Malaria in pregnancy (MiP) is a major cause of fetal growth restriction and low birth weight in endemic areas of sub-Saharan Africa. Understanding of the impact of MiP on infant growth and infant risk of malaria or morbidity is poorly characterized. The objective of this study was to describe the impact of MIP on subsequent infant growth, malaria and morbidity.Between 2006 and 2009, 82 % (832/1018) of pregnant women with live-born singletons and ultrasound determined gestational age were enrolled in a prospective cohort with active weekly screening and treatment for malaria. Infants were followed monthly for growth and morbidity and received active monthly screening and treatment for malaria during their first year of life. Multivariate analyses were performed to analyse the association between malaria exposure during pregnancy and infants’ growth, malaria infections, diarrhoea episodes and acute respiratory infections.Median time of infant follow-up was 12 months and infants born to a mother who had MiP were at increased risk of impaired height and weight gain  and of malaria infection . The risks of infant growth restriction and infant malaria infection were maximal when maternal malaria occurred in the 12 weeks prior to delivery. Recurrent MiP was also associated with acute respiratory infection  and diarrhoea during infancy .This study shows that despite frequent active screening and prompt treatment of MiP, impaired growth and an increased risk of malaria and non-malaria infections can be observed in the infants. Effective preventive measures in pregnancy remain a research priority.This study was registered with ClinicalTrials.gov, number NCT00495508. Malaria in pregnancy (MiP) remains a leading cause of miscarriage, preterm delivery, intrauterine growth restriction (IUGR) and low birth weight (LBW) in malaria-endemic areas of sub-Saharan Africa, Asia and South America –5. As a MiP may increase infant morbidity through different mechanisms. First, MiP is responsible for IUGR and preterm birth that are, in turn, associated with infant mortality and morbidity –19. AlsoThe objective of this work was to analyse the effect of MiP on infant growth and morbidity,  with respect to MiP timing using data from a prospectively and previously published cohort of pregnant women and their infants . This woThis mother–baby cohort study was conducted in Mbarara district, southwestern Uganda. This predominantly rural area lies at an altitude of about 1500 m above sea level and has a tropical climate with a bimodal rainfall pattern averaging 1200 mm per annum in September–January and March–May. Malaria transmission was considered as mesoendemic although significant heterogeneity has been observed recently , 26.The study design was a prospective cohort of 1218 pregnant women of estimated GA ≥13 weeks with a nested clinical trial conducted between October 2006 and May 2009, in which 304 pregnant women were enrolled . All wom®  rapid diagnostic test (RDT) and confirmed with a blood smear test.At enrolment, a comprehensive assessment of the mothers was performed that included the collection of information on their demographic, socioeconomic, medical and obstetric characteristics, a clinical and obstetric examination, an ultrasound evaluation, blood smear and haemoglobin measurements. An estimation of GA by ultrasound for foetal biometry using biparietal diameter and femur length was performed between 16 and 22 weeks of pregnancy . After tWomen in the cohort received standard supervised IPT with two doses of sulfadoxine-pyrimethamine (SP) given at intervals of one month or more during the second and third trimesters as recommended by national guidelines. IPT was not given to the women who receive anti-malarial treatment (quinine or AL). All treatments were provided free-of-charge.® RDT and treated with AL, and a medical examination by a paediatrician was performed. Morbidity definitions in infancy were based on national guidelines [At delivery, blood smears were obtained from the mother, the placenta, cord and from the newborn to verify the presence of malaria infection. Newborns were weighed to the nearest 10 g using a SECA mechanical type scale and received an initial standardized physical examination by a medical officer. Length was measured using a Stadiometer. After the initial evaluation, infants were seen every month or more frequently if required until 12 months. At each visit, anthropometric characteristics were measured once, malaria infection was screened with a Paracheckidelines .Thick and thin blood smears were prepared and stained with Giemsa. Parasitaemia was calculated by counting parasites against 200 white blood cells. Placenta smears were taken by incising a fresh placenta on the maternal surface halfway between the cord and the periphery.HIV testing and treatment was proposed for all women and performed according to the national guidelines.Small-for-GA (SGA) was defined as a birth weight less than the 10th percentile of sex-specific birth weight-for-GA . PeripheThe change in weight and height between birth and 12 months (weight and height gain) were analysed using a linear model. Missing data at 12 months because of irregular visit schedules (n = 150/794) were imputed and confidence intervals were adapted using Rubin’s formula , 32. TheMalaria exposure during pregnancy The occurrence of any peripheral malaria infection, the number  of peripheral malaria infections and the occurrence of placental malaria infection were considered in the analysis. To investigate if infant outcomes were associated with malaria infections occurring at a specific time during pregnancy, four time periods were defined starting from delivery; first 4 weeks before delivery, 4–12 weeks before delivery, 12–20 weeks before delivery and >20 weeks before delivery. As women were followed up from their first antenatal visit, malaria infection may have occurred before inclusion in the study and exposure to malaria during pregnancy was incompletely observed resulting in left-censoring. This missing information should not be coded as the absence of malaria infection, which may result in misclassification of true exposure but accounted for using statistical method for left-censoring [ensoring . In thisMaternal characteristics and other potential confounders Education level, mother age, gravidity, residential area, season, maternal HIV infection status and use of a bed net were considered in the analysis as potential confounders and included in all multivariate models. GA was also included as a covariate to account for the effect of preterm birth on infant growth.Potential effect modifier Maternal gravidity (primigravidae vs multigravidae) was also assessed as potential effect modifiers of malaria exposure.Two categories of explanatory variables were considered in the analysis:This study was powered to assess the primary outcome and not for this secondary analysis. All analyses were performed using the open source statistical software R .The study was approved by the institutional review boards of Mbarara University of Science and Technology, Uganda National Council for Science and Technology, and France’s “Comité de protection des personnes—Ile-de-France XI”. This study was registered with ClinicalTrials.gov, number NCT00495508.The sponsor of the study had no role in study design, data collection, data analysis, data interpretation, or writing of the report. The corresponding author had full access to all the data in the study and had final responsibility for the decision to submit for publication.Of the 1218 women enrolled in the cohort, 60 % were enrolled before 20 weeks gestation, 1069 had delivery outcomes, and 1018 newborns were enrolled in the infant cohort. There were 832 (82 %) live-born singletons with a valid ultrasound assessment of GA included in this analysis  were SGA at birth. In adjusted analysis without including malaria variables, weight gain at 12 months was lower in girls, infants born by vaginal delivery, infants born to mothers infected with HIV and in those born SGA, while height gain was greater in boys, preterm infants and in those born to mothers with higher education level  and was higher in girls compared to boys  children experienced at least one malaria episode, 416 (51 %) at least one acute respiratory infection and 177 22 %) at least one diarrhoea episode. Of the 45 children with malaria only 7 had more than one infection but analysis of malaria was restricted to first occurrence. There was a significant positive association between the risks of diarrhoea and acute respiratory infection (p < 0.001) and a borderline association between the risks of malaria and of diarrhoea or acute respiratory infection (respectively p = 0.08 and p = 0.09). Only infections with 2 % at leRegarding acute respiratory infection, there was a greater risk of infection in children of mothers who experienced peripheral malaria  or placental malaria . No interaction was detected either with maternal gravidity (p = 0.2) or malaria timing (Fig. Lastly, the risk of diarrhoea was mainly increased in children born SGA Table . An incrIn this study, microscopic malaria during pregnancy, more than one peripheral malaria infection or placental malaria infection, were associated with various impaired infant health outcomes during the first year of life, with greater adverse consequences when MiP was confirmed late in pregnancy.A major association of malaria infection during pregnancy observed in this study was an increased risk of malaria during infancy, confirming previous reports –12, 14. Detailed studies have related the number and timing of malaria infection in pregnancy to the impact on low birth weight , 37, 38.The consequence of MiP for the newborns in this study extended beyond the in utero period confirming results from Benin , the onlThis study shows that, despite active screening and treatment, and IPTp for the majority of women, MiP, particularly late pregnancy infection, was associated with impaired infant growth and with both malaria and non-malaria infections during the first year of life. Prevention of MiP in pregnancy by efficacious treatment has the potential to reduce the significant burden of adverse consequences for mothers and infants.


