Malaria and HIV/AIDS are the two most common infections in sub-Sahara Africa. There are hypotheses and study reports on the possible association between these two infections, hence the prevalence and outcome of their co-infection in an endemic population will be important in defining healthcare strategies. A cross sectional study was carried out at the Holy Family Hospital in Techiman, Ghana, between November 2011 and January 2012, to determine the prevalence of malaria among HIV sero-positive patients and its impact on hemoglobin levels.A total of 400 HIV sero-positive participants  aged between 1 and 73 years were randomly sampled for the study. A questionnaire was administered and 2 ml of venous blood samples were drawn for malaria parasites detection, CD4 count and haemoglobin level estimations.Malaria parasites were detected in 47 (11.75%) of the participants. There was no statistically significant difference between the malaria prevalence rate of females (12.1%) and males (10.2%) P = 0.6047. An overall anaemia prevalence of 67% was observed. Among participants with malaria the anaemia prevalence was 93.6%. The CD4 cell count of all the participants ranged between 3 and 1604 cells/μl with a mean of 386.2 (±274.3) cells/μl. Participants with malaria had CD4 cell count ranged 3 and 512 Cells/μl with the mean being 186.33 (±133.49) Cells/μl. Out of 377 participants  interviewed on knowledge of malaria transmission and prevention, 87.0% had knowledge on transmission but only 8.5% use in bed nets.It was revealed that almost all the patients with malaria infection were anemic. Malaria and Human immunodeficiency virus (HIV) infections are major public health problems in many parts of the world. Both infections kill millions of people each year with disproportionate heavy burden on Africa, India, Southeast Asia and South America .Sub-Saharan Africa harbors 90% of the estimated 219 million cases that results in over 600,000 deaths annually . Severe Because of the high prevalence of HIV and malaria in sub-Saharan Africa, co-infections are common. Recent estimates put HIV/AIDS prevalence in Ghana at 2.9% . It is kfalciparum malaria where HIV infection was associated with severe/complicated malaria [Because of the high prevalence of HIV and malaria in sub-Saharan Africa, co-infections are common, Because of the geographic overlap between high-prevalence areas for malaria and HIV infection, there is growing evidence that the two infections may synergistically intensify each other, increasing incidence and complicating treatment efforts . In a re malaria . Recentl malaria .As the number of malaria and HIV co-infection increased, it has become apparent that anti-retroviral drugs interact with the few anti-malaria drugs in use, complicating treatment efforts for both infections . MalariaThe study was conducted in the Holy Family Hospital; the only facility that provides ART services to HIV patients in the municipality. It has bed capacity of 167 beds. Patients diagnosed to have HIV/AIDS infection and who sought treatment at ART clinic at the Holy Family Hospital were the source population for the study. The drugs administered for the first line of treatment were Azidovudine (d4T), Lamivudine (3TC) plus Nevirapine or Efavirenz. Nelfinavir, Kaletra and Indinavir were occasionally used in combination with nucleoside based reverse transcriptase inhibitor drugs. The study was cross-sectional serological survey where HIV sero-positive patients attending ART Clinic at the hospital were randomly approached and invited to participate in the study provided they gave their consent. The study took place between November 2011 and January 2012.Sample size was determined using the binomial model to estimate the confidence interval (CI). The HIV prevalence in the area is known to be less than 3% so the malaria prevalence in the area which is higher was used to estimate the minimum sample size needed to achieve enough statistical power. Malaria prevalence in the area had previously been determined by Owusu-Adjei et al. to be about 60% in all age cohorts . We calcn is the sample size, z is the critical value of the standard normal distribution at the 5% level (1.96), p is the estimated malaria prevalence (0.60), q = 1 – p, and d is the precision level. This is used for a small population of up to 3,000. The sample size obtained was 369. A total of 400 HIV sero-positive individuals who sought care at the ART Clinic of the Holy Family Hospital in Techiman and were willing to participate in the study were recruited.In the equation below, Techiman, is a major commercial town in the Brong Ahafo region linking not only most of Ghana’s major cities, but also the republic of Togo, Burkina Faso and Cote D’Ivoire. It has an estimated total land area of about 669.7 square kilometers. According to the 2000 population and housing census, the population of the municipality was estimated to be 202,409 by December 2005, with an average growth rate of 3.0% per annum. Agriculture and related trades are the major economic activities in the municipality. Over half of the economically active population is engaged in these activities. This makes Techiman market the largest food crop market in Ghana. The municipality has twenty four (24) health care facilities; including two mission hospitals in Techiman, , nine government health centers, four private maternity homes and three private clinics.The study was approved by the Committee on Human Research Publication and Ethics from Kwame Nkrumah University of Science Technology and the management of Holy Family Hospital - Techiman. Consent of participants was also obtained prior to the study. All consenting patients attending the ART clinic were eligible for participation except infants less than 6 months. Refusal of some patients to participate in the study did not interfere with their routine care at the hospital.Twi  which included the basic socio- demographics of the study subjects as well as their knowledge and prevention of malaria was used. Two independent translators were engaged, one translated the English to Twi, the other was who had no prior copy of the English was tasked to translate the local language back into English. This was done to ensure the consistency of thought. No personal identifiers were included and individuals were given unique codes on the questionnaires and their laboratory specimens.A questionnaire, in both English and Laboratory investigation was conducted using the Thin Blood Film method. A drop of blood, 3–5 mm in diameter was put on a slide and spread with the corner of another slide to form a thin blood smear. The smear was thoroughly allowed to dry, fixed with methanol and stained with Giemsa stain for about 15 minutes. The stained smear was washed with running tap water, allowed to dry in air and examined microscopically for the presence of malaria parasites.HIV test was conducted using First Response HIV Card Test 1–2.0 . Reactive blood samples were confirmed with Oraquick Rapid HIV – ½ Antibody Test . Both test kits are immuno-chromatographic rapid tests for qualitative detection of antibodies specific to HIV in human serum, plasma or whole blood.The CD4 count of the study population was determined using Becton-Dickinson FASCount flow cytometer  whilst the haemoglobin concentration was estimated with Sysmex XT – 2000i Haematology Analyzer .A total of 400 HIV sero-positive patients between 1 and 73 years were included in the study. Majority of them (73%). the mean was between 30 and 34 years old. Most patients were married (38%). Majority (37.1%) had no formal education, with only 3% having had some tertiary education. 49.5% of the participants were unemployed with a further 30.7% being farmers. Further details are reported in Table Hemoglobin (Hb) concentration levels of the patients ranged between 6.4 and 15.4 g/dl with majority (18.0%) of patients had Hb levels in the range of 12.-12.9 g/dl. The mean Hb level of the patients was 10.8 g/dl with mean (SD) for male and female as 11.5 g/dl (2.26) and 10.56 g/dl (2.22) respectively (Table All patients studied had a CD4 cell count ranging from 3 – 1604 cells/μl. The mean (SD) of CD4 cell count of the patients was 386.2 (274.3) cells/μl. Majority of the participants (34.5%) had CD4 count below 200 cells/μl (this represents the advanced stage of immuno-suppression). Another 33.3% had CD4 counts above 500cells/μl. The rest of the participants had CD4 counts between 200 and 499 cells/μl. further details of CD4 cell count based on gender differences are shown in the tables  were found to be slide positive for malaria parasite with ages ranging from 2 years to 56 years. Malaria positivity was mostly within the age range of 30–34 years, followed by those in the age ranges of 25–29 years and 35–39 years. The least infected malaria patients were within the age ranges of 15-19years and 55–59 years. Out of the 47 participants with patent parasitemia 36 (76%) of them were females with only 11 being males  haemoglobin level to be 9.9 g/dl (1.61). The hemoglobin level ranged was from 6.2 g/dl to 13.2 g/dl. All the participants with malaria infection were anemic except for one participant who had 13.2 g/dl. Most of the study participants with malaria infection (13 out of 47) had hemoglobin level between the ranges of 10.0 g/dl-10.9 g/dl  CD4 cell count of 186.3 (133.5) cell/ul. Males had a mean of 209 (198.4) cells/μl and females 178.7 (110.8) cells/μl. The majority, a whopping 66% of participants with patent malaria infection had their CD4 cell count below 200 cells/μl. With respect to gender, 63.6% (7 out of 11) males infected with malaria infection and 66.7% (24 out of 36) females infected with malaria infection had CD4 cell count less than 200 cells/μl. Only one patient with malaria infection had CD4 cell count greater than or equal to 500 cells/μl and was observed in only males. Further details are provided in  interviewed on malaria transmission and prevention. 