mature forms of infected erythrocytes.,It is considered an important target of naturally acquired immunity.,Despite its extreme sequence heterogeneity, variants of PfEMP1 can be stratified into distinct groups.,Group A PfEMP1 have been independently associated with low host immunity and severe disease in several studies and are now of potential interest as vaccine candidates.,Although antigen-specific antibodies are considered the main effector mechanism in immunity to malaria, the induction of efficient and long-lasting antibody responses requires CD4+ T-cell help.,To date, very little is known about CD4+ T-cell responses to PfEMP1 expressed on clinical isolates.,The DBLα-tag is a small region from the DBLα-domain of PfEMP1 that can be amplified with universal primers and is accessible in clinical parasite isolates.,We identified the dominant expressed PfEMP1 in 41 individual clinical parasite isolates and expressed the corresponding DBLα-tag as recombinant antigen.,Individual DBLα-tags were then used to activate CD4+ T-cells from acute and convalescent blood samples in children who were infected with the respective clinical parasite isolate.,Here we show that CD4+ T-cell responses to the homologous DBLα-tag were induced in almost all children during acute malaria and maintained in some for 4 months.,Children infected with parasites that dominantly expressed group A-like PfEMP1 were more likely to maintain antigen-specific IFNγ-producing CD4+ T-cells than children infected with parasites dominantly expressing other PfEMP1.,These results suggest that group A-like PfEMP1 may induce long-lasting effector memory T-cells that might be able to provide rapid help to variant-specific B cells.,Furthermore, a number of children induced CD4+ T-cell responses to heterologous DBLα-tags, suggesting that CD4+ T-cells may recognise shared epitopes between several DBLα-tags.

Cellular responses to Plasmodium falciparum parasites, in particular interferon-gamma (IFNγ) production, play an important role in anti-malarial immunity.,However, clinical immunity to malaria develops slowly amongst naturally exposed populations, the dynamics of cellular responses in relation to exposure are difficult to study and data about the persistence of such responses are controversial.,Here we assess the longevity and composition of cellular immune responses following experimental malaria infection in human volunteers.,We conducted a longitudinal study of cellular immunological responses to sporozoites (PfSpz) and asexual blood-stage (PfRBC) malaria parasites in naïve human volunteers undergoing single (n = 5) or multiple (n = 10) experimental P. falciparum infections under highly controlled conditions.,IFNγ and interleukin-2 (IL-2) responses following in vitro re-stimulation were measured by flow-cytometry prior to, during and more than one year post infection.,We show that cellular responses to both PfSpz and PfRBC are induced and remain almost undiminished up to 14 months after even a single malaria episode.,Remarkably, not only ‘adaptive’ but also ‘innate’ lymphocyte subsets contribute to the increased IFNγ response, including αβT cells, γδT cells and NK cells.,Furthermore, results from depletion and autologous recombination experiments of lymphocyte subsets suggest that immunological memory for PfRBC is carried within both the αβT cells and γδT compartments.,Indeed, the majority of cytokine producing T lymphocytes express an CD45RO+ CD62L- effector memory (EM) phenotype both early and late post infection.,Finally, we demonstrate that malaria infection induces and maintains polyfunctional (IFNγ+IL-2+) EM responses against both PfRBC and PfSpz, previously found to be associated with protection.,These data demonstrate that cellular responses can be readily induced and are long-lived following infection with P. falciparum, with a persisting contribution by not only adaptive but also (semi-)innate lymphocyte subsets.,The implications hereof are positive for malaria vaccine development, but focus attention on those factors potentially inhibiting such responses in the field.

Heterogeneity in malaria exposure complicates survival analyses of vaccine efficacy trials and confounds the association between immune correlates of protection and malaria infection in longitudinal studies.,Analysis may be facilitated by taking into account the variability in individual exposure levels, but it is unclear how exposure can be estimated at an individual level.,We studied three cohorts (Chonyi, Junju and Ngerenya) in Kilifi District, Kenya to assess measures of malaria exposure.,Prospective data were available on malaria episodes, geospatial coordinates, proximity to infected and uninfected individuals and residence in predefined malaria hotspots for 2,425 individuals.,Antibody levels to the malaria antigens AMA1 and MSP1142 were available for 291 children from Junju.,We calculated distance-weighted local prevalence of malaria infection within 1 km radius as a marker of individual's malaria exposure.,We used multivariable modified Poisson regression model to assess the discriminatory power of these markers for malaria infection (i.e. asymptomatic parasitaemia or clinical malaria).,The area under the receiver operating characteristic (ROC) curve was used to assess the discriminatory power of the models.,Local malaria prevalence within 1 km radius and AMA1 and MSP1142 antibodies levels were independently associated with malaria infection.,Weighted local malaria prevalence had an area under ROC curve of 0.72 (95%CI: 0.66-0.73), 0.71 (95%CI: 0.69-0.73) and 0.82 (95%CI: 0.80-0.83) among cohorts in Chonyi, Junju and Ngerenya respectively.,In a small subset of children from Junju, a model incorporating weighted local malaria prevalence with AMA1 and MSP1142 antibody levels provided an AUC of 0.83 (95%CI: 0.79-0.88).,We have proposed an approach to estimating the intensity of an individual's malaria exposure in the field.,The weighted local malaria prevalence can be used as individual marker of malaria exposure in malaria vaccine trials and longitudinal studies of natural immunity to malaria.

Immunity to Plasmodium falciparum (Pf) malaria is only acquired after years of repeated infections and wanes rapidly without ongoing parasite exposure.,Antibodies are central to malaria immunity, yet little is known about the B-cell biology that underlies the inefficient acquisition of Pf-specific humoral immunity.,This year-long prospective study in Mali of 185 individuals aged 2 to 25 years shows that Pf-specific memory B-cells and antibodies are acquired gradually in a stepwise fashion over years of repeated Pf exposure.,Both Pf-specific memory B cells and antibody titers increased after acute malaria and then, after six months of decreased Pf exposure, contracted to a point slightly higher than pre-infection levels.,This inefficient, stepwise expansion of both the Pf-specific memory B-cell and long-lived antibody compartments depends on Pf exposure rather than age, based on the comparator response to tetanus vaccination that was efficient and stable.,These observations lend new insights into the cellular basis of the delayed acquisition of malaria immunity.

Our knowledge and control of the pathogenesis induced by the filariae remain limited due to experimental obstacles presented by parasitic nematode biology and the lack of selective prophylactic or curative drugs.,Here we thought to investigate the role of neutrophils in the host innate immune response to the infection caused by the Litomosoides sigmodontis murine model of human filariasis using mice harboring a gain-of-function mutation of the chemokine receptor CXCR4 and characterized by a profound blood neutropenia (Cxcr4+/1013).,We provided manifold evidence emphasizing the major role of neutrophils in the control of the early stages of infection occurring in the skin.,Firstly, we uncovered that the filarial parasitic success was dramatically decreased in Cxcr4+/1013 mice upon subcutaneous delivery of the infective stages of filariae (infective larvae, L3).,This protection was linked to a larger number of neutrophils constitutively present in the skin of the mutant mice herein characterized as compared to wild type (wt) mice.,Indeed, the parasitic success in Cxcr4+/1013 mice was normalized either upon depleting neutrophils, including the pool in the skin, or bypassing the skin via the intravenous infection of L3.,Second, extending these observations to wt mice we found that subcutaneous delivery of L3 elicited an increase of neutrophils in the skin.,Finally, living L3 larvae were able to promote in both wt and mutant mice, an oxidative burst response and the release of neutrophil extracellular traps (NET).,This response of neutrophils, which is adapted to the large size of the L3 infective stages, likely directly contributes to the anti-parasitic strategies implemented by the host.,Collectively, our results are demonstrating the contribution of neutrophils in early anti-filarial host responses through their capacity to undertake different anti-filarial strategies such as oxidative burst, degranulation and NETosis.

Helminths immunomodulate their hosts and induce a regulatory, anti-inflammatory milieu that prevents allergies and autoimmune diseases.,Helminth immunomodulation may benefit sepsis outcome by preventing exacerbated inflammation and severe pathology, but the influence on bacterial clearance remains unclear.,To address this, mice were chronically infected with the filarial nematode Litomosoides sigmodontis (L.s.) and the outcome of acute systemic inflammation caused by i.p.,Escherichia coli injection was determined.,L.s. infection significantly improved E. coli-induced hypothermia, bacterial clearance and sepsis survival and correlated with reduced concentrations of associated pro-inflammatory cytokines/chemokines and a less pronounced pro-inflammatory macrophage gene expression profile.,Improved sepsis outcome in L.s.-infected animals was mediated by macrophages, but independent of the alternatively activated macrophage subset.,Endosymbiotic Wolbachia bacteria that are present in most human pathogenic filariae, as well as L.s., signal via TLR2 and modulate macrophage function.,Here, gene expression profiles of peritoneal macrophages from L.s.-infected mice revealed a downregulation of genes involved in TLR signaling, and pulsing of macrophages in vitro with L.s. extract reduced LPS-triggered activation.,Subsequent transfer improved sepsis outcome in naïve mice in a Wolbachia- and TLR2-dependent manner.,In vivo, phagocytosis was increased in macrophages from L.s.-infected wild type, but not TLR2-deficient animals.,In association, L.s. infection neither improved bacterial clearance in TLR2-deficient animals nor ameliorated E. coli-induced hypothermia and sepsis survival.,These results indicate that chronic L.s. infection has a dual beneficial effect on bacterial sepsis, reducing pro-inflammatory immune responses and improving bacterial control.,Thus, helminths and their antigens may not only improve the outcome of autoimmune and allergic diseases, but may also present new therapeutic approaches for acute inflammatory diseases that do not impair bacterial control.

In a prospective infant cohort, 21 infants developed Plasmodium vivax malaria during their first year.,Twelve of their mothers also had vivax malaria in the corresponding pregnancies or postpartum period.,The genotypes of the maternal and infant infections were all different.,Eight of the 12 mothers and 9 of the 21 infants had recurrent infections.,Relapse parasite genotypes were different to the initial infection in 13 of 20 (65%) mothers compared with 5 of 24 (21%) infants (P = .02).,The first P. vivax relapses of life are usually genetically homologous, whereas relapse in adults may result from activation of heterologous latent hypnozoites acquired from previous inoculations.

Many countries are scaling up malaria interventions towards elimination.,This transition changes demands on malaria diagnostics from diagnosing ill patients to detecting parasites in all carriers including asymptomatic infections and infections with low parasite densities.,Detection methods suitable to local malaria epidemiology must be selected prior to transitioning a malaria control programme to elimination.,A baseline malaria survey conducted in Temotu Province, Solomon Islands in late 2008, as the first step in a provincial malaria elimination programme, provided malaria epidemiology data and an opportunity to assess how well different diagnostic methods performed in this setting.,During the survey, 9,491 blood samples were collected and examined by microscopy for Plasmodium species and density, with a subset also examined by polymerase chain reaction (PCR) and rapid diagnostic tests (RDTs).,The performances of these diagnostic methods were compared.,A total of 256 samples were positive by microscopy, giving a point prevalence of 2.7%.,The species distribution was 17.5% Plasmodium falciparum and 82.4% Plasmodium vivax.,In this low transmission setting, only 17.8% of the P. falciparum and 2.9% of P. vivax infected subjects were febrile (≥38°C) at the time of the survey.,A significant proportion of infections detected by microscopy, 40% and 65.6% for P. falciparum and P. vivax respectively, had parasite density below 100/μL.,There was an age correlation for the proportion of parasite density below 100/μL for P. vivax infections, but not for P. falciparum infections.,PCR detected substantially more infections than microscopy (point prevalence of 8.71%), indicating a large number of subjects had sub-microscopic parasitemia.,The concordance between PCR and microscopy in detecting single species was greater for P. vivax (135/162) compared to P. falciparum (36/118).,The malaria RDT detected the 12 microscopy and PCR positive P. falciparum, but failed to detect 12/13 microscopy and PCR positive P. vivax infections.,Asymptomatic malaria infections and infections with low and sub-microscopic parasite densities are highly prevalent in Temotu province where malaria transmission is low.,This presents a challenge for elimination since the large proportion of the parasite reservoir will not be detected by standard active and passive case detection.,Therefore effective mass screening and treatment campaigns will most likely need more sensitive assays such as a field deployable molecular based assay.

Controlled human malaria infection (CHMI) provides a highly informative means to investigate host-pathogen interactions and enable in vivo proof-of-concept efficacy testing of new drugs and vaccines.,However, unlike Plasmodium falciparum, well-characterized P. vivax parasites that are safe and suitable for use in modern CHMI models are limited.,Here, 2 healthy malaria-naive United Kingdom adults with universal donor blood group were safely infected with a clone of P. vivax from Thailand by mosquito-bite CHMI.,Parasitemia developed in both volunteers, and prior to treatment, each volunteer donated blood to produce a cryopreserved stabilate of infected RBCs.,Following stringent safety screening, the parasite stabilate from one of these donors (PvW1) was thawed and used to inoculate 6 healthy malaria-naive United Kingdom adults by blood-stage CHMI, at 3 different dilutions.,Parasitemia developed in all volunteers, who were then successfully drug treated.,PvW1 parasite DNA was isolated and sequenced to produce a high-quality genome assembly by using a hybrid assembly method.,We analyzed leading vaccine candidate antigens and multigene families, including the vivax interspersed repeat (VIR) genes, of which we identified 1145 in the PvW1 genome.,Our genomic analysis will guide future assessment of candidate vaccines and drugs, as well as experimental medicine studies.

Jane Carlton, Kazuyuki Tanabe and colleagues report the draft genome sequences of three Plasmodium cynomolgi strains isolated from infected monkeys.,Their comparative genomic analysis with P. vivax and P. knowlesi offers insights into these simian malaria parasites.,The online version of this article (doi:10.1038/ng.2375) contains supplementary material, which is available to authorized users.,P. cynomolgi, a malaria-causing parasite of Asian Old World monkeys, is the sister taxon of P. vivax, the most prevalent malaria-causing species in humans outside of Africa.,Because P. cynomolgi shares many phenotypic, biological and genetic characteristics with P. vivax, we generated draft genome sequences for three P. cynomolgi strains and performed genomic analysis comparing them with the P. vivax genome, as well as with the genome of a third previously sequenced simian parasite, Plasmodium knowlesi.,Here, we show that genomes of the monkey malaria clade can be characterized by copy-number variants (CNVs) in multigene families involved in evasion of the human immune system and invasion of host erythrocytes.,We identify genome-wide SNPs, microsatellites and CNVs in the P. cynomolgi genome, providing a map of genetic variation that can be used to map parasite traits and study parasite populations.,The sequencing of the P. cynomolgi genome is a critical step in developing a model system for P. vivax research and in counteracting the neglect of P. vivax.,The online version of this article (doi:10.1038/ng.2375) contains supplementary material, which is available to authorized users.

Private sector drug shops are an important source of malaria treatment in Africa, yet diagnosis without parasitological testing is common among these providers.,Accurate rapid diagnostic tests for malaria (mRDTs) require limited training and present an opportunity to increase access to correct diagnosis.,The present study was a cost-effectiveness analysis of the introduction of mRDTs in Ugandan drug shops.,Drug shop vendors were trained to perform and sell subsidised mRDTs and artemisinin-based combination therapies (ACTs) in the intervention arm while vendors offered ACTs following presumptive diagnosis of malaria in the control arm.,The effect on the proportion of customers with fever ‘appropriately treated of malaria with ACT’ was captured during a randomised trial in drug shops in Mukono District, Uganda.,Health sector costs included: training of drug shop vendors, community sensitisation, supervision and provision of mRDTs and ACTs to drug shops.,Household costs of treatment-seeking were captured in a representative sample of drug shop customers.,The introduction of mRDTs in drug shops was associated with a large improvement of diagnosis and treatment of malaria, resulting in low incremental costs for the health sector at US$0.55 per patient appropriately treated of malaria.,High expenditure on non-ACT drugs by households contributed to higher incremental societal costs of US$3.83.,Sensitivity analysis showed that mRDTs would become less cost-effective compared to presumptive diagnosis with increasing malaria prevalence and lower adherence to negative mRDT results.,mRDTs in drug shops improved the targeting of ACTs to malaria patients and are likely to be considered cost-effective compared to presumptive diagnosis, although the increased costs borne by households when the test result is negative are a concern.

Plasmodium vivax and Plasmodium ovale are often considered the malaria parasites best adapted to long-term survival in the human host because of their latent exo-erythrocytic forms.,The prevailing opinion until the middle of the last century was that the maximum duration of Plasmodium falciparum infections was less than two years.,Case reports and series investigating blood donors following accidental malaria infection of blood transfusion recipients and other sporadic malaria cases in non-endemic countries have shown clearly that asymptomatic P. falciparum infections may persist for up to a decade or longer (maximum confirmed 13 years).,Current policies in malaria-free countries of excluding blood donors who have lived in malarious areas are justified.,Vigilance for longer than three years after declaring elimination in an area may be needed.

This study identified CD16+ DCs as the only blood DC subset distinctively activated during primary blood-stage human Plasmodium infection.,As TNF/IL-10 coproducers, CD16+ DCs contribute to early inflammatory processes, yet P falciparum restimulation skewed cytokine responses further towards IL-10 production.,The malaria causing parasite Plasmodium subverts host immune responses by several strategies including the modulation of dendritic cells (DCs).,In this study, we show that Plasmodium falciparum skewed CD16+ DC cytokine responses towards interleukin (IL)-10 production in vitro, distinct to the cytokine profile induced by Toll-like receptor ligation.,To determine CD16+ DC responsiveness in vivo, we assessed their function after induced P falciparum infection in malaria-naive volunteers.,CD16+ DCs underwent distinctive activation, with increased expression of maturation markers human leukocyte antigen (HLA)-DR and CD86, enhanced tumor necrosis factor (TNF) production, and coproduction of TNF/IL-10.,In vitro restimulation with P falciparum further increased IL-10 production.,In contrast, during naturally acquired malaria episode, CD16+ DCs showed diminished maturation, suggesting increased parasite burden and previous exposure influence DC subset function.,These findings identify CD16+ DCs as the only DC subset activated during primary blood-stage human Plasmodium infection.,As dual cytokine producers, CD16+ DCs contribute to inflammatory as well as regulatory innate immune processes.

In the last century, vaccination has been the most effective medical intervention to reduce death and morbidity caused by infectious diseases.,It is believed that vaccines save at least 2-3 million lives per year worldwide.,Smallpox has been eradicated and polio has almost disappeared worldwide through global vaccine campaigns.,Most of the viral and bacterial infections that traditionally affected children have been drastically reduced thanks to national immunization programs in developed countries.,However, many diseases are not yet preventable by vaccination, and vaccines have not been fully exploited for target populations such as elderly and pregnant women.,This review focuses on the state of the art of recent clinical trials of vaccines for major unmet medical needs such as HIV, malaria, TB, and cancer.,In addition, we describe the innovative technologies currently used in vaccine research and development including adjuvants, vectors, nucleic acid vaccines, and structure‐based antigen design.,The hope is that thanks to these technologies, more diseases will be addressed in the 21st century by novel preventative and therapeutic vaccines.,This novel review of the host‐pathogen interactions series highlights the scientific and practical challenges facing vaccine development: starting with a historical perspective, the authors illustrate the current novel technologies with a focus on vaccines for infectious diseases.

Macrocyclic lactone (ML) anthelmintics are the most important class of anthelmintics because of our high dependence on them for the control of nematode parasites and some ectoparasites in livestock, companion animals and in humans.,However, resistance to MLs is of increasing concern.,Resistance is commonplace throughout the world in nematode parasites of small ruminants and is of increasing concern in horses, cattle, dogs and other animals.,It is suspected in Onchocerca volvulus in humans.,In most animals, resistance first arose to the avermectins, such as ivermectin (IVM), and subsequently to moxidectin (MOX).,Usually when parasite populations are ML-resistant, MOX is more effective than avermectins.,MOX may have higher intrinsic potency against some parasites, especially filarial nematodes, than the avermectins.,However, it clearly has a significantly different pharmacokinetic profile.,It is highly distributed to lipid tissues, less likely to be removed by ABC efflux transporters, is poorly metabolized and has a long half-life.,This results in effective concentrations persisting for longer in target hosts.,It also has a high safety index.,Limited data suggest that anthelmintic resistance may be overcome, at least temporarily, if a high concentration can be maintained at the site of the parasites for a prolonged period of time.,Because of the properties of MOX, there are reasonable prospects that strains of parasites that are resistant to avermectins at currently recommended doses will be controlled by MOX if it can be administered at sufficiently high doses and in formulations that enhance its persistence in the host.,This review examines the properties of MOX that support this contention and compares them with the properties of other MLs.,The case for using MOX to better control ML-resistant parasites is summarised and some outstanding research questions are presented.,Image 1,•Moxidectin (MOX) exhibits a long half-life and high potency.,•MOX shows low toxicity in the host and low ecotoxicity.,•MOX has properties suitable for high dose rate, long acting formulation.,•MOX can be effective against macrocyclic lactone (ML)-resistant parasites.,•Properties of MOX can be exploited to better control ML-resistant nematodes.,Moxidectin (MOX) exhibits a long half-life and high potency.,MOX shows low toxicity in the host and low ecotoxicity.,MOX has properties suitable for high dose rate, long acting formulation.,MOX can be effective against macrocyclic lactone (ML)-resistant parasites.,Properties of MOX can be exploited to better control ML-resistant nematodes.

Strongyloidiasis is a disease caused by soil transmitted helminths of the Strongyloides genus.,Currently, it is predominately described as a neglected tropical disease.,However, this description is misleading as it focuses on the geographical location of the disease and not the primary consideration, which is the socioeconomic conditions and poor infrastructure found within endemic regions.,This classification may result in misdiagnosis and mistreatment by physicians, but more importantly, it influences how the disease is fundamentally viewed.,Strongyloidiasis must be first and foremost considered as a disease of disadvantage, to ensure the correct strategies and control measures are used to prevent infection.,Changing how strongyloidiasis is perceived from a geographic and clinical issue to an environmental health issue represents the first step in identifying appropriate long term control measures.,This includes emphasis on environmental health controls, such as better infrastructure, sanitation and living conditions.,This review explores the global prevalence of strongyloidiasis in relation to its presence in subtropical, tropical and temperate climate zones with mild and cold winters, but also explores the corresponding socioeconomic conditions of these regions.,The evidence shows that strongyloidiasis is primarily determined by the socioeconomic status of the communities rather than geographic or climatic conditions.,It demonstrates that strongyloidiasis should no longer be referred to as a “tropical” disease but rather a disease of disadvantage.,This philosophical shift will promote the development of correct control strategies for preventing this disease of disadvantage.

Objectives To determine which travellers with malaria are at greatest risk of dying, highlighting factors which can be used to target health messages to travellers.,Design Observational study based on 20 years of UK national data.,Setting National register of malaria cases.,Participants 25 054 patients notified with Plasmodium falciparum malaria, of whom 184 died, between 1987 and 2006.,Main outcome measures Comparison between those with falciparum malaria who died and non-fatal cases, including age, reason for travel, country of birth, time of year diagnosed, malaria prophylaxis used.,Results Mortality increased steadily with age, with a case fatality of 25/548 (4.6%) in people aged >65 years, adjusted odds ratio 10.68 (95% confidence interval 6.4 to 17.8), P<0.001 compared with 18-35 year olds.,There were no deaths in the ≤5 year age group.,Case fatality was 3.0% (81/2740 cases) in tourists compared with 0.32% (26/8077) in travellers visiting friends and relatives (adjusted odds ratio 8.2 (5.1 to 13.3), P<0.001).,Those born in African countries with endemic malaria had a case fatality of 0.4% (36/8937) compared with 2.4% (142/5849) in others (adjusted odds ratio 4.6 (3.1 to 9.9), P<0.001).,Case fatality was particularly high from the Gambia.,There was an inverse correlation in mortality between region of presentation and number of cases seen in the region (R2=0.72, P<0.001).,Most delay in fatal cases was in seeking care.,Conclusions Most travellers acquiring malaria are of African heritage visiting friends and relatives.,In contrast the risks of dying from malaria once acquired are highest in the elderly, tourists, and those presenting in areas in which malaria is seldom seen.,Doctors often do not think of these as high risk groups for malaria; for this reason they are important groups to target in pre-travel advice.

Rapid and fast acting anti-malarials are essential to treat severe malaria.,Quinine has been the only option for parenteral therapy until recently.,While current evidence shows that intravenous artesunate is more effective than quinine in treating severe malaria in endemic countries, some questions remain regarding safety profiles and drug resistance.,For imported severe malaria, additional unanswered questions are related to generalizability of the findings from endemic countries and to legal aspects, as there is no Good Manufacturing Practice-conform drug available yet.,Here, the implications of existing evidence for the treatment of imported severe malaria are discussed.

There is growing interest in local elimination of soil-transmitted helminth (STH) infection in endemic settings.,In such settings, highly sensitive diagnostics are needed to detect STH infection.,We compared double-slide Kato-Katz, the most commonly used copromicroscopic detection method, to multi-parallel quantitative polymerase chain reaction (qPCR) in 2,799 stool samples from children aged 2-12 years in a setting in rural Bangladesh with predominantly low STH infection intensity.,We estimated the sensitivity and specificity of each diagnostic using Bayesian latent class analysis.,Compared to double-slide Kato-Katz, STH prevalence using qPCR was almost 3-fold higher for hookworm species and nearly 2-fold higher for Trichuris trichiura.,Ascaris lumbricoides prevalence was lower using qPCR, and 26% of samples classified as A. lumbricoides positive by Kato-Katz were negative by qPCR.,Amplicon sequencing of the 18S rDNA from 10 samples confirmed that A. lumbricoides was absent in samples classified as positive by Kato-Katz and negative by qPCR.,The sensitivity of Kato-Katz was 49% for A. lumbricoides, 32% for hookworm, and 52% for T. trichiura; the sensitivity of qPCR was 79% for A. lumbricoides, 93% for hookworm, and 90% for T. trichiura.,Specificity was ≥ 97% for both tests for all STH except for Kato-Katz for A. lumbricoides (specificity = 68%).,There were moderate negative, monotonic correlations between qPCR cycle quantification values and eggs per gram quantified by Kato-Katz.,While it is widely assumed that double-slide Kato-Katz has few false positives, our results indicate otherwise and highlight inherent limitations of the Kato-Katz technique. qPCR had higher sensitivity than Kato-Katz in this low intensity infection setting.

Sanitation affects health, especially that of young children.,Residents of Salvador, in Northeast Brazil, have had a high prevalence of intestinal parasites.,A citywide sanitation intervention started in 1996 aimed to raise the level of sewer coverage from 26% to 80% of households.,We evaluated the impact of this intervention on the prevalence of Ascaris lumbricoides, Trichuris trichuria, and Giardia duodenalis infections in preschool children.,The evaluation was composed of two cross-sectional studies (1998 and 2003-2004), each of a sample of 681 and 976 children 1-4 years of age, respectively.,Children were sampled from 24 sentinel areas chosen to represent the range of environmental conditions in the study site.,Data were collected using an individual/household questionnaire, and an environmental survey was conducted in each area before and after the intervention to assess basic household and neighborhood sanitation conditions.,Stool samples were examined for the presence of intestinal parasites.,The effect of the intervention was estimated by hierarchical modeling, fitting a sequence of multivariate regression models.,The prevalence of A. lumbricoides infection was reduced from 24.4% to 12.0%, T. trichuria from 18.0% to 5.0%, and G. duodenalis from 14.1% to 5.3%.,Most of this reduction appeared to be explained by the increased coverage in each neighborhood by the sewage system constructed during the intervention.,The key explanatory variable was thus an ecological measure of exposure and not household-based, suggesting that the parasite transmission prevented by the program was mainly in the public (vs. the domestic) domain.,This study, using advanced statistical modeling to control for individual and ecological potential confounders, demonstrates the impact on intestinal parasites of sanitation improvements implemented at the scale of a large population.

In recent years an increasing number of public investments and policy changes have been made to improve the availability, affordability and quality of medicines available to consumers in developing countries, including anti-malarials.,It is important to monitor the extent to which these interventions are successful in achieving their aims using quantitative data on the supply side of the market.,There are a number of challenges related to studying supply, including outlet sampling, gaining provider cooperation and collecting accurate data on medicines.,This paper provides guidance on key steps to address these issues when conducting a medicine outlet survey in a developing country context.,While the basic principles of good survey design and implementation are important for all surveys, there are a set of specific issues that should be considered when conducting a medicine outlet survey.,This paper draws on the authors’ experience of designing and implementing outlet surveys, including the lessons learnt from ACTwatch outlet surveys on anti-malarial retail supply, and other key studies in the field.,Key lessons and points of debate are distilled around the following areas: selecting a sample of outlets; techniques for collecting and analysing data on medicine availability, price and sales volumes; and methods for ensuring high quality data in general.,The authors first consider the inclusion criteria for outlets, contrasting comprehensive versus more focused approaches.,Methods for developing a reliable sampling frame of outlets are then presented, including use of existing lists, key informants and an outlet census.,Specific issues in the collection of data on medicine prices and sales volumes are discussed; and approaches for generating comparable price and sales volume data across products using the adult equivalent treatment dose (AETD) are explored.,The paper concludes with advice on practical considerations, including questionnaire design, field worker training, and data collection.,Survey materials developed by ACTwatch for investigating anti-malarial markets in sub-Saharan Africa and Asia provide a helpful resource for future studies in this area.

Artemisinin-based combination therapy (ACT) is the first-line malaria treatment throughout most of the malaria-endemic world.,Data on ACT availability, price and market share are needed to provide a firm evidence base from which to assess the current situation concerning quality-assured ACT supply.,This paper presents supply side data from ACTwatch outlet surveys in Benin, the Democratic Republic of Congo (DRC), Madagascar, Nigeria, Uganda and Zambia.,Between March 2009 and June 2010, nationally representative surveys of outlets providing anti-malarials to consumers were conducted.,A census of all outlets with the potential to provide anti-malarials was conducted in clusters sampled randomly.,28,263 outlets were censused, 51,158 anti-malarials were audited, and 9,118 providers interviewed.,The proportion of public health facilities with at least one first-line quality-assured ACT in stock ranged between 43% and 85%.,Among private sector outlets stocking at least one anti-malarial, non-artemisinin therapies, such as chloroquine and sulphadoxine-pyrimethamine, were widely available (> 95% of outlets) as compared to first-line quality-assured ACT (< 25%).,In the public/not-for-profit sector, first-line quality-assured ACT was available for free in all countries except Benin and the DRC (US$1.29 [Inter Quartile Range (IQR): $1.29-$1.29] and $0.52[IQR: $0.00-$1.29] per adult equivalent dose respectively).,In the private sector, first-line quality-assured ACT was 5-24 times more expensive than non-artemisinin therapies.,The exception was Madagascar where, due to national social marketing of subsidized ACT, the price of first-line quality-assured ACT ($0.14 [IQR: $0.10, $0.57]) was significantly lower than the most popular treatment (chloroquine, $0.36 [IQR: $0.36, $0.36]).,Quality-assured ACT accounted for less than 25% of total anti-malarial volumes; private-sector quality-assured ACT volumes represented less than 6% of the total market share.,Most anti-malarials were distributed through the private sector, but often comprised non-artemisinin therapies, and in the DRC and Nigeria, oral artemisinin monotherapies.,Provider knowledge of the first-line treatment was significantly lower in the private sector than in the public/not-for-profit sector.,These standardized, nationally representative results demonstrate the typically low availability, low market share and high prices of ACT, in the private sector where most anti-malarials are accessed, with some exceptions.,The results confirm that there is substantial room to improve availability and affordability of ACT treatment in the surveyed countries.,The data will also be useful for monitoring the impact of interventions such as the Affordable Medicines Facility for malaria.