Endemic malaria in Thailand continues to only exist along international borders. This pattern is frequently attributed to importation of malaria from surrounding nations. A microgeographical approach was used to investigate malaria cases in a study village along the Thailand–Myanmar border.Three mass blood surveys were conducted during the study period  and were matched to a cohort-based demographic surveillance system. Blood slides and filter papers were taken from each participant. Slides were cross-verified by an expert microscopist and filter papers were analysed using nested PCR. Cases were then mapped to households and analysed using spatial statistics. A risk factor analysis was done using mixed effects logistic regression.Plasmodium vivax and 20 Plasmodium falciparum cases (out of 547 participants) were detected through PCR, compared to six and two (respectively) cases detected by field microscopy. The single largest risk factor for infection was citizenship. Many study participants were ethnic Karen people with no citizenship in either Thailand or Myanmar. This subpopulation had over eight times the odds of malaria infection when compared to Thai citizens. Cases also appeared to cluster near a major drainage system and year–round water source within the study village.In total, 55 This research indicates that many cases of malaria remain undiagnosed in the region. The spatial and demographic clustering of cases in a sub-group of the population indicates either transmission within the Thai village or shared exposure to malaria vectors outside of the village. While it is possible that malaria is imported to Thailand from Myanmar, the existence of undetected infections, coupled with an ecological setting that is conducive to malaria transmission, means that indigenous transmission could also occur on the Thai side of the border. Improved, timely, and active case detection is warranted. Although the global situation appears to be improving, malaria remains one of the biggest threats to populations living within the tropical world. The World Health Organization (WHO) estimates that there were 207 million cases of infection and 627,000 malaria-related deaths in 2012 . The malThe ecological, political and demographic situations along this border are conducive to persistent malaria. There are at least three major, almost omnipresent mosquito vector complexes within the border region . The arePlasmodium vivax and Plasmodium falciparum, for many years [P. falciparum to P. vivax appears to have decreased, with vivax cases now making up the largest proportion of the cases on the Thai side of the border [On the Thai side of the Thailand-Myanmar border, Tak Province has consistently had the highest numbers of reported malaria cases, both ny years . In recee border . Within As many nations in the GMS are progressing toward regional malaria elimination, a better understanding of malaria epidemiology is essential. The overarching goal of this study was to better understand the epidemiology of malaria on the Thai side of the international border through the use of cross-sectional mass blood surveys coupled with a cohort-based demographic surveillance system. More specifically, the research aim was to determine the microgeographical distribution of malaria cases within the study site and the potential for indigenous, rather than imported, malaria to be present on the Thai side of the border, especially with regard to sub-microscopic malaria and asymptomatic carriers.The study site is located along the Moei River on the Thai side of the international border Fig. . The intThe protocol of this study has been reviewed and approved by the institutional review boards of the Pennsylvania State University and the Thai Ministry of Health. Informed consent was obtained from the head of each participating household. A full-scale census was conducted and each villager who agreed to participate was given a unique identification code. Demographic variables included sex, self-reported age, occupation, education level, and nationality. Households were also given identification codes and their spatial coordinates were recorded. Household demographic surveys were conducted almost weekly, beginning in October 2011. These surveys noted both additions to a household (through in-migrations or birth) and subtractions from a household (through out-migration or death). Individuals who moved into a household and stayed for a month or longer were coded as in-migrants . When a household member moved out of a household, the study team asked other remaining household members when that person was expected to return. If they were expected to be away for a month or more they are counted as an out-migrant.Three mass blood surveys (MBS 1–3) were conducted in the study hamlet in July and December 2011, and May 2012. During these surveys, thick and thin blood films were made for each available participant, and these films were immediately checked at the nearest malaria clinic for malaria infection by microscopy. In addition, about 100 μl of finger-prick blood was spotted on Whatman 3-mm filter paper, air dried and stored individually in silicon desiccant for subsequent PCR detection of malaria parasites. Persons with malaria-positive slides were then visited by public health workers and administered anti-malarials according to official Thai protocol. Slides and filter papers were marked with villager and household identification codes and were stored for subsequent analyses .Plasmodium knowlesi, which is known to occur in this region [Malaria infections were diagnosed by microscopy using Giemsa-stained thick and thin blood smears at a malaria clinic near the field site. Infections found at this stage were considered to be symptomatic. The results were read again by an expert microscopist at Mahidol University with over 20 years’ experience. For molecular analysis, samples were sent to a collaborating laboratory and a nested PCR method was used to detect malaria infections . Brieflys region . InfectiP. vivax infections. Because of the small number of P. falciparum cases, it was not possible to conduct the same analysis for falciparum malaria. Both household- and individual-level factors were investigated with regard to the individual risk of having a P. vivax infection. Individual-level covariates included age group , sex, nationality  and migration status . Household-level covariates included: the mean household size for the household with which an individual was associated during the surveys prior to infection; household dependency ratio (ratio of young (age up to 12 years) and elderly (over age 69 years) household members to working age (age 13 to 69) household members); and, whether or not a person had moved in or out of the household during the study period. A random intercept was included for each household to attempt to control for unexplained heterogeneity at the household level.A mixed effects logistic regression was used to look for statistically significant risk factors for carrying PCR-detected Several of the covariates in this model act as proxies for social and economic status. People with no nationality are unable to own land, travel freely in Thailand and work most jobs. It is therefore reasonable to associate a lack of nationality with low socio-economic status. The household dependency ratio is also a measure of economic status at the household level. Households with high dependency ratios may be less likely to be able to accrue and sustain surplus finances or food.Different model specifications were tested, including models that incorporated occupation and education measurements (hindered by high non-response), as well as interaction terms between age and migration, dependency ratio and household size, and nationality and migration. The final model was chosen based on Akaike Information Criterion scores, a measurement of model fit that is penalized by the inclusion of more parameters. Where possible, odds ratios for falciparum risk factors were calculated using contingency tables.P. vivax cases were mapped by household for each MBS individually  was used to assign spatial weights matrices. For the Moran’s I test, cases were standardized in households by household size. For the join-count based test of global autocorrelation the data were transformed into a binary format . Next, SaTScan was used to test for clustering of cases (‘hot spots’) or non-cases (‘cold spots’) [The distribution of PCR-confirmed lly Fig.  and comblly Fig. . CrimeSt spots’) . SaTScan spots’) .Fig. 2MaAt the beginning of the study period, the study site had approximately 512 inhabitants, 48 % of which were male. The study population is an open cohort, with relatively frequent movement in and out of the population over time. The census was updated regularly through household visits and the average (mean) population size during the study period was approximately 494, with a slightly female biased sex ratio . The study population was mostly composed of ethnic Karen, with approximately 78 % of the inhabitants self-identified as Karen, 7 % claimed to be Thai and 16 % did not respond to any of the demographic questions. Conversely, 18 % had Thai citizenship and 66 % had no citizenship (neither Burmese nor Thai). Sixty-six per cent of respondents were illiterate, 13 % had completed primary school and 5 % had completed middle school. Thirty-nine per cent were children and students, 4 % worked in plantations, and 41 % were either not regularly employed or worked in various temporary labour positions.The population screened during MBS largely followed the age and sex patterns of the census, with an exception of slightly fewer adult males. This pattern is also evident when looking at the cohort that completed all three MBS, with a sex ratio  in subjects above age 14 of 0.52. Twelve per cent of the participants who were present in censuses were never surveyed during the MBS, most of which (67 %) moved out of the village during the study period. Participation during the three MBS was 74, 79, and 81 %, respectively. The mean and median census ages were 24 and 18, respectively and the mean and median age distributions for MBS closely matched this . During the study period there were 85 out-migrations and 31 in-migrations (Table P. vivax infections were in adults (>14 years), with slightly more infections occurring in females than males  occurred in participants who claimed no nationality while six percent of malaria infections occurred in participants who never responded to questions about demographic characteristics. Malaria infections also appeared to be associated with the levels of education: 70 and 76 % of all P. vivax and P. falciparum cases, respectively, occurred in illiterate persons and, likewise, 24 and 18 % were in those with only primary school education. Also, 48 and 53 % were in persons with only temporary labour positions, and two and six percent occurred in those who worked in plantations. This latter category consists of highly mobile people, and it is possible that this population was under-sampled because of their mobile nature. Altogether, malaria disproportionally affected people of different demographic groups, with people who were stateless, ethnic Karen, illiterate, and working in only temporary occupations being most heavily affected.Most PCR-detected  adults >4 years,  adults >4 years, P. vivax and two cases of P. falciparum. The expert microscopist diagnosed 18 (18/547 = three percent) P. vivax and 16 (16/547 = three percent) P. falciparum infections. Six of the vivax cases (6/18 = 33 %) and three of the falciparum cases (3/16 = 19 %) were carrying gametocytes. Parasite counts were lower in cases that were detected by expert microscopy but missed by the field microscopist. The mean asexual P. vivax parasite count per 500 white blood cells for P. vivax that was undetected by field microscopist was 17.5, compared to a mean P. vivax parasite count of 321 in cases detected by both field and expert microscopists. Finally, 55 P. vivax and 20 P. falciparum cases were detected by PCR. Five cases were mixed infections that were completely