87.0% out of 377 of the participants claimed to have some knowledge about malaria transmission. Out of the 328 respondents that claimed to have knowledge about malaria, 216 (65.9%) claimed that malaria could be transmitted from an infected person to a healthy person and the rest 112 34.1%) claimed that either malaria cannot be transmitted from person to person or they had no idea at all. Among those who claimed that malaria is transmissible (n = 216), 91.2% (n = 197) reported mosquito bite as a means of transmission  CD4 cell count of the patients was 386.2 (274.3). Males and females had CD4 count mean (SD) of 345.7(270.1) cells/μl and 386.1(276.0) cells/μl respectively. The difference in the mean CD4 count is due to the fact that HIV infection is detected earlier in females than their male counterparts. With the introduction of Prevention of Mother -To- Child Transmission of HIV (PMTCT) programme, women of child bearing age are screened for HIV infection during antenatal care or at obstetrics and gynecology clinics. Those who test positive are then incorporated into ART clinics while there is no similar program for males for the early detection of HIV.+ T lymphocyte cells <200 cells/μl is associated with a higher risk of opportunistic infection and poor disease progression [CD4 cell count less than 200 cells/μl  was seen in 34.5% patients. Obviously the major reason for this high proportion of AIDS is because of late presentation, largely due to the fact that we are yet to imbibe the culture of voluntary screening for early detection and treatment. Fear of stigmatization, lack of awareness and inadequate trained counseling personnel are some of the factors militating against voluntary screening. Many patients only seek medical attention and are diagnosed when HIV infection becomes complicated by AIDS defining illnesses. Majority of the patients (66.0%) with malaria infection had CD4 cells count less than 200 cells/μl. This can be attributed to the well establishment that CD4gression .Mycobacterium tuberculosis, Histoplasma, Cryptococcus, Coccidiodes, Pneumocystis carinii, and Leishmania have been shown to infiltrate the bone marrow and disrupt erythropoiesis [Anemia is a frequent complication of infection with the human immunodeficiency virus, and could be clinically important. Multifactorial origin of anemia complicates determining its original cause and/or its proper treatment . Using hopoiesis . AlternaSeveral drugs used to combat HIV and its complications may contribute to the anemia that is seen in HIV infection. The administration of Zidovudine is recognized to cause anemia because of myelo-suppression .Males and females did not show significant difference in the prevalence of anemia. Different studies have reported increase prevalence of anemia in females than males which were largely attributed to menstrual blood loss and to the drains on iron stores that occur with pregnancy and delivery . HoweverMajority of the HIV patients with anemia were mild to moderate anemia with few patients (2.75%) with severe anemia. This is in agreement with studies by Meidani and co workers  where miAbout 87% of the patients who responded to the questionnaire claimed to have some knowledge on malaria transmission in their area. This is an indication that the area selected for the study is malarious and known to have malaria transmission. More than half (65.9%) of the respondents who claimed to know or have heard of malaria, reported malaria to be transmissible. The rest (34.1%) reported that malaria cannot be transmitted from infected person to healthy ones or they have no idea about it at all. Among those who knew that malaria is transmitted, 91.2% reported mosquito bite as a means of transmission. These are encouraging results and show the presence of a better knowledge in the method of malaria transmission however despite good knowledge about malaria transmission, this study also revealed evidence of knowledge gaps about malaria by some respondents misconception that that malaria is transmitted through drinking contaminated water, eating contaminated food, staying in the sun and working in rain.Over 92.0% of the patients in this study reported that malaria is preventable. Over 75% of the patients who reported malaria are preventable stated taking tablets and use of bednets as methods of malaria prevention however only 8.5% use bednets. Discomfort, primarily due to heat, and perceived (low) mosquito density were the most widely identified reason for non-use of mosquito net. There were concerns by respondents about higher prices of mosquito nets to the extent of not being affordable by some respondents.Malaria infection was high in HIV positive patients with CD4 count less than 200 cells/μl. Mild to moderate anemia was frequent in HIV positive patients but severe anemia was not prevalent in the study population. Almost all study participants with malaria were found to be anemic. This confirms the association between malaria and anemia. Future studies should compare prevalence of malaria co-infection among HIV/AIDS Sero-positive individuals and non HIV/AIDS individuals with malaria.


The contradictory results on the interaction between nutritional status and malaria warrants further investigation in various epidemiological settings, to assert the antagonistic or synergistic relationship. This study examines the prevalence, severity and predictors of malnutrition and its influence on malaria parasitaemia and anaemia severity in children in the Mount Cameroon area.A cross-sectional study involving 454 children ≤ 14 years was carried out from February to May 2013 in Muea community. Anthropometric measures of malnutrition (z-scores < −2 standard deviations below mean) were obtained and spleen size assessed. The prevalence and density of malaria parasites were determined and haemoglobin concentration and white blood cell count obtained using an automated haematology analyzer. Univariate and multivariate analyses were used to evaluate influence of malnutrition on anaemia, malaria parasitaemia and predictors respectively.P < 0.01) in males (23.1 %) than in females (11.9 %). The prevalence of malnutrition was significantly highest (P = 0.03) in children ≤5 years old (29.5 %) than their counterparts. Severe stunting, wasting and underweight were prevalent in 4.9 %, 1.6 % and 1.8 % of the children respectively. Clinical malaria parasitaemia was significantly higher (P = 0.01) in children who were stunted (16.9 %) and underweight (21.6 %) than their normal counterparts . The model demonstrated sex (P = 0.006) and age group 1.1-3 years (P = 0.03) as significant predictors of malnutrition. In children who were malaria parasite negative, the prevalence of anaemia as well as severities were significantly higher (P = 0.04 and P = 0.001 respectively) in those malnourished.The overall prevalence of malnutrition was 22.8 %, with stunting being the most common form (17.1 %), followed by underweight (8.2 %) and wasting (5.5 %). Stunting was significantly higher (Plasmodium infection. Malnutrition enhanced the severity of anaemia in malaria parasite negative children hence, their health and growth potential needs to be improved upon.The presence of stunting in the community significantly augmented the prevalence and clinical presentation of  In developing countries, including those in sub-Saharan Africa, malnutrition represents an additional burden and often co-exists with malaria . While uNutritional status may be assessed by subjective clinical evaluation, or by the use of anthropometric indicators and reference standards to determine poor nutritional status based on low weight-for-age (underweight), low height-for-age (stunting), or low weight-for-height (wasting). Wasting is considered a manifestation of acute malnutrition, whereas stunting represents long-term malnutrition . UndernuThe influence of nutrition on the disease burden of malaria is unclear. The contradictory results on the interaction between nutritional status and malaria , 11, warPlasmodium falciparum accounts for up to 96 % of malaria infections in this area [The study was carried out in Muea, a semi-rural setting in the rain forest ecozone on the Eastern flank of the active volcanic Mount Cameroon. The coordinates of the study area ranged from altitude 540 m, latitude 04°10.464′N, longitude 009°18.168′E to 556 m, 04° 10.015′N and 009°18.009′E. Muea is about 29 km from the Atlantic Ocean, has an equatorial climate with relative humidity of above 80 %, a temperature range of 18 - 28 °C and an annual rainfall of about 4096 mm. The rainy season characterised by frequent light showers, spans from March to October. The dry season runs from November to February. his area . Muea han = z2pq/d2 [n = the sample size required, z = 1.96: confidence level test statistic at the desired level of significance, p = 85.4 %: proportion of malaria prevalence, q = 1-p: proportion of malaria negative children and d = acceptable error willing to be committed. The minimum sample size was estimated as n = 192. This was adjusted to an optimum of at