Malaria parasite population genetic structure varies among areas of differing endemicity, but this has not been systematically studied across Plasmodium falciparum populations in Africa where most infections occur.,Ten polymorphic P. falciparum microsatellite loci were genotyped in 268 infections from eight locations in four West African countries (Republic of Guinea, Guinea Bissau, The Gambia and Senegal), spanning a highly endemic forested region in the south to a low endemic Sahelian region in the north.,Analysis was performed on proportions of mixed genotype infections, genotypic diversity among isolates, multilocus standardized index of association, and inter-population differentiation.,Each location had similar levels of pairwise genotypic diversity among isolates, although there were many more mixed parasite genotype infections in the south.,Apart from a few isolates that were virtually identical, the multilocus index of association was not significant in any population.,Genetic differentiation between populations was low (most pairwise FST values < 0.03), and an overall test for isolation by distance was not significant.,Although proportions of mixed genotype infections varied with endemicity as expected, population genetic structure was similar across the diverse sites.,Very substantial reduction in transmission would be needed to cause fragmented or epidemic sub-structure in this region.

The malaria vaccine candidate antigens erythrocyte binding antigen 175 (EBA-175), merozoite surface protein 3 (MSP-3), and apical membrane antigen (AMA-1) from Plasmodium falciparum isolates from countries in central and west Africa were assessed for allelic diversity.,Samples were collected on filter paper from 600 P. falciparum-infected symptomatic patients in Cameroon, Republic of Congo, Burkina Faso, Ghana, and Senegal and screened for class-specific amplification fragments.,Genetic diversity, assessed by mean heterozygosity, was comparable among countries.,We detected a clinical increase in eba 175 F-allele frequency from west to east across the study region.,No statistical difference in msp-3 allele distribution between countries was observed.,The ama-1 3D7 alleles were present at a lower frequency in central Africa than in West Africa.,We also detected little to no genetic differentiation among sampling locations.,This finding indicates that, at least at the level of resolution offered by restriction fragment length polymorphism analysis, these antigens showed remarkable genetic homogeneity throughout the region sampled, perhaps caused by balancing selection to maintain a diverse array of antigen haplotyes.

Macrophages have long been center stage in the host response to microbial infection, but only in the past 10-15 years has there been a growing appreciation for their role in helminth infection and the associated type 2 response.,Through the actions of the IL-4 receptor α (IL-4Rα), type 2 cytokines result in the accumulation of macrophages with a distinctive activation phenotype.,Although our knowledge of IL-4Rα-induced genes is growing rapidly, the specific functions of these macrophages have yet to be established in most disease settings.,Understanding the interplay between IL-4Rα-activated macrophages and the other cellular players is confounded by the enormous transcriptional heterogeneity within the macrophage population and by their highly plastic nature.,Another level of complexity is added by the new knowledge that tissue macrophages can be derived either from a resident prenatal population or from blood monocyte recruitment and that IL-4 can increase macrophage numbers through proliferative expansion.,Here, we review current knowledge on the contribution of macrophages to helminth killing and wound repair, with specific attention paid to distinct cellular origins and plasticity potential.

The suppression of protective Type 2 immunity is a principal factor driving the chronicity of helminth infections, and has been attributed to a range of Th2 cell-extrinsic immune-regulators.,However, the intrinsic fate of parasite-specific Th2 cells within a chronic immune down-regulatory environment, and the resultant impact such fate changes may have on host resistance is unknown.,We used IL-4gfp reporter mice to demonstrate that during chronic helminth infection with the filarial nematode Litomosoides sigmodontis, CD4+ Th2 cells are conditioned towards an intrinsically hypo-responsive phenotype, characterised by a loss of functional ability to proliferate and produce the cytokines IL-4, IL-5 and IL-2.,Th2 cell hypo-responsiveness was a key element determining susceptibility to L. sigmodontis infection, and could be reversed in vivo by blockade of PD-1 resulting in long-term recovery of Th2 cell functional quality and enhanced resistance.,Contrasting with T cell dysfunction in Type 1 settings, the control of Th2 cell hypo-responsiveness by PD-1 was mediated through PD-L2, and not PD-L1.,Thus, intrinsic changes in Th2 cell quality leading to a functionally hypo-responsive phenotype play a key role in determining susceptibility to filarial infection, and the therapeutic manipulation of Th2 cell-intrinsic quality provides a potential avenue for promoting resistance to helminths.

Although the burden of Plasmodium falciparum malaria is gradually declining in many parts of Africa, it is characterized by spatial and temporal variability that presents new and evolving challenges for malaria control programs.,Reductions in the malaria burden need to be sustained in the face of changing epidemiology whilst simultaneously tackling significant pockets of sustained or increasing transmission.,Large-scale, robust surveillance mechanisms that measure rather than estimate the actual burden of malaria over time from large areas of the continent where such data are lacking need to be prioritized.,We review these fascinating developments, caution against complacency, and make the case that improving the extent and quality of malaria surveillance is vital for Africa as she marches on towards elimination.

Heterogeneity in malaria risk is considered a challenge for malaria elimination.,A cross-sectional study was conducted to describe and explain micro-epidemiological variation in Plasmodium infection prevalence at household and village level in three villages in Ratanakiri Province, Cambodia.,A two-level logistic regression model with a random intercept fitted for each household was used to model the odds of Plasmodium infection, with sequential adjustment for individual-level then household-level risk factors.,Individual-level risk factors for Plasmodium infection included hammock net use and frequency of evening outdoor farm gatherings in adults, and older age in children.,Household-level risk factors included house wall material, crop types, and satellite dish and farm machine ownership.,Individual-level risk factors did not explain differences in odds of Plasmodium infection between households or between villages.,In contrast, once household-level risk factors were taken into account, there was no significant difference in odds of Plasmodium infection between households and between villages.,This study shows the importance of ongoing indoor and peridomestic transmission in a region where forest workers and mobile populations have previously been the focus of attention.,Interventions targeting malaria risk at household level should be further explored.

In order to eliminate Lymphatic Filariasis (LF) as a public health problem, the World Health Assembly recommends an approach which includes interruption of transmission of infection and the alleviation of morbidity.,In 2000, the Togolese National Program to Eliminate Lymphatic Filariasis (PNELF) started the annual mass drug administrations and in 2007, the program added a morbidity component for the management of lymphedema.,This manuscript describes the methods of an evaluation aimed at assessing the strengths and weaknesses of the Togolese National Lymphedema Morbidity Program.,The evaluation was conducted through in-depth interviews with stakeholders at each programmatic level.,Interviews focused on message dissemination, health provider training, patient self-care practices, social dynamics, and program impact.,The evaluation demonstrated that the program strengths include the standardization and in-depth training of health staff, dissemination of the program’s treatment message, a positive change in the community’s perception of lymphedema, and successful patient recruitment and training in care techniques.,The lessons learned from this evaluation helped to improve Togo’s program, but may also provide guidance and strategies for other countries desiring to develop a morbidity program.,The methods of program evaluation described in this paper can serve as a model for monitoring components of other decentralized national health programs in low resource settings.

Lymphatic filariasis (LF) is a chronic and often disfiguring condition that predominantly affects the rural poor and leads to social exclusion, stigma, and discrimination.,Little is currently known about the emotional difficulties and stigma experiences among persons living with LF in Nigeria.,Our study evaluated the emotional difficulties and stigma experienced by persons with LF in Plateau State, Nigeria.,We utilized a combination of qualitative data instruments comprising focus group discussions, McGill’s Illness Narrative Interviews, and key informant interviews.,We transcribed and analyzed the data using a combination of inductive and deductive coding approaches.,Sixty-nine respondents were interviewed: 37 females and 32 males.,The prevalent community perception of LF was the belief that it was a spiritual problem.,Emotional reactions included feelings of sadness, hopelessness, anger, frustration, worry, and suicidal ideation.,These experiences, including those of stigma, discrimination, and social exclusion, culminated in difficulties with occupational functioning, marital life, and community participation.,Our findings highlight the value of a rights-based approach that emphasizes state and non-state actors’ need to provide access to the highest attainable standard of health, including mental health, and to protect persons with LF from stigma, discrimination, and social exclusion.

Helminths are extraordinarily successful parasites due to their ability to modulate the host immune response.,They have evolved a spectrum of immunomodulatory molecules that are now beginning to be defined, heralding a molecular revolution in parasite immunology.,These discoveries have the potential both to transform our understanding of parasite adaptation to the host and to develop possible therapies for immune-mediated disease.,In this review we will summarize the current state of the art in parasite immunomodulation and discuss perspectives on future areas for research and discovery.,Parasitic helminths modulate the immune system, preventing immune-mediated ejection and suppressing immune-mediated diseases.,In this review, Maizels and colleagues describe the secreted molecules by which parasites achieve this and the methods by which these molecules have evolved.

The constant increase of aquaculture production and wealthy seafood consumption has forced the industry to explore alternative and more sustainable raw aquafeed materials, and plant ingredients have been used to replace marine feedstuffs in many farmed fish.,The objective of the present study was to assess whether plant-based diets can induce changes in the intestinal mucus proteome, gut autochthonous microbiota and disease susceptibility of fish, and whether these changes could be reversed by the addition of sodium butyrate to the diets.,Three different trials were performed using the teleostean gilthead sea bream (Sparus aurata) as model.,In a first preliminary short-term trial, fish were fed with the additive (0.8%) supplementing a basal diet with low vegetable inclusion (D1) and then challenged with a bacteria to detect possible effects on survival.,In a second trial, fish were fed with diets with greater vegetable inclusion levels (D2, D3) and the long-term effect of sodium butyrate at a lower dose (0.4%) added to D3 (D4 diet) was tested on the intestinal proteome and microbiome.,In a third trial, the long-term effectiveness of sodium butyrate (D4) to prevent disease outcome after an intestinal parasite (Enteromyxum leei) challenge was tested.,The results showed that opposed forces were driven by dietary plant ingredients and sodium butyrate supplementation in fish diet.,On the one hand, vegetable diets induced high parasite infection levels that provoked drops in growth performance, decreased intestinal microbiota diversity, induced the dominance of the Photobacterium genus, as well as altered the gut mucosal proteome suggesting detrimental effects on intestinal function.,On the other hand, butyrate addition slightly decreased cumulative mortality after bacterial challenge, avoided growth retardation in parasitized fish, increased intestinal microbiota diversity with a higher representation of butyrate-producing bacteria and reversed most vegetable diet-induced changes in the gut proteome.,This integrative work gives insights on the pleiotropic effects of a dietary additive on the restoration of intestinal homeostasis and disease resilience, using a multifaceted approach.,The online version of this article (10.1186/s40168-017-0390-3) contains supplementary material, which is available to authorized users.

Brazil’s southernmost state, Rio Grande do Sul (RGS), was considered schistosomiasis-free until 1998 when a low endemic focus was identified in Esteio, a city located next to the capital of RGS.,In the last two decades, the control interventions applied in the region have been apparently successful, and the absence of new cases indicated the possibility of interrupted schistosomiasis transmission.,The objective of this study was to update the clinical and epidemiological data of schistosomiasis in Esteio.,We reviewed all 28 individuals diagnosed with the infection since 1997 and a survey was applied to a group of 29 school-aged children residing in Vila Pedreira, one of the most affected neighborhoods.,No eggs were detected in fecal samples using the Helmintex method, and all samples were negative for serum antibodies on examination by the western blot technique using the Schistosoma mansoni microsomal antigen (MAMA- WB).,In contrast, 23 individuals (79%) tested positive for the cathodic circulating antigen with the point-of-care immunochromatographic test (POC-CCA) on urine samples.,Of the 28 formerly infected individuals, only eight were located, of which four tested positive, and four tested negative for serum antibodies using the MAMA-WB technique.,Current adverse conditions for S. mansoni transmission in Esteio and the absence of a confirmed diagnosis suggests that there is (i) a lack of specificity of the POC-CCA test in low endemic settings, and (ii) a high probability that interruption of schistosomiasis has been achieved in Esteio.

In Ghana, pre-school-aged children (PSAC) are at risk of intestinal schistosomiasis and are living in need of praziquantel treatment.,To better assess the infection burden within this vulnerable demographic group, we have provided a comparative assessment of the prevalence of Schistosoma mansoni in pre-school-aged children by urine circulating cathodic antigen (CCA) dipsticks, real-time PCR Taqman® faecal assays and Kato-Katz coproscopy.,In all, 190 pre-school-aged children were sampled from three endemic communities (viz.,Tomefa, Torgahkope/Adakope, and Manheam) around Weija dam, Southern Ghana.,Fresh stool and urine samples were collected from all participants for diagnosis.,Among all the three communities, the urine-CCA assay recorded the highest prevalence values of 90.5% (95% CI 80.4-96.4), 87.9% (95% CI 76.7-95), and 81.2% (95% CI 69.9-89.6) in Tomefa, Torgahkope/Adakope, and Manheam respectively.,Prevalence by real-time PCR was 50% (95% CI 35.5-64.5), 8% (95% CI 2.2-19.2) and 16.7% (95% CI 8.3-28.5), while by Kato-Katz was 55.6% (95% CI 42.5-68.1), 8.6% (95% CI 2.9-19) and 11.6% (95% CI 5.1-21.6) respectively.,Children aged 1 year and over were found to be positive with the urine-CCA assay; by the ages of 3-4, over 50% were urine-CCA patent.,The sensitivity and specificity of the POC-CCA dipsticks, when compared against the combined results of Kato-Katz/TaqMan results was found to be 84.1% (95% CI = 72.7-92.1) and 12.9% (95% CI = 6.6-22) respectively.,We propose that the urine-CCA dipstick may be a useful rapid diagnostic tool to estimate the prevalence of intestinal schistosomiasis in PSAC, particularly in rapid identification of at-risk areas.,However, our assessment has shown that it possible to record false positives when compared to combined Kato-Katz and qPCR results.,To guide PSAC praziquantel treatment needs, we propose the urine CCA assay should be included in routine surveillance of intestinal schistosomiasis alongside other diagnostics such as Kato-Katz and urine filtration.

An accurate diagnosis of helminth infection is important to improve patient management.,However, there is considerable intra- and inter-specimen variation of helminth egg counts in human feces.,Homogenization of stool samples has been suggested to improve diagnostic accuracy, but there are no detailed investigations.,Rapid disintegration of hookworm eggs constitutes another problem in epidemiological surveys.,We studied the spatial distribution of Schistosoma mansoni and hookworm eggs in stool samples, the effect of homogenization, and determined egg counts over time in stool samples stored under different conditions.,Whole-stool samples were collected from 222 individuals in a rural part of south Côte d'Ivoire.,Samples were cut into four pieces and helminth egg locations from the front to the back and from the center to the surface were analyzed.,Some samples were homogenized and fecal egg counts (FECs) compared before and after homogenization.,The effect of stool storing methods on FECs was investigated over time, comparing stool storage on ice, covering stool samples with a water-soaked tissue, or keeping stool samples in the shade.,We found no clear spatial pattern of S. mansoni and hookworm eggs in fecal samples.,Homogenization decreased S. mansoni FECs (p = 0.026), while no effect was observed for hookworm and other soil-transmitted helminths.,Hookworm FECs decreased over time.,Storing stool samples on ice or covered with a moist tissue slowed down hookworm egg decay (p<0.005).,Our findings have important implications for helminth diagnosis at the individual patient level and for epidemiological surveys, anthelmintic drug efficacy studies and monitoring of control programs.,Specifically, homogenization of fecal samples is recommended for an accurate detection of S. mansoni eggs, while keeping collected stool samples cool and moist delayed the disintegration of hookworm eggs.

In the past decade there have been an increasing number of studies on co-infections between worms and malaria.,However, this increased interest has yielded results that have been at times conflicting and made it difficult to clearly grasp the outcome of this interaction.,Despite the heterogeneity of study designs, reviewing the growing body of research may be synthesized into some broad trends: Ascaris emerges mostly as protective from malaria and its severe manifestations, whereas hookworm seems to increase malaria incidence.,As efforts are made to de-worm populations in malaria endemic areas, there is still no clear picture of the impact these programmes have in terms of quantitative and qualitative changes in malaria.

Reactive case detection could be a powerful tool in malaria elimination, as it selectively targets transmission pockets.,However, field operations have yet to demonstrate under which conditions, if any, reactive case detection is best poised to push a region to elimination.,This study uses mathematical modelling to assess how baseline transmission intensity and local interconnectedness affect the impact of reactive activities in the context of other possible intervention packages.,Communities in Southern Province, Zambia, where elimination operations are currently underway, were used as representatives of three archetypes of malaria transmission: low-transmission, high household density; high-transmission, low household density; and high-transmission, high household density.,Transmission at the spatially-connected household level was simulated with a dynamical model of malaria transmission, and local variation in vectorial capacity and intervention coverage were parameterized according to data collected from the area.,Various potential intervention packages were imposed on each of the archetypical settings and the resulting likelihoods of elimination by the end of 2020 were compared.,Simulations predict that success of elimination campaigns in both low- and high-transmission areas is strongly dependent on stemming the flow of imported infections, underscoring the need for regional-scale strategies capable of reducing transmission concurrently across many connected areas.,In historically low-transmission areas, treatment of clinical malaria should form the cornerstone of elimination operations, as most malaria infections in these areas are symptomatic and onward transmission would be mitigated through health system strengthening; reactive case detection has minimal impact in these settings.,In historically high-transmission areas, vector control and case management are crucial for limiting outbreak size, and the asymptomatic reservoir must be addressed through reactive case detection or mass drug campaigns.,Reactive case detection is recommended only for settings where transmission has recently been reduced rather than all low-transmission settings.,This is demonstrated in a modelling framework with strong out-of-sample accuracy across a range of transmission settings while including methodologies for understanding the most resource-effective allocations of health workers.,This approach generalizes to providing a platform for planning rational scale-up of health systems based on locally-optimized impact according to simplified stratification.,The online version of this article (doi:10.1186/s12936-017-1903-z) contains supplementary material, which is available to authorized users.

As malaria is being pushed back on many frontiers and global case numbers are declining, accurate measurement and prediction of transmission becomes increasingly difficult.,Low transmission settings are characterised by high levels of spatial heterogeneity, which stands in stark contrast to the widely used assumption of spatially homogeneous transmission used in mathematical transmission models for malaria.,In the present study an individual-based mathematical malaria transmission model that incorporates multiple parasite clones, variable human exposure and duration of infection, limited mosquito flight distance and most importantly geographically heterogeneous human and mosquito population densities was used to illustrate the differences between homogeneous and heterogeneous transmission assumptions when aiming to predict surrogate indicators of transmission intensity such as population parasite prevalence or multiplicity of infection (MOI).,In traditionally highly malaria endemic regions where most of the population harbours malaria parasites, humans are often infected with multiple parasite clones.,However, studies have shown also in areas with low overall parasite prevalence, infection with multiple parasite clones is a common occurrence.,Mathematical models assuming homogeneous transmission between humans and mosquitoes cannot explain these observations.,Heterogeneity of transmission can arise from many factors including acquired immunity, body size and occupational exposure.,In this study, we show that spatial heterogeneity has a profound effect on predictions of MOI and parasite prevalence.,We illustrate, that models assuming homogeneous transmission underestimate average MOI in low transmission settings when compared to field data and that spatially heterogeneous models predict stable transmission at much lower overall parasite prevalence.,Therefore it is very important that models used to guide malaria surveillance and control strategies in low transmission and elimination settings take into account the spatial features of the specific target area, including human and mosquito vector distribution.

This study was part of the work to prepare for a cluster-randomized controlled trial to evaluate the effect of combining indoor residual spraying and long-lasting insecticidal nets on malaria incidence.,A pilot study was done to estimate the variations of malaria incidence among villages, combined with entomological collections and an assessment of susceptibility to insecticides in malaria vectors.,A cohort of 5309 residents from four kebeles (the lowest government administrative unit) in 996 households was followed from August to December 2013 in south-central Ethiopia.,Blood samples were collected by a finger prick for a microscopic examination of malaria infections.,A multilevel mixed effect model was applied to measure the predictors of malaria episode.,Adult mosquitoes were collected using light traps set indoors close to a sleeping person, pyrethrum spray sheet catches and artificial outdoor pit shelters.,Enzyme-linked immunosorbent assays were used to detect the sources of mosquito blood meals, while mosquito longevity was estimated based on parity.,The World Health Organization’s tube bioassay test was used to assess the insecticide susceptibility status of malaria vectors to pyrethroids and carbamates.,The average incidence of malaria episode was 4.6 per 10,000 person weeks of observation.,The age group from 5 to 14 years (IRR = 2.7; 95 % CI 1.1-6.6) and kebeles near a lake or river (IRR = 14.2, 95 % CI 3.1-64) were significantly associated with malaria episode.,Only 271 (27.3 %) of the households owned insecticide-treated nets.,Of 232 adult Anopheles mosquitoes collected, Anopheles arabiensis (71.1 %) was the predominant species.,The average longevity of An. arabiensis was 14 days (range: 7-25 human blood index days).,The overall human blood index (0.69) for An. arabiensis was higher than the bovine blood index (0.38).,Statistically significant differences in Anopheline mosquitoes abundance were observed between the kebeles (P = 0.001).,Anopheles arabiensis was susceptible to propoxur, but resistant to pyrethroids.,However, An. pharoensis was susceptible to all pyrethroids and carbamates tested.,This study showed a high variation in malaria incidence and Anopheles between kebeles.,The observed susceptibility of the malaria vectors to propoxur warrants using this insecticide for indoor residual spraying, and the results from this study will be used as a baseline for the trial.

The Government of Ethiopia and its partners have deployed artemisinin-based combination therapies (ACT) since 2004 and long-lasting insecticidal nets (LLINs) since 2005.,Malaria interventions and trends in malaria cases and deaths were assessed at hospitals in malaria transmission areas during 2001-2011.,Regional LLINs distribution records were used to estimate the proportion of the population-at-risk protected by LLINs.,Hospital records were reviewed to estimate ACT availability.,Time-series analysis was applied to data from 41 hospitals in malaria risk areas to assess trends of malaria cases and deaths during pre-intervention (2001-2005) and post-interventions (2006-2011) periods.,The proportion of the population-at-risk potentially protected by LLINs increased to 51% in 2011.,The proportion of facilities with ACTs in stock exceeded 87% during 2006-2011.,Among all ages, confirmed malaria cases in 2011 declined by 66% (95% confidence interval [CI], 44-79%) and SPR by 37% (CI, 20%-51%) compared to the level predicted by pre-intervention trends.,In children under 5 years of age, malaria admissions and deaths fell by 81% (CI, 47%-94%) and 73% (CI, 48%-86%) respectively.,Optimal breakpoint of the trendlines occurred between January and June 2006, consistent with the timing of malaria interventions.,Over the same period, non-malaria cases and deaths either increased or remained unchanged, the number of malaria diagnostic tests performed reflected the decline in malaria cases, and rainfall remained at levels supportive of malaria transmission.,Malaria cases and deaths in Ethiopian hospitals decreased substantially during 2006-2011 in conjunction with scale-up of malaria interventions.,The decrease could not be accounted for by changes in hospital visits, malaria diagnostic testing or rainfall.,However, given the history of variable malaria transmission in Ethiopia, more data would be required to exclude the possibility that the decrease is due to other factors.

A mosquito repellent has the potential to prevent malaria infection, but there has been few studies demonstrating the effectiveness of combining this strategy with the highly effective long-lasting insecticidal nets (LLINs).,This study aimed to determine the effect of combining community-based mosquito repellent with LLINs in the reduction of malaria.,A community-based clustered-randomised trial was conducted in 16 rural villages with 1,235 households in southern Ethiopia between September and December of 2008.,The villages were randomly assigned to intervention (mosquito repellent and LLINs, eight villages) and control (LLINs alone, eight villages) groups.,Households in the intervention villages received mosquito repellent (i.e., Buzz-Off® petroleum jelly, essential oil blend) applied every evening.,The baseline survey was followed by two follow-up surveys, at one month interval.,The primary outcome was detection of Plasmodium falciparum, Plasmodium vivax, or both parasites, through microscopic examination of blood slides.,Analysis was by intention to treat.,Baseline imbalances and clustering at individual, household and village levels were adjusted using a generalized linear mixed model.,3,078 individuals in intervention and 3,004 in control group were enrolled into the study.,Compared with the control arm, the combined use of mosquito repellent and LLINs significantly reduced malaria infection of all types over time [adjusted Odds Ratio (aOR) = 0.66; 95% CI = 0.45-0.97].,Similarly, a substantial reduction in P. falciparum malaria infection during the follow-up surveys was observed in the intervention group (aOR = 0.53, 95% CI = 0.31-0.89).,The protective efficacy of using mosquito repellent and LLINs against malaria infection of both P. falciparum/P. vivax and P. falciparum was 34% and 47%, respectively.,Daily application of mosquito repellent during the evening followed by the use of LLINs during bedtime at community level has significantly reduced malaria infection.,The finding has strong implication particularly in areas where malaria vectors feed mainly in the evening before bedtime.,ClinicalTrials.gov identifier: NCT01160809.

Current front line malaria vector control methods such as indoor residual spraying (IRS) and long-lasting insecticidal nets (LLINs), rely upon the preference of many primary vectors to feed and/or rest inside human habitations where they can be targeted with domestically-applied insecticidal products.,We studied the human biting behaviour of the malaria vector Anopheles funestus Giles and the potential malaria vector Anopheles quadriannulatus Theobald in Luangwa valley, south-east Zambia.,Mosquitoes were collected by human landing catch in blocks of houses with either combined use of deltamethrin-based IRS and LLINs or LLINs alone.,Human behaviour data were collected to estimate how much exposure to mosquito bites indoors and outdoors occurred at various times of the night for LLIN users and non-users.,Anopheles funestus and An. quadriannulatus did not show preference to bite either indoors or outdoors: the proportions [95% confidence interval] caught indoors were 0.586 [0.303, 0.821] and 0.624 [0.324, 0.852], respectively.,However, the overwhelming majority of both species were caught at times when most people are indoors.,The proportion of mosquitoes caught at a time when most people are indoors were 0.981 [0.881, 0.997] and 0.897 [0.731, 0.965], respectively, so the proportion of human exposure to both species occuring indoors was high for individuals lacking LLINs (An. funestus: 0.983 and An. quadriannulatus: 0.970, respectively).,While LLIN users were better protected, more than half of their exposure was nevertheless estimated to occur indoors (An. funestus: 0.570 and An. quadriannulatus: 0.584).,The proportion of human exposure to both An. funestus and An. quadriannulatus occuring indoors was high in the area and hence both species might be responsive to further peri-domestic measures if these mosquitoes are susceptible to insecticidal products.

Malaria persists in some high-transmission areas despite extensive control efforts.,Progress toward elimination may require effective targeting of specific human populations that act as key transmission reservoirs.,Parameterized using molecular-based Plasmodium falciparum infection data from cross-sectional community studies in southern Malawi, a simulation model was developed to predict the proportions of human-to-mosquito transmission arising from (a) children under 5 years old (U5s), (b) school-age children (SAC, 5-15 years), (c) young adults (16-30 years), and (d) adults > 30 years.,The model incorporates mosquito biting heterogeneity and differential infectivity (i.e. probability that a blood-fed mosquito develops oocysts) by age and gametocyte density.,The model predicted that SAC were responsible for more than 60% of new mosquito infections in both dry and rainy seasons, even though they comprise only 30% of this southern Malawi population.,Young adults were the second largest contributors, while U5s and adults over 30 were each responsible for < 10% of transmission.,While the specific predicted values are sensitive to the relative infectiousness of SAC, this group remained the most important contributor to mosquito infections under all realistic estimates.,These results suggest that U5 children play a small role compared to SAC in maintaining P. falciparum transmission in southern Malawi.,Models that assume biting homogeneity overestimate the importance of U5s.,To reduce transmission, interventions will need to reach more SAC and young adults.,This publicly available model can be used by others to estimate age-specific transmission contributions in epidemiologically similar sites with local parameter estimates of P. falciparum prevalence and bed net use.,The online version of this article (10.1186/s12936-018-2295-4) contains supplementary material, which is available to authorized users.

In 2010, the World Health Organization shifted its malaria guidelines from recommending the empiric treatment of all febrile children to treating only those with laboratory-confirmed malaria.,This study evaluated the frequency and predictors of malaria over-treatment among febrile malaria-negative children in Kenya.,Between 2012 and 2013, 1,362 children presenting consecutively with temperature ≥37.5°C to Kisii and Homa Bay hospitals were enrolled in a cross-sectional study evaluating causes of fever.,Children were screened for malaria using smear microscopy and rapid diagnostic tests and managed according to standard of care at the hospitals.,The frequency of anti-malarial prescriptions among children with laboratory-confirmed malaria negative children (malaria over-treatment) was determined; and clinical and demographic correlates of overtreatment evaluated using logistic regression.,Because of differences in malaria endemicity, analyses were stratified and compared by site.,Among 1,362 children enrolled, 46 (7%) of 685 children in Kisii, and 310 (45.8%) of 677 in Homa Bay had laboratory-confirmed malaria; p < 0.001.,Among malaria-negative children; 210 (57.2%) in Homa Bay and 45 (7.0%) in Kisii received anti-malarials; p < 0.001.,Predictors of over-treatment in Homa Bay included ≥ one integrated management of childhood illness (IMCI) danger sign (aOR = 8.47; 95% CI: 4.81-14.89), fever lasting ≥ seven days (aOR = 4.94; 95% CI: 1.90-12.86), and fever ≥39°C (aOR = 3.07; 95% CI: 1.58-5.96).,In Kisii, only fever ≥39°C predicted over-treatment (aOR = 2.13; 95% CI: 1.02-4.45).,Malaria over-treatment was common, particularly in Homa Bay, where the prevalence of malaria was extremely high.,Severe illness and high or prolonged fever were associated with overtreatment.,Overtreatment may result in failure to treat other serious causes of fever, drug resistance, and unnecessarily treatment costs.

Improving access to parasitological diagnosis of malaria is a central strategy for control and elimination of the disease.,Malaria rapid diagnostic tests (RDTs) are relatively easy to perform and could be used in primary level clinics to increase coverage of diagnostics and improve treatment of malaria.,A cost-effectiveness analysis was undertaken of RDT-based diagnosis in public health sector facilities in Afghanistan comparing the societal and health sector costs of RDTs versus microscopy and RDTs versus clinical diagnosis in low and moderate transmission areas.,The effect measure was ‘appropriate treatment for malaria’ defined using a reference diagnosis.,Effects were obtained from a recent trial of RDTs in 22 public health centres with cost data collected directly from health centres and from patients enrolled in the trial.,Decision models were used to compare the cost of RDT diagnosis versus the current diagnostic method in use at the clinic per appropriately treated case (incremental cost-effectiveness ratio, ICER).,RDT diagnosis of Plasmodium vivax and Plasmodium falciparum malaria in patients with uncomplicated febrile illness had higher effectiveness and lower cost compared to microscopy and was cost-effective across the moderate and low transmission settings.,RDTs remained cost-effective when microscopy was used for other clinical purposes.,In the low transmission setting, RDTs were much more effective than clinical diagnosis (65.2% (212/325) vs 12.5% (40/321)) but at an additional cost (ICER) of US$4.5 per appropriately treated patient including a health sector cost (ICER) of US$2.5 and household cost of US$2.0.,Sensitivity analysis, which varied drug costs, indicated that RDTs would remain cost-effective if artemisinin combination therapy was used for treating both P. vivax and P. falciparum.,Cost-effectiveness of microscopy relative to RDT is further reduced if the former is used exclusively for malaria diagnosis.,In the health service setting of Afghanistan, RDTs are a cost-effective intervention compared to microscopy.,RDTs remain cost-effective across a range of drug costs and if microscopy is used for a range of diagnostic services.,RDTs have significant advantages over clinical diagnosis with minor increases in the cost of service provision.,The trial was registered at ClinicalTrials.gov under identifier NCT00935688.,The online version of this article (doi:10.1186/s12936-015-0696-1) contains supplementary material, which is available to authorized users.