missed by microscopy and one Plasmodium malariae cases was detected via PCR in a 15 years old male. Five individuals had vivax infections across multiple MBS.This study revealed stark differences by diagnosis approaches. The field microscopist only diagnosed six cases of P. vivax parasites  were analysed for increased risks of carrying PCR detectable, blood stage es Table . The moses Table  and alsoThere was no statistically significant difference in infections by sex or migration status. Furthermore, household size, household dependency ratio, and living in a household with other migrants did not appear to increase an individual’s risk of infection. There was an effect of household elevation on the risk of individual infection. For each increase in household elevation of 1 m, an individual appeared to have about a 13 % decrease in the odds of vivax infection. Finally, children aged five to 14 years appeared to have the greatest risk of infection (by age), but this effect did not reach statistical significance in the model. Since there are relatively few cases and there is no differentiation between new infections and recurrence, it is important to not over-interpret these results with regard to age groups. Patients with detected vivax parasites across multiple MBS were counted as a single infection in the statistical model.P. vivax infections by household indicated variation in the spatial distribution of P. vivax cases across the MBS  and an expansion of cases in the wet season (MBS1 and MBS3). MBS1 was the most dispersed and occurred toward the middle-end of the rainy season (standard distance deviation (SDD): 125.79 m), MBS2 occurred during the dry season (SDD: 116.70 m), and MBS3 occurred as the rainy season was beginning (SDD: 118.37 m). The clusters that are present in the dry season remain in the wet season, but spatial clustering is less evident in the wet season because cases are more widespread throughout the village.Maps of PCR-detected MBS Fig. . In partThe scan statistics (using SaTScan) gave more detailed, local tests of spatial clustering. The strongest pattern that emerged was the absence of cases in the northwestern quadrant. This area was identified as a cold spot, with a lower than expected number of cases when compared to the rest of the village, in each MBS (MBS1 relative risk (RR) = 0.00; P-value = 0.0310; MBS2: RR = 0.00; P-value = 0.0390; MBS3: RR = 0.17; P-value = 0.0678) and in the combined data  case detection and sensitive approaches to case detection. Currently, malaria diagnosis by microscopy in Thailand is the norm, with any patient presenting at a malaria clinic or hospital first being diagnosed by microscopy. However, parasite densities in asymptomatic parasite carriers are often below the detection limit of microscopes  [Timely identification and prompt treatment of malaria infected people are both essential to eliminate the transmission source, perhaps especially for regions entering the malaria elimination phase. In many malaria hypo-endemic areas, the presence of asymptomatic patients who can serve as parasite reservoirs requires the use of active (l blood) –20. Sevel blood) , 22. In l blood) –25.In this study individuals with low parasitaemia were more likely to be missed by the field microscopist when compared to the expert microscopist. This also highlights the need for strengthened programmes of training for microscopists in malaria diagnosis. Around 90 % of malaria infections  were missed through field microscopy. Another recent paper reports similar discrepancies in malaria diagnoses from the same region . It is lMalaria cases in endemic areas often occur in hotspots, with close spatial associations with vector-breeding habitats, and in certain ‘high-risk’ sub-sets of the population, ‘hot-pops’ (those with higher exposure to vector-breeding habitats). Some previous work in the GMS has indicated that malaria clusters along the international borders and is associated with forests and forest edges , 27. It P. vivax infections occurred disproportionately in the five to 14 years age group  as well as socio-economic (lack of citizenship and lower socio-economic standing) characteristics that appear related to malaria infections. It is likely that the pattern seen in this short time interval continues over longer stretches of time.Some of the residents were found malaria-positive by PCR but remained asymptomatic through all MBSs. Five of the participants had vivax infections across consecutive MBS. Therefore some of the villagers are potentially carrying chronic, asymptomatic infections and are therefore potential parasite reservoirs. During the dry season these asymptomatic cases cluster near year-round water sources, while during the wet season they expand. These asymptomatic, potentially long-term infections might be sufficient for sustaining malaria transmission and therefore measures to improve diagnosis and targeted control through active surveillance are essential for malaria elimination.versus long-term migration affects malaria introduction and transmission. Finally, in this study it was not possible to differentiate between new infections, recrudescent infections and chronic infections. This limitation means that risk factors should be carefully interpreted as risk factors for being diagnosed as having a vivax infection, given that the point of actual infection is unknown and a participant’s demographic and ecological characteristics  can change over time.There are several limitations to this study. Malaria infections were detected in three cross-sectional waves rather than longitudinally and only consist of roughly a year’s worth of time. It is possible that the spatial patterns and the risk factors in this area differ from year to year. The relatively small number of cases and the small size of the population make some analysis difficult. This is a common problem in this region, where low transmission and small population sizes dominate. While this study found no association between migration and risk of vivax infections, the definition and measurement of migration may not be sensitive enough to capture important movement patterns. The study hamlet is located on the international border and residents move back and forth over short time intervals (even within a single day). Such movements are not recorded in this study, can vary by season, and are potentially more common in the study population without citizenship. It is not known whether and how short-term Regardless, these findings have profound implications for malaria work in this region and potentially others. These results suggest that there are a large proportion of missed cases on the Thai side of the border. In this study, many of the cases were detected in children five to 14 years old and in clusters near year-round water sources on the Thai side of the border. Also, most of the infections in this study were submicroscopic and several appeared to be chronic. Malaria vector species are known to inhabit the Thai side of the border and many people carrying parasites in their blood are unlikely to be detected through passive case detection and microscopy. Importation of malaria is therefore possible, but not necessary, for continued transmission within Thailand. Such reservoirs will remain crucial targets in these efforts as national and sub-national programmes begin to move towards elimination.


Plasmodium infections do not cause clinical signs and symptoms of disease and persist at densities in blood that are not detectable by microscopy or rapid diagnostic tests. These infections may be critical as a transmission reservoir in areas of low malaria endemicity. Understanding the epidemiology of these infections would be helpful for malaria elimination.A large fraction of Plasmodium infections were diagnosed by rapid diagnostic tests (RDT) and high volume, ultra-sensitive quantitative polymerase chain reaction (uPCR).A cross-sectional survey was conducted in Thapangthong and Nong Districts of Savannakhet Province, Lao PDR, to determine the prevalence of parasitaemia. A total of 888 blood samples were collected from afebrile volunteers aged ≥15 years in 18 villages during March and July 2015. Plasmodium infections in 175 of 888 samples (20 %). The species distribution was Plasmodiumfalciparum 3.6 % (32/888), Plasmodium vivax 11.1 % (99/888), mixed infections with P. falciparum and P. vivax 1.6 % (14/888) and Plasmodium of undetermined species 3.4 % (30/888). RDT identified only 2 % (18/888) positive cases. Using uPCR as reference, the sensitivity and specificity of RDTs were 28 and 100 %, respectively, in detecting P. falciparum infections, and 3 and 99 % in detecting asymptomatic P. vivax infections. The K13 kelch propeller domain C580Y mutation, associated with reduced susceptibility to artemisinin derivatives, was found in 75 % (12/18) of P. falciparum isolates from Thapangthong and in 7 % (2/28) from Nong (p < 0.001). In a multivariate analysis, males were more likely to have P. vivax infections [adjusted odds ratio (aOR) 4.76 (95 % CI 2.84–8.00)] while older villagers were at lower risk for parasitaemia [aOR for increasing age 0.98 (95 % CI 0.96–0.99)].uPCR detected Plasmodium infections in southern Savannakhet. Artemisinin-resistant P. falciparum strains form an increasing proportion of the parasite population in Thapangthong District and are already present in the more remote Nong District. This worrying trend has wider implications for Laos and could reverse the gains achieved by the successful control of malaria in Laos and the Greater Mekong Sub-region (GMS). Rapid elimination of P. falciparum has to be a top priority in Laos as well as in the wider GMS.There is a high prevalence of asymptomatic  Plasmodium falciparum cases per 1000 people. The survey ranked Savannakhet as the province with the third highest P. falciparum cases recorded in 2008  than in Thapangthong . In contrast, the prevalence of P. falciparum mono-infections was higher in Nong [5 % (24/455)] compared to Thapangthong  but not in the multivariate analysis [aOR 0.98 (0.95–1.00)].Five covariates were independently and significantly associated with ns Table : male sePlasmodium infections using uPCR. The study found that one-fifth of the afebrile population in southern Savannakhet was carrying Plasmodium infections, a third of which P. falciparum infections may be resistant to artemisinin derivatives. The prevalence of asymptomatic Plasmodium infection was very heterogeneously distributed not only between districts but also between villages separated by short distances.This is the first survey conducted in Laos of sub-clinical and sub-microscopic P. falciparum, which used to be the most prevalent (≥90 %) species in Laos, towards P. vivax [P. vivax infections has been reported from Thailand [P. vivax infections compared to P. falciparum infections among a total of 988 Plasmodium infections [P. falciparum than P. vivax. The complete, radical cure of vivax infections requires a 14-day course with 8-aminoquinolines, such as primaquine, and this is not implemented currently. There remains considerable reluctance to use primaquine in radical cure while G6PD testing is unavailable and there is therefore a significant haemolytic risk.There has been a shift from the traditional dominance of P. vivax –25. An iThailand , CambodiThailand , SolomonThailand , Amazon Thailand , 30, andThailand  as falcifections . CurrentP. falciparum strains had the K13 C580Y mutation. In contrast, in Nong District the K13 mutation was only detected in 7 % of P. falciparum strains. This finding supports the hypothesis that with decreasing falciparum malaria transmission the more resistant strains replace wild type strains infections form an increasing proportion of the dwindling parasite population [A high geographical heterogeneity was also found in the distribution of the K13 mutation C580Y which is associated with resistance against artemisinin derivatives , 19. In pulation .Plasmodium infections may at least in part be explained by environmental factors, such as the location of homes in relation to mosquito breeding sites, the design and