least 400 samples taking into consideration the decline in malaria parasite prevalence in the Mount Cameroon area [A cross-sectional study was carried out from February 2013 to May 2013, which included the rainy season reported as the peak malaria transmission period in the Mount Cameroon Region . The sam z2pq/d2  where n oon area  as well Clinical evaluation was carried out by trained medical personnel. The clinical evaluation consisted of measurement of body temperature and examination of the spleen. Axillary body temperature was measured using a digital thermometer. A child with a body temperature ≥37.5 °C was considered febrile. The tip of the spleen was felt by pressing the abdomen under the left coastal border and splenomegaly was graded according to the classification of Hackett . Ages ofPlasmodium with an axillary temperature of <37.5 °C while clinical malaria parasitaemia (CMP) was defined as the presence of any species of Plasmodium, with an axillary temperature of ≥37.5 °C or reported fever in previous 48 h/headache/joint paint.Approximately 4 mL of venous blood was collected from each participant into sterile disposable syringe and used for the preparation of thick and thin blood films. The remaining blood was dispensed into labelled ethelenediaminetetraacetate (EDTA) tubes. Labelled blood samples were transported on ice in a cool box of temperature between 8-10 °C to the University of Buea Malaria Research Laboratory for further analyses. The thick and thin blood films prepared on glass slides at the time of blood sampling were stained with Giemsa and examined following standard protocols . Parasitχ2). Differences between group means were compared using non parametric test, the Mann–Whitney U test. Malaria parasite counts were log transformed before analysis. A binomial logistic regression model analysis was conducted to predict factors associated with malnutrition with sex, age groups, spleen size, anaemic and parasite status as independent variables. The interaction among confounders was also examined. Significant levels were measured at 95 % confidence interval (CI) with significant differences set at P < 0.05.Data was entered into spread sheets using Microsoft Excel and analysed with the Statistical Package for Social Sciences (SPSS) version 19 . Data were summarized into means and standard deviations, and percentages were used in the evaluation of the descriptive statistics. Proportions were compared using the Chi-square test  were males while 243 (53.5 %) were females. Only 451 children had complete anthropometric measurements. The mean ± SD of HAZ, WAZ and WHZ scores were −0.58 ± 1.7, −0.40 ± 1.3 and 0.06 ± 1.5 respectively. The overall prevalence of malnutrition in the study population was 22.8 % (CI = 19.2-26.9 %), with stunting being the most common form , followed by underweight  and wasting  as shown in Table P <0.01. While stunting was significantly higher (P < 0.01) in males  than in females , the difference in prevalence of underweight and wasting amongst the sexes was not significant (P >0.05).As revealed in Table P <0.05) in children in the less than or equal to 5 years age group  when compared with the 6–10  and the 11–14 years  age groups. Similarly, the prevalence of underweight was significantly highest (P = 0.01) in children in the ≤5 years age group , than their 6–10  and 11–14 years old  counterparts. On the other hand, a comparison of the prevalence of stunting and wasting amongst the different age groups revealed no significant differences , malnutrition was most common in children aged between 1.1-3 years , when compared with those ≤1 year  and those in the 3.1-5 years  age groups.Amongst children in the less than or equal to 5 years age groups, although not statistically significant  1.6 % (7) and 1.8 % (8) respectively.P. falciparum was higher in malnourished children (39.8 %), more especially in those stunted (42.9 %) and underweight (43.2 %) than their normal equivalent. On the other hand, P. falciparum parasite prevalence was lower in children who were wasted than those normal as shown in Fig. Although not statistically significant (P >0.05), the prevalence of P = 0.81). Specifically, malaria parasite counts were highest in those wasted than those stunted, underweight and normal as shown in Fig. Similarly, the GMPD (geometric mean parasite density)/μL of blood was higher in malnourished children (915.8) when compared with their well nourished counterparts (816.6) although the difference was not statistically significant (P <0.01) in malnourished children  when compared with well nourished children . On the other hand, the difference in prevalence of AMP in the different categories of children was none significant as shown in Table P <0.05) in children who were stunted  and underweight  than their normal counterparts , the prevalence of CMP was comparable (P = 0.78) in those wasted  indicating that the independent variable sets reliably distinguished between malnourished and nourished children. The binomial logistic regression model demonstrated sex (P = 0.006) and age group 1.1-3 years (P = 0.03) as significant predictors of malnutrition as shown in Table A test of the full model against a constant only model was statistically significant , the prevalence of anaemia was higher in malnourished children than their well nourished counterparts. Mild, moderate and severe anaemia were significantly highest  in malnourished than those normal  in malnourished than in well nourished children. On the other hand, no statistically significant difference in prevalence of anaemia and severities of anaemia (P = 0.69 and P = 0.95 respectively) were observed in malnourished and well nourished children who were malaria parasite positive.As revealed in Table meso endemic for malaria as well as its influence on the prevalence of asymptomatic and clinical malaria parasitaemia and anaemia severity.The nutritional status of a person is the most important determinant factor in the health status of that individual, especially children and adolescents for a period of growth. The fundamental relationship between undernutrition and malaria is multifaceted. While some findings show that undernutrition increases susceptibility to malaria , others Malnutrition was common (22.8 %) in the community with an overall prevalence of 17.1 % for stunting, the most common form of malnutrition. This is lower than the 58.1 % observed in children of the same community in 2006 by Nkuo-Akenji et al.  as well Malnutrition was significantly higher in males 29.3 %) than females (17.3 %) and the binomial logistic regression analysis revealed male children were significantly at odds of being malnourished than females. More specifically, stunting was significantly higher in males while the prevalence of wasting although not significant was common in females than males. The observation is in line with Kamugisha et al.  who repo.3 % thanSevere nutritional conditions (z score less than −3) such as underweight and wasting were uncommon in the study population, while the presence of severe stunting (4.9 %) was comparable to that reported by Ehrhardt et al.  in AfricThe observation of age as a significant predictor of malnutrition is not unusual. In line with Ehrhardt et al. , the preAlthough the relationship between the presence of malaria parasite and nutritional status was not significant, malnourished children were 1.35 times at odds of being malaria parasite positive and had higher GMPD than normal children. The manifestation of chronic and acute nutritional deficits which results in stunting and wasting respectively influenced the prevalence of malaria parasite in the population. Overall, while children who were stunted and underweight had a higher prevalence of malaria parasite, those wasted had a lower prevalence. On closer examination, in line with Crookston et al.  in Kenyameso endemic area were able to regulate or were protected to some extent against infection per se, its clinical presentation but not the parasite densities. However these findings need further investigation in a holo endemic area to assert the role of acute malnutrition in malaria endemic areas.Wasting which is a form of acute malnutrition has been reported as a risk factor for malaria following the low humoral responses to malarial antigens in wasted children . InteresP. falciparum infection as a significant public health problem. Hence in malaria endemic areas there is a need for integrated interventions targeting both malnutrition and malaria so as to improve upon the health and growth potential of the children.Malnutrition is known to be a leading factor to anaemia and findings from the study revealed mild, moderate and severe anaemia to be significantly higher in malnourished children. The multivariate analysis revealed anaemic children were 1.4 times at odds of being malnourished than their well nourished counterparts but it was not a statistically significant risk factor when compared with being male and of the 1.1 – 3 years age group. However, the significant influence of malnutrition on the prevalence and severity of anaemia was only discernible in children who were malaria parasite negative while its additive influence was insignificant in those positive Table . While tPlasmodium infection while wasting ensured some protection per se. Being male and 1.1 to 3 years of age are significant clinical risk factors of malnutrition and malnutrition enhanced the severity of anaemia especially in malaria parasite negative children. Hence the health and growth potential of children in this meso endemic area can be improved upon by integrating interventions directly linked to growth to the malaria and helminth control programmes already in place.The presence of stunting in the community significantly augmented the prevalence and clinical presentation of