Malaria elimination requires a variety of approaches individually optimized for different transmission settings.,A recent field study in an area of low seasonal transmission in South West Cambodia demonstrated dramatic reductions in malaria parasite prevalence following both mass drug administration (MDA) and high treatment coverage of symptomatic patients with artemisinin-piperaquine plus primaquine.,This study employed multiple combined strategies and it was unclear what contribution each made to the reductions in malaria.,A mathematical model fitted to the trial results was used to assess the effects of the various components of these interventions, design optimal elimination strategies, and explore their interactions with artemisinin resistance, which has recently been discovered in Western Cambodia.,The modelling indicated that most of the initial reduction of P. falciparum malaria resulted from MDA with artemisinin-piperaquine.,The subsequent continued decline and near elimination resulted mainly from high coverage with artemisinin-piperaquine treatment.,Both these strategies were more effective with the addition of primaquine.,MDA with artemisinin combination therapy (ACT) increased the proportion of artemisinin resistant infections, although much less than treatment of symptomatic cases with ACT, and this increase was slowed by adding primaquine.,Artemisinin resistance reduced the effectiveness of interventions using ACT when the prevalence of resistance was very high.,The main results were robust to assumptions about primaquine action, and immunity.,The key messages of these modelling results for policy makers were: high coverage with ACT treatment can produce a long-term reduction in malaria whereas the impact of MDA is generally only short-term; primaquine enhances the effect of ACT in eliminating malaria and reduces the increase in proportion of artemisinin resistant infections; parasite prevalence is a better surveillance measure for elimination programmes than numbers of symptomatic cases; combinations of interventions are most effective and sustained efforts are crucial for successful elimination.

Leishmaniasis remains a worldwide public health problem.,The limited therapeutic options, drug toxicity and reports of resistance, reinforce the need for the development of new treatment options.,Previously, we showed that 17-(allylamino)-17-demethoxygeldanamycin (17-AAG), a Heat Shock Protein 90 (HSP90)-specific inhibitor, reduces L.,(L.) amazonensis infection in vitro.,Herein, we expand the current knowledge on the leishmanicidal activity of 17-AAG against cutaneous leishmaniasis, employing an experimental model of infection with L.,(V.) braziliensis.,Exposure of axenic L.,(V.) braziliensis promastigotes to 17-AAG resulted in direct dose-dependent parasite killing.,These results were extended to L.,(V.) braziliensis-infected macrophages, an effect that was dissociated from the production of nitric oxide (NO), superoxide (O−2) or inflammatory mediators such as TNF-α, IL-6 and MCP-1.,The leishmanicidal effect was then demonstrated in vivo, employing BALB/c mice infected with L. braziliensis.,In this model, 17-AAG treatment resulted in smaller skin lesions and parasite counts were also significantly reduced.,Lastly, 17-AAG showed a similar effect to amphotericin B regarding the ability to reduce parasite viability.,17-AAG effectively inhibited the growth of L. braziliensis, both in vitro and in vivo.,Given the chronicity of L.,(V.) braziliensis infection and its association with mucocutaneous leishmaniasis, 17-AAG can be envisaged as a new chemotherapeutic alternative for cutaneous Leishmaniasis.

Systems biology holds promise as a new approach to drug target identification and drug discovery against neglected tropical diseases.,Genome-scale metabolic reconstructions, assembled from annotated genomes and a vast array of bioinformatics/biochemical resources, provide a framework for the interrogation of human pathogens and serve as a platform for generation of future experimental hypotheses.,In this article, with the application of selection criteria for both Leishmania major targets (e.g. in silico gene lethality) and drugs (e.g. toxicity), a method (MetDP) to rationally focus on a subset of low-toxic Food and Drug Administration (FDA)-approved drugs is introduced.,This metabolic network-driven approach identified 15 L. major genes as high-priority targets, 8 high-priority synthetic lethal targets, and 254 FDA-approved drugs.,Results were compared to previous literature findings and existing high-throughput screens.,Halofantrine, an antimalarial agent that was prioritized using MetDP, showed noticeable antileishmanial activity when experimentally evaluated in vitro against L. major promastigotes.,Furthermore, synthetic lethality predictions also aided in the prediction of superadditive drug combinations.,For proof-of-concept, double-drug combinations were evaluated in vitro against L. major and four combinations involving the drug disulfiram that showed superadditivity are presented.,A direct metabolic network-driven method that incorporates single gene essentiality and synthetic lethality predictions is proposed that generates a set of high-priority L. major targets, which are in turn associated with a select number of FDA-approved drugs that are candidate antileishmanials.,Additionally, selection of high-priority double-drug combinations might provide for an attractive and alternative avenue for drug discovery against leishmaniasis.

Leishmaniases are tropical zoonotic diseases, caused by kinetoplastid parasites from the genus Leishmania.,New World (NW) species are related to sylvatic cycles although urbanization processes have been reported in some South American Countries such as Colombia.,Currently, few studies show the relative distribution of Leishmania species related to cutaneous Leishmaniasis (CL) in South America due to the lack of accurate surveillance and public health systems.,Herein, we conducted a systematic estimation of the Leishmania species causing CL in Colombia from 1980 to 2001 via molecular typing and isoenzymes.,A total of 327 Leishmania isolates from humans, sandflies and reservoirs were typed as L. panamensis 61.3% (201), L. braziliensis 27.1% (88), L. lainsoni 0.6% (2), L. guyanensis 0.9% (3), L. infantum chagasi 4% (12), L. equatoriensis 0.6% (2), L. mexicana 2.1% (8), L. amazonensis 2.8% (9) and L. colombiensis 0.6% (2).,This is the first report of two new Leishmania species circulating in Colombia and suggests the need to convince the Colombian government about the need to deploy and standardize tools for the species identification to provide adequate management to individuals suffering this pathology.

Leishmania (Leishmania) mexicana causes cutaneous leishmaniasis, an endemic zoonosis affecting a growing number of patients in the southeastern states of Mexico.,Some foci are found in shade-grown cocoa and coffee plantations, or near perennial forests that provide rich breeding grounds for the sand fly vectors, but also harbor a variety of bat species that live off the abundant fruits provided by these shade-giving trees.,The close proximity between sand flies and bats makes their interaction feasible, yet bats infected with Leishmania (L.) mexicana have not been reported.,Here we analyzed 420 bats from six states of Mexico that had reported patients with leishmaniasis.,Tissues of bats, including skin, heart, liver and/or spleen were screened by PCR for Leishmania (L.) mexicana DNA.,We found that 41 bats (9.77%), belonging to 13 species, showed positive PCR results in various tissues.,The infected tissues showed no evidence of macroscopic lesions.,Of the infected bats, 12 species were frugivorous, insectivorous or nectarivorous, and only one species was sanguivorous (Desmodus rotundus), and most of them belonged to the family Phyllostomidae.,The eco-region where most of the infected bats were caught is the Gulf Coastal Plain of Chiapas and Tabasco.,Through experimental infections of two Tadarida brasiliensis bats in captivity, we show that this species can harbor viable, infective Leishmania (L.) mexicana parasites that are capable of infecting BALB/c mice.,We conclude that various species of bats belonging to the family Phyllostomidae are possible reservoir hosts for Leishmania (L.) mexicana, if it can be shown that such bats are infective for the sand fly vector.,Further studies are needed to determine how these bats become infected, how long the parasite remains viable inside these potential hosts and whether they are infective to sand flies to fully evaluate their impact on disease epidemiology.

Exosomes are small vesicles of endocytic origin, which are released into the extracellular environment and mediate a variety of physiological and pathological conditions.,Here we show that Schistosoma mansoni releases exosome-like vesicles in vitro.,Vesicles were purified from culture medium by sucrose gradient fractionation and fractions containing vesicles verified by western blot analyses and electron microscopy.,Proteomic analyses of exosomal contents unveiled 130 schistosome proteins.,Among these proteins are common exosomal markers such as heat shock proteins, energy-generating enzymes, cytoskeletal proteins, and others.,In addition, the schistosome extracellular vesicles contain proteins of potential importance for host-parasite interaction, notably peptidases, signaling proteins, cell adhesion proteins (e.g., integrins) and previously described vaccine candidates, including glutathione-S-transferase (GST), tetraspanin (TSP-2) and calpain.,S. mansoni exosomes also contain 143 microRNAs (miRNA), of which 25 are present at high levels, including miRNAs detected in sera of infected hosts.,Quantitative PCR analysis confirmed the presence of schistosome-derived miRNAs in exosomes purified from infected mouse sera.,The results provide evidence of vesicle-mediated secretion in these parasites and suggest that schistosome-derived exosomes could play important roles in host-parasite interactions and could be a useful tool in the development of vaccines and therapeutics.

In mammalian systems RNA can move between cells via vesicles.,Here we demonstrate that the gastrointestinal nematode Heligmosomoides polygyrus, which infects mice, secretes vesicles containing microRNAs (miRNAs) and Y RNAs as well as a nematode Argonaute protein.,These vesicles are of intestinal origin and are enriched for homologues of mammalian exosome proteins.,Administration of the nematode exosomes to mice suppresses Type 2 innate responses and eosinophilia induced by the allergen Alternaria.,Microarray analysis of mouse cells incubated with nematode exosomes in vitro identifies Il33r and Dusp1 as suppressed genes, and Dusp1 can be repressed by nematode miRNAs based on a reporter assay.,We further identify miRNAs from the filarial nematode Litomosoides sigmodontis in the serum of infected mice, suggesting that miRNA secretion into host tissues is conserved among parasitic nematodes.,These results reveal exosomes as another mechanism by which helminths manipulate their hosts and provide a mechanistic framework for RNA transfer between animal species.,Mammalian cell-derived exosomes can carry RNA and proteins from cell to cell, but this mode of transport has not been shown in nematodes.,Here the authors show that a gastrointestinal parasite secretes exosomes that transfer microRNAs to mammalian cells and regulate innate immunity.

Malaria is one of the primary health concerns in Madagascar.,Based on the duration and intensity of transmission, Madagascar is divided into five epidemiological strata that range from low to mesoendemic transmission.,In this study, the spatial and temporal dynamics of malaria within each epidemiological zone were studied.,The number of reported cases of uncomplicated malaria from 112 health districts between 2010 and 2014 were compiled and analysed.,First, a Standardized Incidence Ratio was calculated to detect districts with anomalous incidence compared to the stratum-level incidence.,Building on this, spatial and temporal malaria clusters were identified throughout the country and their variability across zones and over time was analysed.,The incidence of malaria increased from 2010 to 2014 within each stratum.,A basic analysis showed that districts with more than 50 cases per 1000 inhabitants are mainly located in two strata: East and West.,Lower incidence values were found in the Highlands and Fringe zones.,The standardization method revealed that the number of districts with a higher than expected numbers of cases increased through time and expanded into the Highlands and Fringe zones.,The cluster analysis showed that for the endemic coastal region, clusters of districts migrated southward and the incidence of malaria was the highest between January and July with some variation within strata.,This study identified critical districts with low incidence that shifted to high incidence and district that were consistent clusters across each year.,The current study provided a detailed description of changes in malaria epidemiology and can aid the national malaria programme to reduce and prevent the expansion of the disease by targeting the appropriate areas.,The online version of this article (10.1186/s12936-018-2206-8) contains supplementary material, which is available to authorized users.

Rational decision making on malaria control depends on an understanding of the epidemiological risks and control measures.,National Malaria Control Programmes across Africa have access to a range of state-of-the-art malaria risk mapping products that might serve their decision-making needs.,The use of cartography in planning malaria control has never been methodically reviewed.,An audit of the risk maps used by NMCPs in 47 malaria endemic countries in Africa was undertaken by examining the most recent national malaria strategies, monitoring and evaluation plans, malaria programme reviews and applications submitted to the Global Fund.,The types of maps presented and how they have been used to define priorities for investment and control was investigated.,91% of endemic countries in Africa have defined malaria risk at sub-national levels using at least one risk map.,The range of risk maps varies from maps based on suitability of climate for transmission; predicted malaria seasons and temperature/altitude limitations, to representations of clinical data and modelled parasite prevalence.,The choice of maps is influenced by the source of the information.,Maps developed using national data through in-country research partnerships have greater utility than more readily accessible web-based options developed without inputs from national control programmes.,Although almost all countries have stratification maps, only a few use them to guide decisions on the selection of interventions allocation of resources for malaria control.,The way information on the epidemiology of malaria is presented and used needs to be addressed to ensure evidence-based added value in planning control.,The science on modelled impact of interventions must be integrated into new mapping products to allow a translation of risk into rational decision making for malaria control.,As overseas and domestic funding diminishes, strategic planning will be necessary to guide appropriate financing for malaria control.

Acanthamoebiasis is most often found in patients with immune deficiency, with infections facilitated by the intake of immunosuppressive drugs.,The host immune response to Acanthamoeba spp. infection is poorly understood.,Thus, in this study, we aimed to examine the course of Acanthamoeba spp. infection taking into account the host’s immunological status, including assessment of the hematological parameters, cytokine analysis, immunophenotypic changes in spleen populations, and histological spleen changes, which could help clarify some aspects of the immune response to acanthamoebiasis.,In our experimental study, we used Acanthamoeba strain AM 22 isolated from the bronchoaspirate of a patient with acute myeloid leukaemia (AML) and atypical pneumonia symptoms.,Acanthamoeba spp. affected the hematological parameters in immunocompetent and immunosuppressed mice and induced a change in spleen weight during infection.,Moreover, analysis of anti-inflammatory (IL-4 and IL-10) and pro-inflammatory (IL-17A and IFN-γ) cytokines produced by splenocytes stimulated with concanavalin A demonstrated that Acanthamoeba spp. induced a selective Th1, Th2 and Th17 response at later stages of the infection in immunocompetent hosts.,In the case of hosts with low immunity, Acanthamoeba elicited robust Th1 cell-mediated immunity without the participation of Th17.,We observed suppression of CD8+ and CD4+ T lymphocytes and CD3+CD4-CD8- double-negative (DN) T lymphocyte populations in the beginning, and in the case of CD3+/CD4+/CD8+ double-positive (DP) T cells in the final phase of Acanthamoeba spp. infection in hosts with low immunity.,Also, CD4+T lymphocytes and CD3+/CD4+ and CD3+/CD8+ lymphocyte counts during each stage of acanthamoebiasis were shown to be upregulated.,We demonstrated that analysis of the immune response and pathogenesis mechanisms of clinical isolates of Acanthamoeba spp. in an animal model not only has purely cognitive significance but above all, may help in the development of effective methods of pharmacological therapy especially in patients with low immunity.

Th17 cells are a subset of CD4+ T cells known to play a central role in the pathogenesis of many autoimmune diseases, as well as in the defense against some extracellular bacteria and fungi.,However, Th17 cells are not believed to have a significant function against intracellular infections.,In contrast to this paradigm, we have discovered that Th17 cells provide robust protection against Trypanosoma cruzi, the intracellular protozoan parasite that causes Chagas disease.,Th17 cells confer significantly stronger protection against T. cruzi-related mortality than even Th1 cells, traditionally thought to be the CD4+ T cell subset most important for immunity to T. cruzi and other intracellular microorganisms.,Mechanistically, Th17 cells can directly protect infected cells through the IL-17A-dependent induction of NADPH oxidase, involved in the phagocyte respiratory burst response, and provide indirect help through IL-21-dependent activation of CD8+ T cells.,The discovery of these novel Th17 cell-mediated direct protective and indirect helper effects important for intracellular immunity highlights the diversity of Th17 cell roles, and increases understanding of protective T. cruzi immunity, aiding the development of therapeutics and vaccines for Chagas disease.

Achieving a malaria-free world presents exciting scientific challenges as well as overwhelming health, equity, and economic benefits.,WHO and countries are setting ambitious goals for reducing the burden and eliminating malaria through the “Global Technical Strategy” and 21 countries are aiming to eliminate malaria by 2020.,The commitment to achieve these targets should be celebrated.,However, the need for innovation to achieve these goals, sustain elimination, and free the world of malaria is greater than ever.,Over 180 experts across multiple disciplines are engaged in the Malaria Eradication Research Agenda (malERA) Refresh process to address problems that need to be solved.,The result is a research and development agenda to accelerate malaria elimination and, in the longer term, transform the malaria community’s ability to eradicate it globally.,The malERA Refresh Consultative Panel on Health Systems and Policy Research summarize a research and development agenda to accelerate malaria elimination and eradicate globally.

Distribution, abundance, feeding behaviour, host preference, parity status and human-biting and infection rates are among the medical entomological parameters evaluated when determining the vector capacity of mosquito species.,To evaluate these parameters, mosquitoes must be collected using an appropriate method.,Malaria is primarily transmitted by anthropophilic and synanthropic anophelines.,Thus, collection methods must result in the identification of the anthropophilic species and efficiently evaluate the parameters involved in malaria transmission dynamics.,Consequently, human landing catches would be the most appropriate method if not for their inherent risk.,The choice of alternative anopheline collection methods, such as traps, must consider their effectiveness in reproducing the efficiency of human attraction.,Collection methods lure mosquitoes by using a mixture of olfactory, visual and thermal cues.,Here, we reviewed, classified and compared the efficiency of anopheline collection methods, with an emphasis on Neotropical anthropophilic species, especially Anopheles darlingi, in distinct malaria epidemiological conditions in Brazil.

Spurred by success in several foci, onchocerciasis control policy in Africa has shifted from morbidity control to elimination of infection.,Clinical trials have demonstrated that moxidectin is substantially more efficacious than ivermectin in effecting sustained reductions in skin microfilarial load and, therefore, may accelerate progress towards elimination.,We compare the potential cost-effectiveness of annual moxidectin with annual and biannual ivermectin treatment.,Data from the first clinical study of moxidectin were used to parameterise the onchocerciasis transmission model EPIONCHO to investigate, for different epidemiological and programmatic scenarios in African savannah settings, the number of years and in-country costs necessary to reach the operational thresholds for cessation of treatment, comparing annual and biannual ivermectin with annual moxidectin treatment.,Annual moxidectin and biannual ivermectin treatment would achieve similar reductions in programme duration relative to annual ivermectin treatment.,Unlike biannual ivermectin treatment, annual moxidectin treatment would not incur a considerable increase in programmatic costs and, therefore, would generate sizeable in-country cost savings (assuming the drug is donated).,Furthermore, the impact of moxidectin, unlike ivermectin, was not substantively influenced by the timing of treatment relative to seasonal patterns of transmission.,Moxidectin is a promising new drug for the control and elimination of onchocerciasis.,It has high programmatic value particularly when resource limitation prevents a biannual treatment strategy, or optimal timing of treatment relative to peak transmission season is not feasible.,The online version of this article (doi:10.1186/s13071-015-0779-4) contains supplementary material, which is available to authorized users.

A systematic review and meta-analysis of all available case-control studies on the relationship between onchocerciasis and epilepsy.,Because age and level of onchocerciasis endemicity in the area of residence are major determinants for infection, an additional analysis was performed, restricted to studies achieving control of these confounding factors.,Medical databases, the “African Neurology Database, Institute of Neuroepidemiology and Tropical Neurology, Limoges,” reference lists of relevant articles, commercial search engines, up to May 2012.,We searched for studies examining infection status with Onchocerca volvulus in persons with epilepsy (PWE) and without epilepsy (PWOE) providing data suitable for the calculation of pooled odds ratios (ORp) and/or standardized mean differences (SMD) using random-effects models.,Eleven studies providing data of qualitative skin biopsies for diagnosis of onchocerciasis were identified.,Combined analysis on the total sample of 876 PWE and 4712 PWOE resulted in an ORp of 2.49 (95% confidence interval (95%CI): 1.61-3.86, p<0.001).,When this analysis was restricted to those studies achieving control for age, residence and sex (367 PWE, 624 PWOE), an ORp of 1.29 (95% CI: 0.93-1.79; p = 0.139) was found.,Presence of nodules for diagnosis of onchocerciasis was analyzed in four studies (225 PWE, 189 PWOE; ORp 1.74; 95%CI: 0.94-3.20; p<0.076), including two studies of the restricted analysis (106 PWE, 106 PWOE; ORp 2.81; 95%CI: 1.57-5.00; p<0.001).,One study examined quantitative microfilariae counts in patients without preceding microfilaricidal treatment and demonstrated significantly higher counts in PWE than in PWOE.,Our results strengthen the hypothesis that, in onchocerciasis foci, epilepsy and infection with O. volvulus are associated.,Analysis of indicators giving information on infection intensity, namely nodule palpation and quantitative microfilaria count in untreated patients, support the hypothesis that intensity of infection with O. volvulus is involved in the etiology of epilepsy.

This article reviews essential topics of canine visceral leishmaniasis (CVL) due to Leishmania infantum infection.,It focuses on the current serological and molecular diagnostic methods used in epidemiological research and veterinary clinics to diagnose CVL and includes new point-of-care (POC) tests under development.,The efficacy of different treatment regimens on the clinical improvement and infectiousness of dogs is also addressed.,In the last section, the review provides a critical appraisal of the effectiveness of different control measures that have been implemented to curb disease transmission.

Traditional diagnostic methods used to detect American Tegumentary Leishmaniasis, such as histopathology using biopsy samples, culture techniques, and direct search for parasites, have low sensitivity and require invasive collection procedures.,This study evaluates the efficiency of noninvasive sampling methods (swab) along with Polymerase Chain Reaction (PCR) for diagnosing American Tegumentary Leishmaniasis using skin and mucous samples from 25 patients who had tested positive for leishmaniasis.,The outcome of the tests performance on swab samples was compatible with PCR results on biopsy samples.,The findings have also shown that PCR-kDNA test is more efficient than PCR-HSP70 and qPCR tests (sensitivity of 92.3%, 40.7%, and 41%, respectively).,Given the high sensitivity of the tests and the fact that the sampling method using swabs affords greater patient comfort and safety, it could be said that this method is a promising alternative to conventional biopsy-based methods for the molecular diagnosis of leishmaniasis.

Malaria and schistosomiasis often overlap in tropical and subtropical countries and impose tremendous disease burdens; however, the extent to which schistosomiasis modifies the risk of febrile malaria remains unclear.,We evaluated the effect of baseline S. haematobium mono-infection, baseline P. falciparum mono-infection, and co-infection with both parasites on the risk of febrile malaria in a prospective cohort study of 616 children and adults living in Kalifabougou, Mali.,Individuals with S. haematobium were treated with praziquantel within 6 weeks of enrollment.,Malaria episodes were detected by weekly physical examination and self-referral for 7 months.,The primary outcome was time to first or only malaria episode defined as fever (≥37.5°C) and parasitemia (≥2500 asexual parasites/µl).,Secondary definitions of malaria using different parasite densities were also explored.,After adjusting for age, anemia status, sickle cell trait, distance from home to river, residence within a cluster of high S. haematobium transmission, and housing type, baseline P. falciparum mono-infection (n = 254) and co-infection (n = 39) were significantly associated with protection from febrile malaria by Cox regression (hazard ratios 0.71 and 0.44; P = 0.01 and 0.02; reference group: uninfected at baseline).,Baseline S. haematobium mono-infection (n = 23) did not associate with malaria protection in the adjusted analysis, but this may be due to lack of statistical power.,Anemia significantly interacted with co-infection (P = 0.009), and the malaria-protective effect of co-infection was strongest in non-anemic individuals.,Co-infection was an independent negative predictor of lower parasite density at the first febrile malaria episode.,Co-infection with S. haematobium and P. falciparum is significantly associated with reduced risk of febrile malaria in long-term asymptomatic carriers of P. falciparum.,Future studies are needed to determine whether co-infection induces immunomodulatory mechanisms that protect against febrile malaria or whether genetic, behavioral, or environmental factors not accounted for here explain these findings.

Sequestration of Plasmodium falciparum-infected erythrocytes in host blood vessels is a key triggering event in the pathogenesis of severe childhood malaria, which is responsible for about one million deaths every year1.,Sequestration is mediated by specific interactions between members of the P. falciparum erythrocyte membrane protein 1 (PfEMP1) family and receptors on the endothelial lining2.,Severe malaria is associated with expression of specific PfEMP1 subtypes containing domain cassettes (DC) 8 and 133, but the endothelial receptor for parasites expressing these proteins was unknown4,5.,Here, we identify endothelial protein C receptor (EPCR), which mediates cytoprotective effects of activated protein C6, as the endothelial receptor for DC8 and DC13 PfEMP1.,We show that EPCR binding is mediated through the N-terminal cysteine-rich interdomain region (CIDRα1) of DC8 and group A PfEMP1 subfamilies and that CIDRα1 interferes with protein C binding to EPCR.,This PfEMP1 adhesive property links P. falciparum cytoadhesion to a host receptor involved in anticoagulation and endothelial cytoprotective pathways and has implications for understanding malaria pathology and the development of new malaria interventions.

Giardia duodenalis is an important protozoan parasite.,It is an established zoonotic pathogen and dairy calves have been implicated as one of the most important sources of human infection.,This study was conducted to assess the prevalence and multilocus genotyping of G. duodenalis in dairy calves in the Xinjiang Uyghur Autonomous Region, northwestern China.,A total of 514 fresh fecal samples were randomly collected from dairy calves in 15 farms in Xinjiang, 13.4 % (69/514) tested positive for G. duodenalis by polymerase chain reaction (PCR) detection of the small subunit ribosomal RNA (SSU rRNA) gene, with the prevalence being 9.7 % (23/237) and 16.6 % (46/277) in pre- and post-weaned calves, respectively.,Sequence analysis of the SSU rRNA gene predominantly detected G. duodenalis assemblage E (92.8 %, 64/69), whereas assemblage A was identified in five samples (7.2 %, 5/69).,All G. duodenalis-positive samples were assayed with PCR followed by sequencing at β-giardin (bg), glutamate dehydrogenase (gdh) and triosephosphate isomerase (tpi) genes, and 29, 37 and 33 sequences were obtained, respectively.,The presence of mixed G. duodenalis assemblage A and E was detected in only one sample.,Multilocus genotyping yielded 15 multilocus genotypes (MLGs), one new assemblage A MLG, and 14 assemblage E MLGs.,All assemblage E MLGs identified here differed genetically from those of cattle from Henan Province, Central China.,Our data indicate that G. duodenalis is a common parasite in dairy calves in Xinjiang, China, and calves appear to be a reservoir of G. duodenalis that is infectious to humans.,The differences in the distribution of G. duodenalis assemblage E MLGs from cattle were likely to be because of geographical segregation.

Cryptosporidiosis is an important cause for chronic diarrhea and death in HIV/AIDS patients.,Among common Cryptosporidium species in humans, C. parvum is responsible for most zoonotic infections in industrialized nations.,Nevertheless, the clinical significance of C. parvum and role of zoonotic transmission in cryptosporidiosis epidemiology in developing countries remain unclear.,In this cross-sectional study, 520 HIV/AIDS patients were examined for Cryptosporidium presence in stool samples using genotyping and subtyping techniques.,Altogether, 140 (26.9%) patients were positive for Cryptosporidium spp. by PCR-RFLP analysis of the small subunit rRNA gene, belonging to C. parvum (92 patients), C. hominis (25 patients), C. viatorum (10 patients), C. felis (5 patients), C. meleagridis (3 patients), C. canis (2 patients), C. xiaoi (2 patients), and mixture of C. parvum and C. hominis (1 patient).,Sequence analyses of the 60 kDa glycoprotein gene revealed a high genetic diversity within the 82 C. parvum and 19 C. hominis specimens subtyped, including C. parvum zoonotic subtype families IIa (71) and IId (5) and anthroponotic subtype families IIc (2), IIb (1), IIe (1) and If-like (2), and C. hominis subtype families Id (13), Ie (5), and Ib (1).,Overall, Cryptosporidium infection was associated with the occurrence of diarrhea and vomiting.,Diarrhea was attributable mostly to C. parvum subtype family IIa and C. hominis, whereas vomiting was largely attributable to C. hominis and rare Cryptosporidium species.,Calf contact was identified as a significant risk factor for infection with Cryptosporidium spp., especially C. parvum subtype family IIa.,Results of the study indicate that C. parvum is a major cause of cryptosporidiosis in HIV-positive patients and zoonotic transmission is important in cryptosporidiosis epidemiology in Ethiopia.,In addition, they confirm that different Cryptosporidium species and subtypes are linked to different clinical manifestations.

Most measurements of malaria are based on cross-sectional data and do not reflect the dynamic nature of transmission, particularly when interventions require timely data for planning strategies.,Such data can be collected from local rural health centres (RHCs) where the infrastructure is sufficiently developed and where rapid diagnostics are in use.,Because in rural areas, the population served by RHC is reasonably static, the regular use of malaria rapid diagnosis in RHCs can provide data to assess local weekly incidence rates, and such data are easily dispersed by cell phones.,Essentially each RHC is a potential sentinel site that can deliver critical information to programme planners.,Data collected during this process of passive case detection over a five-year period in the Macha area of Zambia show the importance of ecological zones and refugia in the seasonal fluctuation of malaria cases.,If this process is implemented nationally it can assist in planning efficient use of resources and may contribute to local management and even elimination of malaria in this region.

Malaria control has been scaled up in many developing countries in their efforts to achieve the Millennium Development Goals.,Cambodia recently scaled up their Village Malaria Worker (VMW) project by substantially increasing the number of VMWs and expanding the project's health services to include treatment of fever, diarrhoea, and Acute Respiratory Infections (ARI) in children under five.,This study examined if the scale-up interfered with VMWs' service quality, actions, and knowledge of malaria control, and analysed VMWs' overall achievements and perceptions of the newly added health services.,Structured interviews were conducted pre scale-up in February-March 2008 with 251 VMWs and post scale-up in July-August 2010 with 252 VMWs.,Comparing the pre and post scale-up survey results (n = 195), changes were examined in terms of VMWs' 1) service quality, 2) malaria prevention and vector control actions, and 3) knowledge of malaria epidemiology and vector ecology.,In addition, VMWs' newly added health services were descriptively analysed based on the post scale-up survey (n = 252).,VMWs' service quality and actions significantly improved overall during the scale-up of the VMW project (mean index score: +0.805, p < 0.001; +2.923, p < 0.001; respectively).,Although most of knowledge areas also showed significant improvement (between +0.256 and +0.499, p < 0.001), less than half (10.3%-47.7%) of the VMWs correctly answered a set of questions on malaria epidemiology and vector ecology, even in the post scale-up survey.,About 70% of the respondents reported that their health services to control malaria remained the same or that they were more active after the scale-up.,Two-thirds (66.3%) had become more enthusiastic about serving as a VMW since the scale-up, and all but one respondent reported being willing to continue the new services.,The Cambodian experience clearly demonstrated that a nationwide scale-up of community-based malaria control can be achieved without degrading community health workers' service quality.,The government's strategy to expand VMWs' health services, while providing sufficient training to maintain the quality of their original malaria control services, could have contributed to the improvement of VMW's service quality, actions, and knowledge in spite of the rapid scale-up of the project.

Malaria rapid diagnostic tests (RDTs) are nowadays widely used in malaria endemic countries as an alternative to microscopy for the diagnosis of malaria.,However, quality control of test performance and execution in the field are important in order to ensure proper use and adequate diagnosis of malaria.,The current study compared the performance of a histidine-rich protein 2-based RDT used at peripheral health facilities level in real life conditions with that performed at central reference laboratory level with strict adherence to manufacturer instructions.,Febrile children attending rural health clinics were tested for malaria with a RDT provided by the Ministry of Health of Burkina Faso as recommended by the National Malaria Control Programme.,In addition, a blood sample was collected in an EDTA tube from all study cases for retesting with the same brand of RDT following the manufacturer’s instructions with expert malaria microscopy as gold standard at the central reference laboratory.,Fisher exact test was used to compare the proportions by estimating the p-value (p ≤ 0.05) as statistically significant.,In total, 407 febrile children were included in the study and malaria was diagnosed in 59.9% (244/407) of the cases with expert malaria microscopy.,The sensitivity of malaria RDT testing performed at health facilities was 97.5% and comparable to that achieved at the laboratory (98.8%).,The number of malaria false negatives was not statistically significant between the two groups (p = 0.5209).,However, the malaria RDT testing performed at health facilities had a specificity issue (52.8%) and was much lower compared to RDT testing performed at laboratory (74.2%).,The number of malaria false positives was statistically significantly different between the two groups (p = 0.0005).,Malaria RDT testing performed at the participating rural health facilities resulted in more malaria false positives compared to those performed at central laboratory.,Several factors, including storage and transportation conditions but also training of health workers, are most likely to influence test performance.,Therefore, it is very important to have appropriate quality control and training programmes in place to ensure correct performance of RDT testing.