construction materials of the home, and protective measures taken by the residents. The heterogeneity in the prevalence of Plasmodium infections in this study is consistent with an earlier study conducted in Laos [Anopheles dirus and Anopheles minimus [An. dirus and An. minimus, combined with the anthropophilic behaviour of An. minimus was thought to explain at least some of the variability in malaria prevalence between villages [Plasmodium infections compared to villages more distant from forested areas [P. falciparum infections found similar large differences between villages in sub-Saharan Africa and in Europe in the last century [The heterogeneity in the prevalence of  in Laos . The rea minimus . The disvillages , 34. In ed areas . Detaile century . Differe century . Genetic century .P. falciparum infections and 3 % for P. vivax infections using uPCR as reference. The wide discrepancy in prevalence measured by RDT compared to uPCR in this current study is consistent with a multi-national survey, which used the same uPCR detection technique [Plasmodium prevalence of 4 % by RDT compared to 20 % by uPCR. A survey using RDT conducted in Laos in 2006–2008 [P. falciparum infections—similar to the 0.9 % P. falciparum prevalence detected by RDT in the current study.The sensitivity of RDTs in this study was 28 % for echnique . This ea006–2008 , 2 foundP. vivax mono-infections. Being a male was associated with higher prevalence of P. vivax infection than being female. The increased risk of contracting malaria for males may be explained by work-related exposure in the field and forested areas [P. vivax prevalence. Forest workers have been traditionally a high-risk group for malaria in the Greater Mekong Sub-region [Several factors were associated with ed areas . A similed areas  and Ethied areas , 38. A hb-region –43. ContPlasmodium infections in this study was in the age group 15–35 years and decreased with older age. Younger participants may have been less exposed to vectors while older participants may have developed sufficient immunity to clear infections. A similar peak prevalence in adults has been observed in past studies in Laos [The peak risk for  in Laos  and CambPlasmodium infections as detected by uPCR and three times more P. vivax than P. falciparum infections in the southern Savannakhet Province. The distribution of infections was very heterogeneous, with some villages nearly free of infections while in other villages more than half of the village population was infected. The majority of P. falciparum strains in Thapangthong District carried markers suggesting reduced susceptibility to artemisinin derivatives. These strains are also already present in the more remote Nong District. This worrying trend has wider implications for Laos and could reverse the gains achieved by the successful control of malaria in Laos and the GMS. The rapid elimination of P. falciparum should be a top priority in Laos and the GMS before malaria there becomes untreatable. Such elimination will require targeted interventions in high prevalence villages.The study found a high prevalence of asymptomatic


Afghan refugees in northern Pakistan have been resident for over 30 years and current information on malaria in this population is sparse. Understanding malaria risk and distribution in refugee camps is important for effective management both in camps and on return to Afghanistan.Plasmodium falciparum and Plasmodium vivax. Factors associated with malaria infection and exposure were analysed using logistic regression, and spatial heterogeneity within camps was investigated with SatScan.Cross-sectional malariometric surveys were conducted in five Afghan refugee camps to determine infection and exposure to both P. falciparum and P. vivax, respectively. Prevalence of anti-malarial antibodies to P. falciparum antigens was 3–11 and 17–45 % for P. vivax antigens. Significant foci of P. vivax infection and exposure were detected in three of the five camps. Hotspots of P. falciparum were also detected in three camps, only one of which also showed evidence of P. vivax hotspots.In this low-transmission setting, prevalence of infection in the five camps ranged from 0–0.2 to 0.4–9 % by rapid diagnostic test and 0–1.39 and 5–15 % by polymerase chain reaction for There is low and spatially heterogeneous malaria transmission in the refugee camps in northern Pakistan. Understanding malaria risk in refugee camps is important so the malaria risk faced by these populations in the camps and upon their return to Afghanistan can be effectively managed. Prior to the conflict, Afghanistan had an effective malaria control programme with a focus on vector control, with transmission maintained at very low levels , 2. In 1The state of malaria infection and exposure in this refugee population after residing in northern Pakistan has received little attention in recent times as well as which diagnostic tool is most suited to such low-transmission settings , 11. As Plasmodium vivax and Plasmodium falciparum; (2) identify factors associated with a current infection as well as exposure to P. vivax and P. falciparum in a stable refugee population; and, (3) to identify any spatial patterns of malaria present within the Afghan refugee camps in Pakistan.To provide current data to inform decision-making for managing malaria in this vulnerable population, a malariometic survey was conducted in five Afghan refugee camps in northern Pakistan to: (1) assess the utility of diagnostic tools in this low-transmission setting, including rapid diagnostic test (RDT), polymerase chain reaction (PCR) and the presence of anti-malarial antibodies for P. vivax transmission season and before the P. falciparum transmission season, which typically peaks in late October [Anopheles stephensi and Anopheles culicifacies and the majority of the malaria infections are due to P. vivax [Study participants were selected from five Afghan refugee camps in Mardan  and Peshawar (Adezai) districts in the province of Khyber Pakhunkwa (KPK) in Pakistan, as well as the Zangal Patai camp in the Malakand agency tribal area Fig. . Camps w October , 9, 16. P. vivax . The areP. vivax .Fig. 1StSample size calculations for the survey were derived based on estimating anti-malarial antibody seroconversion rates (λ) of 0.01 with a residual standard deviation less than 0.25, which resulted in a sample of three people per household with a minimum of 167 households , 18. A nP. vivax (pLDH) and/or P. falciparum (HRP2). All individuals found to be RDT positive were referred to a BHU for full evaluation and for appropriate treatment. Blood was also collected onto Whatman 3 mm filter paper  for laboratory analysis.The household heads in all selected households were approached for written informed consent and questionnaires were administered to collect information on household characteristics, including wealth indices, travel history, malaria control behaviour, and demographic information. Finger-prick blood samples were collected on Whatman 3 mm filter paper  from the selected individuals for subsequent laboratory analysis after written consent was obtained. The CareStart Pf/Pv combo  RDT was performed to detect current malaria infections with P. falciparum and P. vivax Apical Membrane Antigen-1 (AMA-1) and Merozoite Surface Protein-119 (MSP-1) were detected using enzyme-linked immunosorbent assay (ELISA) as previously described [P. vivax and P. falciparum.Filter-paper blood spots were dried in the field and stored with desiccant at −20 °C and shipped to London for analysis. Antibodies to Data analysis was conducted using Stata v12.0  and R v3.2  statistical software. Duplicate ELISA OD values were averaged and normalized against the positive control sample on each plate. OD data were then converted to antibody titres, expressed in arbitrary units (AU/ml), using a standard curve obtained from hyperendemic control sera. Seropositivity was defined by fitting a mixture model to normalized OD values . The modP. falciparum and P. vivax using the survey command, weighted for household population size, and adjusting for clustering within camps. Spearman’s rank correlation coefficient was calculated to compare diagnostic tools within camps. Hotspots were determined assuming a Bernoulli model with SatScan software v9.2 . Elliptical and circular windows were used allowing for a maximum spatial cluster size of both 50 and 25 % of the population at risk. Those households showing evidence of a significantly (p < 0.05) increased prevalence compared to the rest of the camp by any of the scans were considered to be part of a hotspot [P. vivax and P. falciparum and results were analysed using ArcGis v10.2 . Due to the sub-set of samples analysed, spatial analysis was not conducted on PCR results.Principal component analysis was used to generate a score for socio-economic status (SES) based on household asset ownership data and grouped according to quintiles . Logisti hotspot , 24. SepEthics approval for the study was granted by both Peshawar University (#02/EC/Pharm) and the London School of Hygiene and Tropical Medicine (#5715). Individual written informed consent was sought from heads of included households, and from all selected participants by signature. Consent for children under the age of 18 was provided by a parent/guardian.In total, 2522 people were sampled in 845 households across the five refugee camps Table . ReporteP. vivax ranged from 47.5 % (95 % CI 43.1–51.9 %) in Jalala camp and 17.6 % (95 % CI 14.2–20.9 %) in Adezai. Similarly, PCR prevalence was highest in Jalala with 15.6 % (95 % CI 12.5–18.6 %) for P. vivax malaria and the lowest in Kagan with 3.7 % (95 % CI 0–6.2 %). Plasmodium vivax infection by RDT was lower than PCR: Jalala camp reported the highest RDT prevalence at 9.7 % (95 % CI 7.1–12.3 %) and lowest was in Adezai camp . Overall, P. falciparum infection and exposure was lower than that of P. vivax. Seroprevalence estimates ranged from 9.9 % (95 % CI 7.2–12.5 %) in Zangla Patai to 2.4 % (95 % CI 1.1–3.8 %) in Kagan refugee camp. Evidence of P. falciparum infection by PCR was only observed in Jalala  and Kagan  camps and by RDT in Zangal Patai .Estimates of malaria infection and exposure were consistent with low endemicity in all camps Table . SeroprePlasmodium vivax transmission intensity, as estimated by SCR, followed a similar pattern to other infection metrics in that it was comparatively low in all camps with the highest SCR observed in Jalala camp  and lowest in Adezai   and RDT . PCR bootstrapping estimates correctly classified Jalala as having the highest transmission but Adezai was estimated to have higher PCR prevalence than both Kagan and Zangal Patai despite the lowest SCR. SCR estimates for P. falciparum suggest residual very low level exposure is occurring in all camps, however despite an indication of limited transmission, Jalala and Kagan as well as Zangal Patai had evidence of current infection based on PCR and RDT.P. vivax RDT positivity, adults over 20 years of age were significantly less likely  to have an infection compared to children under 5 years of age . Those reporting a fever in the previous 2 weeks had over seven times the odds  of being infected compared to those not reporting a fever. Both reported use of an ITN the previous night and use of mosquito repellants in the household were associated with a reduced odds of having a P. vivax infection while those of higher SES were also less likely to be infected  and 2.73 (95 % CI 1.69–4.39) the odds of being positive for anti-malarial antibodies to P. vivax and P. falciparum, respectively, compared to those younger than 5 years. Those reporting fever in the previous 2 weeks also had increased odds of being seropositive for both P. vivax  and P. falciparum . Reported use of mosquito repellents was associated with a 30 % reduction in odds of exposure for both species . Living in a household with an iron roof was associated with an increase in odds with being seropositive to P. falciparum . Owning animals showed a 1.63 (95 % CI 1.30–2.05) increase in the odds of being seropositive for P. vivax compared to not owning any