Plasmodium knowlesi parasitemia is unknown. In this study, samples were obtained from individuals residing in households or villages of symptomatic malaria cases with the aim of detecting submicroscopic P. knowlesi in this population. Four published molecular assays were used to confirm the presence of P. knowlesi. Latent class analysis revealed that the estimated proportion of asymptomatic individuals was 6.9% . This study confirms the presence of a substantial number of asymptomatic monoinfections across all age groups; further work is needed to estimate prevalence in the wider community.Although asymptomatic carriage of human malaria species has been widely reported, the extent of asymptomatic, submicroscopic  Malaria epidemiological surveys have reported a substantial proportion of individuals with low-density infections that are not detectable by conventional microscopy . Meta-anPlasmodium falciparum and Plasmodium vivax, has been described, limited data about such carriage are available for zoonotic malaria species. P. knowlesi, a zoonotic malaria parasite maintained by macaques, has been described throughout Southeast Asia and is now the most common cause of human malaria in Malaysian Borneo [P. knowlesi infection has only been identified in 2 studies, both of which were performed in Vietnam, and submicroscopic parasitemia in people has not been widely reported. During 2 cross-sectional malariometric surveys in Vietnam, 3 individuals were identified by molecular techniques as P. knowlesi positive [P. knowlesi were detected in younger age groups through active case detection [Although submicroscopic carriage of human malaria parasite species, particularly n Borneo . To our positive . These ietection .Despite rarely causing clinical disease, submicroscopic malaria infections can contribute to malaria transmission. Experimental evidence has demonstrated that individuals with submicroscopic infections are capable of infecting mosquitoes; while these individuals may infect fewer mosquitoes than individuals with higher parasite counts, the high numbers of individuals with low-density infections may lead them to contribute substantially to malaria transmission . UnderstP. knowlesi infection dynamics in exposed populations are very limited. The parasite has a distinct 24-hour asexual development cycle, with common-severe-disease and case-fatality rates similar to those recorded for P. falciparum [P. knowlesi particularly important.Data on submicroscopic parasitemia are also needed to better understand disease progression. Both parasite and host factors will influence whether infections remain asymptomatic or become symptomatic and potentially life threatening. The data on lciparum . This poP. knowlesi cases by screening individuals residing in the same households and villages of clinical P. knowlesi cases recruited during a population-based case control study in an area of known P. knowlesi transmission in Northwestern Sabah, Malaysia [P. knowlesi is the main cause of clinical human malaria in this region and clustering of cases at household level has previously been reported [P. knowlesi carriage is present in this population and to estimate the proportion of infected individuals.This study aimed to detect potential asymptomatic Malaysia . P. knowreported . IndividThe study sites in Kudat and Kota Marudu districts, Sabah, Malaysia, have been described elsewhere . The areAs part of a case control study, consenting clinical cases positive for any species of malaria by microscopy were recruited at district hospitals and visited at their homes within 2 weeks of initial infection detection. Community controls were randomly selected afebrile individuals residing in the same village as malaria cases for the previous 3 weeks, as described elsewhere . Blood sThis study was approved by the Medical Research Sub-Committee of the Malaysian Ministry of Health and by the research ethics committees of the London School of Hygiene and Tropical Medicine and the Menzies School of Health Research (NMRR-12-537-12568). Written informed consent was obtained from all participants in this study.Plasmodium small subunit ribosomal RNA (ssRNA) gene was performed to identify Plasmodium genus–positive samples as described elsewhere [Supplementary Materials. Primers targeting a region of the ssRNA product of the first nested PCR were then used to detect P. knowlesi [P. knowlesi and other species were used for all PCR reactions.Thick and thin blood smears were examined by a trained malaria microscopist. DNA was extracted from 10-µL red blood cell pellets by using the Chelex-100 boiling method, and a nested polymerase chain reaction (PCR) assay targeting the knowlesi . PositivPlasmodium genus–positive samples, additional methods were performed on a subset of 374 samples. A nested PCR assay targeting the cytochrome B gene of P. knowlesi was used to identify P. knowlesi–positive individuals [P. knowlesi ssRNA gene and the other targeting the P. knowlesi strain H chromosome 13 plasmepsin gene [Supplementary Materials.Owing to difficulties in determining species in some of the ividuals . Samplessin gene , as deschttp://www.R-project.org). In the absence of a gold standard for P. knowlesi species–specific diagnosis, latent class analysis was used to estimate the proportion of infected individuals and the sensitivity and specificity of these tests, using the randomLCA package in R (v1.0.2) [Data were analyzed using R statistical software, version 3.1.1  . Test tyPlasmodium genus-specific PCR results, obtaining using the ssRNA primers as described previously [Plasmodium species. From this sample set, 1.7%  were confirmed to be P. knowlesi positive, using the P. knowlesi–specific ssRNA primers [P. knowlesi is the predominant cause of human malaria in this area and many Plasmodium genus–positive samples could not be identified to the species level, alternate assays were performed on all 206 genus-positive samples and a subset of 168 genus-negative samples [A total of 1147 blood samples were collected from December 2012 through May 2014. Only 1 individual was microscopy positive but did not report a history of fever. Initial eviously , found tP. knowlesi infections identified by any other method. A total of 9.8% of samples (112 of 1147) had at least 1 positive P. knowlesi test result; of these 112, 26.8% (30) had 2 positive results, and 30.3% (34) had ≥3 positive test results. The diagnostic sensitivity and specificity of each P. knowlesi–specific assay for this population was estimated using latent class analysis  than the other molecular assays used. Using these estimates of sensitivity and specificity, the infection prevalence in this population was estimated at 6.9% .The genus-specific nested PCR was highly sensitive , detecting all P. knowlesi–infected individuals predicted by the latent class analysis did not report a history of a fever  were coinfections with P. falciparum, and 2% (2) were coinfections with P. malariae.The majority  of P. knowlesi carriage in an exposed human population. Although this is not a true prevalence survey and many of the infections detected were from individuals residing in the same household as symptomatic cases, infections were also found in unrelated individuals residing in the same village during that time. Moreover, a high proportion of infections were detected in children aged <15 years and women, groups not previously considered to be at high risk for P. knowlesi infection. Although a small proportion of infected individuals reported a history of fever, none had infections that were reported to develop into symptomatic malaria. However, longitudinal studies are needed to fully understand the disease progression and potential development of acute disease. Given the ongoing case recruitment in these health facilities [P. knowlesi infections in the community. Further, the distribution of these infections in different demographic groups may not be captured by the passive health surveillance systems.This is the first study to describe a high level of submicroscopic, asymptomatic cilities , the manThe majority of infections were submicroscopic and could not be detected by conventional malaria parasite microscopy. Unlike previously reported submicroscopic infections, the majority (93%) of infections were not associated with coinfection involving other species. Additionally, the inconsistent results obtained from multiple published and validated molecular assays demonstrate that the parasites causing these infections may be at or below the level of detection for assays developed for use primarily on human clinical samples. Analysis of relatively small volumes of blood collected from individuals with very-low-density infections means that parasites present in such samples may be missed even by repeat PCR assays. Understanding the wider community prevalence will require better-optimized molecular assays, as well as population-level surveys.P. knowlesi transmission. While the submicroscopic parasite densities of other malaria parasite species have been shown to be capable of infecting mosquitoes, all experimental infections with P. knowlesi have involved specimens collected from clinical