Rapid diagnostic tests (RDT) and light microscopy are still recommended for diagnosis to guide the clinical management of malaria despite difficult challenges in rural settings.,The performance of these tests may be affected by several factors, including malaria prevalence and intensity of transmission.,The study evaluated the diagnostic performance of malaria RDT, light microscopy and polymerase chain reaction (PCR) in detecting malaria infections among febrile children at outpatient clinic in Korogwe District, northeastern Tanzania.,The study enrolled children aged 2-59 months with fever and/or history of fever in the previous 48 h attending outpatient clinics.,Blood samples were collected for identification of Plasmodium falciparum infection using histidine-rich-protein-2 (HRP-2)-based malaria RDT, light microscopy and conventional PCR.,A total of 867 febrile patients were enrolled into the study.,Malaria-positive samples were 85/867 (9.8 %, 95 % CI, 7.9-12.0 %) by RDT, 72/867 (8.3 %, 95 % CI, 6.5-10.1 %) by microscopy and 79/677 (11.7 %, 95 % CI, 9.3-14.3 %) by PCR.,The performance of malaria RDT compared with microscopy results had sensitivity and positive predictive value (PPV) of 88.9 % (95 % CI, 79.3-95.1 %) and 75.3 % (95 % CI, 64.8-84.0 %), respectively.,Confirmation of P. falciparum infection with PCR analysis provided lower sensitivity and PPV of 88.6 % (95 % CI, 79.5-94.7 %) and 84.3 % (95 % CI, 74.7-91.4 %) for RDT compared to microscopy.,Diagnosis of malaria infection is still a challenge due to variation in results among diagnostic methods.,HRP-2 malaria RDT and microscopy were less sensitive than PCR.,Diagnostic tools with high sensitivity are required in areas of low malaria transmission.

The life-threatening zoonotic malaria cases caused by Plasmodium knowlesi in Malaysia has recently been reported to be the highest among all malaria cases; however, previous studies have mainly focused on the transmission of P. knowlesi in Malaysian Borneo (East Malaysia).,This study aimed to describe the transmission patterns of P. knowlesi infection in Peninsular Malaysia (West Malaysia).,The spatial distribution of P. knowlesi was mapped across Peninsular Malaysia using Geographic Information System techniques.,Local indicators of spatial associations were used to evaluate spatial patterns of P. knowlesi incidence.,Seasonal autoregressive integrated moving average models were utilized to analyze the monthly incidence of knowlesi malaria in the hotspot region from 2012 to 2017 and to forecast subsequent incidence in 2018.,Spatial analysis revealed that hotspots were clustered in the central-northern region of Peninsular Malaysia.,Time series analysis revealed the strong seasonality of transmission from January to March.,This study provides fundamental information on the spatial distribution and temporal dynamic of P. knowlesi in Peninsular Malaysia from 2011 to 2018.,Current control policy should consider different strategies to prevent the transmission of both human and zoonotic malaria, particularly in the hotspot region, to ensure a successful elimination of malaria in the future.

Since 1960, a total of seven species of monkey malaria have been reported as transmissible to man by mosquito bite: Plasmodium cynomolgi, Plasmodium brasilianum, Plasmodium eylesi, Plasmodium knowlesi, Plasmodium inui, Plasmodium schwetzi and Plasmodium simium.,With the exception of P. knowlesi, none of the other species has been found to infect humans in nature.,In this report, it is described the first known case of a naturally acquired P. cynomolgi malaria in humans.,The patient was a 39-year-old woman from a malaria-free area with no previous history of malaria or travel to endemic areas.,Initially, malaria was diagnosed and identified as Plasmodium malariae/P. knowlesi by microscopy in the Terengganu State Health Department.,Thick and thin blood films stained with 10% Giemsa were performed for microscopy examination.,Molecular species identification was performed at the Institute for Medical Research (IMR, Malaysia) and in the Malaria & Emerging Parasitic Diseases Laboratory (MAPELAB, Spain) using different nested PCR methods.,Microscopic re-examination in the IMR showed characteristics of Plasmodium vivax and was confirmed by a nested PCR assay developed by Snounou et al.,Instead, a different PCR assay plus sequencing performed at the MAPELAB confirmed that the patient was infected with P. cynomolgi and not with P. vivax.,This is the first report of human P. cynomolgi infection acquired in a natural way, but there might be more undiagnosed or misdiagnosed cases, since P. cynomolgi is morphologically indistinguishable from P. vivax, and one of the most used PCR methods for malaria infection detection may identify a P. cynomolgi infection as P. vivax.,Simian Plasmodium species may routinely infect humans in Southeast Asia.,New diagnostic methods are necessary to distinguish between the human and monkey malaria species.,Further epidemiological studies, incriminating also the mosquito vector(s), must be performed to know the relevance of cynomolgi malaria and its implication on human public health and in the control of human malaria.,The zoonotic malaria cannot be ignored in view of increasing interactions between man and wild animals in the process of urbanization.

Live cell imaging of recombinant malarial parasites encoding fluorescent probes provides critical insights into parasite-host interactions and life cycle progression.,In this study, we generated a red fluorescent line of the murine malarial parasite Plasmodium berghei.,To allow constitutive and abundant expression of the mCherry protein we profiled expression of all members of the P. berghei heat shock protein 70 (HSP70) family.,We identified PbHSP70/1, an invariant ortholog of Plasmodium falciparum HSP70-1, as the protein with the highest expression levels during Plasmodium blood, mosquito, and liver infection.,Stable allelic insertion of a mCherry expression cassette into the PbHsp70/1 locus created constitutive red fluorescent P. berghei lines, termed Pbred.,We show that these parasites can be used for live imaging of infected host cells and organs, including hepatocytes, erythrocytes, and whole Anopheles mosquitoes.,Quantification of the fluorescence intensity of several Pbred parasite stages revealed significantly enhanced signal intensities in comparison to GFP expressed under the control of the constitutive EF1alpha promoter.,We propose that systematic transcript profiling permits generation of reporter parasites, such as the Pbred lines described herein.

► Rapid, robust isolation of recombinant Plasmodium berghei lines by flow cytometry.,► Reduction by >80% of animal use for the generation of mutant parasite lines.,► Plasmodium berghei aquaglyceroporin is dispensable for all life cycle stages.,► Tagged aquaglyceroporin localizes to perinuclear structures inside the parasite.,The most critical bottleneck in the generation of recombinant Plasmodium berghei parasites is the mandatory in vivo cloning step following successful genetic manipulation.,This study describes a new technique for rapid selection of recombinant P. berghei parasites.,The method is based on flow cytometry to isolate isogenic parasite lines and represents a major advance for the field, in that it will speed the generation of recombinant parasites as well as cut down on animal use significantly.,High expression of GFP during blood infection, a prerequisite for robust separation of transgenic lines by flow cytometry, was achieved.,Isogenic recombinant parasite populations were isolated even in the presence of a 100-fold excess of wild-type (WT) parasites.,Aquaglyceroporin (AQP) loss-of-function mutants and parasites expressing a tagged AQP were generated to validate this approach. aqp− parasites grow normally within the WT phenotypic range during blood infection of NMRI mice.,Similarly, colonization of the insect vector and establishment of an infection after mosquito transmission were unaffected, indicating that AQP is dispensable for life cycle progression in vivo under physiological conditions, refuting its use as a suitable drug target.,Tagged AQP localized to perinuclear structures and not the parasite plasma membrane.,We suggest that flow-cytometric isolation of isogenic parasites overcomes the major roadblock towards a genome-scale repository of mutant and transgenic malaria parasite lines.

Background.,Parasite clearance time after artemisinin-based combination therapy (ACT) may be increasing in Asian and African settings.,The association between parasite clearance following ACT and transmissibility is currently unknown.,Methods.,We determined parasite clearance dynamics by duplex quantitative polymerase chain reaction (qPCR) in samples collected in the first 3 days after treatment of uncomplicated malaria with ACT.,Gametocyte carriage was determined by Pfs25 quantitative nucleic acid sequence-based amplification assays; infectiousness to mosquitoes by membrane-feeding assays on day 7 after treatment.,Results.,Residual parasitemia was detected by qPCR in 31.8% (95% confidence interval [CI], 24.6-39.8) of the children on day 3 after initiation of treatment.,Residual parasitemia was associated with a 2-fold longer duration of gametocyte carriage (P = .0007), a higher likelihood of infecting mosquitoes (relative risk, 1.95; 95% CI, 1.17-3.24; P = .015), and a higher parasite burden in mosquitoes (incidence rate ratio, 2.92; 95% CI, 1.61-5.31; P < .001).,Children with residual parasitemia were also significantly more likely to experience microscopically detectable parasitemia during follow-up (relative risk, 11.25; 95% CI, 4.08-31.01; P < .001).,Conclusions.,Residual submicroscopic parasitemia is common after ACT and is associated with a higher transmission potential.,Residual parasitemia may also have consequences for individual patients because of its higher risk of recurrent parasitemia.

This study describes the use of malaria rapid diagnostic tests (RDTs) as a source of DNA for Plasmodium species-specific real-time PCR.,First, the best method to recover DNA from RDTs was investigated and then the applicability of this DNA extraction method was assessed on 12 different RDT brands.,Finally, two RDT brands (OptiMAL Rapid Malaria Test and SDFK60 malaria Ag Plasmodium falciparum/Pan test) were comprehensively evaluated on a panel of clinical samples submitted for routine malaria diagnosis at ITM.,DNA amplification was done with the 18S rRNA real-time PCR targeting the four Plasmodium species.,Results of PCR on RDT were compared to those obtained by PCR on whole blood samples.,Best results were obtained by isolating DNA from the proximal part of the nitrocellulose component of the RDT strip with a simple DNA elution method.,The PCR on RDT showed a detection limit of 0.02 asexual parasites/μl, which was identical to the same PCR on whole blood.,For all 12 RDT brands tested, DNA was detected except for one brand when a low parasite density sample was applied.,In RDTs with a plastic seal covering the nitrocellulose strip, DNA extraction was hampered.,PCR analysis on clinical RDT samples demonstrated correct identification for single species infections for all RDT samples with asexual parasites of P. falciparum (n = 60), Plasmodium vivax (n = 10), Plasmodium ovale (n = 10) and Plasmodium malariae (n = 10).,Samples with only gametocytes were detected in all OptiMAL and in 10 of the 11 SDFK60 tests.,None of the negative samples (n = 20) gave a signal by PCR on RDT.,With PCR on RDT, higher Ct-values were observed than with PCR on whole blood, with a mean difference of 2.68 for OptiMAL and 3.53 for SDFK60.,Mixed infections were correctly identified with PCR on RDT in 4/5 OptiMAL tests and 2/5 SDFK60 tests.,RDTs are a reliable source of DNA for Plasmodium real-time PCR.,This study demonstrates the best method of RDT fragment sampling for a wide range of RDT brands in combination with a simple and low cost extraction method, allowing RDT quality control.

By 2020, the global health community aims to control and eliminate human helminthiases, including schistosomiasis in selected African countries, principally by preventive chemotherapy (PCT) through mass drug administration (MDA) of anthelminthics.,Quantitative monitoring of anthelminthic responses is crucial for promptly detecting changes in efficacy, potentially indicative of emerging drug resistance.,Statistical models offer a powerful means to delineate and compare efficacy among individuals, among groups of individuals and among populations.,We illustrate a variety of statistical frameworks that offer different levels of inference by analysing data from nine previous studies on egg counts collected from African children before and after administration of praziquantel.,We quantify responses to praziquantel as egg reduction rates (ERRs), using different frameworks to estimate ERRs among population strata, as average responses, and within strata, as individual responses.,We compare our model-based average ERRs to corresponding model-free estimates, using as reference the World Health Organization (WHO) 90 % threshold of optimal efficacy.,We estimate distributions of individual responses and summarize the variation among these responses as the fraction of ERRs falling below the WHO threshold.,Generic models for evaluating responses to anthelminthics deepen our understanding of variation among populations, sub-populations and individuals.,We discuss the future application of statistical modelling approaches for monitoring and evaluation of PCT programmes targeting human helminthiases in the context of the WHO 2020 control and elimination goals.,The online version of this article (doi:10.1186/s13071-016-1312-0) contains supplementary material, which is available to authorized users.

Extensive use of praziquantel for treatment and control of schistosomiasis requires a comprehensive understanding of efficacy and safety of various doses for different Schistosoma species.,A systematic review and meta-analysis of comparative and non-comparative trials of praziquantel at any dose for any Schistosoma species assessed within two months post-treatment.,Of 273 studies identified, 55 were eligible (19,499 subjects treated with praziquantel, control treatment or placebo).,Most studied were in school-aged children (64%), S. mansoni (58%), and the 40 mg/kg dose (56%); 68% of subjects were in Africa.,Efficacy was assessed as cure rate (CR, n = 17,017) and egg reduction rate (ERR, n = 13,007); safety as adverse events (AE) incidence.,The WHO-recommended dose of praziquantel 40 mg/kg achieved CRs of 94.7% (95%CI 92.2-98.0) for S. japonicum, 77.1% (68.4-85.1) for S. haematobium, 76.7% (95%CI 71.9-81.2) for S. mansoni, and 63.5% (95%CI 48.2-77.0) for mixed S. haematobium/S. mansoni infections.,Using a random-effect meta-analysis regression model, a dose-effect for CR was found up to 40 mg/kg for S. mansoni and 30 mg/kg for S. haematobium.,The mean ERR was 95% for S. japonicum, 94.1% for S. haematobium, and 86.3% for S. mansoni.,No significant relationship between dose and ERR was detected.,Tolerability was assessed in 40 studies (12,435 subjects).,On average, 56.9% (95%CI 47.4-67.9) of the subjects receiving praziquantel 40 mg/kg experienced an AE.,The incidence of AEs ranged from 2.3% for urticaria to 31.1% for abdominal pain.,The large number of subjects allows generalizable conclusions despite the inherent limitations of aggregated-data meta-analyses.,The choice of praziquantel dose of 40 mg/kg is justified as a reasonable compromise for all species and ages, although in a proportion of sites efficacy may be lower than expected and age effects could not be fully explored.

Control of mosquito-borne diseases is greatly compromised by spread of insecticide resistance, high implementation costs and sub-optimal compliance among users.,Improved housing has potential to reduce malaria transmission nearly as much as long-lasting insecticide-treated nets (LLINs), while also preventing other arthropod-borne diseases and improving overall well-being.,Yet, it is hardly promoted as mainstream intervention, partly because of high costs, minimal communal benefits to people in non-improved houses, and low scalability.,By exploiting biological observations of mosquito behaviours around dwellings, scientists have developed a new approach that integrates effective vector control into housing developments.,The technique involves blocking eave spaces in local houses, leaving a few cylindrical holes into which plastic tubes with insecticide-laden electrostatic nettings are inserted.,Where houses already have blocked eaves, these cylindrical holes are drilled and the tubes inserted.,The eave tube technology, as it is called, is an innovative new approach for implementing housing improvements, by creating a new scalable product that can be integrated in houses during or after construction.,It takes away insecticides from proximity of users, and instead puts them where mosquitoes are most likely to enter houses, thereby reducing insecticidal exposure among household occupants, while maximizing exposure of mosquitoes.,This way, lower quantities of insecticides are used, better house ventilation achieved, intervention costs reduced, and mass communal benefits achieved even were vectors are resistant to similar insecticides when delivered conventionally.,There are however still some critical pieces missing, notably epidemiological, social and economic evidence that the above assertions are true and sustainable.,Besides, there also some technical limitations to be considered, namely: (1) need for extensive house modifications before eave tubes are inserted, (2) ineligibility of poorest and highest-risk households living in housing structures not amenable to eave tubes, and (3) poor synergies when eave tubes are combined with LLINs or IRS in same households.,Overall, this paradigm significantly improves delivery of insecticides against disease-transmitting mosquitoes, and provides opportunities for scaling-up the long-neglected concept of house improvement as a malaria intervention.

Malaria prevalence has halved in endemic Africa since 2000, largely driven by the concerted international control effort.,To achieve the new global targets for malaria control and elimination by 2030, and to sustain elimination once achieved, additional vector control interventions are urgently needed to supplement long‐lasting insecticide-treated nets and indoor residual spraying, which both rely on effective insecticides for optimal protection.,Improving housing and the built environment is a promising strategy to address this need, with an expanding body of evidence that simple modifications to reduce house entry by malaria vectors, such as closing eaves and screening doors and windows, can help protect residents from malaria.,However, numerous questions remain unanswered, from basic science relating to the optimal design of house improvements through to their translation into operational use.,The Malaria Journal thematic series on ‘housing and malaria’ collates articles that contribute to the evidence base on approaches for improving housing to reduce domestic malaria transmission.

Objective To evaluate efficacies of anthelmintic drugs against soil transmitted helminths in terms of cure rates and egg reduction rates.,Design Systematic review and network meta-analysis.,Data Sources PubMed, ISI Web of Science, Embase, ScienceDirect, the Cochrane Central Register of Clinical Trials, and the World Health Organization library database from 1960 until 31 December 2016.,Study selection Randomised controlled trials evaluating the efficacy of a single dose regimen of albendazole, mebendazole, levamisole, and pyrantel pamoate against Ascaris lumbricoides, hookworm (Necator americanus and Ancylostoma duodenale) and Trichuris trichiura.,The primary outcomes included cure rates analysed by network meta-analysis with mixed logistic regression models and egg reduction rates with mixed linear models.,Results 55 and 46 randomised controlled trials were included in the analysis of cure rates and egg reduction rates, respectively.,All drugs were highly efficacious against A lumbricoides.,Albendazole showed the highest efficacy against hookworm infections with a cure rate of 79.5% (95% confidence interval 71.5% to 85.6%) and an egg reduction rate of 89.6% (81.9% to 97.3%).,All drugs had low efficacy against T trichiura, with mebendazole showing the highest cure rate of 42.1% (25.9% to 60.2%) and egg reduction rate of 66.0% (54.6% to 77.3%).,Estimates for the years 1995 and 2015 showed significant reductions in efficacy of albendazole against T trichiura: by 2015 the egg reduction rates fell from 72.6% (53.7% to 91.5%) to 43.4% (23.5% to 63.3%; P=0.049) and the cure rates fell from 38.6% (26.2% to 52.7%) to 16.4 (7.7% to 31.3%; P=0.027).,Conclusions All four currently recommended drugs show limitations in their efficacy profile.,While only albendazole showed good efficacy against hookworm infection, all drugs had low efficacy against T trichiura.,The decrease in efficacy of albendazole against T trichiura over the past two decades is of concern.,The findings indicate the need for strengthening efforts to develop new drug treatments, with a particular focus on drugs against T trichiura.

Kato-Katz is a widely used method for the diagnosis of soil-transmitted helminth infection.,Fecal samples cannot be preserved, and hence, should be processed on the day of collection and examined under a microscope within 60 min of slide preparation.,Mini-FLOTAC is a technique that allows examining fixed fecal samples.,We assessed the performance of Mini-FLOTAC using formalin-fixed stool samples compared to Kato-Katz and determined the dynamics of prevalence and intensity estimates of soil-transmitted helminth infection over a 31-day time period.,The study was carried out in late 2013 on Pemba Island, Tanzania.,Forty-one children were enrolled and stool samples were subjected on the day of collection to a single Kato-Katz thick smear and Mini-FLOTAC examination; 12 aliquots of stool were fixed in 5% formalin and subsequently examined by Mini-FLOTAC up to 31 days after collection.,The combined results from Kato-Katz and Mini-FLOTAC revealed that 100% of children were positive for Trichuris trichiura, 85% for Ascaris lumbricoides, and 54% for hookworm.,Kato-Katz and Mini-FLOTAC techniques found similar prevalence estimates for A. lumbricoides (85% versus 76%), T. trichiura (98% versus 100%), and hookworm (42% versus 51%).,The mean eggs per gram of stool (EPG) according to Kato-Katz and Mini-FLOTAC was 12,075 and 11,679 for A. lumbricoides, 1,074 and 1,592 for T. trichiura, and 255 and 220 for hookworm, respectively.,The mean EPG from day 1 to 31 of fixation was stable for A. lumbricoides and T. trichiura, but gradually declined for hookworm, starting at day 15.,The findings of our study suggest that for a qualitative diagnosis of soil-transmitted helminth infection, stool samples can be fixed in 5% formalin for at least 30 days.,However, for an accurate quantitative diagnosis of hookworm, we suggest a limit of 15 days of preservation.,Our results have direct implication for integrating soil-transmitted helminthiasis into transmission assessment surveys for lymphatic filariasis.

Colombia contributes a significant proportion of malaria cases in the Americas, which are predominantly rural.,However, in the last 8 years ~ 10 % of the endemic municipalities have also reported urban and peri-urban malaria cases, a growing concern for health authorities.,This study focused on the characterization of the officially reported urban malaria cases.,A descriptive retrospective study based on secondary information provided by the Colombian National Surveillance System-SIVIGILA for the 2008-2012 period was conducted.,A total of 17 municipalities with consistent and persistent reports of urban and peri-urban malaria were selected for analysis, which included site of origin and of residence, age, gender and ethnicity of patients, health system affiliation, Plasmodium species and the presence of malaria vectors.,A total of 18,113 malaria cases were reported from urban and peri-urban areas of 17 endemic municipalities.,Almost 70 % of the reports originated in localities in the departments of Chocó and Nariño, located on the Pacific Coast where a predominantly Afro-Colombian population, of individuals of under 30 years of age, was the most affected (80.7 %), mainly with Plasmodium falciparum infections (52.1 %).,Median annual parasite index (API) was 6.4 per 1000 inhabitants (3.4 in 2008; 10.8 in 2010 and 6.0 in 2012).,Between 2011 and 2012 complicated cases (2.4 %) and malaria in pregnant women (1.4 %) were reported.,Study areas reported the presence of at least seven Anopheles species considered malaria vectors.,These analyses did not allow ascertaining the presumable origin of the recorded urban cases due to the lack of a consensus on a definition of urban, peri-urban and rural limits and the lack of proper verification of the geographical source of infection.,The study indicates the probable presence of endemic, unstable and low-intensity malaria transmission in Colombian urban and peri-urban areas of a group of municipalities located mainly on the Pacific coast region and a few others in the eastern region.,There is a need to unequivocally confirm the urban or peri-urban origin of the malaria cases reported and the transmission conditions, as well as to develop and implement new strategies for urban and peri-urban malaria control and elimination.

Although Colombia has witnessed an important decrease in malaria transmission, the disease remains a public health problem with an estimated ~10 million people currently living in areas with malaria risk and ~61,000 cases reported in 2012.,This study aimed to determine and compare the level of knowledge, attitudes and practices (KAP) about malaria in three endemic communities of Colombia to provide the knowledge framework for development of new intervention strategies for malaria elimination.,A cross-sectional KAP survey was conducted in the municipalities of Tierralta, Buenaventura and Tumaco, categorized according to high risk (HR) and moderate risk (MR) based on the annual parasite index (API).,Surveys were managed using REDCap and analysed using MATLAB and GraphPad Prism.,A total of 267 residents, mostly women (74%) were surveyed.,Although no differences were observed on the knowledge of classical malaria symptoms between HR and MR regions, significant differences were found in knowledge and attitudes about transmission mechanisms, anti-malarial use and malaria diagnosis.,Most responders in both regions (93.5% in MR, and 94.3% in HR areas) indicated use of insecticide-treated nets (ITNs) to protect themselves from malaria, and 75.5% of responders in HR indicated they did nothing to prevent malaria transmission outdoors.,Despite a high level of knowledge in the study regions, significant gaps persisted relating to practices.,Self-medication and poor adherence to treatment, as well as lack of both indoor and outdoor vector control measures, were significantly associated with higher malaria risk.,Although significant efforts are currently being made by the Ministry of Health to use community education as one of the main components of the control strategy, these generic education programmes may not be applicable to all endemic regions of Colombia given the substantial geographic, ethnic and cultural diversity.

In the Republic of Congo, artemisinin-based combinations have been recommended for the treatment of uncomplicated malaria since 2006.,However, the emergence of resistant parasites again these combinations in Southeast Asia is a threat for the control of this disease, especially in sub-Saharan Africa where the weight of the disease is important.,Indeed, polymorphisms in Plasmodium falciparum K13-propeller gene have been involved in variations of drug sensitivity of Plasmodium falciparum to artemisinin-based combinations.,The aim of the current study is to determine the prevalence of mutations of this gene in isolates collected in three health centers in Brazzaville.,From May 2015 to May 2016, a total of 131, 259 and 416 samples from patients with suspected malaria were collected at the Laboratoire National de Santé Publique, Hôpital de Mfilou, and the CSI «Maman Mboualé» respectively.,After DNA isolation, genotyping and sequencing of Plasmodium falciparum K13-propeller were performed in positive Plasmodium falciparum isolates identified after msp-2 gene genotyping.,All 806 samples collected were msp-2 genotyped and Plasmodium falciparum infections were confirmed in 287 samples with 43, 85, 159 samples from Laboratoire National de Santé Publique, Hôpital de Mfilou, and the CSI «Maman Mboualé» respectively.,Of these 287 msp-2 positives samples, K13-propeller nested PCR products were successfully obtained from 145 (50.52%) isolates and sequences were generated from 127(87.58%) nested products.,None of mutations that were associated with ACTs resistance in Southeast Asia were detected on the samples from three different study sites from Brazzaville.,However, one mutation type was observed at position 578, where alanine was substituted by serine (A578S) in two isolates (1.57%, 2/127), those from the Hôpital de Mfilou.,No mutation was found in isolates from the two other sites.,The current study shows a very limited polymorphism in the K13-propeller gene in isolates from the Republic of Congo and K13 polymorphisms associate with ACT resistance are not present in this country.,However, permanent and large surveillance of resistant parasite population using K13-propeller gene is recommended.

Malaria, particularly due to Plasmodium falciparum, remains a major public health threat in Ethiopia.,Artemether-lumefantine (AL) has been the first-line antimalarial drug against uncomplicated P. falciparum malaria in the country since 2004.,Regular monitoring of antimalarial drugs is recommended by the World Health Organization (WHO) to help early detection of drug resistant strains of the parasite and contain their rapid spread.,The objective of this study was to assess the therapeutic efficacy of AL in a high-transmission setting in Ethiopia.,The study site was Setit Humera, northwest Ethiopia.,Single-arm prospective study of a 28-day follow-up was conducted from October 2014 to January 2015 according to the revised WHO 2009 drug efficacy study protocol.,Study end-points were classified into primary end-point and secondary end-point.,While the primary end-point was the day-28 adequate clinical and parasitological response the secondary end-points were clinical and parasitological evaluations (parasite, fever and gametocyte clearance rate, incidence of drug adverse events) and the relative increment in hemoglobin (Hb) level from baseline to day (D) 14 and D28.,A total of 92 patients were enrolled and 79 had completed the 28-day follow-up period.,The overall cure rate was 98.8% with 95% confidence interval of 0.915-0.998 without polymerase chain reaction correction.,The parasite clearance rate was high with fast resolution of clinical symptoms; 100% of the study participants cleared parasitaemia and fever on D3.,Gametocyte carriage was reduced from 7% on D0 to 1% on D3 and complete clearance was achieved on D14.,Mean Hb concentration significantly increased on D28 compared to that on D14.,There was no serious adverse event.,AL was efficacious and safe in a high-transmission setting for treatment of uncomplicated falciparum malaria.

Infants are thought to be protected against malaria during the first months of life mainly due to passage of maternal antibodies.,However, in high transmission settings, malaria in early infancy is not uncommon and susceptibility to the infections varies between individuals.,This study aimed to determine malaria morbidity and infection during early childhood in rural Burkina Faso.,Malariometric indices were determined over 1-year follow-up in a birth cohort of 734 infants living in Nanoro health district.,Clinical malaria episodes were determined by passive case detection at peripheral health centres while asymptomatic malaria infections were identified during 4 cross-sectional surveys at 3, 6, 9 and 12 months of age.,Plasmodium falciparum infections were detected by rapid diagnostic test and/or light microscopy (LM) and quantitative PCR (qPCR).,In total, 717 clinical episodes were diagnosed by qPCR over 8335.18 person-months at risk.,The overall malaria incidence was 1.03 per child-year and increased from 0.27 per child-year at 0-3 months of age to 1.92 per child-year at 9-12 months of age.,Some 59% of children experienced at least one clinical episode with a median survival time estimated at 9.9 months, while 20% of infants experienced the first episode before 6 months of age.,The majority of the clinical episodes were attributable to microscopic parasitaemia (84.2%), and there was a positive correlation between parasite density and age (Spearman’s rho = 0.30; P < 0.0001).,Prevalence of asymptomatic infections was similar at 3, 6 and 9 months of age (17.7-20.1%) and nearly 1.6 times higher at 12 months (31.3%).,Importantly, gametocyte prevalence among the LM-positive study population was 6.7%, but increased to 10% among asymptomatic infections.,In addition, 46% of asymptomatic infections were only detected by qPCR suggesting that infants below 1 year are a potential reservoir for sustaining malaria transmission.,Both symptomatic and asymptomatic infections showed marked seasonal distribution with the highest transmission period (July to December) accounting for about 89 and 77% of those infections, respectively.,These findings indicate high and marked age and seasonal-dependency of malaria infections and disease during the first year of life in Nanoro, calling for intensified efforts to control malaria in rural Burkina Faso.

Existing information has shown that infants who are prenatally exposed to P. falciparum are susceptible to subsequent malaria infections.,However, the effect of prenatal exposure to P. falciparum on parasite density during clinical malaria episodes has not been fully elucidated.,This study is a component of a prospective cohort study for which initial results have been published.,This component was designed to determine the effect of prenatal exposure to P. falciparum on parasite density during clinical malaria episodes in the first 24 months of life.,A total of 215 infants were involved and monitored for clinical malaria episodes defined by fever (≥ 37 °C) and parasitaemia.,The geometric mean parasite counts between exposed and unexposed infants were compared using independent samples t test.,The effect of in utero exposure to P. falciparum on parasite density was assessed using binary logistic regression.,The geometric mean parasite count per µl of blood during clinical malaria episodes in exposed infants was 24,889 (95% CI 18,286-31,490) while in unexposed infants it was 14,035 (95% CI 12,111-15,960), P < 0.05.,Prenatal exposure to P. falciparum was associated with hyperparasitaemia during clinical malaria episodes (OR 7.04, 95% CI 2.31-21.74), while other factors were not significantly associated (P > 0.05).

Plasmodium vivax has the widest geographic distribution of the human malaria parasites and nearly 2.5 billion people live at risk of infection.,The control of P. vivax in individuals and populations is complicated by its ability to relapse weeks to months after initial infection.,Strains of P. vivax from different geographical areas are thought to exhibit varied relapse timings.,In tropical regions strains relapse quickly (three to six weeks), whereas those in temperate regions do so more slowly (six to twelve months), but no comprehensive assessment of evidence has been conducted.,Here observed patterns of relapse periodicity are used to generate predictions of relapse incidence within geographic regions representative of varying parasite transmission.,A global review of reports of P. vivax relapse in patients not treated with a radical cure was conducted.,Records of time to first P. vivax relapse were positioned by geographic origin relative to expert opinion regions of relapse behaviour and epidemiological zones.,Mixed-effects meta-analysis was conducted to determine which geographic classification best described the data, such that a description of the pattern of relapse periodicity within each region could be described.,Model outputs of incidence and mean time to relapse were mapped to illustrate the global variation in relapse.,Differences in relapse periodicity were best described by a historical geographic classification system used to describe malaria transmission zones based on areas sharing zoological and ecological features.,Maps of incidence and time to relapse showed high relapse frequency to be predominant in tropical regions and prolonged relapse in temperate areas.,The results indicate that relapse periodicity varies systematically by geographic region and are categorized by nine global regions characterized by similar malaria transmission dynamics.,This indicates that relapse may be an adaptation evolved to exploit seasonal changes in vector survival and therefore optimize transmission.,Geographic patterns in P. vivax relapse are important to clinicians treating individual infections, epidemiologists trying to infer P. vivax burden, and public health officials trying to control and eliminate the disease in human populations.