animals but had no association with P. falciparum.As expected, both P. vivax was observed in three of the five refugee camps (Fig. P. vivax transmission was the highest, 51.3 % of sampled households were found to be part of a hotspot by at least one metric and 17.8 % of households showing evidence of significant clustering for all markers (Fig. P. vivax whereas hotspots consisting of 14.8 % of households in Adezai (Fig. P. falciparum seroprevalence (Fig. Evidence of spatial clustering of both infection and exposure to mps Fig. . In Jalaers Fig. c. Baghicers Fig. b and Kagers Fig. d showed zai Fig. a and 28.P. vivax and P. falciparum in five Afghan refugee camps in Pakistan. Plasmodium vivax infections were detected in all camps by both RDT and PCR and ranked camps in order of transmission intensity similarly to the order quantified by SCR. No P. falciparum infections by either RDT or PCR were detected in two of the camps although there was evidence of low transmission detected through serological tools. The limited sensitivity of diagnostic tools for current infection observed in this very low-transmission setting is consistent with other studies and further highlights the importance in having combined diagnostic approaches to ensure that current infections as well as transmission potential are included in decision-making [This study shows evidence of comparatively low and highly heterogeneous transmission for both n-making , 25. In n-making .P. vivax as well as exposure to P. falciparum were identified in this stable refugee population. The use of mosquito repellants, such as sprays or coils, were consistently associated with a reduction in odds of both infection and exposure. This finding may be related to the limited reported use of IRS and ITNs in some of the camps and conversely, the availability and ease of use of repellents. It may also reflect increased awareness of malaria by those that use repellents. Continuing to promote and ensure the availability of mosquito repellents in addition to ITNs or providing these tools as part of a repatriation package upon returning to Afghanistan could be a useful and simple addition to malaria control programmes [Several factors associated with infection and exposure to ogrammes .P. falciparum-infected individual had reported recent travel to Mozambique where malaria transmission is still high [Residing in the camp for the previous 6 months was associated with a significant reduction in the odds of malaria exposure whereas recent travel showed increased odds. These findings suggest that importation of malaria from other areas may be contributing to the maintenance of malaria transmission within these camps . This still high . Additioill high . FurtherP. vivax but was not associated with exposure to P. falciparum. Different Anopheline vector species have been identified in Afghan refugee camps and it is likely that they have different blood-feeding behaviours [P. falciparum exposure may also be due to low levels of seroreactivity observed which is likely a product of the low levels of infections, but also due the differences in the timing of sampling in relation to the sampling with the survey taking place after the main P. vivax season and before the P. falciparum one.Owning animals was associated with increased odds of being seropositive for haviours . HoweverP. vivax infection and exposure to P. vivax and P. falciparum. The association with malaria is well known and serves as a useful symptom with which to identify malaria infection. Targeting efforts to areas with a high occurrence of fever could provide a simple indicator to initiate re-active case detection, or targeting populations reporting a higher incidence of fever. However, due to the non-specific nature of using fever to diagnose malaria, particularly in low transmission settings, this approach would need to be validated or be accompanied by a malaria diagnostic tool to confirm infection.Finally, a history of fever was associated with both increased odds of P. vivax transmission season. This may have had some impact on the ability to correctly rank transmission intensity with the different metrics. RDT positivity for example, may persist after infection and this will be more likely to occur at the end of the transmission season. However, the low seroprevalence and SCR suggest that seasonal effects on prevalence will be minimal.There are a number of limitations to this study. Firstly, the camps were sampled at different time points in the transmission season with Baghicha and Kagan sampled before and Adezai, Jalala and Zangal patai sampled during the main P. falciparum prevalence may have been the result of sampling all camps prior to the main transmission season, which typically occurs in October [The very low  October . HoweverP. vivax it is unclear if the infection and exposure dynamics described are the result of de novo infection or transmission maintained by hypnozoite-derived infections. This is common with most studies on P. vivax as there is no diagnostic to identify hypnozoite infections. It is possible that elevated antibody levels in the absence of an infection could be used to indicate the possibility of hypnozoite carriage but this needs to be validated in individuals with known relapses, and with probability a broader range of antigenic targets.PCR could only be conducted on a sub-set of samples due to time and financial constraints. Whilst bootstrapping techniques were used to obtain population level prevalence estimates, these could not be used to assess risk factors or spatial patterns of infection. The factors associated with current infection are not expected to have varied significantly as findings are consistent with previous studies in the Afghan refugee population as well as other studies in low transmission settings , 30, 31.P. vivax and P. falciparum transmission occurring in the refugee camps included in this survey. However, although risk is low, it is still higher than reports from the rest of KPK, which suggest 1 % prevalence by RDT [P. falciparum strains in Pakistan [This study suggests that there are low levels of both e by RDT , 35. ThePakistan  as well Pakistan . The proPakistan .Ultimately, understanding the epidemiology behind malaria transmission in this vulnerable population is essential so that malaria control programmes can effectively target their resources where they can be most effective . As heal


Plasmodium falciparum to avoid host immune responses. There are known associations between high levels of circulating soluble HLA-G (sHLA-G) and either parasite or viral infections and it has been suggested that the induction of sHLA-G expression could be a mechanism via which infectious agents subvert host immune defence. The study presented here is the first to investigate the possible association between sHLA-G and malaria or malaria related risk factors in Benin.The immunosuppressive properties of HLA-G protein can create a tolerogenic environment that may allow A parasitological and clinical follow-up of 165 mothers and their newborns from delivery through to one year of age was conducted in the Tori Bossito area of southern Benin. Plasma levels of sHLA-G were determined by ELISA in maternal peripheral and cord blood and again in infants' peripheral blood at 3, 6, 9 and 12 months of age. The associations between the levels of sHLA-G and malaria risk factors were investigated through multivariate mixed models.P. falciparum infection in infancy.Strong correlations were observed between the maternal and cord plasma concentrations of sHLA-G. In multivariate analyses, high cord plasma levels of sHLA-G were independently associated with (i) low birth weight and (ii) an increased risk of These results show for the first time the possible involvement of sHLA-G in generating immune tolerance during pregnancy-associated malaria. Soluble HLA-G may represent a useful marker of susceptibility to malaria in infants and be associated with the higher susceptibility to infection observed for LBW children. Human Leucocyte Antigen-G (HLA-G) is a non-classical HLA class I antigen that differs from other HLA class I molecules by its limited polymorphism, its restricted tissue distribution and the characteristics of its protein expression. Seven protein isoforms can be generated from alternative splicing, comprising four membrane-bound isoforms  and three soluble isoforms . A soluble form of HLA-G1 can be generated by proteolytic cleavage of membrane-bound HLA-G1. The main isoforms present in plasma are shed HLA-G1 and secreted HLA-G5 proteins.in vitro fertilization[HLA-G plays a crucial role in immune tolerance and differs from HLA class I molecules in its negative immunoregulatory functions and its interactions with leukocyte immunoglobulin-like inhibitory receptors ILT2 and ILT4 or killer cell immunoglobulin-like receptor (KIR2DL4) that are expressed on a range of immune cells, 2. The lization, 4. Morelization. HLA-G ilization, 7 and vlization, 9. To flization–13.Plasmodium falciparum malaria is endemic especially in the tropical areas, of Africa. Malaria due to P. falciparum infection during pregnancy is associated with a range of poor outcomes including low birth weight[in utero leading to immune tolerance[P. falciparum compared with uninfected placentas, suggesting that HLA-G down-regulation may be involved in the poor birth outcomes associated with P. falciparum infection[h weight, 15. Morh weight–18. Thisolerance. In the nfection. The levPossible associations between malaria and sHLA-G have not been explored to date. Here, the immunosuppressive properties of sHLA-G might contribute to an individual's susceptibility to malaria and this study investigates this possible association in pregnant Beninese and their offspring.This cohort study was conducted in Tori Bossito area, located 40 km north-east of Cotonou in southern Benin, from June 2007 to January 2010, evaluating the determinants of malaria incidence in the first months of life. Women (n = 620) were enrolled at delivery and their infants were actively followed-up during the first year of life. Among them, 165 infants were selected according to the placental malaria status of the mother and to the availability of plasma for sHLA-G quantification at delivery , and at 3, 6, 9 and 12 months. One group comprised all the mother/infant pairs associated with an infected placenta (n = 51), whilst a second group comprised 114 mother-infant pairs selected randomly amongst infants born to mothers with uninfected placentas. Details of the follow-up procedures have been published elsewhere. They arP. falciparum. Smears were read by two technicians and in case of discordance a third reading was performed by a senior biologist.At delivery, a questionnaire was conducted to gather information on women’s characteristics and on the course of their current pregnancy. After delivery, thick and thin placental blood smears were examined to detect placental infection defined by the presence of asexual forms of At birth, newborn’s weight and length were measured by midwives and gestational age was estimated using the Ballard method. During Soluble HLA-G concentrations were evaluated by a specific sandwich ELISA in plasma using MEM-G/9 and antiDue to the skewed distribution of values, a logarithmic transformation was applied to sHLA-G levels. All subsequent analyses were performed using the log transformed sHLA-G level, defined as sHLA-G variable.Univariate and multivariate analyses were performed to identify the different factors associated with the sHLA-G levels in maternal peripheral and cord blood.The relationships between the levels of sHLA-G at a given quarterly visit and the occurrence of malaria episodes in the previous trimester were determined. For this first objective, the relationship between the dependent variable (sHLAG) and the number of malaria episodes during the previous trimester was analysed using a linear mixed model.The study was also interested in determining whether the level of sHLA-G at a quarterly measurement was associated with the risk of developing malaria during the following trimester. For this