malaria cases [P. knowlesi identified within the same areas are likely to have a common source. Entomological and primatological studies are also needed to evaluate the presence of potential P. knowlesi vectors in these village environments and the proximity of infected reservoirs.It remains unknown whether and how much humans contribute to the infectious reservoir for ia cases . The ideP. knowlesi or to further understand spatial and temporal patterns of P. knowlesi infection. Similarly, because samples were collected at a single time point for each individual, the duration and fluctuations in parasite densities over time cannot be determined. Longitudinal data, as well as data on treatment-seeking behaviors, for different demographic groups are required to determine factors contributing to whether specific groups are underrepresented by hospital surveillance systems.Because this study included only individuals in the same household or village as that of a symptomatic case, these data cannot be used to generalize about the community prevalence of P. knowlesi monoinfections within communities located in P. knowlesi–endemic areas and highlights the need for further studies to evaluate population-wide prevalence. Current molecular tools are still limited for detection of parasites present at very low densities, and these need further evaluation and optimization. Additional community-based surveys are currently planned to evaluate the prevalence of these infections in the wider community.Despite these limitations, this study illustrates the presence of asymptomatic


Thoroughly neglected over the past 60 years, the chemotherapy of this complex infection has been dangerous and ineffective until the present. Work is at last being done, but seeing that translate to real improvements at the periphery of care delivery will take years of deliberate effort. In the meantime, patients face substantial risk of debilitating, threatening, and fatal courses of illness associated with a diagnosis of vivax malaria. For some of the most vulnerable to such outcomes — pregnant women and infants — repeated attacks of acute vivax malaria from a single infectious anopheline bite is now not preventable. One of the few measures than can be immediately applied with rigor is vector control, thereby effectively preventing as many of these difficult and dangerous infections as possible. This commentary emphasizes the dire consequences of infection by P. vivax and the real difficulty of dealing with them. That, in turn, emphasizes the many benefits to be derived by preventing them in the first place. The maxim ‘ Plasmodium vivax occurs all across the globe, from the Korean Peninsula to the northern fringes of Argentina . However, the supposition of harmlessness in vivax malaria does stand to available evidencergentina 1. The exPlasmodium naturally infecting humans are complex, but P. vivax  has a single additional stage that hugely magnifies its epidemiological and clinical complexity. This parasite places dormant forms in the liver that cause multiple clinical attacks  over about 2 years. In contrast, a single infectious bite with P. falciparum causes a single attack within less than 2 weeks. The risk, timing, and frequency of these clinical attacks emanating from the liver appears evolved to coincide with both a relatively high likelihood of encountering a different strain of P. vivax in the bloodThe life cycles of all of the five species of P. vivax represent the two extremes of relapse behaviors. Chesson strain came from an American soldier infected in New Guinea during the Pacific War.P. vivax strain exhibits no primary parasitemia, but will relapse only 8–12 months after inoculation.8The Chesson and North Korea strains of P. vivax consisted of two types — those that immediately went into full development of liver and blood stages, and those that became the dormant forms responsible for relapse — called hypnozoites. The latter greatly outnumbered the former in that temperate strain, demonstrated by primary parasitemias after inoculating relatively vast numbers of sporozoites. This ratio presumably represents adaptation to the brevity of seasonal anopheline abundance. The parasites emerge into the relative danger of the bloodstream only when the likelihood of encountering feeding anophelines is relatively high. Each such sortie provokes the human misery known as malaria.Shute and colleaguesThe hypnozoite impels departure from convention when considering terminology as basic as ‘infection’. The biology of falciparum malaria permits classifying an infectious bite seeding the liver with sporozoites, and subsequent seeding of the blood by merozoites as a single infectious event, i.e. an ‘infection’. If one thinks of the defining event of malaria as the presence of the disease-causing asexual stages in the blood, then the term in vivax malaria takes on different meaning. While hosts harboring quiescent hypnozoites are indeed ‘infected’, there is no active blood infection and therefore, no acute malaria. In this sense, both mosquitoes and hypnozoites in the liver may be considered contributors to the force of infection of the blood.P. vivax in any given endemic community may indeed be substantial. While it is now not possible to diagnose latent liver stages, one can, under some circumstances, observe their force of infection. One such study reported by Douglas and colleaguesP. vivax after just 2 months. That number may be considered an absolutely minimal estimation of the prevalence of hypnozoites among people having falciparum malaria . Another study reveals the force of infection by hypnozoites: Downs et al.The liver reservoir of P. vivax) at about 2 infections/person-year.In some communities, the hypnozoite probably represents the more common origin of a new blood infection event. No study has yet measured both compartments of infection simultaneously. Several studies in Indonesian Papua, where malaria is very heavily endemic, consistently showed incidence density of new infection among subjects  (to terminate the acute attack), and hypnozoitocide(s) (to prevent subsequent acute attacks). The two classes compose what is referred to in malariology as ‘radical cure’. This partnership comes with a list of therapeutic issues regarding drug–drug interactions impacting safety or efficacy. Since chloroquine and primaquine were partnered in this capacity in 1952, no other pairs of drugs for radical cure of vivax have been demonstrated safe and effective . Resistance to chloroquine by P. vivax is primaquine, a seriously flawed drug that causes mild to severe and fatal acute hemolytic anemia in patients having an inborn deficiency of glucose-6-phosphate dehydrogenase (G6PD).Most of these fear-related issues could be resolved with a point-of-care device that is practical and robust at the periphery of healthcare delivery where most malaria patients live.Recent evidence has uncovered yet another potentially serious problem with primaquine — a mutation to cytochrome P-450 2D6 enzyme seriously impacts primaquine metabolism and degrades its efficacy against relapse.Even assuming the availability of a robust point-of-care diagnostic device, proven safe and efficacious short dosing regimens of primaquine, and relatively low frequencies of CYP2D6 mutants , there still remain very significant sub-populations that cannot be treated with primaquine. Unfortunately, these happen to be the same subpopulations most vulnerable to serious illness caused by vivax malaria — pregnant and lactating women, and infants.P. vivax, which is the rule in most of the endemic world, results in repeated clinical attacks and serious illness, and further opportunities for transmission to others. Owing to the chronic neglect of this infection — largely driven by the erroneous supposition of its harmlessness — primaquine remains the only drug with which to combat that threat in the clinic. The conspicuous inadequacy of that drug, and the improbability of a rapid solution to it being grossly ineffective, should mobilize the global health community to re-examine measures aimed at minimizing mosquito–human contact, especially among the most vulnerable and untreatable (pregnant women and infants). Relatively aggressive measures are both indicated and likely achievable. These groups already represent the highest priority in programs distributing long-lasting insecticide-treated netting. Expanding such protection to treated curtains, indoor residual spraying of insecticides, spatial and topical repellants, and a variety of other personal protection measures ought to be strategized and implemented. For the time being, such represents the sole practical means of acting to mitigate the harm caused by vivax malaria.The successful treatment of vivax malaria in endemic zones requires overcoming a number of serious obstacles, and yet much depends on being able to do so. The failure to systematically attack the hypnozoite reservoir of