The prevalence of Plasmodium falciparum malaria in Zanzibar has reached historic lows.,Improving control requires quantifying malaria importation rates, identifying high-risk travelers, and assessing onwards transmission.,Estimates of Zanzibar's importation rate were calculated through two independent methodologies.,First, mobile phone usage data and ferry traffic between Zanzibar and mainland Tanzania were re-analyzed using a model of heterogeneous travel risk.,Second, a dynamic mathematical model of importation and transmission rates was used.,Zanzibar residents traveling to malaria endemic regions were estimated to contribute 1-15 times more imported cases than infected visitors.,The malaria importation rate was estimated to be 1.6 incoming infections per 1,000 inhabitants per year.,Local transmission was estimated too low to sustain transmission in most places.,Malaria infections in Zanzibar largely result from imported malaria and subsequent transmission.,Plasmodium falciparum malaria elimination appears feasible by implementing control measures based on detecting imported malaria cases and controlling onward transmission.

Haemonchus contortus is a haematophagous parasitic nematode of veterinary interest.,We have performed a survey of its genome-wide diversity using single-worm whole genome sequencing of 223 individuals sampled from 19 isolates spanning five continents.,We find an African origin for the species, together with evidence for parasites spreading during the transatlantic slave trade and colonisation of Australia.,Strong selective sweeps surrounding the β-tubulin locus, a target of benzimidazole anthelmintic drug, are identified in independent populations.,These sweeps are further supported by signals of diversifying selection enriched in genes involved in response to drugs and other anthelmintic-associated biological functions.,We also identify some candidate genes that may play a role in ivermectin resistance.,Finally, genetic signatures of climate-driven adaptation are described, revealing a gene acting as an epigenetic regulator and components of the dauer pathway.,These results begin to define genetic adaptation to climate in a parasitic nematode.,Based on single worm whole genome sequencing, the authors here characterise the global evolution of the gastrointestinal parasite Haemonchus contortus and identify genes that play a role in drug resistance as well as climate-driven adaptations involving an epigenetic regulator.

Hookworms infect over 400 million people, stunting and impoverishing them1-3.,Sequencing hookworm genomes and finding which genes they express during infection should help in devising new drugs or vaccines against hookworms4,5.,Unlike other hookworms, Ancylostoma ceylanicum infects both humans and other mammals, providing a laboratory model for hookworm disease6,7.,We determined an A. ceylanicum genome sequence of 313 Mb, with transcriptomic data throughout infection showing expression of 30,738 genes.,Approximately 900 genes were upregulated during early infection in vivo, including ASPRs, a cryptic subfamily of activation-associated secreted proteins (ASPs)8.,Genes downregulated during early infection included ion channels and G protein-coupled receptors; this downregulation was observed in both parasitic and free-living nematodes.,Later, at the onset of heavy blood feeding, C-lectin genes were upregulated along with genes for secreted clade V proteins (SCVPs), encoding a previously undescribed protein family.,These findings provide new drug and vaccine targets and should help elucidate hookworm pathogenesis.

Results of Chagas’ disease diagnosis show disagreement.,The aim of this study was to compare commercial tests for Chagas’ disease serodiagnosis in southern Brazil.,A total of 161 samples were evaluated.,Three enzyme-linked immunosorbent assays, one indirect hemagglutination and one indirect immunofluorescence were assessed.,Trypomastigote excreted-secreted antigen-blot was a confirmatory method.,From 161 samples, 65.84% were positive in all tests, while 34.16% presents mismatch result in at least one of the tests.,All techniques tested presented false-positive and/or false-negative results as follows: Enzyme-linked immunosorbent assay 1 had more false-positive results (lower specificity), indirect immunofluorescence had the highest rate of false-negative results (lower sensitivity), enzyme-linked immunosorbent assays had fewer false-negative results (higher sensitivity), while indirect hemagglutination showed no false-positive result (higher specificity).,Knowing the characteristics of techniques make it possible to combine them and obtain more reliable diagnosis.,Therefore, it seems useful to combine techniques for diagnosing this infection.

The protozoan Trypanosoma cruzi is the etiologic agent of Chagas disease, an infection that afflicts approximately 8 million people in Latin America.,Diagnosis of chronic Chagas disease is currently based on serological tests because this condition is usually characterized by high anti-T. cruzi IgG titers and low parasitemia.,The antigens used in these assays may have low specificity due to cross reactivity with antigens from related parasite infections, such as leishmaniasis, and low sensitivity caused by the high polymorphism among T. cruzi strains.,Therefore, the identification of new T. cruzi-specific antigens that are conserved among the various parasite discrete typing units (DTUs) is still required.,In the present study, we have explored the hybrid nature of the T. cruzi CL Brener strain using a broad genome screening approach to select new T. cruzi antigens that are conserved among the different parasite DTUs and that are absent in other trypanosomatid species.,Peptide arrays containing the conserved antigens with the highest epitope prediction scores were synthesized, and the reactivity of the peptides were tested by immunoblot using sera from C57BL/6 mice chronically infected with T. cruzi strains from the TcI, TcII or TcVI DTU.,The two T. cruzi proteins that contained the most promising peptides were expressed as recombinant proteins and tested in ELISA experiments with sera from chagasic patients with distinct clinical manifestations: those infected with T. cruzi from different DTUs and those with cutaneous or visceral leishmaniasis.,These proteins, named rTc_11623.20 and rTc_N_10421.310, exhibited 94.83 and 89.66% sensitivity, 98.2 and 94.6% specificity, respectively, and a pool of these 2 proteins exhibited 96.55% sensitivity and 98.18% specificity.,This work led to the identification of two new antigens with great potential application in the diagnosis of chronic Chagas disease.

Copeptin has recently been identified to be a stable surrogate marker for the unstable hormone arginine vasopressin (AVP).,Copeptin has been shown to correlate with disease severity in leptospirosis and bacterial sepsis.,Hyponatraemia is common in severe imported malaria and dysregulation of AVP release has been hypothesized as an underlying pathophysiological mechanism.,The aim of the present study was to evaluate the performance of copeptin as a predictor of disease severity in imported malaria.,Copeptin was measured in stored serum samples of 204 patients with imported malaria that were admitted to our Institute for Tropical Diseases in Rotterdam in the period 1999-2010.,The occurrence of WHO defined severe malaria was the primary end-point.,The diagnostic performance of copeptin was compared to that of previously evaluated biomarkers C-reactive protein, procalcitonin, lactate and sodium.,Of the 204 patients (141 Plasmodium falciparum, 63 non-falciparum infection), 25 had severe malaria.,The Area Under the ROC curve of copeptin for severe disease (0.66 [95% confidence interval 0.59-0.72]) was comparable to that of lactate, sodium and procalcitonin.,C-reactive protein (0.84 [95% CI 0.79-0.89]) had a significantly better performance as a biomarker for severe malaria than the other biomarkers.,C-reactive protein but not copeptin was found to be an accurate predictor for disease severity in imported malaria.,The applicability of copeptin as a marker for severe malaria in clinical practice is limited to exclusion of severe malaria.

Severe malaria is a leading cause of childhood mortality in Africa.,However, at presentation, it is difficult to predict which children with severe malaria are at greatest risk of death.,Dysregulated host inflammatory responses and endothelial activation play central roles in severe malaria pathogenesis.,We hypothesized that biomarkers of these processes would accurately predict outcome among children with severe malaria.,Plasma was obtained from children with uncomplicated malaria (n = 53), cerebral malaria (n = 44) and severe malarial anemia (n = 59) at time of presentation to hospital in Kampala, Uganda.,Levels of angiopoietin-2, von Willebrand Factor (vWF), vWF propeptide, soluble P-selectin, soluble intercellular adhesion molecule-1 (ICAM-1), soluble endoglin, soluble FMS-like tyrosine kinase-1 (Flt-1), soluble Tie-2, C-reactive protein, procalcitonin, 10 kDa interferon gamma-induced protein (IP-10), and soluble triggering receptor expressed on myeloid cells-1 (TREM-1) were determined by ELISA.,Receiver operating characteristic (ROC) curve analysis was used to assess predictive accuracy of individual biomarkers.,Six biomarkers (angiopoietin-2, soluble ICAM-1, soluble Flt-1, procalcitonin, IP-10, soluble TREM-1) discriminated well between children who survived severe malaria infection and those who subsequently died (area under ROC curve>0.7).,Combinational approaches were applied in an attempt to improve accuracy.,A biomarker score was developed based on dichotomization and summation of the six biomarkers, resulting in 95.7% (95% CI: 78.1-99.9) sensitivity and 88.8% (79.7-94.7) specificity for predicting death.,Similar predictive accuracy was achieved with models comprised of 3 biomarkers.,Classification tree analysis generated a 3-marker model with 100% sensitivity and 92.5% specificity (cross-validated misclassification rate: 15.4%, standard error 4.9%).,We identified novel host biomarkers of pediatric severe and fatal malaria (soluble TREM-1 and soluble Flt-1) and generated simple biomarker combinations that accurately predicted death in an African pediatric population.,While requiring validation in further studies, these results suggest the utility of combinatorial biomarker strategies as prognostic tests for severe malaria.

Primaquine is the only available antimalarial drug that kills dormant liver stages of Plasmodium vivax and Plasmodium ovale malarias and therefore prevents their relapse (‘radical cure’).,It is also the only generally available antimalarial that rapidly sterilises mature P. falciparum gametocytes.,Radical cure requires extended courses of primaquine (usually 14 days; total dose 3.5-7 mg/kg), whereas transmissibility reduction in falciparum malaria requires a single dose (formerly 0.75 mg/kg, now a single low dose [SLD] of 0.25 mg/kg is recommended).,The main adverse effect of primaquine is dose-dependent haemolysis in glucose 6-phosphate dehydrogenase (G6PD) deficiency, the most common human enzymopathy.,X-linked mutations conferring varying degrees of G6PD deficiency are prevalent throughout malaria-endemic regions.,Phenotypic screening tests usually detect <30% of normal G6PD activity, identifying nearly all male hemizygotes and female homozygotes and some heterozygotes.,Unfortunately, G6PD deficiency screening is usually unavailable at point of care, and, as a consequence, radical cure is greatly underused.,Both haemolytic risk (determined by the prevalence and severity of G6PD deficiency polymorphisms) and relapse rates vary, so there has been considerable uncertainty in both policies and practices related to G6PD deficiency testing and use of primaquine for radical cure.,Review of available information on the prevalence and severity of G6PD variants together with countries’ policies for the use of primaquine and G6PD deficiency testing confirms a wide range of practices.,There remains lack of consensus on the requirement for G6PD deficiency testing before prescribing primaquine radical cure regimens.,Despite substantially lower haemolytic risks, implementation of SLD primaquine as a P. falciparum gametocytocide also varies.,In Africa, a few countries have recently adopted SLD primaquine, yet many with areas of low seasonal transmission do not use primaquine as an antimalarial at all.,Most countries that recommended the higher 0.75 mg/kg single primaquine dose for falciparum malaria (e.g., most countries in the Americas) have not changed their recommendation.,Some vivax malaria-endemic countries where G6PD deficiency testing is generally unavailable have adopted the once-weekly radical cure regimen (0.75 mg/kg/week for 8 weeks), known to be safer in less severe G6PD deficiency variants.,There is substantial room for improvement in radical cure policies and practices.

Malaria elimination will be possible only with serious attempts to address asymptomatic infection and chronic infection by both Plasmodium falciparum and Plasmodium vivax.,Currently available drugs that can completely clear a human of P. vivax (known as “radical cure”), and that can reduce transmission of malaria parasites, are those in the 8-aminoquinoline drug family, such as primaquine.,Unfortunately, people with glucose-6-phosphate dehydrogenase (G6PD) deficiency risk having severe adverse reactions if exposed to these drugs at certain doses.,G6PD deficiency is the most common human enzyme defect, affecting approximately 400 million people worldwide.,Scaling up radical cure regimens will require testing for G6PD deficiency, at two levels: 1) the individual level to ensure safe case management, and 2) the population level to understand the risk in the local population to guide Plasmodium vivax treatment policy.,Several technical and operational knowledge gaps must be addressed to expand access to G6PD deficiency testing and to ensure that a patient’s G6PD status is known before deciding to administer an 8-aminoquinoline-based drug.,In this report from a stakeholder meeting held in Thailand on October 4 and 5, 2012, G6PD testing in support of radical cure is discussed in detail.,The focus is on challenges to the development and evaluation of G6PD diagnostic tests, and on challenges related to the operational aspects of implementing G6PD testing in support of radical cure.,The report also describes recommendations for evaluation of diagnostic tests for G6PD deficiency in support of radical cure.

The local immune mechanisms responsible for either self-healing or sustained chronic infection are not clear, in the development of E. multilocularis larvae.,Here, we developed a suitable experimental model that mimics naturally infected livers, according to the parasite load.,We demonstrated that local cellular immunity and fibrogenesis are actually protective and fully able to limit metacestode growth in the liver of low or medium dose-infected mice (LDG or MDG), or even to clear it, while impairment of cellular immunity is followed by a more rapid and severe course of the disease in high dose-infected mice (HDG).,And recruitment and/ or proliferation of memory T cells (including CD4 Tem, CD8 Tcm and CD8 Tem) and imbalance of T1/T2/T17/Treg-type T cells in liver were not only associated with clearance of the parasite infection in LDG, but also with increased hepatic injury in HDG; in particular the dual role of CD8 T cells depending on the parasite load and the various stages of metacestode growth.,Besides, we first demonstrate the association between LAG3- or 2B4-expressing T cells exhaustion and HD inocula in late stages.,Our quantitative experimental model appears fully appropriate to study immunomodulation as a therapeutic strategy for patients with Alveolar Echinococcosis.

To investigate the potential role of transforming growth factor (TGF)-β1 in liver fibrosis during Echinococcus granulosus infection, 96 BALB/c mice were randomly divided into 2 groups, experimental group infected by intraperitoneal injection with a metacestode suspension and control group given sterile physiological saline.,The liver and blood samples were collected at days 2, 8, 30, 90, 180, and 270 post infection (PI), and the expression of TGF-β1 mRNA and protein was determined by real-time quantitative RT-PCR and ELISA, respectively.,We also evaluated the pathological changes in the liver during the infection using hematoxylin and eosin (H-E) and Masson staining of the liver sections.,Pathological analysis of H-E stained infected liver sections revealed liver cell edema, bile duct proliferation, and structural damages of the liver as evidenced by not clearly visible lobular architecture of the infected liver, degeneration of liver cell vacuoles, and infiltration of lymphocytes at late stages of infection.,The liver tissue sections from control mice remained normal.,Masson staining showed worsening of liver fibrosis at the end stages of the infection.,The levels of TGF-β1 did not show significant changes at the early stages of infection, but there were significant increases in the levels of TGF-β1 at the middle and late stages of infection (P<0.05).,RT-PCR results showed that, when compared with the control group, TGF-β1 mRNA was low and comparable with that in control mice at the early stages of infection, and that it was significantly increased at day 30 PI and remained at high levels until day 270 PI (P<0.05).,The results of this study suggested that increased expression of TGF-β1 during E. granulosus infection may play a significant role in liver fibrosis associated with E. granulosus infection.

Malaria transmission in Senegal is highly stratified, from low in the dry north to moderately high in the moist south.,In northern Senegal, along the Senegal River Valley and in the Ferlo semi-desert region, annual incidence is less than five cases per 1000 inhabitants.,Many nomadic pastoralists have permanent dwellings in the Ferlo Desert and Senegal River Valley, but spend dry season in the south with their herds, returning north when the rains start, leading to a concern that this population could contribute to ongoing transmission in the north.,A modified snowball sampling survey was conducted at six sites in northern Senegal to determine the malaria prevention and treatment seeking practices and parasite prevalence among nomadic pastoralists in the Senegal River Valley and the Ferlo Desert.,Nomadic pastoralists aged 6 months and older were surveyed during September and October 2014, and data regarding demographics, access to care and preventive measures were collected.,Parasite infection was detected using rapid diagnostic tests (RDTs), microscopy (thin and thick smears) and polymerase chain reaction (PCR).,Molecular barcodes were determined by high resolution melting (HRM).,Of 1800 participants, 61% were male.,Sixty-four percent had at least one bed net in the household, and 53% reported using a net the night before.,Only 29% had received a net from a mass distribution campaign.,Of the 8% (142) who reported having had fever in the last month, 55% sought care, 20% of whom received a diagnostic test, one-third of which (n = 5) were reported to be positive.,Parasite prevalence was 0.44% by thick smear and 0.50% by PCR.,None of the molecular barcodes identified among the nomadic pastoralists had been previously identified in Senegal.,While access to and utilization of malaria control interventions among nomadic pastoralists was lower than the general population, parasite prevalence was lower than expected and sheds doubt on the perception that they are a source of ongoing transmission in the north.,The National Malaria Control Program is making efforts to improve access to malaria prevention and case management for nomadic populations.,The online version of this article (doi:10.1186/s12936-017-2055-x) contains supplementary material, which is available to authorized users.

Information about malaria risk factors at high altitudes is scanty.,Understanding the risk factors that determine the risk of malaria transmission at high altitude villages is important to facilitate implementing sustainable malaria control and prevention programs.,An unmatched case control study was conducted among patients seeking treatment at health centers in high altitude areas.,Either microscopy or rapid diagnostic tests were used to confirm the presence of plasmodium species.,A generalized linear model was used to identify the predictors of malaria transmission in high altitude villages.,Males (AOR = 3.11, 95%CI: 2.28, 4.23), and those who traveled away from the home in the previous month (AOR = 2.01, 95% CI: 1.56, 2.58) were strongly associated with presence of malaria in high altitude villages.,Other significant factors, including agriculture in occupation (AOR = 1.41, 95% CI: 1.05, 1.93), plants used for fencing (AOR = 1.70, 95% CI: 1.18, 2.52) and forests near the house (AOR = 1.60, 95% CI: 1.15, 2.47), were found predictors for malaria in high altitude villages.,Travel outside of their home was an important risk of malaria infections acquisition.,Targeting males who frequently travel to malarious areas can reduce malaria transmission risks in high altitude areas.

In most malaria situations, mass drug administration (MDA) will result in a rapid reduction in the incidence and prevalence of malaria in the target population.,However, due to practical reasons MDA hardly ever achieves coverage of the entire population and, therefore, will leave residual malaria infections in the population, from which malaria transmission can be resumed.,Depending on the degree of access to prompt diagnosis and treatment and to effective vector control in the area, previous levels of incidence and prevalence will eventually be reached after MDA.,It is, therefore, imperative that coverage with these interventions is ensured if MDA is to be implemented.,Both effective vector control and access to treatment in combination will also reduce the malaria incidence and prevalence in an area, albeit more slowly than MDA.,MDA’s role in elimination has to be considered in relation to the following: (1) MDA is logistically difficult, ethically questionable and may evoke parasite resistance to the medicines being used, (2) MDA will only accelerate elimination by reducing the starting number of infections, but that (3) it will be of no benefit to elimination unless both effective vector control and good access to treatment are in place.,All malaria elimination efforts have, and will, succeed with good access to treatment, effective vector control, and case surveillance and response systems, and most have not, and will not require MDA.,The role of MDA in elimination, if any, will be limited to some very specific situations-small foci of high transmission within a larger area which has made progress towards elimination, to which the former constitutes a continuing source of parasites and, therefore, could jeopardize the elimination effort in the larger area.,Elimination of malaria needs not only to be achieved but also be sustained.,This is particularly challenging in tropical countries where the risk of re-introduction is high.,The haste to eliminate malaria using MDA must be balanced by investment of time and effort to establish effective vector control programmes, and case surveillance and response systems based on diagnosis and treatment services, which are core requisites for achieving elimination, and the latter for sustaining it.

Assessing the Plasmodium vivax burden in India is complicated by the potential threat of an emerging chloroquine (CQ) resistant parasite population from neighbouring countries in Southeast Asia.,Chennai, the capital of Tamil Nadu and an urban setting for P. vivax in southern India, was selected as a sentinel site for investigating CQ efficacy and sensitivity in vivax malaria.,CQ efficacy was evaluated with a 28-day in vivo therapeutic study, while CQ sensitivity was measured with an in vitro drug susceptibility assay.,In both studies, isolates also underwent molecular genotyping to investigate correlations between parasite diversity and drug susceptibility to CQ.,Molecular genotyping included sequencing a 604 base pair (bp) fragment of the P. vivax multidrug resistant gene-1 (Pvmdr1) for single nucleotide polymorphisms (SNPs) and also the amplification of eight microsatellite (MS) loci located across the genome on eight different chromosomes.,In the 28-day in vivo study (N=125), all subjects were aparasitaemic by Day 14.,Passive case surveillance continuing beyond Day 28 in 22 subjects exposed 17 recurrent infections, which ranged from 44 to 148 days post-enrollment.,Pvmdr1 sequencing of these recurrent infections revealed that 93.3% had identical mutant haplotypes (958M/Y976/1076L) to their baseline Day 0 infection.,MS genotyping further revealed that nine infection pairs were related with ≥75% haplotype similarity (same allele at six or more loci).,To test the impact of this mutation on CQ efficacy, an in vitro drug assay (N=68) was performed.,No correlation between IC50 values and the percentage of ring-stage parasites prior to culture was observed (rsadj: -0.00063, p = 0.3307) and the distribution of alleles among the Pvmdr1 SNPs and MS haplotypes showed no significant associations with IC50 values.,Plasmodium vivax was found to be susceptible to CQ drug treatment in both the in vivo therapeutic drug study and the in vitro drug assay.,Though the mutant 1076L of Pvmdr1 was found in a majority of isolates tested, this single mutation did not associate with CQ resistance.,MS haplotypes revealed strong heterogeneity in this population, indicating a low probability of reinfection with highly related haplotypes.

Safe treatment of Plasmodium vivax requires diagnosis of both the infection and status of erythrocytic glucose-6-phosphate dehydrogenase (G6PD) activity because hypnozoitocidal therapy against relapse requires primaquine, which causes a mild to severe acute hemolytic anemia in G6PD deficient patients.,Many national malaria control programs recommend primaquine therapy without G6PD screening but with monitoring due to a broad lack of G6PD deficiency screening capacity.,The degree of risk in doing so hinges upon the level of residual G6PD activity among the variants present in any given area.,We conducted studies on Sumba Island in eastern Indonesia in order to assess the potential threat posed by primaquine therapy without G6PD screening.,We sampled 2,033 residents of three separate districts in western Sumba for quantitative G6PD activity and 104 (5.1%) were phenotypically deficient (<4.6U/gHb; median normal 10U/gHb).,The villages were in two distinct ecosystems, coastal and inland.,A positive correlation occurred between the prevalence of malaria and G6PD deficiency: 5.9% coastal versus inland 0.2% for malaria (P<0.001), and 6.7% and 3.1% for G6PD deficiency (P<0.001) at coastal and inland sites, respectively.,The dominant genotypes of G6PD deficiency were Vanua Lava, Viangchan, and Chatham, accounting for 98.5% of the 70 samples genotyped.,Subjects expressing the dominant genotypes all had less than 10% of normal enzyme activities and were thus considered severe variants.,Blind administration of anti-relapse primaquine therapy at Sumba would likely impose risk of serious harm.

Malaria elimination will be possible only with serious attempts to address asymptomatic infection and chronic infection by both Plasmodium falciparum and Plasmodium vivax.,Currently available drugs that can completely clear a human of P. vivax (known as “radical cure”), and that can reduce transmission of malaria parasites, are those in the 8-aminoquinoline drug family, such as primaquine.,Unfortunately, people with glucose-6-phosphate dehydrogenase (G6PD) deficiency risk having severe adverse reactions if exposed to these drugs at certain doses.,G6PD deficiency is the most common human enzyme defect, affecting approximately 400 million people worldwide.,Scaling up radical cure regimens will require testing for G6PD deficiency, at two levels: 1) the individual level to ensure safe case management, and 2) the population level to understand the risk in the local population to guide Plasmodium vivax treatment policy.,Several technical and operational knowledge gaps must be addressed to expand access to G6PD deficiency testing and to ensure that a patient’s G6PD status is known before deciding to administer an 8-aminoquinoline-based drug.,In this report from a stakeholder meeting held in Thailand on October 4 and 5, 2012, G6PD testing in support of radical cure is discussed in detail.,The focus is on challenges to the development and evaluation of G6PD diagnostic tests, and on challenges related to the operational aspects of implementing G6PD testing in support of radical cure.,The report also describes recommendations for evaluation of diagnostic tests for G6PD deficiency in support of radical cure.

Malaria control interventions have led to a decline in transmission intensity in many endemic areas, and resulted in elimination in some areas.,This decline, however, will lead to delayed acquisition of protective immunity and thus impact disease manifestation and outcomes.,Therefore, the variation in clinical and haematological parameters in children with malaria was assessed across three areas in Ghana with varying transmission intensities.,A total of 568 children between the ages of 2 and 14 years with confirmed malaria were recruited in hospitals in three areas with varying transmission intensities (Kintampo > Navrongo > Accra) and a comprehensive analysis of parasitological, clinical, haematological and socio-economic parameters was performed.,Areas of lower malaria transmission tended to have lower disease severity in children with malaria, characterized by lower parasitaemias and higher haemoglobin levels.,In addition, total white cell counts and percent lymphocytes decreased with decreasing transmission intensity.,The heterozygous sickle haemoglobin genotype was protective against disease severity in Kintampo (P = 0.016), although this was not significant in Accra and Navrongo.,Parasitaemia levels were not a significant predictor of haemoglobin level after controlling for age and gender.,However, higher haemoglobin levels in children were associated with certain socioeconomic factors, such as having fathers who had any type of employment (P < 0.05) and mothers who were teachers (P < 0.05).,The findings demonstrate significant differences in the haematological presentation and severity of malaria among areas with different transmission intensity in Ghana, indicating that these factors need to be considered in planning the management of the disease as the endemicity is expected to decline after control interventions.

To determine whether sequestration of parasitized red blood cells differs between children with uncomplicated and severe Plasmodium falciparum malaria.,We quantified circulating-, total- and sequestered-parasite biomass, using a mathematical model based on plasma concentration of P. falciparum histidine rich protein 2, in Gambian children with severe (n = 127) and uncomplicated (n = 169) malaria.,Circulating- and total-, but not sequestered-, parasite biomass estimates were significantly greater in children with severe malaria than in those with uncomplicated malaria.,Sequestered biomass estimates in children with hyperlactataemia or prostration were similar to those in uncomplicated malaria, whereas sequestered biomass was higher in patients with severe anaemia, and showed a trend to higher values in cerebral malaria and fatal cases.,Blood lactate concentration correlated with circulating- and total-, but not sequestered parasite biomass.,These findings were robust after controlling for age, prior antimalarial treatment and clonality of infection, and over a realistic range of variation in model parameters.,Extensive sequestration is not a uniform requirement for severe paediatric malaria.,The pathophysiology of hyperlactataemia and prostration appears to be unrelated to sequestered parasite biomass.,Different mechanisms may underlie different severe malaria syndromes, and different therapeutic strategies may be required to improve survival.

The diversity of circulating human B cells is unknown.,We use single-cell RNA sequencing (RNA-seq) to examine the diversity of both antigen-specific and total B cells in healthy subjects and malaria-exposed individuals.,This reveals two B cell lineages: a classical lineage of activated and resting memory B cells and an alternative lineage, which includes previously described atypical B cells.,Although atypical B cells have previously been associated with disease states, the alternative lineage is common in healthy controls, as well as malaria-exposed individuals.,We further track Plasmodium-specific B cells after malaria vaccination in naive volunteers.,We find that alternative lineage cells are primed after the initial immunization and respond to booster doses.,However, alternative lineage cells develop an atypical phenotype with repeated boosts.,The data highlight that atypical cells are part of a wider alternative lineage of B cells that are a normal component of healthy immune responses.,•Single-cell RNA-seq reveals two distinct B cell lineages•An alternative lineage contains CXCR3+ and atypical B cells•Alternative B cells are primed after primary vaccination and respond to boosters•Alternative B cells adopt a more atypical phenotype following repeated antigen exposure,Single-cell RNA-seq reveals two distinct B cell lineages,An alternative lineage contains CXCR3+ and atypical B cells,Alternative B cells are primed after primary vaccination and respond to boosters,Alternative B cells adopt a more atypical phenotype following repeated antigen exposure,Using single-cell RNA sequencing, Sutton et al. show that a population of “atypical” B cells, normally associated with disease, are part of a wider landscape of alternative B cells that participate in normal responses to vaccination.

Malaria elimination strategies require a thorough understanding of parasite transmission from human to mosquito.,A clinical model to induce gametocytes to understand their dynamics and evaluate transmission-blocking interventions (TBI) is currently unavailable.,Here, we explore the use of the well-established Controlled Human Malaria Infection model (CHMI) to induce gametocyte carriage with different antimalarial drug regimens.,In a single centre, open-label randomised trial, healthy malaria-naive participants (aged 18-35 years) were infected with Plasmodium falciparum by bites of infected Anopheles mosquitoes.,Participants were randomly allocated to four different treatment arms (n = 4 per arm) comprising low-dose (LD) piperaquine (PIP) or sulfadoxine-pyrimethamine (SP), followed by a curative regimen upon recrudescence.,Male and female gametocyte densities were determined by molecular assays.,Mature gametocytes were observed in all participants (16/16, 100%).,Gametocytes appeared 8.5-12 days after the first detection of asexual parasites.,Peak gametocyte densities and gametocyte burden was highest in the LD-PIP/SP arm, and associated with the preceding asexual parasite biomass (p=0.026).,Male gametocytes had a mean estimated circulation time of 2.7 days (95% CI 1.5-3.9) compared to 5.1 days (95% CI 4.1-6.1) for female gametocytes.,Exploratory mosquito feeding assays showed successful sporadic mosquito infections.,There were no serious adverse events or significant differences in the occurrence and severity of adverse events between study arms (p=0.49 and p=0.28).,The early appearance of gametocytes indicates gametocyte commitment during the first wave of asexual parasites emerging from the liver.,Treatment by LD-PIP followed by a curative SP regimen, results in the highest gametocyte densities and the largest number of gametocyte-positive days.,This model can be used to evaluate the effect of drugs and vaccines on gametocyte dynamics, and lays the foundation for fulfilling the critical unmet need to evaluate transmission-blocking interventions against falciparum malaria for downstream selection and clinical development.,Funded by PATH Malaria Vaccine Initiative (MVI).,NCT02836002.,The parasite that causes malaria, named Plasmodium falciparum, has a life cycle that involves both humans and mosquitoes.,Starting in the saliva of female Anopheles mosquitoes, it enters a person’s bloodstream when the insects feed.,It then moves to the person’s liver, where it infects liver cells and matures into a stage known as schizonts.,The schizonts then divide to form thousands of so-called merozoites, which burst out of the liver cells and into the bloodstream.,The merozoites infect red blood cells, producing more schizonts and yet more merozoites, which continue the infection.,To complete its life cycle, the parasite must return to a mosquito.,Some of the parasites in the person’s blood transform into male and female cells called gametocytes that are taken up by a mosquito when it feeds on that person.,Inside the mosquito, male and female parasites reproduce to create the next generation of parasites.,The new parasites then move to the mosquito’s salivary glands, ready to begin another infection.,Stopping the parasite being transmitted from humans to mosquitoes will stop the spread of malaria in the population.,Yet it has proven difficult to study this part of the life cycle from natural infections.,Here, Reuling et al. report a new method for generating gametocytes in human volunteers that will enable closer study of the biology of malaria transmission.,The method is developed using the Controlled Human Malaria Infection (CHMI) model.,Healthy volunteers without a history of malaria are bitten by mosquitoes infected with malaria parasites.,Shortly afterwards, the volunteers are given a drug treatment to control and reduce their symptoms.,The gametocytes form during this phase of the infection.,At the end of the experiment, all the volunteers receive a final treatment that completely cures the infection.,Reuling et al. recruited 16 volunteers and assigned them to four groups at random.,Each group received a different drug regime.,Roughly a week after the mosquito bites, all participants showed malaria parasites in their blood, and between 8.5 and 12 days later, mature gametocytes started to appear.,This early appearance suggests that the parasites start to transform into gametocytes when they first emerge from the liver.,The experiment also revealed that female gametocytes stay in the blood for a longer period than their male counterparts.,These results are proof of principle for a new way to investigate malaria infection.,The new model provides a controlled method for studying P. falciparum gametocytes in people.,In the future, it could help to test the impact of drugs and vaccines on gametocytes.,Understanding more about these parasites’ biology could lead to treatments that block malaria transmission.