second objective, the relationship between the number of infections at each trimester (dependent variable) and the sHLAG level at the corresponding quarterly visit was studied through a Poisson mixed model. The sHLA-G level was used quantitatively or categorized into four classes according to the quartiles, and then adjacent classes were grouped if they showed similar results in the final regression model.All analyses were adjusted on maternal and newborn’s covariates: The maternal covariates were: age (years), placental malaria infection, gravidity, administration of intermittent preventive treatment against malaria in pregnancy (IPTp), ethnicity group and village of residence. The newborn covariates were: age (months), birth weight (low birth weight (LBW) if <2500 g), gender, prematurity, malaria episodes by trimester, and environmental risk of exposure to malaria (RE).All variables with p value below 0.20 in univariate analysis were initially introduced into the multivariate model. The final multivariate model was selected through a backward procedure, and only covariates with a p-value below 0.05 were kept. Malaria episodes (when treated as the explanatory variable in the first approach), sHLA-G (when treated as the explanatory variable in the second approach), placental malaria and environmental risk of exposition to malaria were forced in the final models. All analyses were performed using Stata v.11.The study protocol was approved by the University of Abomey-Calavi’s institutional review board and the IRD’s Consultative Ethics Committee. All women signed informed consent before enrolment and were able to withdraw their consent at any time.P. falciparum infections before 12 months was 143 (range =1-4 infections/newborn) with 109 symptomatic infections (with fever). For 22 of the infants no parasites were detected at any time during the 12 months of follow-up.The mean age of mothers was 26.5 years ; 19.7% were primigravidae and 86.2% declared having received an intermittent preventive treatment (at least one dose of sulphadoxine-pyrimethamine); 51 had an infected placenta at delivery. Newborn’s mean birth weight was 3001.4 g , and 7.8% of them had a low birth weight  (Table -3) in maternal and cord blood samples. The mean level in the maternal blood (19.2 ± 25.6 ng/mL) was significantly higher than in the cord blood (16.3 ± 26.8 ng/mL) .In the first year of life the mean level of sHLA-G in infants varied over time  at delivery. Overall, the average level of sHLA-G in maternal blood was 19.2 ng/mL . In the 129 mothers with detectable levels of sHLA-G at delivery, the mean level was 24.4 ng/mL . At birth, the average level of sHLA-G in cord blood was 16.3 ng/mL  and 60.0% of children (99/165) had detectable sHLA-G . Levels of sHLA-G were highly correlated  with the level in cord blood, whereas IPTp was associated with a lower level (p = 0.014). Ethnic group (p = 0.10) was included in multivariate analysis. Although non-significant, placental malaria infection (p = 0.39) was forced in multivariate analyses. Multivariate analysis confirmed these associations, except that belonging to “other ethnic groups” became significantly associated with a higher level of sHLA-G in mothers (p = 0.03). Placental malaria infection remained non-significant  and LBW (p = 0.02) were significantly associated with a higher level of sHLA-G in cord blood. This was confirmed by multivariate analysis, whereas placental malaria infection was not related to sHLA-G in cord blood , with the village of residence (p = 0.035), and with a high level of sHLA-G both in maternal (p < 10-3) and in cord blood (p < 10-3). LBW was also associated with a high level of sHLA-G both in cord (p = 0.04) and in peripheral blood during the first year of life (p = 0.004). Malaria infections occurring during the trimester preceding blood samples and placental malaria infection were not related to sHLA-G. In the multivariate linear mixed model, age, LBW, environmental risk of malaria and sHLA-G in cord blood were significantly associated with a high level of sHLA-G  did not vary significantly (P = 0.569) between children with no detectable soluble HLA-G at birth and others.-3) and age (p = 10-3) were significantly associated with an increased risk of malaria. Moreover, a significant association (p = 0.016) was detected between the level of sHLA-G at a quarterly measurement and the appearance of malaria in the following months. LBW and placental malaria were not associated with an increased risk of malaria during the first year of life. The multivariate analyses confirmed these results, although the sHLA-G variable became marginally significant (0.06), and only the highest sHLA-G levels were strictly significantly related to an increased risk of malaria during the following trimester (p = 0.02)  Table .Table 5P. falciparum may alter infants’ immunological responses and be responsible for an immune tolerance phenomenon[P. falciparum infection was also a risk factor for non-malarial infections in infancy[This study is the first to investigate the association of soluble HLA-G and malaria in pregnant women and newborns. Children born to a mother with an infected placenta have an increased risk of malaria and/or parasitaemia during the first months of life, 25, 26  infancy strength infancy. The priP. falciparum-infected placentas may be involved in poor birth outcomes[HLA-G 3’UTR could influence the clinical and immunological responses directed to P. falciparum[P. falciparum, and in particular the IgG1 and IgG3 antibody subclasses involved in anti-malarial protection[HLA-G modulates host immune response via interactions with its inhibitory receptors that are expressed on the surface of NK cells, T and B lymphocytes, monocytes, dendritic cells and neutrophils, and could thus play a role in susceptibility to infectious diseases. To date, only three studies have explored the relationship between HLA-G and malaria. The first of them suggested that HLA-G down-regulation in outcomes. Two reclciparum, 29. In otection–32. In aP. falciparum infection on sHLA-G levels was not observed. However, as shown previously, other infections  but also other cellular stresses (hypoxia…) can be associated with different levels of sHLA-G. Since these factors have not been taken into account in the follow-up, the effect of malaria alone was too small to be detectable and the possibility that some infections went undetected despite close monitoring cannot be excluded. Moreover this study showed that the intake of antimalarial preventive treatment during pregnancy was correlated with decreased levels of sHLA-G at delivery and that an increased exposure to malaria  was associated with higher levels of sHLA-G. Both these results suggest indirectly that malaria could be related to the levels of sHLA-G. However, a lack of statistical power due to low number of samples cannot be excluded in this preliminary study. In the present study, higher levels of sHLA-G in cord blood were associated with low birth weight, which itself is highly related to infant morbidity and mortality[Previous studies showed an association between high levels of sHLA-G and parasitic or viral infections, 12, 33.ortality. It was ortality. The preortality, a higheortality, 37. Put-3) as already reported[HLA-G polymorphism influences sHLA-G plasma level in Brazilian and French populations[The plasma levels of sHLA-G in the peripheral blood of the mother at delivery and in the cord blood were highly correlated (r = 0.74; p = 10reported. Althougreported, 40. Thireported. The expulations.In conclusion, this work had shown an association between high levels of sHLA-G and an increased risk of malaria, and of low birth weight. These results suggest that HLA-G could be associated not only with malaria susceptibility during the first months of life but also with the higher burden of infections low birth weight babies are faced with. Further studies are ongoing including the follow-up of pregnant women and their newborns and the detection of both malarial and non-malarial infections.


The importance of fevers not due to malaria  in children in sub-Saharan Africa is increasingly being recognised. We have investigated the influence of exposure-related factors and placental malaria on the risk of non-malaria fevers among children in Kintampo, an area of Ghana with high malaria transmission.Between 2008 and 2011, a cohort of 1855 newborns was enrolled and followed for at least 12 months. Episodes of illness were detected by passive case detection. The primary analysis covered the period from birth up to 12 months of age, with an exploratory analysis of a sub-group of children followed for up to 24 months.p = 0.012], infants from households of poor socio-economic status [aHR 1.22 (95 % CI 1.02–1.46) p = 0.027] and infants living furthest from a health facility [aHR 1.20 (95 % CI 1.01–1.43) p = 0.037]. The incidence of all episodes of NMF was similar among infants born to mothers with or without placental malaria [aHR 0.97 ].The incidence of all episodes of NMF in the first year of life (first and subsequent) was 1.60 per child-year . The incidence of NMF was higher among infants with low birth weight [adjusted hazard ratio (aHR) 1.22 (95 % CI 1.04–1.42) The incidence of NMF in infancy is high in the study area. The incidence of NMF is associated with low birth weight and poor socioeconomic status but not with placental malaria.The online version of this article (doi:10.1186/s12879-016-1654-4) contains supplementary material, which is available to authorized users. The burden of malaria in sub-Saharan Africa is still high  althoughSome environmental and social factors are known to be associated with NMF. In a study undertaken in Nigeria, the risk of NMF was increased among the poor and among rural populations . PovertyTo investigate the influence of social and environmental factors, placental malaria and gravidity on the risk of NMFs among young children, we have analysed data from the Kintampo Birth Cohort Study which was conducted between 2008 and 2011 in an area of Ghana with high malaria transmission . This stA prospective birth cohort study to explore the relationship between placental malaria and malaria in infancy was conducted between 2008 and 2011 in the Brong-Ahafo region of Ghana; this study is described in detail elsewhere . MalariaThe study procedures have been reported in detail elsewhere . In summNewborns of mothers who had been enrolled in the study prior to delivery were included in the infant cohort study. All infants recruited to the study  were followed for a minimum of 12 months. However, because recruitment to the study was gradual and children remained in follow-up until the end of the study in May 2011, some children were followed up to 24 months of age.Episodes of illness were detected passively at study clinics. To maximise capture of fevers, families were provided with health insurance for the duration of the study and encouraged to attend clinics whenever an infant was unwell. Furthermore, community-based fieldworkers facilitated transportation of sick infants to see a study clinician for clinical evaluation. On evaluation by a study clinician, a history of fever within the 48 h prior to the clinic visit was recorded and an axillary temperature was measured with a digital thermometer.Infants’ illnesses were investigated and managed according to the Ghana National Treatment Guidelines. Rapid diagnostic tests were used to diagnose malaria prior to treatment at the clinic. Thin and thick peripheral blood smears were also made and read subsequently, following the methods described by Swysen et al. . Blood cCleaned data were analyzed using STATA 13 . Principal component analysis of women’s durable assets was used to derive quintiles of socio-economic status (SES), as described previously , 25–27. The primary analysis covered the period from birth up to the age of 12 months. A previous study of non-malaria fevers in Benin  investigThe study was approved by the ethics committees of the Kintampo Health Research Centre (KHRC), Ghana Health Service, London School of Hygiene & Tropical Medicine and