The significance of thrombocytopenia to the morbidity and mortality of malaria is poorly defined. We compared the platelet counts and clinical correlates of patients with and those without malaria in southern Papua, Indonesia.Data were collated on patients presenting to a referral hospital between April 2004 and December 2012.Plasmodium falciparum monoinfection had the lowest platelet counts and greatest risk of severe thrombocytopenia , compared with those without malaria . The corresponding risks were 5.4  for mixed infections, 3.73  for Plasmodium vivax infection, and 2.16  for Plasmodium malariae infection (P < .001). In total, 1.3% of patients (2701 of 215 479) died. Patients with severe malarial anemia alone  had an adjusted OR for death of 4.93 , those with severe malarial thrombocytopenia alone had an adjusted OR of 2.77 , and those with both risk factors had an adjusted OR of 13.76 .Platelet measurements were available in 215 479 patients (23.4%), 66 421 (30.8%) of whom had clinical malaria. Patients with Severe thrombocytopenia identifies both children and adults at increased risk of death from falciparum or vivax malaria, particularly in those with concurrent severe anemia. Plasmodium falciparum accounts for the majority of severe malarial disease in sub-Saharan Africa, outside of Africa, nonfalciparum malarias are responsible for an increasing proportion of infections ) are included in the baseline values and the univariable analyses but excluded from the multivariable analyses.Adjusted PAFs of severe thrombocytopenia were calculated from multivariable logistic regression models, using the punaf module for Stata, which derives PAFs by means of the formulae provided in Greenland and Dreschler . BecauseEthics approval for this study was obtained from the Health Research Ethics Committees of the University of Gadjah Mada, Indonesia, and the Menzies School of Health Research, Darwin, Australia. Since data were gathered from routine hospital surveillance, informed consent was not requested from participants. However, all records were anonymized, to ensure patient confidentiality.P. falciparum accounting for 53.3% of monoinfections, P. vivax for 32.3%, P. malariae for 2.7%, and P. ovale for 0.07%. Mixed-species infections were detected in 19 569 presentations (11.6%), which, in 18 489 (94.5%) cases, were mixed P. falciparum and P. vivax infections  were to the outpatient department alone, and 84 131 (9.1%) resulted in hospital admission (Table P < .001). The corresponding figures for patients admitted to the wards were . Patients who had a platelet measurement had a median age of 21.0 years, compared with 23.0 years among those without a measurement. Measurement of platelets was also slightly more common in males, compared with females (23.6% vs 23.1%), and in Papuans, compared with non-Papuans (23.7% vs 21.5%).Overall, 215 479 presentations (23.4%) could be matched with at least 1 platelet count measurement , compared with that for Lowland Papuans (278 × 103 platelets/μL) and non-Papuans . Whereas the overall risk of severe thrombocytopenia with each presentation fell to <2% from early childhood in non-Papuans and lowlanders, highlanders remained at significantly greater risk throughout adulthood .The mean platelet count was significantly lower in Highland Papuans . After adjustment for confounding factors, patients presenting to hospital with malaria had lower mean platelet counts and higher odds of severe thrombocytopenia than patients without malaria at all ages  without a history of presentation to the hospital with malaria within the preceding 2 months had significantly lower platelet counts , compared with those with a single recent episode of malaria  and those with ≥2 episodes . The influence of recent history of malaria was not apparent in patients presenting without malaria or in those with P. vivax monoinfection.The mean platelet concentration and prevalence of severe thrombocytopenia varied significantly with es Table . Overall3 platelets/μL, 12 722 (5.9%) had counts of <50 × 103 platelets/μL, and 2001 (0.9%) had counts of <20 × 103 platelets/μL. Compared with patients without malaria, patients with P. falciparum infection were at the greatest risk of severe thrombocytopenia , followed by those with mixed infections , those with P. vivax infection , and those with P. malariae infection ; P < .001 for all comparisons; Table In total, 75 029 (34.8%) of the 215 479 presentations were associated with a platelet count of <150 × 10Plasmodium species were at a lower risk of severe thrombocytopenia, compared with those with no recent malaria , compared with those without malaria  or those with P. vivax .Patients with a recent presentation to the hospital with malaria due to any P < .001). The overall adjusted population fraction of severe thrombocytopenia attributable to P. falciparum infection was 35.9% , with 9.1%  attributable to P. vivax, 0.5%  attributable to P. malariae, and 7.0%  attributable to mixed species infections  of patients with platelet counts available also had hemoglobin levels measured; of these, 3.7% (7931) had severe anemia. The risk of severe thrombocytopenia was 18.7% (1484 of 7931) among patients with severe anemia, compared with 5.4% (11 221 of 207 113) among those without severe anemia . Overall, 1.3% of patients (2701 of 215 479) with a platelet measurement died, with the risk of death rising exponentially as the platelet count fell  among those with P. vivax infection, 1.7% (2 of 114) among those with P. malariae infection, and 1.7% (19 of 1148) among those with mixed infections. When platelet counts fell to <20 000 platelets/μL, the risk of death increased to 11% (108 of 978) among patients without malaria, 5.6% (40 of 708) among those with P. falciparum infection, 3.6% (6 of 168) among those with P. vivax infection, 0% (0 of 15) among those with P. malariae infection, and 3.1% (4 of 131) among those with mixed infections.Admission for inpatient care was required in 49.6% of patients (6196 12 499) initially presenting to the outpatient department with severe thrombocytopenia, compared with 29.0% (57 966 of 200 066) among patients without severe thrombocytopenia  among those with severe anemia alone, 4.65  among those with severe thrombocytopenia alone, and 16.44  among those with both (Table .53–5.98 P < .001), whereas the risk among patients with malaria was 2.77 , with no difference between infecting species (Table P = .228).In the absence of severe anemia, the greatest risk of mortality associated with severe thrombocytopenia was among patients without malaria , accounting for >40% of observed cases. Severe thrombocytopenia was associated with a 2.4-fold greater risk of admission to hospital and a 4.7-fold increased risk of death, rising to 16-fold when both severe anemia and severe thrombocytopenia were present , with 13% of patients presenting with platelet counts of <50 000 platelets/μL. The greatest risk of severe thrombocytopenia was in patients infected with Malaria causes a variety of hematological insults arising from hemolysis, host inflammatory response, hematopoietic suppression, and splenic pooling , 25. SevP. falciparum infections, compared with patients infected with P. vivax [. falciparum infection , compared with those with P. vivax .Previous studies have shown a consistent inverse correlation between parasitemia at presentation and the platelet count , but ourP. vivax , 30. ThiP. falciparum but not in those presenting with P. vivax monoinfection or without malaria. Furthermore, after the first year of life, lowland and non-Papuan patients had a low risk of severe thrombocytopenia. The risk of thrombocytopenia was significantly higher in Highland Papuans, and this was sustained throughout adulthood. Highlanders constitute an ethnic group originating from non–malaria-endemic regions who have not been under genetic selection pressure from malaria parasite infections. In the last decade, many highlanders have migrated at all ages to the lowland areas, where they have been exposed to malaria, often getting their first episodes of malaria in later life. Our findings are consistent with lowland ethnicity or recent malaria resulting in a reduction of the host inflammatory response to acute malaria and decreased platelet activation and consumption.We have shown previously that the risk of anemia in this population is greatest in young patients, highlanders, and those presenting with recurrent episodes of malaria . In contP. falciparum molecular patterns, release prepackaged inflammatory mediators [The pathogenic mechanisms by which platelets mediate disease severity remain to be delineated. However, clinical, autopsy, ex vivo, and in vitro studies have shown that platelets are involved in parasite sequestration , as wellediators . This coediators . Nitric ediators  and adulediators  with sevOur large-scale observational study has a number of limitations. First, platelet counts were only available in 26% of all presentations, and so there may be a degree of residual confounding in our multivariable analyses. However, the available hematology data rose to 80% in patients requiring admission. Although the risk of thrombocytopenia was greater in inpatients than outpatients, the magnitude of the other risk factors remained similar in both departments. Second, the surveillance program did not document the presence of all severe manifestations of malaria in these patients, so it is not possible in this data set to determine whether the presence of severe thrombocytopenia would have identified patients at risk of death in whom other World Health Organization (WHO) criteria for severe disease were not apparent . PreviouSupplementary materials are available at The Journal of Infectious Diseases online . Supplementary materials consist of data provided by the author that are published to benefit the reader. The posted materials are not copyedited. The contents of all supplementary data are the sole responsibility of the authors. Questions or messages regarding errors should be addressed to the author.