The World Health Organization (WHO) recommends use of parasitological diagnosis of malaria for all age groups in all malaria transmission settings.,Many private health facilities rely on malaria microscopy for malaria diagnosis.,However, quality of malaria microscopy is affected by number of factors including availability of skilled laboratory microscopists and lack of quality assurance systems in many malaria endemic countries.,This study was carried out to assess quality of malaria microscopy in selected private health facilities in Tanzania.,A cross sectional study was conducted from August to September, 2017.,A total of 40 private health laboratories in five regions were invited to participate in the study.,Data were collected by distributing standardized pre-validated malaria slide-panels to each health facility.,Sensitivity, specificity, and strength of agreement (with kappa score) were calculated to assess performance in detecting and quantification of Plasmodium species.,Among the 40 health facilities, 31 (77.5%) returned their results to the reference centre (Muhimbili University of Health and Allied Sciences).,Overall, the measures of malaria diagnostic accuracy were high, i.e. the sensitivity and specificity of malaria parasite detection by microscopy in the health facilities were 84.3% (95% CI 77-90) and 90.8% (95% CI 83.3-95.7), respectively.,There was substantial agreement in parasite detection with (Kappa value: 0.74 (95% 0.65-0.83).,However, only 17.8% (24 of 134) of blood slides were interpreted correctly at the health facilities in terms of parasite density counts.,Although there was substantial agreement between the private health microscopists and experienced microscopists in malaria parasite detection, there was poor performance in parasite counts.,This calls for regular in-service training and external quality assessments at private health facilities to enhance the skills of private health facility microscopists in malaria microscopy.

Significant headway has been made in the global fight against malaria in the past decade and as more countries enter the elimination phase, attention is now focused on identifying effective strategies to shrink the malaria map.,Saudi Arabia experienced an outbreak of malaria in 1998, but is now on the brink of malaria elimination, with just 82 autochthonous cases reported in 2012.,A review of published and grey literature was performed to identify the control strategies that have contributed to this achievement.,The number of autochthonous malaria cases in Saudi Arabia decreased by 99.8% between 1998 and 2012.,The initial steep decline in malaria cases coincided with a rapid scaling up of vector control measures.,Incidence continued to be reported at low levels (between 0.01 and 0.1 per 1,000 of the population) until the adoption of artesunate plus sulfadoxine-pyrimethamine as first line treatment and the establishment of a regional partnership for a malaria-free Arabian Peninsula, both of which occurred in 2007.,Since 2007, incidence has decreased by nearly an order of magnitude.,Malaria incidence is now very low, but a high proportion of imported cases, continued potential for autochthonous transmission, and an increased proportion of cases attributable to Plasmodium vivax all present challenges to Saudi Arabia as they work toward elimination by 2015.

Taenia solium cysticercosis and taeniasis (TSCT), caused by the tapeworm T. solium, is a foodborne and zoonotic disease classified since 2010 by WHO as a neglected tropical isease.,It causes considerable impact on health and economy and is one of the leading causes of acquired epilepsy in most endemic countries of Latin America, Sub-Saharan Africa, and Asia.,There is some evidence that the prevalence of TSCT in high-income countries has recently increased, mainly due to immigration from endemic areas.,In regions endemic for TSCT, human cysticercosis can manifest clinically as neurocysticercosis (NCC), resulting in epileptic seizures and severe progressive headaches, amongst other neurological signs and/or symptoms.,The development of these symptoms results from a complex interplay between anatomical cyst localization, environmental factors, parasite’s infective potential, host genetics, and, especially, host immune responses.,Treatment of individuals with active NCC (presence of viable cerebral cysts) with anthelmintic drugs together with steroids is usually effective and, in the majority, reduces the number and/or size of cerebral lesions as well as the neurological symptoms.,However, in some cases, treatment may profoundly enhance anthelmintic inflammatory responses with ensuing symptoms, which, otherwise, would have remained silent as long as the cysts are viable.,This intriguing silencing process is not yet fully understood but may involve active modulation of host responses by cyst-derived immunomodulatory components released directly into the surrounding brain tissue or by the induction of regulatory networks including regulatory T cells (Treg) or regulatory B cells (Breg).,These processes might be disturbed once the cysts undergo treatment-induced apoptosis and necrosis or in a coinfection setting such as HIV.,Herein, we review the current literature regarding the immunology and pathogenesis of NCC with a highlight on the mobilization of immune cells during human NCC and their interaction with viable and degenerating cysticerci.,Moreover, the immunological parameters associated with NCC in people living with HIV/AIDS and treatments are discussed.,Eventually, we propose open questions to understand the role of the immune system and its impact in this intriguing host-parasite crosstalk.

Egg-induced immune response and granuloma formation are thought to be the basis of central nervous system (CNS)-related clinical symptoms of Schistosoma japonicum.,Microglia/macrophages are the major immune cells involved in detection and subsequent elimination of pathogens and injured tissue in the brain.,However, little is known about their role in the pathogenesis of neuroschistosomiasis.,The main purpose of the study is to clarify the pathological involvement of microglia/macrophages in the pathogenesis of neuroschistosomiasis (NS).,Staining techniques were applied to the granuloma tissues excised from 4 patients, as well as mice model which was established by microinjecting viable S. japonicum eggs into the brain.,Clinical features of the patients and neurological symptoms in mice were also collected and analyzed in terms of their correlation with microglia/macrophages.,Microglia/macrophages constituted the major portions of the granulomas surrounding the eggs in both all human cases and S. japonicum egg-injected mice.,Granuloma persisted in all patients accompanied by unremitted neurological symptoms, while in mice granuloma formation initiated on day 3, peaked on day 7 and subsided on day 30 post injection with S. japonicum eggs.,No neurological abnormalities were observed in egg-injected mice except for significant weight decrease on day 3 compared with saline-injected control.,M1 polarization of microglia/macrophages was confirmed in egg-injected mice 3 days post injection and in all human cases.,M2 polarization was absent in human patients despite the duration of complaints but dominated in the whole progression of egg-induced pathology in mice until the elimination of eggs and subsidence of neuroinflammation on day 30 post injection.,Microglia/macrophages participated actively in the granuloma microenvironment of encephalic schistosomiasis japonicum in both human and mice.,The polarization pattern of microglia/macrophages coincided with the symptomatic features in human cases and S. japonicum egg-injected mice, indicating M2 instead of M1 activation as a probably more important mediator in the battle against egg-induced pathology and concomitant manifestations.,These new findings will shed light on the pathogenesis of NS from a brand-new perspective, and may contribute to the immunotherapy development for such disease, favoring perhaps M2 polarization of microglia/macrophages as a feasible strategy.

In certain regions in Southeast Asia, where malaria is reduced to forested regions populated by ethnic minorities dependent on slash-and-burn agriculture, malaria vector populations have developed a propensity to feed early and outdoors, limiting the effectiveness of long-lasting insecticide-treated nets (LLIN) and indoor residual spraying (IRS).,The interplay between heterogeneous human, as well as mosquito behaviour, radically challenges malaria control in such residual transmission contexts.,This study examines human behavioural patterns in relation to the vector behaviour.,The anthropological research used a sequential mixed-methods study design in which quantitative survey research methods were used to complement findings from qualitative ethnographic research.,The qualitative research existed of in-depth interviews and participant observation.,For the entomological research, indoor and outdoor human landing collections were performed.,All research was conducted in selected villages in Ratanakiri province, Cambodia.,Variability in human behaviour resulted in variable exposure to outdoor and early biting vectors: (i) indigenous people were found to commute between farms in the forest, where malaria exposure is higher, and village homes; (ii) the indoor/outdoor biting distinction was less clear in forest housing often completely or partly open to the outside; (iii) reported sleeping times varied according to the context of economic activities, impacting on the proportion of infections that could be accounted for by early or nighttime biting; (iv) protection by LLINs may not be as high as self-reported survey data indicate, as observations showed around 40% (non-treated) market net use while (v) unprotected evening resting and deep forest activities impacted further on the suboptimal use of LLINs.,The heterogeneity of human behaviour and the variation of vector densities and biting behaviours may lead to a considerable proportion of exposure occurring during times that people are assumed to be protected by the distributed LLINs.,Additional efforts in improving LLIN use during times when people are resting in the evening and during the night might still have an impact on further reducing malaria transmission in Cambodia.

Despite Vietnam's success in reducing malaria mortality and morbidity over the last decade, malaria persists in the forested and mountainous areas of the central and southern provinces, where more than 50% of the clinical cases and 90% of severe cases and malaria deaths occur.,Between July 2005 and September 2006, a multi-method study, triangulating a malariometric cross-sectional survey and qualitative data from focused ethnography, was carried out among the Ra-glai ethnic minority in the hilly forested areas of south-central Vietnam.,Despite the relatively high malaria burden among the Ra-glai and their general awareness that mosquitoes can transmit an unspecific kind of fever (84.2%), the use of bed nets, distributed free of charge by the national malaria control programme, remains low at the farmers' forest fields where the malaria risk is the highest.,However, to meet work requirements during the labour intensive malaria transmission and rainy season, Ra-glai farmers combine living in government supported villages along the road with a second home or shelter at their slash and burn fields located in the forest.,Bed net use was 84.6% in the villages but only 52.9% at the forest fields; 20.6% of the respondents slept unprotected in both places.,Such low use may be explained by the low perception of the risk for malaria, decreasing the perceived need to sleep protected.,Several reasons may account for this: (1) only 15.6% acknowledged the higher risk of contracting malaria in the forest than in the village; (2) perceived mosquito biting times only partially coincided with Anopheles dirus ss and Anopheles minimus A true biting times; (3) the disease locally identified as 'malaria' was hardly perceived as having an impact on forest farmers' daily lives as they were unaware of the specific kind of fevers from which they had suffered even after being diagnosed with malaria at the health centre (20.9%).,The progressive confinement of malaria to minority groups and settings in the Greater Mekong sub-region implies that further success in malaria control will be linked to research into these specific socio-cultural contexts.,Findings highlight the need for context sensitive malaria control policies; not only to reduce the local malaria burden but also to minimize the risk of malaria spreading to other areas where transmission has virtually ceased.

The early and correct diagnosis of human leishmaniasis is essential for disease treatment.,Another important step in the control of visceral leishmaniasis is the identification of infected dogs, which are the main domestic reservoir of L. infantum.,Recombinant proteins and synthetic peptides based on Leishmania genes have emerged as valuable targets for serodiagnosis due to their increased sensitivity, specificity and potential for standardization.,Cathepsin L-like genes are surface antigens that are secreted by amastigotes and have little similarity to host proteins, factors that enable this protein as a good target for serodiagnosis of the leishmaniasis.,We mapped a linear B-cell epitope within the Cathepsin L-like protein from L. braziliensis.,A synthetic peptide containing the epitope and the recombinant protein was evaluated for serodiagnosis of human tegumentary and visceral leishmaniasis, as well as canine visceral leishmaniasis.,The recombinant protein performed best for human tegumentary and canine visceral leishmaniasis, with 96.30% and 89.33% accuracy, respectively.,The synthetic peptide was the best to discriminate human visceral leishmaniasis, with 97.14% specificity, 94.55% sensitivity and 96.00% accuracy.,Comparison with T. cruzi-infected humans and dogs suggests that the identified epitope is specific to Leishmania parasites, which minimizes the likelihood of cross-reactions.

The search toward the establishment of novel serological tests for the diagnosis of leishmaniasis and proper differential diagnosis may represent one alternative to the invasive parasitological methods currently used to identify infected individuals.,In the present work, we investigated the potential use of recombinant peroxidoxin (rPeroxidoxin) of Leishmania (Viannia) braziliensis as a potential antigen for the immunodiagnosis of human tegumentary (TL) and visceral leishmaniasis (VL) and canine visceral leishmaniasis (CVL).,Linear B-cell epitope mapping was performed to identify polymorphic epitopes when comparing orthologous sequences present in Trypanosoma cruzi, the agent for Chagas disease (CD), and the Homo sapiens and Canis familiaris hosts.,The serological assay (ELISA) demonstrated that TL, VL and CVL individuals showed high levels of antibodies against rPeroxidoxin, allowing identification of infected ones with considerable sensitivity and great ability to discriminate (specificity) between non-infected and CD individuals (98.46% and 100%; 98.18% and 95.71%; 95.79% and 100%, respectively).,An rPeroxidoxin ELISA also showed a greater ability to discriminate between vaccinated and infected animals, which is an important requirement for the public campaign control of CVL.,A depletion ELISA assay using soluble peptides of this B-cell epitope confirmed the recognition of these sites only by Leishmania-infected individuals.,Moreover, this work identifies two antigenic polymorphic linear B-cell epitopes of L. braziliensis.,Specific recognition of TL and VL patients was confirmed by significantly decreased IgG reactivity against rPeroxidoxin after depletion of peptide-1- and peptide-2-specific antibodies (peptide 1: reduced by 32%, 42% and 5% for CL, ML and VL, respectively; peptide-2: reduced by 24%, 22% and 13% for CL, ML and VL, respectively) and only peptide-2 for CVL (reduced 9%).,Overall, rPeroxidoxin may be a potential antigen for the immunodiagnosis of TL, VL or CVL, as it has a higher agreement with parasitological assays and is better than other reference tests that use soluble Leishmania antigens for diagnosing CVL in Brazil (EIE-LVC, Bio-manguinhos, FIOCRUZ).

Although intralesional meglumine antimoniate (MA) infiltration is considered an option for cutaneous leishmaniasis (CL) therapy and is widely used in the Old World, there have been few studies supporting this therapeutic approach in the Americas.,This study aims to describe outcomes and adverse events associated with intralesional therapy for CL.,This retrospective study reviewed the experience of a Brazilian leishmaniasis reference centre using intralesional MA to treat 31 patients over five years (2008 and 2013).,The median age was 63 years (22-86) and the median duration time of the lesions up to treatment was 16 weeks.,In 22 patients (71%), intralesional therapy was indicated due to the presence of contraindications or previous serious adverse events with systemic MA.,Other indications were failure of systemic therapy or ease of administration.,Intralesional treatment consisted of one-six infiltrations (median three) for a period of up to 12 weeks.,The initial (three months) and definitive (six months) cure rates were 70.9% and 67.7%, respectively.,Most patients reported mild discomfort during infiltration and no serious adverse events were observed.,In conclusion, these results show that the intralesional MA efficacy rate was very similar to that of systemic MA treatment, and reinforce the need for further studies with adequate design to establish the efficacy and safety of this therapeutic approach.

The clinical and epidemiological significance of Leishmania DNA in extralesional sites is obscured by uncertainty of whether the DNA derives from viable parasites.,To examine dissemination of Leishmania during active disease and the potential participation of human infection in transmission, Leishmania 7SLRNA was exploited to establish viability and estimate parasite burden in extralesional sites of dermal leishmaniasis patients.,The feasibility of discriminating parasite viability by PCR of Leishmania 7SLRNA was evaluated in relation with luciferase activity of luc transfected intracellular amastigotes in dose-response assays of Glucantime cytotoxicity.,Monocytes, tonsil swabs, aspirates of normal skin and lesions of 28 cutaneous and 2 mucocutaneous leishmaniasis patients were screened by kDNA amplification/Southern blot.,Positive samples were analyzed by quantitative PCR of Leishmania 7SLRNA genes and transcripts.,7SLRNA amplification coincided with luciferase activity, confirming discrimination of parasite viability.,Of 22 patients presenting kDNA in extralesional samples, Leishmania 7SLRNA genes or transcripts were detected in one or more kDNA positive samples in 100% and 73% of patients, respectively.,Gene and transcript copy number amplified from extralesional tissues were comparable to lesions.,7SLRNA transcripts were detected in 13/19 (68%) monocyte samples, 5/12 (42%) tonsil swabs, 4/11 (36%) normal skin aspirates, and 22/25 (88%) lesions; genes were quantifiable in 15/19 (79%) monocyte samples, 12/13 (92%) tonsil swabs, 8/11 (73%) normal skin aspirates.,Viable parasites are present in extralesional sites, including blood monocytes, tonsils and normal skin of dermal leishmaniasis patients.,Leishmania 7SLRNA is an informative target for clinical and epidemiologic investigations of human leishmaniasis.

Passive surveillance of malaria in health facilities remains vital for implementation of control and elimination programs.,It is therefore essential understanding current age profile of clinical malaria morbidity, mortality and presentations in areas with variant infection susceptibility.,This study aimed at understanding the current malaria morbidity and mortality in Western Kenya.,Surveillance of clinical and asymptomatic parasitological positivity rates of all malaria suspected patients and school children were respectively determined from June 2015 to August 2016.,From 2014 to 2016, register books in hospitals were referred and the confirmed malaria cases in conjunction with total number of monthly outpatient visits (OPD) counted.,All registered malaria admissions were counted together with other causes of admissions.,Moreover, outcome of malaria admissions in terms of discharge or death was recorded using inpatient charts within the same time frame.,Prospective surveillance of severe malaria collected information on clinical features of the disease.,Giemsa stained blood slides confirmed existence of malaria parasitemia.,Chi-square and analysis of variance tests were used, respectively, to compute proportions and means; then a comparison was made between different age groups, periods, and study areas.,During the survey of asymptomatic infections among school children, overall blood slide positivity ranged from 6.4% at the epidemic prone site to 38.3% at the hyperendemic site.,During the clinical malaria survey, school age children (5-14) presented with overall the highest (45%) blood slide positivity rate among those suspected to have the infection at the epidemic prone study site.,The survey of all malaria confirmed and registered cases at OPD found 17% to 27% of all consultations among <5 children and 9.9% to 20.7% of all OPD visits among the ≥5 patients were due to malaria.,Moreover, survey of all registered causes of admission in hospitals found 47% of admissions were due to malaria.,The disease was a major cause of admission in epidemic prone setting where 63.4% of the <5 children and 62.8% of the ≥5 patients were admitted due to malaria (p>0.05) and 40% of all malaria admissions were school age children.,Malaria related death rate was highest among <5 years at the hyperendemic site, that is 60.9 death per 1000 malaria <5 admissions.,Conversely, the epidemic prone setting experienced highest malaria related death among ≥15 years (18.6 death per 1000 admissions) than the < 15 years (5.7 death per 1000 admissions of the <15 years) (p< 0.001).,Surveillance of severe form of the disease found that hyperpyrexia, hyperparastemia, prostration and convulsions as common presentations of severe disease.,Malaria is still the major cause of hospital consultations in Western Kenya with an alarming number of severe forms of the disease among the school aged children at the epidemic prone setting.,Mortalities were higher among <5 children years in high infection transmission setting and among ≥15 years in low and moderate transmission settings.,Surveillance of asymptomatic and symptomatic malaria along with evaluation of current interventions in different age groups should be implemented in Kenya.

The present study evaluated CareStart pLDH Malaria, a three-band rapid diagnostic test detecting Plasmodium falciparum-specific parasite lactate dehydrogenase (Pf-pLDH) and pan Plasmodium-specific pLDH (pan-pLDH) in a reference setting.,CareStart pLDH was retrospectively and prospectively assessed with a panel of stored (n = 498) and fresh (n = 77) blood samples obtained in international travelers suspected of malaria.,Both panels comprised all four Plasmodium species; the retrospective panel comprised also Plasmodium negative samples.,The reference method was microscopy corrected by PCR.,The prospective panel was run side-to-side with OptiMAL (Pf-pLDH/pan-pLDH) and SDFK60 (histidine-rich protein-2 (HRP-2)/pan-pLDH).,In the retrospective evaluation, overall sensitivity for P. falciparum samples (n = 247) was 94.7%, reaching 98.7% for parasite densities > 1,000/μl.,Most false negative results occurred among samples with pure gametocytaemia (2/12, 16.7%) and at parasite densities ≤ 100/μl (7/12, 58.3%).,None of the Plasmodium negative samples (n = 96) showed visible test lines.,Sensitivities for Plasmodium vivax (n = 70), Plasmodium ovale (n = 69) and Plasmodium malariae (n = 16) were 74.3%, 31.9% and 25.0% respectively.,Wrong species identification occurred in 10 (2.5%) samples and was mainly due to P. vivax samples reacting with the Pf-pLDH test line.,Overall, Pf-pLDH test lines showed higher line intensities compared to the pan-pLDH lines (67.9% and 23.0% medium and strong line intensities for P. falciparum).,In the prospective panel (77 Plasmodium-positive samples), CareStart pLDH showed higher sensitivities for P. falciparum compared to OptiMAL (p = 0.008), lower sensitivities for P. falciparum as compare to SDFK60 (although not reaching statistical significance, p = 0.08) and higher sensitivities for P. ovale compared to both OptiMAL (p = 0.03) and SDFK60 (p = 0.01).,Inter-observer and test reproducibility were good to excellent.,CareStart pLDH performed excellent for the detection of P. falciparum, well for P. vivax, but poor for P. ovale and P. malariae.

This study evaluated parasitological and molecular techniques for the diagnosis and assessment of cure of schistosomiasis mansoni.,A population-based study was performed in 201 inhabitants from a low transmission locality named Pedra Preta, municipality of Montes Claros, state of Minas Gerais, Brazil.,Four stool samples were analysed using two techniques, the Kato-Katz® (KK) technique (18 slides) and the TF-Test®, to establish the infection rate.,The positivity rate of 18 KK slides of four stool samples was 28.9% (58/201) and the combined parasitological techniques (KK+TF-Test®) produced a 35.8% positivity rate (72/201).,Furthermore, a polymerase chain reaction (PCR)-ELISA assay produced a positivity rate of 23.4% (47/201) using the first sample.,All 72 patients with positive parasitological exams were treated with a single dose of Praziquantel® and these patients were followed-up 30, 90 and 180 days after treatment to establish the cure rate.,Cure rates obtained by the analysis of 12 KK slides were 100%, 100% and 98.4% at 30, 90 and 180 days after treatment, respectively.,PCR-ELISA revealed cure rates of 98.5%, 95.5% and 96.5%, respectively.,The diagnostic and assessment of cure for schistosomiasis may require an increased number of KK slides or a test with higher sensitivity, such as PCR-ELISA, in situations of very low parasite load, such as after therapeutic interventions.

Promising results have been reported for a urine circulating cathodic antigen (CCA) test for the diagnosis of Schistosoma mansoni.,We assessed the accuracy of a commercially available CCA cassette test (designated CCA-A) and an experimental formulation (CCA-B) for S. mansoni diagnosis.,We conducted a cross-sectional survey in three settings of Côte d'Ivoire: settings A and B are endemic for S. mansoni, whereas S. haematobium co-exists in setting C.,Overall, 446 children, aged 8-12 years, submitted multiple stool and urine samples.,For S. mansoni diagnosis, stool samples were examined with triplicate Kato-Katz, whereas urine samples were tested with CCA-A.,The first stool and urine samples were additionally subjected to an ether-concentration technique and CCA-B, respectively.,Urine samples were examined for S. haematobium using a filtration method, and for microhematuria using Hemastix dipsticks.,Considering nine Kato-Katz as diagnostic ‘gold’ standard, the prevalence of S. mansoni in setting A, B and C was 32.9%, 53.1% and 91.8%, respectively.,The sensitivity of triplicate Kato-Katz from the first stool and a single CCA-A test was 47.9% and 56.3% (setting A), 73.9% and 69.6% (setting B), and 94.2% and 89.6% (setting C).,The respective sensitivity of a single CCA-B was 10.4%, 29.9% and 75.0%.,The ether-concentration technique showed a low sensitivity for S. mansoni diagnosis (8.3-41.0%).,The specificity of CCA-A was moderate (76.9-84.2%); CCA-B was high (96.7-100%).,The likelihood of a CCA-A color reaction increased with higher S. mansoni fecal egg counts (odds ratio: 1.07, p<0.001).,A concurrent S. haematobium infection or the presence of microhematuria did not influence the CCA-A test results for S. mansoni diagnosis.,CCA-A showed similar sensitivity than triplicate Kato-Katz for S. mansoni diagnosis with no cross-reactivity to S. haematobium and microhematuria.,The low sensitivity of CCA-B in our study area precludes its use for S. mansoni diagnosis.

Understanding and quantifying the sources and implications of error in the measurement of helminth egg intensity using Kato-Katz (KK) and the newly emerging “gold standard” quantitative polymerase chain reaction (qPCR) technique is necessary for the appropriate design of epidemiological studies, including impact assessments for deworming programs.,Repeated measurements of Ascaris lumbricoides infection intensity were made from samples collected in western Kenya using the qPCR and KK techniques.,These data were combined with data on post-treatment worm expulsions.,Random effects regression models were used to quantify the variability associated with different technical and biological factors for qPCR and KK diagnosis.,The relative precision of these methods was compared, as was the precision of multiple qPCR replicates.,For both KK and qPCR, intensity measurements were largely determined by the identity of the stool donor.,Stool donor explained 92.4% of variability in qPCR measurements and 54.5% of observed measurement variance for KK.,An additional 39.1% of variance in KK measurements was attributable to having expelled adult A. lumbricoides worms following anthelmintic treatment.,For qPCR, the remaining 7.6% of variability was explained by the efficiency of the DNA extraction (2.4%), plate-to-plate variability (0.2%) and other residual factors (5%).,Differences in replicate measurements by qPCR were comparatively small.,In addition to KK variability based on stool donor infection levels, the slide reader was highly statistically significant, although it only explained 1.4% of the total variation.,In a comparison of qPCR and KK variance to mean ratios under ideal conditions, the coefficient of variation was on average 3.6 times larger for KK highlighting increased precision of qPCR.,Person-to-person differences explain the majority of variability in egg intensity measurements by qPCR and KK, with very little additional variability explained by the technical factors associated with the practical implementation of these techniques. qPCR provides approximately 3.6 times more precision in estimating A. lumbricoides egg intensity than KK, and could potentially be made more cost-effective by testing each sample only once without diminishing the power of a study to assess population-level intensity and prevalence.,The online version of this article (doi:10.1186/s13071-017-2164-y) contains supplementary material, which is available to authorized users.

There are remarkably few contemporary, population-based studies of intestinal nematode infection for sub-Saharan Africa.,This paper presents a comprehensive epidemiological analysis of hookworm infection intensity in a rural Ugandan community.,Demographic, kinship, socioeconomic and environmental data were collected for 1,803 individuals aged six months to 85 years in 341 households in a cross-sectional community survey.,Hookworm infection was assessed by faecal egg count.,Spatial variation in the intensity of infection was assessed using a Bayesian negative binomial spatial regression model and the proportion of variation explained by host additive genetics (heritability) and common domestic environment was estimated using genetic variance component analysis.,Overall, the prevalence of hookworm was 39.3%, with the majority of infections (87.7%) of light intensity (≤1000 eggs per gram faeces).,Intensity was higher among older individuals and was associated with treatment history with anthelmintics, walking barefoot outside the home, living in a household with a mud floor and education level of the household head.,Infection intensity also exhibited significant household and spatial clustering: the range of spatial correlation was estimated to be 82 m and was reduced by a half over a distance of 19 m.,Heritability of hookworm egg count was 11.2%, whilst the percentage of variance explained by unidentified domestic effects was 17.8%.,In conclusion, we suggest that host genetic relatedness is not a major determinant of infection intensity in this community, with exposure-related factors playing a greater role.

Surgery remains the preferred treatment for hydatid cyst (cystic echinococcosis, CE).,Various scolicidal agents have been used for inactivation of protoscolices during surgery, but most of them are associated with adverse side effects.,The present study aimed to evaluate the in vitro scolicidal effect of Nigella sativa (Ranunculaceae) essential oil and also its active principle, thymoquinone, against protoscolices of hydatid cysts.,Protoscolices were aseptically aspirated from sheep livers having hydatid cysts.,Various concentrations of the essential oil (0.01-10 mg/ml) and thymoquinone (0.125-1.0 mg/ml) were used for 5 to 60 min.,Viability of protoscolices was confirmed by 0.1% eosin staining.,Furthermore, the components of the N. sativa essential oil were identified by gas chromatography/mass spectroscopy (GC/MS).,Our study revealed that the essential oil of N. sativa at the concentration of 10 mg/ml and its main component, thymoquinone, at the concentration of 1 mg/ml had potent scolicidal activities against protoscolices of Echinococcus granulosus after 10 min exposure.,Moreover, thymoquinone (42.4%), p-cymene (14.1%), carvacrol (10.3%), and longifolene (6.1%) were found to be the major components of N. sativa essential oil by GC/MS analysis.,The results of this study indicated the potential of N. sativa as a natural source for production of a new scolicidal agent for use in hydatid cyst surgery.,However, further studies will be needed to confirm these results by checking the essential oil and its active component in in vivo models.

Treatment of hydatid disease is mainly surgical, with medical treatment being reserved as a coadjuvant treatment.,Use of effective scolicidal agents during surgery of cystic echinococcosis is essential to reduce the recurrence rate.,The goal of this study was to evaluate the in vitro scolicidal effects of hydroalcoholic extracts of Satureja khuzestanica leaves and aqueous extracts of Olea europaea leaves on hydatid cyst protoscolices.,Echinococcus granulosus protoscolices were collected from the liver of sheep infected with the hydatid cyst.,Various concentrations of plant extracts were used in different exposure times for viability assay of protoscolices.,Among the olive leaf extracts tested, 0.1% and 0.01% concentrations had strong scolicidal effects in 120 min.,S. khuzestanica 0.1% had very strong scolicidal effects in 30, 60, and 120 min of exposure times and the mortality rate decreased with the lower concentration.,The finding have shown that the scolicidal activity of S. khuzestanica against cystic echinococosis protoscolices were more effective, while the O. europaea extract showed less effects.

The highlands of Ethiopia, situated between 1,500 and 2,500 m above sea level, experienced severe malaria epidemics.,Despite the intensive control attempts, underway since 2005 and followed by an initial decline, the disease remained a major public health concern.,The aim of this study was to identify malaria risk factors in highland-fringe south-central Ethiopia.,This study was conducted in six rural kebeles of Butajira area located 130 km south of Addis Ababa, which are part of demographic surveillance site in Meskan and Mareko Districts, Ethiopia.,Using a multistage sampling technique 750 households was sampled to obtain the 3,398 people, the estimated sample size for this study.,Six repeated cross-sectional surveys were conducted from October 2008 to June 2010.,Multilevel, mixed-effects logistic regression models fitted to Plasmodium infection status (positive or negative) and six variables.,Both fixed- and random-effects differences in malaria infection were estimated using median odds ratio and interval odds ratio 80%.,The odds ratios and 95% confidence intervals were used to estimate the strength of association.,Overall, 19,207 individuals were sampled in six surveys (median and inter-quartile range value three).,Six of the five variables had about two-fold to eight-fold increase in prevalence of malaria.,Furthermore, among these variables, October-November survey seasons of both during 2008 and 2009 were strongly associated with increased prevalence of malaria infection.,Children aged below five years (adjusted OR= 3.62) and children aged five to nine years (adj.,OR= 3.39), low altitude (adj.,OR= 5.22), mid-level altitude (adj.,OR= 3.80), houses with holes (adj.,OR= 1.59), survey seasons such as October-November 2008 (adj.,OR= 7.84), January-February 2009 (adj.,OR= 2.33), June-July 2009 (adj.,OR=3.83), October-November 2009 (adj.,OR= 7.71), and January-February 2010 (adj.,OR= 3.05) were associated with increased malaria infection.,The estimates of cluster variances revealed differences in malaria infection.,The village-level intercept variance for the individual-level predictor (0.71 [95% CI: 0.28-1.82]; SE=0.34) and final (0.034, [95% CI: 0.002-0.615]; SE=0.05) were lower than that of empty (0.80, [95% CI: 0.32-2.01]; SE=0.21).,Malaria control efforts in highland fringes must prioritize children below ten years in designing transmission reduction of malaria elimination strategy.