Noguchi Memorial Institute for Medical Research. Written informed consent was sought from all study women.p = 0.175). Socio-demographic characteristics such are place of residence, household size, or socioeconomic status were not statistically different among children who died and children who survived  completed the scheduled 1 year of follow up. Additionally, 39.5 % (737) and 17.4 % 322) were followed for 18 and 24 months respectively  of which were associated with respiratory symptoms, 911 (32.1 %) with gastro-intestinal symptoms, and 625 (22.0 %) with other symptoms. During the same period of follow-up, 1242 febrile malaria episodes were recorded. Sixty-five percent (1205/1855) of the study children experienced at least one episode of NMF. The incidence of all (first and subsequent) episodes of NMF in infancy was 1.60 per child-year . The incidence of NMF was low in early infancy, and rose quickly to around two episodes per child-year between 6 and 8 months of age, after which the incidence reached a plateau ; adjusted hazard ratio (aHR) 1.39 ], higher among children who had a low birth weight compared with children who had normal birth weight , higher among those living furthest (>8Km) from the nearest health facility  and, unexpectedly, higher among those whose mothers had used three courses of IPTp  (Table p < 0.001). The incidence of NMF was lower among girls than boys  and among children who used their bednet less regularly .The incidence of NMF between 0 and 12 months of age was higher in poor children, with incidence elevated in all SES categories relative to the most wealthy group Table . The incp = 0.516), aHR 0.97 ]  p = 0.367] (Table p = 0.79).The incidence of NMF between 0 and 12 months of age among children born to mothers without placental malaria was very similar to that observed among children born to mothers who had placental malaria  ] , The factors associated with NMFs accompanied by respiratory symptoms were similar to those associated with all NMFs. Between 0 and 12 months of age, the incidence of respiratory NMFs was higher among those of low birth weight, those born during the rainy season and among those of more poor socioeconomic status Table . There wThe incidence of NMFs associated with gastrointestinal symptoms between 0 and 12 months of age was higher among children from larger households, those from more poor or very poor families, those living far from a health centre and those born during the rainy season Table . As in tWe followed a cohort of 1855 children during infancy, and investigated the relationship between social and environmental factors, placental malaria and gravidity on the incidence of non-malaria fevers (NMFs). Our findings indicate that despite the well-documented high burden of malaria in this setting, non-malaria fevers contribute a larger fraction of the febrile disease burden in the first year of life.Since cases of NMF were identified passively and therefore dependent on the health seeking behaviour of mother or caregivers of the infants, it is likely that the true incidence of NMF is higher still. It is possible that children living in this high malaria transmission area are predisposed to other febrile illness due to the modulation of the immune system –30 that The high burden of NMFs in young children is concentrated predominantly among poor families living far from health facilities. Children with low birth weight were found to be at an increased risk of NMFs over the course of the study. Low birth weight infants are known to be at a higher risk of bacterial and viral infections , possiblThe finding that NMFs were more frequent in children born to women who had received several courses of IPTp was unexpected. This result was seen in different sub-categories of NMFs, and remained after adjustment for a number of possible confounders including distance from a health centre, place of residence and SES. It also remained in exploratory analyses over a longer period of follow-up. One possibility is that mothers who received IPTp were especially conscientious about seeking care for their children when they were ill, resulting in higher apparent incidence (i.e. the apparent link between higher IPTp use and NMF incidence is a result of confounding by care-seeking/access to care). However, if this was the case, it might also be expected that the children of these mothers would have an increased incidence of malaria; this was not found in our previous analysis of children in this cohort . It is dNMFs were no more frequent in children born to women with placental malaria at delivery than in children whose mothers did not have placental malaria either in crude or adjusted analyses. There was also no association between the incidence of NMFs and mothers’ gravidity. In a previous study carried out in Benin, placental malaria infection was associated with a higher risk of NMFs among young children  and the The reason for differences between our results and those of the study in Benin is unknown, although we performed analyses to match those undertaken in the Benin study as closely as possible. There were however some methodological differences between the two studies. Firstly, the transmission of malaria in Kintampo was much higher than in Tori Bossito, Benin  269 infectious bites per person per year  and 20.5The following potential biases are acknowledged in this study. Firstly, NMF cases were passively detected, therefore the true incidence may have been under-estimated depending on the health seeking behaviour of caregivers. To address this, care-givers were provided with free transportation and health insurance, and encouraged to attend study clinics whenever their child was unwell. Secondly, since there is no diagnostic test routinely carried out for the non-malarial causes of fever, it is possible that co-infections of malaria and other causes of fever such as viral infections were misclassified as malaria-only infections. This may also have led to underestimation of the incidence of NMF. Similarly the incidence of NMF may be underestimated if mortality among the study participants were as a result of NMF that were not reported.Despite these issues that may lead to an underestimate of malaria incidence, and despite the high level of malaria transmission in this area of Ghana, the incidence of NMF is high. This underscores the importance of other causes of fever in many settings where malaria has previously been the major focus. There is an urgent need to determine the most frequent causes of NMFs in different ecological situations to allow the development of therapeutic and preventative strategies based on sound scientific evidence.The incidence of NMF is high in the middle belt of Ghana. The incidence of NMF is associated with low birth weight and poor socioeconomic status but not with placental malaria.ACT, artemisinin-based combination therapy; aHR, adjusted hazard ratio; CI, confidence interval; EIR, entomological inoculation rate; IPTp, intermittent preventive treatment in pregnancy; IRS, indoor residual spraying; ITN, Insecticide treated nets; KHDSS, Kintampo Health and Demographic Surveillance System; KHRC, Kintampo Health Research Centre; LBW, low birth weight; MG, multigravidae; NMF, non malaria fevers; PG, primigravidae; PM, placental malaria; SES, socio-economic status; uHR, unadjusted hazard ratio


Malaria has become a major public health problem in Mauritania since the 1990s, with an average of 181,000 cases per year and 2,233,066 persons at risk during 1995–2012. This paper provides the first publicly available overview of malaria incidence and distribution in Mauritania. Information on the burden and malaria species distribution is critical for guiding national efforts in malaria control. As the incidence of malaria changes over time, regular updates of epidemiological data are necessary. Poular, Wolof, and Soninke). However, there are no data on the demographic weight of each ethnic group. Sedentarization and rural exodus, partly related to the periods of drought in the 1970s and 1980s, are the most significant demographic phenomena that have occurred in Mauritania since the country’s independence in 1960. Whereas the proportion of urban population was 9% in 1965, it increased to 22.7, 46.7 and 60% in 1977, 2005 and 2010, respectively. Over the same period, the nomad population rapidly decreased from 65% in 1965 to 12 and 6% in 1988 and 2000, respectively [The Islamic Republic of Mauritania is situated in northwest Africa between 15 and 27° N latitude and 5 and 17° W longitude. It occupies a total surface area of 1,030,700 sq km . Accordingly, the country is geographically divided into three ecological areas Figure : arid SaThe history of documented malaria cases in Mauritania is relatively recent. The official statistics, mostly based on clinical diagnosis without laboratory confirmation, show an increase of malaria cases during the last two decades from 26,933 in 1990 to 165,834 in 2012 . MoreovePlasmodium falciparum, Plasmodium vivax, Plasmodium ovale, and Plasmodium malariae [Plasmodium falciparum was the dominant species, diagnosed in 90% of reported clinical malaria cases. The recorded infection rates were variable depending on the season, region and rainfall. In the first published report from the southern region of Gorgol, Sautet et al. [Plasmodium falciparum was detected in 133 (43.3%) of 307 examined slides, followed by P. malariae with (10.7%) and P. vivax (4.5%). In another study conducted in southern Mauritania, Escudie and Hamon [P. falciparum over P. malariae. Three years later, a survey conducted in the cities of Atar in northern Mauritania and Kaedi, Kiffa, Kankoussa, Aioun, and Tamchakett in southern Mauritania, noted the presence of only P. falciparum and P. malariae, with an infection rate of 7% [P. falciparum in Ksar Torchane (Saharan part of the country), 58% in Boutilimit (Sahelian region), and 34-45% in the Sahelian region of Assaba region. The survey also reported a malaria serological prevalence of 12% in March 1973 (during the dry season) and 14% in November 1972 (just after the rainy season) among schoolchildren in Nouadhibou, a coastal city in northwestern Mauritania [et al. [Studies conducted in different regions reported the presence of four malaria species in Mauritania Figure , namely malariae -12. Plast et al.  reportediae with .7% and P [et al.  reportedP. vivax. In 2003, Cortes et al. [P. falciparum and 35.5% due to P. vivax. The authors also found nine malaria cases , which were considered as autochthonous. Moreover, Mint Lekweiry et al. [P. vivax , followed by P. ovale  and P. falciparum  by microscopy. PCR performed on these samples confirmed all P. vivax and P. falciparum infections, but cases initially diagnosed to be P. ovale infections by microscopy turned out to be P. vivax by PCR. Therefore, after PCR correction, the proportion of P. vivax to P. falciparum was 58/61 (95.1%), and no P. ovale or P. malariae malaria parasites were detected by PCR. This study also revealed that among 237 recruited febrile patients, 231 were clinically diagnosed and treated as malaria cases and that false positive constituted 73.6% of the clinically diagnosed malaria. This finding highlights the importance of the timely use of microscopy and, in case of unavailability of microscopes and/or well-trained microscopists, an alternative reliable laboratory tool, in particular rapid diagnostic tests for malaria, will play a major role in establishing the correct diagnosis and appropriate treatment.More recently, studies conducted in Nouakchott, the capital city of Mauritania, showed that infection due to malaria has increased with a high rate of infection due to s et al.  found 77y et al.  reportedP. vivax and 2.9% (three of 105) were caused by P. falciparum. The results of this 2009–2010 study confirmed malaria prevalence among febrile patients and distribution of Plasmodium spp. in Nouakchott. Moreover, 54 of the P. vivax-infected children had never travelled outside Nouakchott, suggesting that malaria transmission occurs within the city and that P. vivax is the principal causative agent.In the follow-up