Severe malaria remains a major cause of childhood mortality globally. Decreased endothelial nitric oxide is associated with severe and fatal malaria. The hypothesis was that adjunctive inhaled nitric oxide (iNO) would improve outcomes in African children with severe malaria.versus room air placebo as adjunctive treatment to artesunate in children with severe malaria was conducted. The primary outcome was the longitudinal course of angiopoietin-2 (Ang-2), an endothelial biomarker of malaria severity and clinical outcome.A randomized, blinded, placebo-controlled trial of iNO at 80 ppm by non-rebreather mask One hundred and eighty children were enrolled; 88 were assigned to iNO and 92 to placebo . Ang-2 levels measured over the first 72 h of hospitalization were not significantly different between groups. The mortality at 48 h was similar between groups . Clinical recovery times and parasite clearance kinetics were similar (p > 0.05). Methaemoglobinaemia >7 % occurred in 25 % of patients receiving iNO and resolved without sequelae. The incidence of neurologic deficits (<14 days), acute kidney injury, hypoglycaemia, anaemia, and haemoglobinuria was similar between groups (p > 0.05).iNO at 80 ppm administered by non-rebreather mask was safe but did not affect circulating levels of Ang-2. Alternative methods of enhancing endothelial NO bioavailability may be necessary to achieve a biological effect and improve clinical outcome.Trial Registration: ClinicalTrials.gov NCT01255215The online version of this article (doi:10.1186/s12936-015-0946-2) contains supplementary material, which is available to authorized users. Plasmodium falciparum claims 0.6–1.2 million lives annually, 86 % of whom are children in sub-Saharan Africa , or other reversible disturbances of capillary hydrostatic or oncotic pressures. As expected, levels of metHb rose in patients receiving iNO80. These levels could be controlled with downward titration of the study gas and required temporary discontinuation of iNO in only 5.7 % of patients. This dose-dependent adverse event provided evidence of biological activity of the administered therapy to alter the redox state of circulating haemoglobin, although an effect on the endothelium was not observed, based on Ang-2 measurements. AKI was identified as a toxicity of iNO in a meta-analysis pooling data from multiple randomized trials involving mostly adult patients, although this effect was not evident in individual studies [Safety was objectively and blindly assessed using standardized toxicity tables. The only clinical sign that differed between patients receiving iNO studies . The rat80 in a murine model of experimental cerebral malaria did not translate to efficacy in humans in this clinical trial; however, pre-clinical data from this model were critical for generating the hypothesis and designing the trial. In mice, unlike humans, iNO altered Ang-2 levels, decreased blood–brain barrier dysfunction, decreased brain accumulation of parasites, and improved survival [80 pharmacokinetics may account for lack of efficacy in the present trial. Rapid conversion of iNO to nitrate and other stable adducts may have reduced bioavailable NO at the endothelium. On the other hand, iNO has been shown to exert pharmacological effects beyond the pulmonary vasculature in other studies in humans [80 was observed, other doses, routes of administration or NO donor molecules remain viable options for future investigation. Likewise, the Ang-Tie2 pathway remains a valid target for experimental interventions, and the pre-clinical murine model remains a useful tool to test novel therapy in vivo prior to clinical trials.Efficacy of iNOsurvival . Inter-sn humans . Althoug80 did not affect mortality or alter the rate of change of Ang-2 in this study; however, targeting the endothelium to improve outcomes in severe malaria remains a viable strategy with broader implications for other life-threatening infections such as sepsis characterized by endothelial dysfunction. Alternative methods to increase NO bioavailability at the endothelial barrier  deserve further investigation. Given the global burden of childhood malaria and the relatively high rate of morbidity and mortality despite treatment with anti-malarials, continued investigation of adjunctive therapy is warranted.Attempts to find host-directed treatments for severe malaria over the past several decades have not yet yielded an effective adjunctive therapy. iNO


Plasmodium vivax is one of the major species of malaria infecting humans. Although emphasis on P. falciparum is appropriate, the burden of vivax malaria should be given due attention. This study aimed to synthesize the evidence on severe malaria in P. vivax infection compared with that in P. falciparum infection.P. vivax infection and P. falciparum mono-infection; a comparable incidence was found in infants , under 5 year age group , the 5–15 year-age group  and adults . Six studies reported the incidences of SA in P. vivax infection and P. falciparum mono-infection; a comparable incidence of SA was found among infants , the 5–15 year-age group . This was significantly lower in adults . Five studies (n = 71079) compared the mortality rate between vivax malaria and falciparum malaria. A lower rate of mortality was found in infants with vivax malaria , while this was comparable in the 5–15 year- age group  and the children of unspecified-age group .We searched relevant studies in electronic databases. The main outcomes required for inclusion in the review were mortality, severe malaria (SM) and severe anaemia (SA). The methodological quality of the included studies was assessed using the Newcastle-Ottawa Scale. Overall, 26 studies were included. The main meta-analysis was restricted to the high quality studies. Eight studies (n = 27490) compared the incidence of SM between P. vivax was considerable, indicating that P. vivax is a major cause of SM. Awareness of the clinical manifestations of vivax malaria should prompt early detection. Subsequent treatment and monitoring of complications can be life-saving.Overall, the present analysis identified that the incidence of SM in patients infected with  Plasmodium vivax to severe malaria in some endemic countries such as Thailand, Brazil, Indonesia, Papua New Guinea and India. We aimed to synthesize the evidence on severe malaria in P. vivax infection compared with that in P. falciparum infection. We searched relevant studies in electronic databases. The combined results of the eight relatively high quality studies showed a comparable incidence between vivax malaria and falciparum malaria in infants, under 5 year age group, the 5–15 year age group and adults. The combined results of the six relatively high quality studies revealed a comparable incidence of severe anaemia between P. vivax infection and P. falciparum mono-infection in both the infants and the 5–15 year age group. Considering that severe malaria and deaths attributable to P. vivax is not a rare event, raised clinical awareness of the manifestations of vivax malaria in patients of any age should prompt early detection of malaria. It is likely that early detection, appropriate treatment commenced in a timely manner and close monitoring of any complications could be life-saving and contribute to the attainment of the global vision of no malaria deaths.Until recently, vivax malaria has received less attention than falciparum malaria and was deemed neglected. There has been a surge in studies that documented the contribution of  Plasmodium falciparum and P. vivax are the two major species of malaria infecting humans. Although emphasis on P. falciparum is appropriate, the burden of vivax malaria should be given due attention as almost 40% of the world population are at risk of vivax malaria P. vivax, indicating that P. vivax is dangerous and not benign P. vivax malaria is prevalent in many regions of the world, and in Asia and Latin America it accounts for more than half of all the malaria cases P. vivax transmission and 91% of these occurred in Central and South East Asia P. vivax to severe malaria (SM) in countries such as Thailand P. vivax infection compared with that in P. falciparum infection.Recently, there has been a surge in studies that reported the contribution of The present study followed the preferred reporting items for systematic reviews and meta-analyses (PRISMA) statements P. vivax infection in electronic databases such as PubMed, Ovid and Google Scholar. The search was limited to studies published in English until February 2014. We used the following medical subject heading (MeSH) and/or text words in any field, “” combined with “.” The search strategy was slightly modified according to the requirements of different databases. We also looked at the references of retrieved articles and relevant reviews for any additional studies.We searched studies on the relative distribution of severe malaria in a Studies were selected for the present meta-analysis if they met the following criteria:P. vivax infection, regardless of age and gender. Microbiological diagnosis of malaria was made based on microscopy of Giemsa-stained blood films or a rapid-onsite diagnostic test and with species confirmation through PCR-based analysis.Participants residing in malaria endemic countries presenting with clinical manifestations of P. vivax and P. falciparum (either mono-infection or mixed infection), and/or compared patients with SM and non-SM in P. vivax malaria were included.Observational designs, prospective cohort and case-control designs (case-control/nested-case control studies carried out with a clear description of the selection of controls) were considered. Studies which compared SM between P. vivax was defined according to standard criteria of the World Health Organization (WHO) for P. falciparumP. vivax preferential invasion of younger red blood cells (reticulocytes) necessarily lowers the threshold at which it would be considered to be hyperparasitaemic. SA was defined as having haemoglobin levels of <7 g/dL in adults and <5 g/dL in children, according to the WHO criteria The outcomes were SM, SA, and other common clinical manifestations related to vivax malaria. SM for Studies were excluded from the meta-analysis, if they (i) were case reports, (ii) assessed particular populations , (iii) had a sample size less than 10, (iv) had measured outcomes which were not clearly presented, or (v) were studies from which appropriate data could not be