In 2005, a nationwide survey estimated that 6.5% of households in Ethiopia owned an insecticide-treated net (ITN), 17% of households had been sprayed with insecticide, and 4% of children under five years of age with a fever were taking an anti-malarial drug.,Similar to other sub-Saharan African countries scaling-up malaria interventions, the Government of Ethiopia set an ambitious national goal in 2005 to (i) provide 100% ITN coverage in malarious areas, with a mean of two ITNs per household; (ii) to scale-up indoor residual spraying of households with insecticide (IRS) to cover 30% of households targeted for IRS; and (iii) scale-up the provision of case management with rapid diagnostic tests (RDTs) and artemisinin-based combination therapy (ACT), particularly at the peripheral level.,A nationally representative malaria indicator survey (MIS) was conducted in Ethiopia between September and December 2007 to determine parasite and anaemia prevalence in the population at risk and to assess coverage, use and access to scaled-up malaria prevention and control interventions.,The survey used a two-stage random cluster sample of 7,621 households in 319 census enumeration areas.,A total of 32,380 people participated in the survey.,Data was collected using standardized Roll Back Malaria Monitoring and Evaluation Reference Group MIS household and women's questionnaires, which were adapted to the local context.,Data presented is for households in malarious areas, which according to the Ethiopian Federal Ministry of Health are defined as being located <2,000 m altitude.,Of 5,083 surveyed households, 3,282 (65.6%) owned at least one ITN.,In ITN-owning households, 53.2% of all persons had slept under an ITN the prior night, including 1,564/2,496 (60.1%) children <5 years of age, 1,891/3,009 (60.9%) of women 15 - 49 years of age, and 166/266 (65.7%) of pregnant women.,Overall, 906 (20.0%) households reported to have had IRS in the past 12 months.,Of 747 children with reported fever in the two weeks preceding the survey, 131 (16.3%) sought medical attention within 24 hours.,Of those with fever, 86 (11.9%) took an anti-malarial drug and 41 (4.7%) took it within 24 hours of fever onset.,Among 7,167 surveyed individuals of all ages, parasitaemia as estimated by microscopy was 1.0% (95% CI 0.5 - 1.5), with 0.7% and 0.3% due to Plasmodium falciparum and Plasmodium vivax, respectively.,Moderate-severe anaemia (haemoglobin <8 g/dl) was observed in 239/3,366 (6.6%, 95% CI 4.9-8.3) children <5 years of age.,Since mid-2005, the Ethiopian National Malaria Control Programme has considerably scaled-up its malaria prevention and control interventions, demonstrating the impact of strong political will and a committed partnership.,The MIS showed, however, that besides sustaining and expanding malaria intervention coverage, efforts will have to be made to increase intervention access and use.,With ongoing efforts to sustain and expand malaria intervention coverage, to increase intervention access and use, and with strong involvement of the community, Ethiopia expects to achieve its targets in terms of coverage and uptake of interventions in the coming years and move towards eliminating malaria.

Pfs48/45 is a leading antigen candidate for a transmission blocking (TB) vaccine.,However, efforts to produce affordable, safe and correctly folded full-length Pfs48/45 using different protein expression systems have not produced an antigen with satisfactory TB activity.,Pfs48/45 has 16 cysteines involved in disulfide bond formation, and the correct formation is critical for proper folding and induction of TB antibodies.,Moreover, Pfs48⁄45 is not a glycoprotein in the native hosts, but contains potential glycosylation sites, which are aberrantly glycosylated during expression in eukaryotic systems.,Here, we demonstrate for the first time that full length, Endo H in vivo enzymatic deglycosylated Pfs48/45 antigen is produced at a high level in plants and is structurally stable at elevated temperatures.,Sera from mice immunized with this antigen showed strong inhibition in SMFA.,Thus, Endo H in vivo enzymatic deglycosylated Pfs48/45 is a promising candidate for the development of an affordable TB vaccine, which may have the potential to save millions.

The putative Plasmodium Translocon of Exported Proteins (PTEX) is essential for transport of malarial effector proteins across a parasite-encasing vacuolar membrane into host erythrocytes, but the mechanism of this process remains unknown.,Here we show PTEX is a bona fide translocon by determining near-atomic resolution cryoEM structures of the endogenous PTEX core complex of EXP2, PTEX150 and HSP101, isolated from Plasmodium falciparum in the engaged and resetting states of endogenous cargo translocation with CRISPR/Cas9-engineered epitope tags.,EXP2 and PTEX150 interdigitate to form a static, funnel-shaped pseudo-sevenfold symmetric protein-conducting channel spanning the vacuolar membrane.,Tethered above this funnel, the spiral-shaped AAA+ HSP101 hexamer undergoes a dramatic compaction that allows three of six tyrosine-bearing pore loops lining the HSP101 channel to dissociate from the cargo, resetting the translocon for the next threading cycle.,Our work reveals the mechanism of P. falciparum effector export, enabling structure-based design of drugs targeting this unique translocon.

Resistance in Plasmodium falciparum to commonly used anti-malarial drugs, especially chloroquine, is being increasingly documented in India.,By 2007, the first-line treatment for uncomplicated malaria has been revised to recommend artemisinin-based combination therapy (ACT) for all confirmed P. falciparum cases.,The objective of this study was to compare the efficacy, safety and tolerability between dihydroartemisinin-piperaquine (DP) and artesunate plus mefloquine (A + M) drug combinations in the treatment of uncomplicated P. falciparum malaria in India.,Between 2006 and 2007, 150 patients with acute uncomplicated P. falciparum malaria were enrolled, randomized to DP (101) or A + M (49) and followed up for 63 days as part of an open-label, non-inferiority, randomized, phase III multicenter trial in Asia.,The heterogeneity analysis showed no statistically significant difference between India and the other countries involved in the phase III study, for both the PCR-corrected and uncorrected cure rates.,As shown at the whole study level, both forms of ACT were highly efficacious in India.,In fact, in the per protocol population, the 63-day cure rates were 100% for A + M and 98.8% for DP.,The DP combination exerted a significant post-treatment prophylactic effect, and compared with A + M a significant reduction in the incidence of new infections for DP was observed (respectively 17.1% versus 7.5% of patients experienced new infection within follow up).,Parasite and fever clearance was rapid in both treatment arms (median time to parasite clearance of one day for both groups).,Both DP and A + M were well tolerated, with the majority of adverse events of mild or moderate severity.,The frequencies of individual adverse events were generally similar between treatments, although the incidence of post treatment adverse events was slightly higher in patients who received A + M with respect to those treated with DP.,DP is a new ACT displaying high efficacy and safety in the treatment of uncomplicated P. falciparum malaria and could potentially be considered for the first-line treatment of uncomplicated falciparum malaria in India.,Current Controlled Trials ISRCTN 81306618

The artemisinin-based combination treatment (ACT) of dihydroartemisinin (DHA) and piperaquine (PQP) is a promising novel anti-malarial drug effective against multi-drug resistant falciparum malaria.,The aim of this study was to show non-inferiority of DHA/PQP vs. artesunate-mefloquine (AS+MQ) in Asia.,This was an open-label, randomised, non-inferiority, 63-day follow-up study conducted in Thailand, Laos and India.,Patients aged 3 months to 65 years with Plasmodium falciparum mono-infection or mixed infection were randomised with an allocation ratio of 2∶1 to a fixed-dose DHA/PQP combination tablet (adults: 40 mg/160 mg; children: 20 mg/320 mg; n = 769) or loose combination of AS+MQ (AS: 50 mg, MQ: 250 mg; n = 381).,The cumulative doses of study treatment over the 3 days were of about 6.75 mg/kg of DHA and 54 mg/kg of PQP and about 12 mg/kg of AS and 25 mg/kg of MQ.,Doses were rounded up to the nearest half tablet.,The primary endpoint was day-63 polymerase chain reaction (PCR) genotype-corrected cure rate.,Results were 87.9% for DHA/PQP and 86.6% for AS+MQ in the intention-to-treat (ITT; 97.5% one-sided confidence interval, CI: >−2.87%), and 98.7% and 97.0%, respectively, in the per protocol population (97.5% CI: >−0.39%).,No country effect was observed.,Kaplan-Meier estimates of proportions of patients with new infections on day 63 (secondary endpoint) were significantly lower for DHA/PQP than AS+MQ: 22.7% versus 30.3% (p = 0.0042; ITT).,Overall gametocyte prevalence (days 7 to 63; secondary endpoint), measured as person-gametocyte-weeks, was significantly higher for DHA/PQP than AS+MQ (10.15% versus 4.88%; p = 0.003; ITT).,Fifteen serious adverse events were reported, 12 (1.6%) in DHA/PQP and three (0.8%) in AS+MQ, among which six (0.8%) were considered related to DHA/PQP and three (0.8%) to AS+MQ.,DHA/PQP was a highly efficacious drug for P. falciparum malaria in areas where multidrug parasites are prevalent.,The DHA/PQP combination can play an important role in the first-line treatment of uncomplicated falciparum malaria.,Controlled-Trials.com ISRCTN81306618

Individuals growing up in malaria endemic areas gradually develop protection against clinical malaria and passive transfer experiments in humans have demonstrated that this protection is mediated in part by protective antibodies.,However, neither the target antigens, specific effector mechanisms, nor the role of continual parasite exposure have been elucidated, which complicates vaccine development.,Progress has been made in defining the innate signaling pathways activated by parasite components, including DNA, RNA, hemozoin, and phospholipids, which initiate the immune response and will be the focus of this review.,The challenge that remains within the field is to understand the role of these early responses in the development of protective adaptive responses that clear iRBC and block merozoite invasion so that optimal vaccines and therapeutics may be produced.

Malaria elimination strategies require a thorough understanding of parasite transmission from human to mosquito.,A clinical model to induce gametocytes to understand their dynamics and evaluate transmission-blocking interventions (TBI) is currently unavailable.,Here, we explore the use of the well-established Controlled Human Malaria Infection model (CHMI) to induce gametocyte carriage with different antimalarial drug regimens.,In a single centre, open-label randomised trial, healthy malaria-naive participants (aged 18-35 years) were infected with Plasmodium falciparum by bites of infected Anopheles mosquitoes.,Participants were randomly allocated to four different treatment arms (n = 4 per arm) comprising low-dose (LD) piperaquine (PIP) or sulfadoxine-pyrimethamine (SP), followed by a curative regimen upon recrudescence.,Male and female gametocyte densities were determined by molecular assays.,Mature gametocytes were observed in all participants (16/16, 100%).,Gametocytes appeared 8.5-12 days after the first detection of asexual parasites.,Peak gametocyte densities and gametocyte burden was highest in the LD-PIP/SP arm, and associated with the preceding asexual parasite biomass (p=0.026).,Male gametocytes had a mean estimated circulation time of 2.7 days (95% CI 1.5-3.9) compared to 5.1 days (95% CI 4.1-6.1) for female gametocytes.,Exploratory mosquito feeding assays showed successful sporadic mosquito infections.,There were no serious adverse events or significant differences in the occurrence and severity of adverse events between study arms (p=0.49 and p=0.28).,The early appearance of gametocytes indicates gametocyte commitment during the first wave of asexual parasites emerging from the liver.,Treatment by LD-PIP followed by a curative SP regimen, results in the highest gametocyte densities and the largest number of gametocyte-positive days.,This model can be used to evaluate the effect of drugs and vaccines on gametocyte dynamics, and lays the foundation for fulfilling the critical unmet need to evaluate transmission-blocking interventions against falciparum malaria for downstream selection and clinical development.,Funded by PATH Malaria Vaccine Initiative (MVI).,NCT02836002.,The parasite that causes malaria, named Plasmodium falciparum, has a life cycle that involves both humans and mosquitoes.,Starting in the saliva of female Anopheles mosquitoes, it enters a person’s bloodstream when the insects feed.,It then moves to the person’s liver, where it infects liver cells and matures into a stage known as schizonts.,The schizonts then divide to form thousands of so-called merozoites, which burst out of the liver cells and into the bloodstream.,The merozoites infect red blood cells, producing more schizonts and yet more merozoites, which continue the infection.,To complete its life cycle, the parasite must return to a mosquito.,Some of the parasites in the person’s blood transform into male and female cells called gametocytes that are taken up by a mosquito when it feeds on that person.,Inside the mosquito, male and female parasites reproduce to create the next generation of parasites.,The new parasites then move to the mosquito’s salivary glands, ready to begin another infection.,Stopping the parasite being transmitted from humans to mosquitoes will stop the spread of malaria in the population.,Yet it has proven difficult to study this part of the life cycle from natural infections.,Here, Reuling et al. report a new method for generating gametocytes in human volunteers that will enable closer study of the biology of malaria transmission.,The method is developed using the Controlled Human Malaria Infection (CHMI) model.,Healthy volunteers without a history of malaria are bitten by mosquitoes infected with malaria parasites.,Shortly afterwards, the volunteers are given a drug treatment to control and reduce their symptoms.,The gametocytes form during this phase of the infection.,At the end of the experiment, all the volunteers receive a final treatment that completely cures the infection.,Reuling et al. recruited 16 volunteers and assigned them to four groups at random.,Each group received a different drug regime.,Roughly a week after the mosquito bites, all participants showed malaria parasites in their blood, and between 8.5 and 12 days later, mature gametocytes started to appear.,This early appearance suggests that the parasites start to transform into gametocytes when they first emerge from the liver.,The experiment also revealed that female gametocytes stay in the blood for a longer period than their male counterparts.,These results are proof of principle for a new way to investigate malaria infection.,The new model provides a controlled method for studying P. falciparum gametocytes in people.,In the future, it could help to test the impact of drugs and vaccines on gametocytes.,Understanding more about these parasites’ biology could lead to treatments that block malaria transmission.

Chagas’ heart disease is an important public health problem in South America.,Several aspects of the pathogenesis are not fully understood, especially in its subclinical phases.,On pathology Chagas’ heart disease is characterized by chronic myocardial inflammation and extensive myocardial fibrosis.,The latter has also been demonstrated by late gadolinium enhancement (LGE) by cardiovascular magnetic resonance (CMR).,In three clinical phases of this disease, we sought to investigate the presence of LGE, myocardial increase in signal intensity in T2-weighted images (T2W) and in T1-weighted myocardial early gadolinium enhancement (MEGE), previously described CMR surrogates for myocardial fibrosis, myocardial edema and hyperemia, respectively.,Fifty-four patients were analyzed.,Sixteen patients with the indeterminate phase (IND), seventeen patients with the cardiac phase with no left ventricular systolic dysfunction (CPND), and twenty-one patients with the cardiac phase with left ventricular systolic dysfunction (CPD).,All patients underwent 1.5 T CMR scan including LGE, T2W and MEGE image sequences to evaluate myocardial abnormalities.,Late gadolinium enhancement was present in 72.2 % of all patients, in 12.5 % of IND, 94.1 % of the CPND and 100 % of the CPD patients (p < 0.0001).,Myocardial increase in signal intensity in T2-weighted images (T2W) was present in 77.8 % of all patients, in 31.3 % of the IND, 94.1 % of the CPND and 100 % of the CPD patients (p < 0.0001).,T1-weighted myocardial early gadolinium enhancement (MEGE) was present in 73.8 % of all patients, in 25.0 % of the IND, 92.3 % of the CPND and 94.1 % of the CPD (p < 0.0001).,A good correlation between LGE and T2W was observed (r = 0.72, and p < 0.001).,Increase in T2-weighted (T2W) myocardial signal intensity and T1-weighted myocardial early gadolinium enhancement (MEGE) can be detected by CMR in patients throughout all phases of Chagas’ heart disease, including its subclinical presentation (IND).,Moreover, those findings were parallel to myocardial fibrosis (LGE) in extent and location and also correlated with the degree of Chagas’ heart disease clinical severity.,These findings contribute to further the knowledge on pathophysiology of Chagas’ heart disease, and might have therapeutic and prognostic usefulness in the future.

Twenty to thirty percent of persons with Trypanosoma cruzi infection eventually develop cardiomyopathy.,If an early indicator were to be identified and validated in longitudinal studies, this could enable treatment to be prioritized for those at highest risk.,We evaluated cardiac and extracellular matrix remodeling markers across cardiac stages in T. cruzi infected (Tc+) and uninfected (Tc−) individuals.,Participants were recruited in a public hospital in Santa Cruz, Bolivia and assigned cardiac severity stages by electrocardiogram and echocardiogram.,BNP, NTproBNP, CKMB, troponin I, MMP-2, MMP-9, TIMP-1, TIMP-2, TGFb1, and TGFb2 were measured in specimens from 265 individuals using multiplex bead systems.,Biomarker levels were compared between Tc+ and Tc− groups, and across cardiac stages.,Receivers operating characteristic (ROC) curves were created; for markers with area under curve>0.60, logistic regression was performed.,Analyses stratified by cardiac stage showed no significant differences in biomarker levels by Tc infection status.,Among Tc+ individuals, those with cardiac insufficiency had higher levels of BNP, NTproBNP, troponin I, MMP-2, TIMP-1, and TIMP-2 than those with normal ejection fraction and left ventricular diameter.,No individual marker distinguished between the two earliest Tc+ stages, but in ROC-based analyses, MMP-2/MMP-9 ratio was significantly higher in those with than those without ECG abnormalities.,BNP, NTproBNP, troponin I, MMP-2, TIMP-1, and TIMP-2 levels rose with increasing severity stage but did not distinguish between Chagas cardiomyopathy and other cardiomyopathies.,Among Tc+ individuals without cardiac insufficiency, only the MMP-2/MMP-9 ratio differed between those with and without ECG changes.

Effective progression of candidate antimalarials is dependent on optimal dosing in clinical studies, which is determined by a sound understanding of pharmacokinetics and pharmacodynamics (PK/PD).,Recently, two important translational models for antimalarials have been developed: the NOD/SCID/IL2Rγ−/− (NSG) model, whereby mice are engrafted with noninfected and Plasmodium falciparum-infected human erythrocytes, and the induced blood-stage malaria (IBSM) model in human volunteers.,The antimalarial mefloquine was used to directly measure the PK/PD in both models, which were compared to previously published trial data for malaria patients.,The clinical part was a single-center, controlled study using a blood-stage Plasmodium falciparum challenge inoculum in volunteers to characterize the effectiveness of mefloquine against early malaria.,The study was conducted in three cohorts (n = 8 each) using different doses of mefloquine.,The characteristic delay in onset of action of about 24 h was seen in both NSG and IBSM systems.,In vivo 50% inhibitory concentrations (IC50s) were estimated at 2.0 μg/ml and 1.8 μg/ml in the NSG and IBSM models, respectively, aligning with 1.8 μg/ml reported previously for patients.,In the IBSM model, the parasite reduction ratios were 157 and 195 for the 10- and 15-mg/kg doses, within the range of previously reported clinical data for patients but significantly lower than observed in the mouse model.,Linking mouse and human challenge models to clinical trial data can accelerate the accrual of critical data on antimalarial drug activity.,Such data can guide large clinical trials required for development of urgently needed novel antimalarial combinations.,(This trial was registered at the Australian New Zealand Clinical Trials Registry [http://anzctr.org.au] under registration number ACTRN12612000323820.)

Sparse data on the safety of pyronaridine-artesunate after repeated treatment of malaria episodes restrict its clinical use.,We therefore compared the safety of pyronaridine-artesunate after treatment of the first episode of malaria versus re-treatment in a substudy analysis.,This planned substudy analysis of the randomised, open-label West African Network for Clinical Trials of Antimalarial Drugs (WANECAM) phase 3b/4 trial was done at six health facilities in Mali, Burkina Faso, and Guinea in patients (aged ≥6 months and bodyweight ≥5 kg) with uncomplicated microscopically confirmed Plasmodium spp malaria (parasite density <200 000 per μL blood) and fever or history of fever.,The primary safety endpoint was incidence of hepatotoxicity: alanine aminotransferase of greater than five times the upper limit of normal (ULN) or Hy's criteria (alanine aminotransferase or aspartate aminotransferase greater than three times the ULN and total bilirubin more than twice the ULN) after treatment of the first episode of malaria and re-treatment (≥28 days after first treatment) with pyronaridine-artesunate.,Pyronaridine-artesunate efficacy was compared with artemether-lumefantrine with the adequate clinical and parasitological response (ACPR) in an intention-to-treat analysis.,WANECAM is registered with PACTR.org, number PACTR201105000286876.,Following first treatment, 13 (1%) of 996 patients had hepatotoxicity (including one [<1%] possible Hy's law case) versus two (1%) of 311 patients on re-treatment (neither a Hy's law case).,No evidence was found that pyronaridine-artesunate re-treatment increased safety risk based on laboratory values, reported adverse event frequencies, or electrocardiograph findings.,For all first treatment or re-treatment episodes, pyronaridine-artesunate (n=673) day 28 crude ACPR was 92·7% (95% CI 91·0-94·3) versus 80·4% (77·8-83·0) for artemether-lumefantrine (n=671).,After exclusion of patients with PCR-confirmed new infections, ACPR was similar on treatment and re-treatment and greater than 95% at day 28 and greater than 91% at day 42 in both treatment groups.,The findings that pyronaridine-artesunate safety and efficacy were similar on first malaria treatment versus re-treatment of subsequent episodes lend support for the wider access to pyronaridine-artesunate as an alternative artemisinin-based combination treatment for malaria in sub-Saharan Africa.,European and Developing Countries Clinical Trial Partnership, Medicines for Malaria Venture (Geneva, Switzerland), UK Medical Research Council, Swedish International Development Cooperation Agency, German Ministry for Education and Research, University Claude Bernard (Lyon, France), Malaria Research and Training Centre (Bamako, Mali), Centre National de Recherche et de Formation sur le Paludisme (Burkina Faso), Institut de Recherche en Sciences de la Santé (Bobo-Dioulasso, Burkina Faso), and Centre National de Formation et de Recherche en Santé Rurale (Republic of Guinea).

Prevalence of and risk factors associated with polymerase chain reaction (PCR)-determined Plasmodium falciparum positivity were assessed on day 3 after initiation of treatment, pre-implementation and up to 8 years post-deployment of artemether-lumefantrine as first-line treatment for uncomplicated malaria in Bagamoyo district, Tanzania.,Samples originated from previously reported trials conducted between 2006 and 2014.,Cytochrome b-nested PCR was used to detect malaria parasites from blood samples collected on a filter paper on day 3.,Chi-square and McNemar chi-squared tests, logistic regression models, and analysis of variance were used as appropriate.,Primary outcome was based on the proportion of patients with day 3 PCR-determined P. falciparum positivity.,Overall, 256/584 (43.8%) of screened patients had day 3 PCR-determined positivity, whereas only 2/584 (0.3%) had microscopy-determined asexual parasitemia.,Day 3 PCR-determined positivity increased from 28.0% (14/50) in 2006 to 74.2% (132/178) in 2007-2008 and declined, thereafter, to 36.0% (50/139) in 2012-2013 and 27.6% (60/217) in 2014.,When data were pooled, pretreatment microscopy-determined asexual parasitemia ≥ 100,000/µL, hemoglobin < 10 g/dL, age < 5 years, temperature ≥ 37.5°C, and year of study 2007-2008 and 2012-2013 were significantly associated with PCR-determined positivity on day 3.,Significant increases in P. falciparum multidrug resistance gene 1 N86 and P. falciparum chloroquine resistant transporter K76 across years were not associated with PCR-determined positivity on day 3.,No statistically significant association was observed between day 3 PCR-determined positivity and PCR-adjusted recrudescence.,Day 3 PCR-determined P. falciparum positivity remained common in patients treated before and after implementation of artemether-lumefantrine in Bagamoyo district, Tanzania.,However, its presence was associated with pretreatment characteristics.,Trials registration numbers: NCT00336375, ISRCTN69189899, NCT01998295, and NCT02090036.

The efficacy of artemisinin-based combination therapy (ACT) for Plasmodium falciparum malaria may be threatened by parasites with reduced responsiveness to artemisinins.,Among 298 ACT-treated children from Mbita, Kenya, submicroscopic persistence of P. falciparum on day 3 posttreatment was associated with subsequent microscopically detected parasitemia at days 28 or 42.,DNA sequences of resistance-associated parasite loci pfcrt, pfmdr1, pfubp1, and pfap2mu were determined in the Mbita cohort before treatment, on days 2 and 3 after initiation of treatment, and on the day of treatment failure.,Parasites surviving ACT on day 2 or day 3 posttreatment were significantly more likely than the baseline population to carry the wild-type haplotypes of pfcrt (CVMNK at codons 72-76; P < .001) and pfmdr1 (NFD at codons 86, 184, 1246; P < .001).,In contrast, variant alleles of the novel candidate resistance genes pfap2mu (S160N/T; P = .006) and pfubp-1 (E1528D; P < .001) were significantly more prevalent posttreatment.,No genetic similarities were found to artemisinin-tolerant parasites recently described in Cambodia.,Among treated children in western Kenya, certain P. falciparum genotypes defined at pfcrt, pfmdr1, pfap2mu, and pfubp1 more often survive ACT at the submicroscopic level, and contribute to onward transmission and subsequent patent recrudescence.

More than half of malaria cases in Zimbabwe are concentrated in Manicaland Province, where seasonal malaria epidemics occur despite intensified control strategies.,Recently, high levels of pyrethroid and carbamate resistance were detected in Anopheles funestus, the major malaria vector in eastern Zimbabwe.,In response, a single round of indoor residual spraying (IRS) using pirimiphos-methyl (an organophosphate) was implemented in four high burden districts of Manicaland Province from November 1, 2014 to December 19, 2014.,The objective of this study was to evaluate the effect of this programmatic switch in insecticides on malaria morbidity reported from health care facilities in Mutasa District, one of the worst affected districts in Manicaland Province.,The number of weekly malaria cases for each health facility 24 months prior to the 2014 IRS campaign and in the subsequent high transmission season were obtained from passive case surveillance.,Environmental variables were extracted from remote-sensing data sources and linked to each health care facility.,Negative binomial regression was used to model the weekly number of malaria cases, adjusted for seasonality and environmental variables.,From December 2012 to May 2015, 124,206 malaria cases were reported from 42 health care facilities in Mutasa District.,Based on a higher burden of malaria, 20 out of 31 municipal wards were sprayed in the district.,Overall, 87.3% of target structures were sprayed and 92.1% of the target population protected.,During the 6 months after the 2014 IRS campaign, a period when transmission would have otherwise peaked, the incidence of malaria was 38% lower than the preceding 24 months at health facilities in the sprayed wards.,Pirimiphos-methyl had a measurable impact on malaria incidence and is an effective insecticide for the control of An. funestus in eastern Zimbabwe.

Anopheles gambiae, the main malaria vector in Benin has developed high level of resistance to pyrethroid insecticides, which is a serious concern to the future use of long-lasting insecticidal nets (LLIN) and indoor residual spraying (IRS).,In this context, one of the pathways available for malaria vector control would be to investigate alternative classes of insecticides with different mode of action than that of pyrethroids.,The goal of this study was to evaluate under field conditions the efficacy of a carbamate (bendiocarb) and an organophosphate (fenitrothion) against pyrethroid-resistant An. gambiae s.s.,Wild populations and females from laboratory colonies of five days old An. gambiae were bio-assayed during this study.,Two pyrethroids (deltamethrin and alphacypermethrin), an organophosphate (fenitrothion), a carbamate (bendiocarb) and a mixture of an organophosphate (chlorpyriphos + a pyrethroid deltamethrin) were compared in experimental huts as IRS treatments.,Insecticides were applied in the huts using a hand-operated compression sprayer.,The deterrency, exophily, blood feeding rate and mortality induced by these insecticides against An. gambiae were compared to the untreated control huts.,Deltamethrin, alphacypermethrin and bendiocarb treatment significantly reduced mosquito entry into the huts (p < 0.05) compared to untreated huts.,Blood feeding rates in huts treated with fenitrothion and the mixture chlorpyriphos/deltamethrin were reduced from 10.95% respectively to 3.7% and 4.47% three months after treatment and from 10.20% to 4.4% and 2.04% four months after treatment.,Exophily rates in huts with deltamethrin, alphacypermethrin and the mixture chlorpyriphos/deltamethrin were significantly higher than in the huts with fenitrothion.,Deltamethrin and alphacypermethrin had the lowest mortality rate while fenitrothion killed 100% of An. gambiae (in the first month) and 77.8% (in the fourth month).,Bendiocarb and the mixture chlorpyriphos/deltamethrin mortality rates ranged from 97.9 to 100% the first month and 77.7-88% the third month respectively.,After four months, fenitrothion, bendiocarb and the mixture chlorpyriphos/deltamethrin performed effectively against pyrethroid-resistant Anopheles.,These results showed that bendiocarb could be recommended as an effective insecticide for use in IRS operations in Benin, particularly as the mixture chlorpyriphos/deltamethrin does not have WHOPES authorization and complaints were mentioned by the sleepers about the safety and smell of fenitrothion.

Policy makers, governments and donors are faced with an information gap when considering ways to improve access to artemisinin-based combination therapy (ACT) and malaria diagnostics including rapid diagnostic tests (RDTs).,To help address some of these gaps, a five-year multi-country research project called ACTwatch was launched.,The project is designed to provide a comprehensive picture of the anti-malarial market to inform national and international anti-malarial drug policy decision-making.,The project is being conducted in seven malaria-endemic countries: Benin, Cambodia, the Democratic Republic of Congo, Madagascar, Nigeria, Uganda and Zambia from 2008 to 2012.,ACTwatch measures which anti-malarials are available, where they are available and at what price and who they are used by.,These indicators are measured over time and across countries through three study components: outlet surveys, supply chain studies and household surveys.,Nationally representative outlet surveys examine the market share of different anti-malarials passing through public facilities and private retail outlets.,Supply chain research provides a picture of the supply chain serving drug outlets, and measures mark-ups at each supply chain level.,On the demand side, nationally representative household surveys capture treatment seeking patterns and use of anti-malarial drugs, as well as respondent knowledge of anti-malarials.,The research project provides findings on both the demand and supply side determinants of anti-malarial access.,There are four key features of ACTwatch.,First is the overlap of the three study components where nationally representative data are collected over similar periods, using a common sampling approach.,A second feature is the number and diversity of countries that are studied which allows for cross-country comparisons.,Another distinguishing feature is its ability to measure trends over time.,Finally, the project aims to disseminate findings widely for decision-making.,ACTwatch is a unique multi-country research project that threads together anti-malarial supply and consumer behaviour to provide an evidence base to policy makers that can help determine where interventions may positively impact access to and use of quality-assured ACT and RDTs.,Because of its ability to detect change over time, it is well suited to monitor the effects of policy or intervention developments in a country.

Malaria continues to be a major public health problem in remote forested areas in Cambodia.,As a national strategy to strengthen community-based malaria control, the Cambodian government has been running the Village Malaria Worker (VMW) project since 2001.,This study sought to examine the nature and quality of the VMWs' services.,Data collection was carried out in February and March 2008 through interviews with one of the two VMWs who takes the lead in malaria control activities in each of the 315 VMW villages (n = 251).,The questionnaire addressed 1) the sociodemographic characteristics of VMWs, 2) service quality, 3) actions for malaria prevention and vector control, and 4) knowledge of malaria epidemiology and vector ecology.,VMWs were effective in conducting diagnosis with Rapid Diagnostic Tests (RDTs) and prescribing anti-malarials to those who had positive RDT results, skills that they had acquired through their training programmes.,However, most other services, such as active detection, explanations about compliance, and follow-up of patients, were carried out by only a small proportion of VMWs.,The variety of actions that VMWs took for malaria prevention and vector control was small (average action index score 12.8/23), and their knowledge was very limited with less than 20% of the VMWs giving correct answers to six out of seven questions on malaria epidemiology and vector ecology.,Knowledge of vector breeding places and malaria transmission were significant determinants of both the quality of VMWs' services and the variety of their actions for malaria prevention and vector control.,VMWs' services focused primarily on diagnosis and treatment.,Their focus needs to be broadened to cover other aspects of malaria control in order to further strengthen community-based malaria control.,VMWs' actions and knowledge also need substantial improvement.,Strengthening training programmes can help achieve better performance by VMWs.