study performed in 2009–2010, the same authors found a malaria prevalence of 34.9% (105 of 301 febrile patients) among children born and residing permanently in Nouakchott . Among tP. vivax and P. falciparum in Nouakchott and southern Mauritania [P. vivax endemicity in Nouakchott, the World Malaria Report 2013 erroneously indicates that Mauritania is free of P. vivax, demonstrating a gap in the quality of national data submitted to WHO [In general, while malaria diagnosis, based on thick and thin smears, previously reported the presence of four malaria species in the country -11, moreuritania ,16,17. Fet al. [P. falciparum was detected in the autochthonous Mauritanian population. Gasquet et al. [P. falciparum attending the health facility in Kiffa (Assaba region) with the following characteristics: a minimum parasite density of 1,000 asexual parasites/μl of blood, absence of chloroquine in the urine, and no recent history of treatment with other anti-malarial agents. The patients received a standard dose of 25 mg base of chloroquine per kg body weight over three days and were followed until day 7. Six patients were lost to follow-up. Three (9.7%) of the 31 enrolled patients had recurrent asexual parasitaemia, and one patient remained febrile on day 7, suggesting clinical resistance to chloroquine.In 1991, during the survey of anti-malarial drug resistance in West Africa, Guiguemde et al.  reportedet al. [P. falciparum chloroquine resistance transporter (pfcrt) and P. falciparum multidrug-resistance gene 1 (pfmdr1), after an unusually heavy rainfall in Aioun and Kobeni, southern Mauritania. Clinical chloroquine resistance was detected in 33 of 85  RI resistance and 14 (16.5%) RII/RIII resistance) P. falciparum-infected patients followed until day 14. Molecular analysis showed a sensitivity for detection of clinical resistance of 60.6% and a specificity of 65.3% for pfmdr1 76-tyrosine mutant allele while Lys76Thr mutation in pfcrt gene showed a very high sensitivity (100%) but low specificity (65.4%) to detect clinical resistance. The combination of mutations in both genes decreased the sensitivity to 60.6% while specificity increased to 76.9%. The authors concluded that pfcrt, but not pfmdr1, may be useful to monitor chloroquine resistance in Mauritania.Jelinek et al.  combinedet al. [P. falciparum isolates collected in Hodh Elgharbi region (southeast Mauritania) from patients recruited at two medical centres in Aioun, the regional capital city and Kobeni, a small city near the border with Mali, for point mutations in dihydrofolate reductase (dhfr)  and dihydropteroate synthase (dhps) genes . Dhfr mutations were found at a low prevalence both in Aioun and Kobeni (18.6% of samples from Aioun and 12.6% of samples from Kobeni showed at least one mutation), whereas a high prevalence of dhps mutations was noted among isolates from Aioun (74.6%) and Kobeni (63.4%), respectively. These results suggested that sulphadoxine-pyrimethamine may be effective for intermittent preventive treatment in pregnant Mauritanian women (the only current indication of sulphadoxine-pyrimethamine in Mauritania), but more clinical data are required to confirm the molecular findings.Molecular analysis of resistance to antifolates (pyrimethamine and sulphadoxine) was performed by Eberl et al.  using thet al. . These aet al. [P. vivax population isolated from 110 malaria-infected patients in Nouakchott. Indeed, the majority of the isolates  were genotyped as wild-type P. vivax dhfr (pvdhfr), while the remaining ten isolates carried the Ser58Arg and Ser117Asn double mutations . All isolates had the wild-type P. vivax dhps (pvdhps) alleles. For P. vivax multidrug resistance gene 1 (pvmdr1), 75 of 103 (73%) had the wild-type Tyr976, and 28 (27%) carried the mutant Phe976. Most (98%) carried the mutant Leu1076 codon. Of 105 isolates, 102 (97%) had one gene copy and three (3%) had two copies of the pvmdr1 gene. Pvmdr1 mutations have been suggested to be associated with chloroquine resistance in P. vivax, whereas an increased number of copy number has been associated with resistance to mefloquine [In 2012, Mint Lekweiry et al.  reportedfloquine ,24.Plasmodium spp. populations in Mauritania are very limited. Jordan et al. [P. falciparum isolates, collected in Aioun and Kobeni in 1998 as part of the clinical study on chloroquine efficacy, for three polymorphic genetic markers: merozoite surface protein 1 (msp1) and merozoite surface protein 2 (msp2), and glutamate-rich protein (glurp). The differences in the population structure between the two study areas were seen in both the mean number of distinct parasite populations per infection (1.57 for Aioun and 2.34 for Kobeni) and their distribution in different allelic groups. For msp2, the differences in the number of size variations and amplified fragments were observed in the msp2 FC27 allelic family. Isolates from Aioun showed one or two bands with six different sizes, while amplification of the samples from Kobeni produced up to four bands with 18 different band sizes. However, analysis of glurp provided no further conclusive information because all samples showed a single band of the same size, suggesting limited heterogeneity of P. falciparum populations circulating in this region. More recently, Ould Ahmedou Salem et al. [msp1 block 2 region among P. falciparum isolates in Nouakchott, the capital city of Mauritania, and Hodh Elgharbi region (southeast of Mauritania). K1, Mad20 and Ro33 msp1 alleles were identified with 27 different sized alleles. Infection with multiple P. falciparum populations was observed in the two regions , as well as a high multiplicity of infection (3.2 genotypes per infection), reflecting both the high endemicity level and malaria transmission in the study areas.Studies on the genetic structure of n et al.  genotypem et al.  examinedet al. [Anopheles species and subspecies in Mauritania: Anopheles funestus, Anopheles gambiae s.l., Anopheles pharoensis, Anopheles rufipes, Anopheles melas, Anopheles dhtali, Anopheles rhodesiensis, Anopheles coustani, Anopheles ziemmani, Anopheles pretoriensis, Anopheles squamosus, and Anopheles demilloni. Among these anopheline species, only An. gambiae and An. funestus are known to be major malaria vectors in Africa. In Mauritania, An. gambiae s.l. appears to be the dominant malaria vector [The first published studies on malaria vectors date back to the 1940s , followeet al. . These aa vector ,28. Howeet al. [Anopheles arabiensis, An. pharoensis and An. funestus, in 21 localities in five regions in Mauritania, namely Trarza, Brakna, Assaba, Hodh Elgharbi and Tagant. They collected 647 anopheline specimens, among which An. gambiae s.l. was the most commonly identified species (92%), followed by An. pharoensis (5%) and An. funestus (3%). Anopheles gambiae was collected in all localities except in Moudjeria (north of the country) where there was no mosquito captured during the study period. The molecular identification of the An. gambiae complex revealed the predominance of An. arabiensis and the presence of An. gambiae (M form) in Assaba, Brakna and Hodh Elgarbi regions. In Nouakchott, the presence of anopheline mosquitoes (An. gambiae s.l.) was first reported in Toujounin district [et al. [An. arabiensis and An. pharoensis in Dar Naim district in Nouakchott. Ould Ahmedou Salem et al. [An. gambiae s.l. larval habitats in Nouakchott and described their ecological and physico-chemical characteristics. They reported that water bodies consisting of water discharged from standpipes and household drinking water tanks served as Anopheles spp. larval habitats. Using multivariate regression analyses, it was further shown that salinity up to 0.1 g/l and shaded habitats were protective factors against high larvae density in breeding sites and that pH up to 7.61 was a risk factor to develop high larvae density in these breeding sites. However, studies on bionomics, epidemiology of anopheline species, and their involvement in malaria transmission remain poorly understood although the presence of P. falciparum and P. vivax sporozoites was demonstrated in the salivary glands of An. arabiensis collected in Mauritania [Recently, Dia et al.  studied district . More re [et al.  demonstrm et al.  have recuritania ,31.The Mauritanian Ministry of Health executes malaria control through the National Malaria Control Programme, which has elaborated a quadrennial strategic plan against malaria epidemics and endemicity. The stated goal of the latest plan for 2011–2015 is to reduce, by 2015, malaria-related morbidity and mortality from 17.5% and 0.39 per 100,000 inhabitants in 2011 to 10.9% and 0.15 per 100,000 inhabitants in 2015, respectively [As of 2014, ITNs have been distributed free of charge to the major risk groups in southern Mauritania, i.e. among pregnant women, and IPT has been effectively implemented since 2008 . HoweverP. falciparum in West Africa, particularly in the Senegal River Basin, the Mauritanian Government decided to replace chloroquine with artemisinin-based combination therapy (ACT). This policy change was principally based on clinical studies conducted in Senegal and extrapolated to the Mauritanian situation. Regardless of the parasite species involved, the treatment of uncomplicated malaria is currently based on artesunate-amodiaquine as the first-line treatment, artemether-lumefantrine as the second choice, and quinine as the third-line drug [P. vivax malaria, the National Malaria Control Programme recommends the use of primaquine for radical treatment if glucose-6-phosphate dehydrogenase (G6PD) test is normal. This drug policy has not yet been implemented in the field. As part of future prospective studies aiming to develop an evidence-based national anti-malarial drug policy, the National Malaria Control Programme and the University of Sciences, Technology and Medicine in Nouakchott have been collaborating since 2012 to conduct clinical studies in several sentinel sites in the country to validate and, if needed, modify the current anti-malarial treatment guidelines.It is worth noting that in 2006, following the emergence of chloroquine-resistant ine drug . MonotheAnopheles spp. in each study site, characterize physico-chemical factors in the breeding sites, determine whether adult female Anopheles mosquitoes are infective, and assess their sensitivity to insecticides. In parallel, malaria burden and drug resistance are being assessed in these sentinel sites to determine the prevalence of laboratory-confirmed malaria among febrile patients and their response to ACT. Research capacity building and training of laboratory technicians and general practitioners are integral parts of these on-going field activities. The introduction of ACT is another challenge facing Mauritania. One of the key issues is the cost of ACT, which is 20 times higher than the cost of conventional therapy, such as quinine ($2.44 per adult dose). Population migration from sub-Saharan endemic countries constitutes another challenge where no official measures for controlling malaria prevalence among these migrants exist. Mauritania still does not have a reliable database on malaria epidemiology. A nationwide malaria indicator survey is being planned to fill this gap in 2015. Updated information and maps on malaria burden and Plasmodium species distribution are critical for guiding national efforts to improve laboratory diagnosis, implement rapid and effective treatment, and coordinate and plan malaria elimination from the country in the near future. As malaria incidence changes over time, regular updates of epidemiological data are necessary.Mauritania faces several challenges in the management of malaria, including limited financial resources, crisis in human resources, shortage of health workers and health structures with reliable diagnostic facilities, insufficient epidemiological data on parasite distribution and malaria vectors, and regular epidemics. Entomological studies are currently being conducted at several sentinel sites in different epidemiological strata in the country to capture and collect mosquito larvae and adults, identify predominant