A significant reduction in parasite clearance rates following artesunate treatment of falciparum malaria, and increased failure rates following artemisinin combination treatments (ACT), signaled emergent artemisinin resistance in Western Cambodia.,Accurate measurement of parasite clearance is therefore essential to assess the spread of artemisinin resistance in Plasmodium falciparum.,The slope of the log-parasitaemia versus time relationship is considered to be the most robust measure of anti-malarial effect.,However, an initial lag phase of numerical instability often precedes a steady exponential decline in the parasite count after the start of anti-malarial treatment.,This lag complicates the clearance estimation, introduces observer subjectivity, and may influence the accuracy and consistency of reported results.,To address this problem, a new approach to modelling clearance of malaria parasites from parasitaemia-time profiles has been explored and validated.,The methodology detects when a lag phase is present, selects the most appropriate model (linear, quadratic or cubic) to fit log-transformed parasite data, and calculates estimates of parasite clearance adjusted for this lag phase.,Departing from previous approaches, parasite counts below the level of detection are accounted for and not excluded from the calculation.,Data from large clinical studies with frequent parasite counts were examined.,The effect of a lag phase on parasite clearance rate estimates is discussed, using individual patient data examples.,As part of the World Wide Antimalarial Resistance Network's (WWARN) efforts to make innovative approaches available to the malaria community, an automated informatics tool: the parasite clearance estimator has been developed.,The parasite clearance estimator provides a consistent, reliable and accurate method to estimate the lag phase and malaria parasite clearance rate.,It could be used to detect early signs of emerging resistance to artemisinin derivatives and other compounds which affect ring-stage clearance.

Although malaria in pregnancy can cause very significant neonatal morbidity, congenital malaria is a very rare condition in both endemic and non-endemic areas.,A case of congenital malaria by Plasmodium vivax, initially mistaken for neonatal sepsis, is described.,The correct diagnosis was accidentally done, as congenital malaria had been missed in the initial differential diagnosis.,Vivax malaria is the leading species in congenital infections in Europe.,This condition should be included in the differential diagnosis of neonatal sepsis even if the mother has no proven malarial episodes during the gestational period.

Although chronic morbidity in humans from soil transmitted helminth (STH) infections can be reduced by anthelmintic treatment, inconsistent diagnostic tools make it difficult to reliably measure the impact of deworming programs and often miss light helminth infections.,Cryopreserved stool samples from 796 people (aged 2-81 years) in four villages in Bungoma County, western Kenya, were assessed using multi-parallel qPCR for 8 parasites and compared to point-of-contact assessments of the same stools by the 2-stool 2-slide Kato-Katz (KK) method.,All subjects were treated with albendazole and all Ascaris lumbricoides expelled post-treatment were collected.,Three months later, samples from 633 of these people were re-assessed by both qPCR and KK, re-treated with albendazole and the expelled worms collected.,Baseline prevalence by qPCR (n = 796) was 17 % for A. lumbricoides, 18 % for Necator americanus, 41 % for Giardia lamblia and 15 % for Entamoeba histolytica.,The prevalence was <1 % for Trichuris trichiura, Ancylostoma duodenale, Strongyloides stercoralis and Cryptosporidium parvum.,The sensitivity of qPCR was 98 % for A. lumbricoides and N. americanus, whereas KK sensitivity was 70 % and 32 %, respectively.,Furthermore, qPCR detected infections with T. trichiura and S. stercoralis that were missed by KK, and infections with G. lamblia and E. histolytica that cannot be detected by KK.,Infection intensities measured by qPCR and by KK were correlated for A. lumbricoides (r = 0.83, p < 0.0001) and N. americanus (r = 0.55, p < 0.0001).,The number of A. lumbricoides worms expelled was correlated (p < 0.0001) with both the KK (r = 0.63) and qPCR intensity measurements (r = 0.60).,KK may be an inadequate tool for stool-based surveillance in areas where hookworm or Strongyloides are common or where intensity of helminth infection is low after repeated rounds of chemotherapy.,Because deworming programs need to distinguish between populations where parasitic infection is controlled and those where further treatment is required, multi-parallel qPCR (or similar high throughput molecular diagnostics) may provide new and important diagnostic information.

The Kato-Katz thick smear (Kato-Katz) is the diagnostic method recommended for monitoring large-scale treatment programs implemented for the control of soil-transmitted helminths (STH) in public health, yet it is difficult to standardize.,A promising alternative is the McMaster egg counting method (McMaster), commonly used in veterinary parasitology, but rarely so for the detection of STH in human stool.,The Kato-Katz and McMaster methods were compared for the detection of STH in 1,543 subjects resident in five countries across Africa, Asia and South America.,The consistency of the performance of both methods in different trials, the validity of the fixed multiplication factor employed in the Kato-Katz method and the accuracy of these methods for estimating ‘true’ drug efficacies were assessed.,The Kato-Katz method detected significantly more Ascaris lumbricoides infections (88.1% vs.,75.6%, p<0.001), whereas the difference in sensitivity between the two methods was non-significant for hookworm (78.3% vs.,72.4%) and Trichuris trichiura (82.6% vs.,80.3%).,The sensitivity of the methods varied significantly across trials and magnitude of fecal egg counts (FEC).,Quantitative comparison revealed a significant correlation (Rs >0.32) in FEC between both methods, and indicated no significant difference in FEC, except for A. lumbricoides, where the Kato-Katz resulted in significantly higher FEC (14,197 eggs per gram of stool (EPG) vs.,5,982 EPG).,For the Kato-Katz, the fixed multiplication factor resulted in significantly higher FEC than the multiplication factor adjusted for mass of feces examined for A. lumbricoides (16,538 EPG vs.,15,396 EPG) and T. trichiura (1,490 EPG vs.,1,363 EPG), but not for hookworm.,The McMaster provided more accurate efficacy results (absolute difference to ‘true’ drug efficacy: 1.7% vs.,4.5%).,The McMaster is an alternative method for monitoring large-scale treatment programs.,It is a robust (accurate multiplication factor) and accurate (reliable efficacy results) method, which can be easily standardized.

Schistosomiasis remains an endemic parasitic disease affecting millions of people around the world.,The World Health Organization (WHO) has set goals of controlling morbidity to be reached by 2020, along with elimination as a public health problem in certain regions by 2025.,Mathematical models of parasite transmission and treatment impact have been developed to assist in controlling the morbidity caused by schistosomiasis.,These models can inform and guide implementation policy for mass drug administration programs, and help design monitoring and evaluation activities.,We use these models to predict whether the guidelines set by the WHO are on track for achieving their 2020 goal for the control of morbidity, specifically for Schistosoma mansoni.,We examine whether programmatic adaptations; namely increases in treatment coverage and/or expansion to adult inclusion in treatment, will improve the likelihood of reaching the WHO goals.,We find that in low-prevalence settings, the goals are likely to be attainable under current WHO guidelines, but in moderate to high-prevalence settings, the goals are less likely to be achieved unless treatment coverage is increased and expanded to at least 85% for school-aged children and 40% for adults.,To improve the likelihood of reaching the WHO goals, programmatic adaptations are required, particularly for moderate- to high-prevalence settings.,Furthermore, improvements in adherence to treatment, potential development of candidate vaccines, and enhanced snail control and WASH (water, sanitation, and hygiene) measures will all assist in achieving the goals.

Schistosomiasis is an infectious disease that affects over 240 million people living in low- and middle-income countries, and is caused by parasitic worms that require snail hosts to complete its lifecycle.,To improve public health control of this disease, there is growing interest in using chemical-based snail control that kills snail populations in environmental water sources, which will reduce infection rate in people.,We modeled transmission of schistosomiasis and cost-effectiveness of various strategies with data from low- and high-prevalence rural Kenyan communities.,Adding snail control alongside conventional mass treatment programs (instead of mass treatment programs alone) was found to be cost-effective, especially in settings with high disease burden and nonparticipation in mass treatment programs.,Schistosomiasis is a parasitic disease that affects over 240 million people globally.,To improve population-level disease control, there is growing interest in adding chemical-based snail control interventions to interrupt the lifecycle of Schistosoma in its snail host to reduce parasite transmission.,However, this approach is not widely implemented, and given environmental concerns, the optimal conditions for when snail control is appropriate are unclear.,We assessed the potential impact and cost-effectiveness of various snail control strategies.,We extended previously published dynamic, age-structured transmission and cost-effectiveness models to simulate mass drug administration (MDA) and focal snail control interventions against Schistosoma haematobium across a range of low-prevalence (5-20%) and high-prevalence (25-50%) rural Kenyan communities.,We simulated strategies over a 10-year period of MDA targeting school children or entire communities, snail control, and combined strategies.,We measured incremental cost-effectiveness in 2016 US dollars per disability-adjusted life year and defined a strategy as optimally cost-effective when maximizing health gains (averted disability-adjusted life years) with an incremental cost-effectiveness below a Kenya-specific economic threshold.,In both low- and high-prevalence settings, community-wide MDA with additional snail control reduced total disability by an additional 40% compared with school-based MDA alone.,The optimally cost-effective scenario included the addition of snail control to MDA in over 95% of simulations.,These results support inclusion of snail control in global guidelines and national schistosomiasis control strategies for optimal disease control, especially in settings with high prevalence, “hot spots” of transmission, and noncompliance to MDA.

Current malaria control and elimination strategies rely mainly on efficacious antimalarial drugs.,However, drug resistance is a major threat facing malaria control programs.,Determination of drug resistance molecular markers is useful in the monitoring and surveillance of malaria drug efficacy.,This study aimed to determine the mutations and haplotypes frequencies of different genes linked with antimalarial drug resistance in certain areas in Sudan.,A total of 226 dried blood spots (DBS) of microscopically diagnosed P. falciparum isolates were collected from Khartoum and three other areas in Sudan during 2015-2017.,Plasmodium falciparum confirmation and multiplicity of infection was assessed using the Sanger’s 101 SNPs-barcode and speciation was confirmed using regions of the parasite mitochondria.,Molecular genotyping of drug resistance genes (Pfcrt, Pfmdr1, Pfdhfr, Pfdhps, exonuclease, Pfk13, parasite genetic background (PGB) (Pfarps10, ferredoxin, Pfcrt, Pfmdr2)) was also performed.,All genotypes were generated by selective regions amplicon sequencing of the parasite genome using the Illumina MiSeq platform at the Wellcome Sanger Institute, UK then genotypes were translated into drug resistance haplotypes and species determination.,In total 225 samples were confirmed to be P. falciparum.,A higher proportion of multiplicity of infection was observed in Gezira (P<0.001) based on the Sanger 101 SNPs -barcode.,The overall frequency of mutant haplotype Pfcrt 72-76 CVIET was 71.8%.,For Pfmdr1, N86Y was detected in 53.6%, Y184F was observed in 88.1% and D1246Y was detected in 1.5% of the samples.,The most frequently observed haplotype was YFD 47.4%.,For Pfdhfr (codons 51, 59,108,164), the ICNI haplotype was the most frequent (80.7%) while for Pfdhps (codons 436, 437, 540, 581, 613) the (SGEAA) was most frequent haplotype (41%).,The Quadruple mutation (dhfr N51I, S108N + dhps A437G, K540E) was the highest frequent combined mutation (33.9%).,In Pfkelch13 gene, 18 non‐synonymous mutations were detected, 7 of them were detected in other African countries.,The most frequent Pfk13 mutation was E433D detected in four samples.,All of the Pfk13 mutant alleles have not been reported to belong to mutations associated with delayed parasite clearance in Southeast Asia.,PGB mutations were detected only in Pfcrt N326S\I (46.3%) and Pfcrt I356T (8.2%).,The exonuclease mutation was not detected.,There was no significant variation in mutant haplotypes between study areas.,There was high frequency of mutations in Pfcrt, Pfdhfr and Pfdhps in this study.,These mutations are associated with chloroquine and sulfadoxine-pyrimethamine (SP) resistance.,Many SNPs in Pfk13 not linked with delayed parasite clearance were observed.,The exonuclease E415G mutation which is linked with piperaquine resistance was not reported.

Intermittent preventive treatment of infants (IPTi) with sulphadoxine pyrimethamine (SP) is recommended as an additional malaria control intervention in high transmission areas of sub-Saharan Africa, provided its protective efficacy is not compromised by SP resistance.,A significant obstacle in implementing SP-IPTi, is in establishing the degree of resistance in an area.,Since SP monotherapy is discontinued, no contemporary measures of in vivo efficacy can be made, so the World Health Organisation has recommended a cut-off based upon molecular markers, stating that SP-IPTi should not be implemented when the prevalence of the dhps 540E mutation among infections exceeds 50%.,We created a geo-referenced database of SP resistance markers in Africa from published literature.,By selecting surveys of malaria infected blood samples conducted since 2004 we have mapped the contemporary prevalence of dhps 540E.,Additional maps are freely available in interactive form at http://www.drugresistancemaps.org/ipti/.,Eight countries in East Africa are classified as unsuitable for SP-IPTi when data are considered at a national level.,Fourteen countries in Central and West Africa were classified as suitable while seven countries had no available contemporary data to guide policy.,There are clear deficiencies in molecular surveillance data coverage.,We discuss requirements for ongoing surveillance of SP resistance markers in support of the use of SP-IPTi.

One hundred and twenty years ago, the Italian malariologists Marchiafava and Bignami proposed that the fundamental pathological process underlying lethal falciparum malaria was microvascular obstruction.,Since then, several alternative hypotheses have been proposed.,These formed the basis for adjunctive interventions, which have either been ineffective or harmful.,Recent evidence strongly suggests that Marchiafava and Bignami were right.

Mild cerebral swelling on CT-scan was common in adult patients with cerebral malaria, but severity of swelling was not correlated with coma depth or survival.,Mannitol as adjunctive treatment for cerebral malaria prolonged coma duration and may be harmful.,Background.,Coma is a frequent presentation of severe malaria in adults and an important cause of death.,The role of cerebral swelling in its pathogenesis, and the possible benefit of intravenous mannitol therapy to treat this, is uncertain.,Methods.,A computed tomographic (CT) scan of the cerebrum and lumbar puncture with measurement of cerebrospinal fluid (CSF) pressure were performed on admission for 126 consecutive adult Indian patients with cerebral malaria.,Patients with brain swelling on CT scan were randomized to adjunctive treatment with intravenous mannitol (1.5 g/kg followed by 0.5 g/kg every 8 hours; n = 30) or no adjunctive therapy (n = 31).,Results.,On CT scan 80 (63%) of 126 patients had cerebral swelling, of whom 36 (29%) had moderate or severe swelling.,Extent of brain swelling was not related to coma depth or mortality.,CSF pressures were elevated (≥200 mm H2O) in 43 (36%) of 120 patients and correlated with CT scan findings (P for trend = .001).,Mortality with mannitol therapy was 9 (30%) of 30 versus 4 (13%) of 31 without adjunctive therapy (hazard ratio, 2.4 [95% confidence interval, 0.8-7.3]; P = .11).,Median coma recovery time was 90 hours (range, 22-380 hours) with mannitol versus 32 hours (range, 5-168 hours) without (P = .02).,Conclusions.,Brain swelling on CT scan is a common finding in adult patients with cerebral malaria but is not related to coma depth or survival.,Mannitol therapy as adjunctive treatment for brain swelling in adult cerebral malaria prolongs coma duration and may be harmful.

The training of health workers in the use of malaria rapid diagnostic tests (RDTs) is an important component of a wider strategy to improve parasite-based malaria diagnosis at lower level health care facilities (LLHFs) where microscopy is not readily available for all patients with suspected malaria.,This study describes the process and cost of training to attain competence of lower level health workers to perform malaria RDTs in a public health system setting in eastern Uganda.,Health workers from 21 health facilities in Uganda were given a one-day central training on the use of RDTs in malaria case management, including practical skills on how to perform read and interpret the test results.,Successful trainees subsequently integrated the use of RDTs into their routine care for febrile patients at their LLHFs and transferred their acquired skills to colleagues (cascade training model).,A cross-sectional evaluation of the health workers’ competence in performing RDTs was conducted six weeks following the training, incorporating observation, in-depth interviews with health workers and the review of health facility records relating to tests offered and antimalarial drug (AMD) prescriptions pre and post training.,The direct costs relating to the training processes were also documented.,Overall, 135 health workers were trained including 63 (47%) nursing assistants, a group of care providers without formal medical training.,All trainees passed the post-training concordance test with ≥ 80% except 12 that required re-training.,Six weeks after the one-day training, 51/64 (80%) of the health workers accurately performed the critical steps in performing the RDT.,The performance was similar among the 10 (16%) participants who were peer-trained by their trained colleagues.,Only 9 (14%) did not draw the appropriate amount of blood using pipette.,The average cost of the one-day training was US$ 101 (range $92-$112), with the main cost drivers being trainee travel and per-diems.,Health workers offered RDTs to 76% of febrile patients and AMD prescriptions reduced by 37% six weeks post-training.,One-day training on the use of RDTs successfully provided adequate skill and competency among health workers to perform RDTs in fever case management at LLHF in a Uganda setting.,The cost averaged at US$101 per health worker trained, with the main cost drivers being trainee travel and per diems.,Given the good peer training noted in this study, there is need to explore the cost-effectiveness of a cascade training model for large scale implementation of RDTs.

The present study assessed malaria RDT kits for adequate and correct packaging, design and labelling of boxes and components.,Information inserts were studied for readability and accuracy of information.,Criteria for packaging, design, labelling and information were compiled from Directive 98/79 of the European Community (EC), relevant World Health Organization (WHO) documents and studies on end-users' performance of RDTs.,Typography and readability level (Flesch-Kincaid grade level) were assessed.,Forty-two RDT kits from 22 manufacturers were assessed, 35 of which had evidence of good manufacturing practice according to available information (i.e.,CE-label affixed or inclusion in the WHO list of ISO13485:2003 certified manufacturers).,Shortcomings in devices were (i) insufficient place for writing sample identification (n = 40) and (ii) ambiguous labelling of the reading window (n = 6).,Buffer vial labels were lacking essential information (n = 24) or were of poor quality (n = 16).,Information inserts had elevated readability levels (median Flesch Kincaid grade 8.9, range 7.1 - 12.9) and user-unfriendly typography (median font size 8, range 5 - 10).,Inadequacies included (i) no referral to biosafety (n = 18), (ii) critical differences between depicted and real devices (n = 8), (iii) figures with unrealistic colours (n = 4), (iv) incomplete information about RDT line interpretations (n = 31) and no data on test characteristics (n = 8).,Other problems included (i) kit names that referred to Plasmodium vivax although targeting a pan-species Plasmodium antigen (n = 4), (ii) not stating the identity of the pan-species antigen (n = 2) and (iii) slight but numerous differences in names displayed on boxes, device packages and information inserts.,Three CE labelled RDT kits produced outside the EC had no authorized representative affixed and the shape and relative dimensions of the CE symbol affixed did not comply with the Directive 98/79/EC.,Overall, RDTs with evidence of GMP scored better compared to those without but inadequacies were observed in both groups.,Overall, malaria RDTs showed shortcomings in quality of construction, design and labelling of boxes, device packages, devices and buffers.,Information inserts were difficult to read and lacked relevant information.

Rapid diagnostic tests (RDTs) detecting the histidine-rich protein 2 (PfHRP2) have a central position for the management of Plasmodium falciparum infections.,Yet, variable detection of certain targeted motifs, low parasitaemia, but also deletion of pfhrp2 gene or its homologue pfhrp3, may result in false-negative RDT leading to misdiagnosis and delayed treatment.,This study aimed at investigating the prevalence, and understanding the possible causes, of P. falciparum RDT-negative infections at Montpellier Academic Hospital, France.,The prevalence of falsely-negative RDT results reported before and after the introduction of a loop-mediated isothermal amplification (LAMP) assay, as part as the malaria screening strategy in January 2017, was analysed.,Negative P. falciparum RDT infections were screened for pfhrp2 or pfhrp3 deletion; and exons 2 were sequenced to show a putative genetic diversity impairing PfHRP2 detection.,The overall prevalence of P. falciparum negative RDTs from January 2006 to December 2018 was low (3/446).,Whereas no cases were reported from 2006 to 2016 (0/373), period during which the malaria diagnostic screen was based on microscopy and RDT, prevalence increased up to 4.1% (3/73) between 2017 and 2018, when molecular detection was implemented for primary screening.,Neither pfhrp2/3 deletion nor major variation in the frequency of repetitive epitopes could explain these false-negative RDT results.,This paper demonstrates the presence of pfhrp2 and pfhrp3 genes in three P. falciparum RDT-negative infections and reviews the possible reasons for non-detection of HRP2/3 antigens in a non-endemic setting.,It highlights the emergence of falsely negative rapid diagnostic tests in a non-endemic setting and draws attention on the risk of missing malaria cases with low parasitaemia infections using the RDT plus microscopy-based strategy currently recommended by French authorities.,The relevance of a novel diagnostic scheme based upon a LAMP assay is discussed.

The diagnosis of malaria can be difficult in non-endemic areas, such as the United States, and delays in diagnosis and errors in treatment occur too often.,A nationwide survey of laboratories in the United States and its nine dependent territories was conducted in 2010 to determine factors that may contribute to shortcomings in the diagnosis of malaria.,This survey explored the availability of malaria diagnostic tests, techniques used, and reporting practices.,The survey was completed by 201 participants.,Ninety percent reported that their laboratories had at least one type of malaria diagnostic test available on-site.,Nearly all of the respondents' laboratories performed thick and thin smears on-site; approximately 50% had access to molecular testing; and only 17% had access to rapid diagnostic tests on-site.,Seventy-three percent reported fewer than five confirmed cases of malaria in their laboratory during the 12-month period preceding the survey.,Twenty-eight percent stated that results of species identification took more than 24 hours to report.,Only five of 149 respondents that performed testing 24 hours a day, 7 days a week complied with all of the Clinical and Laboratory Standards Institute (CLSI) guidelines for analysis and reporting of results.,Although malaria diagnostic testing services were available to a majority of U.S. laboratories surveyed, very few were in complete compliance with all of the CLSI guidelines for analysis and reporting of results, and most respondents reported very few cases of malaria annually.,Laboratories' difficulty in adhering to the rigorous CLSI guidelines and their personnel's lack of practice and proficiency may account for delays and errors in diagnosis.,It is recommended that laboratories that infrequently process samples for malaria seek opportunities for practice and proficiency training annually and take advantage of available resources to assist in species identification.

Glucose 6-phosphate dehydrogenase (G6PD) is an enzyme involved in prevention of cellular oxidative damage, particularly protecting erythrocytes from haemolysis.,An estimated 400 million people present variable degrees of inherited G6PD deficiency (G6PDd) which puts them at risk for developing haemolysis triggered by several risk factors including multiple drugs and certain foods.,Primaquine (PQ) is a widely used anti-malarial drug that can trigger haemolysis in individuals with G6PDd.,Intensification of malaria control programmes worldwide and particularly malaria elimination planning in some regions recommend a more extensive use of PQ and related drugs in populations with different G6PDd prevalence.,This a preliminary study to assess the prevalence of G6PDd in representative malaria endemic areas of Colombia by measuring G6PD phonotype and genotypes.,Volunteers (n = 426) from four malaria endemic areas in Colombia (Buenaventura, Tumaco, Tierralta and Quibdo) were enrolled.,Blood samples were drawn to evaluate G6PD enzymatic activity by using a quantitative G6PD test and a subset of samples was analysed by PCR-RFLP to determine the frequency of the three most common G6PD genotypic variants: A−, A+ and Mediterranean.,A total of 28 individuals (6.56 %) displayed either severe or intermediate G6PDd.,The highest prevalence (3.51 %) was in Buenaventura, whereas G6PDd prevalence was lower (<1 %) in Tierralta and Quibdo.,G6PD A alleles were the most frequent (15.23 %) particularly in Buenaventura and Tumaco.,Overall, a high frequency of G6PD A− genotype, followed by A+ genotype was found in the analysed population.,G6PDd based on enzymatic activity as well as G6PD A allelic variants were found in malaria-endemic populations on the Pacific coast of Colombia, where most of malaria cases are caused by Plasmodium vivax infections.,These infections are treated for 14 days with PQ, however there are no official reports of PQ-induced haemolytic crises.,Further assessment of G6PDd prevalence in malaria endemic areas in Colombia is crucial in view of possible mass drug administration for malaria elimination in these regions, as well as implementation of appropriate G6PDd diagnostic methods.

Plasmodium vivax radical cure requires the use of primaquine (PQ), a drug that induces haemolysis in glucose-6-phosphate dehydrogenase deficient (G6PDd) individuals, which further hampers malaria control efforts.,The aim of this work was to study the G6PDd prevalence and variants in Latin America (LA) and the Caribbean region.,A systematic search of the published literature was undertaken in August 2013.,Bibliographies of manuscripts were also searched and additional references were identified.,Low prevalence rates of G6PDd were documented in Argentina, Bolivia, Mexico, Peru and Uruguay, but studies from Curaçao, Ecuador, Jamaica, Saint Lucia, Suriname and Trinidad, as well as some surveys carried out in areas of Brazil, Colombia and Cuba, have shown a high prevalence (> 10%) of G6PDd.,The G6PD A-202A mutation was the variant most broadly distributed across LA and was identified in 81.1% of the deficient individuals surveyed.,G6PDd is a frequent phenomenon in LA, although certain Amerindian populations may not be affected, suggesting that PQ could be safely used in these specific populations.,Population-wide use of PQ as part of malaria elimination strategies in LA cannot be supported unless a rapid, accurate and field-deployable G6PDd diagnostic test is made available.

Proteins Pfs230 and Pfs48/45 are Plasmodium falciparum transmission-blocking (TB) vaccine candidates that form a membrane-bound protein complex on gametes.,The biological role of Pfs230 or the Pfs230-Pfs48/45 complex remains poorly understood.,Here, we present the crystal structure of recombinant Pfs230 domain 1 (Pfs230D1M), a 6-cysteine domain, in complex with the Fab fragment of a TB monoclonal antibody (mAb) 4F12.,We observed the arrangement of Pfs230 on the surface of macrogametes differed from that on microgametes, and that Pfs230, with no known membrane anchor, may exist on the membrane surface in the absence of Pfs48/45.,4F12 appears to sterically interfere with Pfs230 function.,Combining mAbs against different epitopes of Pfs230D1 or of Pfs230D1 and Pfs48/45, significantly increased TB activity.,These studies elucidate a mechanism of action of the Pfs230D1 vaccine, model the functional activity induced by a polyclonal antibody response and support the development of TB vaccines targeting Pfs230D1 and Pfs230D1-Pfs48/45.,With the aim to advance the development of a P. falciparum transmission blocking vaccine, Singh et al. determine the crystal structure of Pfs230D1 in complex with the Fab fragment of TB mAb 4F12.,They further study the cellular localization of Pfs230 on the surface of sexual stages of parasites and the effect of combining TB mAbs against Pfs230 and Pfs48/45.

Malaria is a leading cause of mortality and morbidity in Mozambique, with nearly three-quarters of the country’s malaria-related deaths occurring in children younger than five years.,A malaria vaccine is not yet available, but planning is underway for a possible introduction, as soon as one becomes available.,In an effort to inform the planning process, this study explored sociocultural and health communications issues among individuals at the community level who are both responsible for decisions about vaccine use and who are likely to influence decisions about vaccine use.,Researchers conducted a qualitative study in two malaria-endemic districts in southern Mozambique.,Using criterion-based sampling, they conducted 23 focus group discussions and 26 in-depth interviews.,Implementation was guided by the engagement of community stakeholders.,Community members recognize that malaria contributes to high death rates and affects the workforce, school attendance, and the economy.,Vaccines are seen as a means to reduce the threat of childhood illnesses and to keep children and the rest of the community healthy.,Perceived constraints to accessing vaccine services include long queues, staff shortages, and a lack of resources at health care facilities.,Local leaders play a significant role in motivating caregivers to have their children vaccinated.,Participants generally felt that a vaccine could help to prevent malaria, although some voiced concern that the focus was only on young children and not on older children, pregnant women, and the elderly.,Probed on their understanding of vaccine efficacy, participants voiced various views, including the perception that while some vaccines did not fully prevent disease they still had important benefits.,Overall, it would be essential for local leaders to be involved in the design of specific messages for a future malaria vaccine communications strategy, and for those messages to be translated into local languages.,Acceptance of routine childhood vaccines bodes well for a future malaria vaccine.,Vaccinating children is a well-established routine that is viewed favourably in Mozambique.,A communications strategy would need to build on existing immunization efforts and use trusted sources-including current government dissemination arrangements-to deliver health information.

The Sahel region of Chad Republic is a prime candidate for malaria pre-elimination.,To facilitate pre-elimination efforts in this region, two populations of Anopheles coluzzii from Central Chad Republic were characterized, their insecticide resistance profile and the possible molecular mechanisms driving the resistance in the field investigated.,Bloodfed female Anopheles gambiae s.l. resting indoor, were collected at N’djamena and Massakory, Chad in 2018 and characterized for species composition, and infection rate was determined using the TaqMan assay.,Susceptibility to various insecticides was assessed using WHO tube bioassays.,Cone bioassays were conducted using various long-lasting insecticidal nets (LLINs).,Results were analysed using Chi Square test.,Knockdown resistance (kdr) and ace-1 markers were investigated by TaqMan genotyping.,Anopheles coluzzii was the major vector found in N’djamena (100%) and Massakory (~ 94%).,No Plasmodium was found in 147 bloodfed F0 An. coluzzii (82 from N’djamena and 65 from Massakory).,High intensity pyrethroid resistance was observed with mortalities of < 2% for permethrin, deltamethrin and etofenprox, and with < 50% and < 60% dead following exposure to 10× diagnostic doses of deltamethrin and permethrin, respectively.,For both sites, < 10% mortalities were observed with DDT.,Synergist bioassays with piperonylbutoxide significantly recovered pyrethroid susceptibility in Massakory populations, implicating CYP450s (mortality = 13.6% for permethrin, χ2 = 22.8, df = 1, P = 0.0006; mortality = 13.0% for deltamethrin, χ2 = 8.8, df = 1, P < 0.00031).,Cone-bioassays established complete loss of efficacy of the pyrethroid-based LLINs; and a 100% recovery of susceptibility following exposure to the roof of PermaNet®3.0, containing piperonylbutoxide.,Both populations were susceptible to malathion, but high bendiocarb resistance was observed in Massakory population.,The absence of ace-1 mutation points to the role of metabolic resistance in the bendiocarb resistance.,Both 1014F and 1014S mutations were found in both populations at around 60% and < 20% respectively.,Sequencing of intron-1 of the voltage-gated sodium channel revealed a low genetic diversity suggesting reduced polymorphism.,Multiple resistance in An. coluzzii populations from Chad highlight challenges associated with deployment of LLINs and indoor residual spraying (IRS) in the Sahel of this country.,The pyrethroid-synergists LLINs (e.g.,PermaNet®3.0) and organophosphate-based IRS maybe the alternatives for malaria control in this region.

Malaria is a major infectious disease that still affects nearly half of the world’s population.,Information on spatial distribution of malaria vector species is needed to improve malaria control efforts.,In this study we used Maximum Entropy Model (MaxEnt) to estimate the potential distribution of Anopheles gambiae sensu lato and its siblings: Anopheles gambiae sensu stricto, and Anopheles arabiensis in Nigeria.,Species occurrence data collected during the period 1900-2010 was used together with 19 bioclimatic, landuse and terrain variables.,Results show that these species are currently widespread across all ecological zones.,Temperature fluctuation from mean diurnal temperature range, extreme temperature and precipitation conditions, high humidity in dry season from precipitation during warm months, and land use and land cover dynamics have the greatest influence on the current seasonal distribution of the Anopheles species.,MaxEnt performed statistically significantly better than random with AUC approximately 0.7 for estimation of the Anopheles species environmental suitability, distribution and variable importance.,This model result can contribute to surveillance efforts and control strategies for malaria eradication.