extracted.Two authors independently screened the titles and abstracts of publications according to the inclusion criteria. These two authors then independently extracted information from each of the included studies using the pre-tested data extraction form prepared for this study. Information collected was author, year of publication, country, patient characteristics, sample size, mean age, gender, study design and the reported clinical outcomes. Disagreements between the two authors were resolved by consensus. The methodological quality of the included studies was assessed using the Newcastle-Ottawa Scale (NOS) P. vivax and P. falciparum infections (either mono or mixed), we extracted adjusted OR and corresponding 95% CI from each study, wherever possible. If RR or OR was not reported, we calculated these from the raw data provided in the study. As the incidence of SM is not very high, a more conservative estimate of the OR was used for the pooled analysis. The heterogeneity between these studies was assessed with the I2 test. A calculated value of I2 over 50% indicated substantial heterogeneity. For pooling of the results, we used a more conservative random-effect model 2I statistic is low or zero, heterogeneity could still be a concern since it is likely to be present but undetected We assumed that the RR from cohort studies approximates OR from case-control studies P. vivax, P. falciparum and mixed infections) and by chloroquine (CQ) resistance status. The presence of publication bias was assessed by visualizing funnel plots. Data entry and analyses were performed using RevMan (version 5.3) . A protocol of this study is available If data allowed, we stratified the incidence of SM by age groups , by transmission intensity , by species  for outcomes to have occurred P. vivax. Compared with P. falciparum malaria, the mortality rate among infants was significantly lower in P. vivax infection . But, the mortality rate between vivax and falciparum malaria was comparable in under 5 year-age –group   2: 84%) .P. vivax infection with mixed infection ; the mortality rates among infants  and among children in the 5–15 year-age group  were comparable (Five studies (n = 33824) mparable .P. vivax infection and P. falciparum mono-infection was found in infants , under 5 year-age group , the 5–15 year-age group , children of any age  as well as in adults  (Eight studies (n = 27490) I2:25%) .P. vivax malaria and mixed infection and reported a significantly lower incidence among 5–15 year- age group  and comparable incidence among infants  (Five studies (n = 3064) 2: 96%) .P. vivax infection and P. falciparum mono-infection were included in the pooled analysis. A comparable incidence of SA between P.vivax infection and P. falciparum mono-infection was found in infants  as well as in the 5–15 year-age group . Of note, there is substantial between-study heterogeneity. This estimate, however, was significantly lower in adults   in under 5 year-age-group  as well as in the 5–15 year-age group  (I2: 0%) (Six studies I2: 0%) . A pooleI2:40%) . Two stuI2: 0%) .P. vivax infection compared to P. falciparum mono or mixed infection. Two studies on adult participants P. vivax infection compared to P. falciparum mono-infection , whilst 2 studies on children of any age (i.e unspecified age group) P. vivax and P. falciparum infections  (data not shown). Only one study P. vivax infection compared with mixed infection .Three studies P.vivax infection than in P. falciparum mono-infection . However, two studies on children (n = 229) P. vivax and P. falciparum infections  (One study on adult participants I2: 0%) .P. falciparum infection and P.vivax infection   . NotablyP. vivax infection than in P. falciparum infection amongst the 5–15 year-age group   (data not shown). An inspection of the funnel plot asymmetry showed a possible publication bias among studies on SM  . Hence, es on SM .P. vivax infection was considerable, indicating that P. vivax infection could be a major cause of SM.Overall, the present analysis identified that the incidence of SM in P. vivax, which is a notoriously virulent strain with relatively good efficacy against neurosyphilis was 10–15% for patients in the United Kingdom P. vivax has a higher chance of fatality is supported by a study on autopsy case series in Latin America, in which 13 of 17 post-mortem characterization of deceased patients have confirmation of P. vivax infections Dating back to the era of induced malaria therapy, the fatality rate with the Madagascar strain of P. vivax allows prolonged periods for the parasite to remain in a host population, even if transmission is interrupted and the primary infection has been treated successfully P. vivaxP. vivax endemic countries are SA and ARD vivax malaria is not fully understood, the inability of infected red blood cells (RBCs) to adhere to vascular endothelium and the parasite's strict preference for invading reticulocytes could explain the widely accepted ‘nonaggressive course’ of vivax malaria There are several possible explanations for this observation of severe vivax malaria. A long-lasting liver stage of P. falciparum could have contributed to the anaemia or there may be different pathways.Findings of the current review highlighted that vivax malaria is related to SM, in which SA is a relatively common clinical manifestation. It has been well established that the primary target of human plasmodium species is the RBCs P.vivax has a very strong predilection for RBCs, particularly reticulocytes, whereas P. falciparum has only a moderate predilection P. falciparum, the continued presence of vivax parasites may have been sufficient to infect and destroy most of the new reticulocytes, thereby hindering the timely restoration of the erythrocytes population P. vivax-infected patients as a result of recrudescence, reinfection, and relapse P. vivax infection compared to P. falciparum infections P. vivax infection, cerebral malaria is relatively rare, but when it occurs it is associated with high mortality P. vivax infections in regions such as Indian subcontinent The lack of rigidity of infected RBCs in vivax malaria makes the blockage of capillary beds in internal organs unlikely. Thus, the frequency of severe organ-specific clinical manifestations is lower in P. falciparum. The lower frequency of ARDS in vivax malaria may be related to the absence of microvascular sequestration of infected RBC Our findings reinforce the finding of individual studies P. vivax. It has been postulated that a greater risk of SA in early life (infants in this case) could be partly explained by a relatively faster acquisition of immunity in P. vivax compared with that in P. falciparumP.vivax infection compared with that in mixed infection among the 5–15 year-old children could also be related to the seemingly uniform lower prevalence of vivax malaria in endemic areas. This could partly be attributed to the parasite density.Published studies reported that the distribution of SM was age-specific P. falciparum infection seems to be applicable to most of the P. vivax patients admitted to the intensive care unit (ICU) as at least one of these severity criteria was present in most of the patients admitted P. vivax are not validated and the adoption of the WHO thresholds for disease severity for another species needs to be reassessed. For instance, severe disease with P. falciparum infection is considered with parasitaemia >200,000/µL, while parasitaemia exceeding 50,000/µL is rare in severe malaria with P. vivaxP. vivax infections have lower parasite biomass compared with P. falciparum malaria patients of the given age. P. vivax has a tendency to achieve and maintain lower density parasitaemia, and the inverse relationship between diagnostic sensitivity and parasitaemia count P.vivax lowers the threshold at which it would be considered to be hyperparasitaemic. Another hypothesis is that vivax malaria may be primarily an infection of haemopoetic tissues rather than the vascular sinus. Thus, a biomass of P. vivax exterior to the vascular sinus could expand dangerously without detection The WHO severity criteria formerly only validated for P. vivax CQ resistance P.vivax in 1946. Although as little as 0.3 gram CQ routinely cured CQ sensitive P. vivax, the treatment protocol made no distinction between P. vivax and P. falciparum for the recommended 1.5 gram total adult dose for treating acute attacks of malaria. This might, in part, explain the relatively late first known appearance of CQ resistant P. vivax in 1989 from PNG pvmdr1 gene are related to variation in the in vitro susceptibility of P. vivax similar to pfmdr1 in P. falciparumGeographical areas that reported severe vivax malaria are the same that demonstrated P. vivax has a strong predilection for reticulocytes, which are highest in the second postnatal month Co-infection with other endemic infectious agents could not be ruled out among the participants in the included studies. For instance, a study in Pakistan reported that 12% of patients with vivax malaria had co-existing infection vivax malaria patients attending the clinics during wet season had approximately two times greater chance of having SM than those patients during the dry season , while it was OR 1.1(95% CI 0.9–1.4) for P. falciparum mono-infection and OR 0.8 (95% CI: 0.4–1.9) for P. falciparum mixed infections 2I value remains high despite sensitivity analysis implies a de facto random distribution of heterogeneity. There may be factors inherent in the included studies such as the level of endemicity, the presence of co-infections, accessibility to effective malaria treatment, and the development of parasite resistance. Inadequate data preclude us from performing stratified analyses based on all these influencing factors.Age as a risk factor for SM could have been confounded by the seasonality of malaria in the study settings. This was supported by a prospective study carried out in PNG in which P. vivax infections can present as severe disease. The current analysis has documented that the two parasites may occur in equal proportions of SM. The global malaria control strategy and action plan need to readdress the fallacy that vivax malaria is ‘benign’ and not fatal. The vision of no deaths from malaria and a malaria free world requires that vivax malaria should be taken seriously; investments in prevention, diagnosis and treatment strategies to control and eliminate vivax malaria are critically part of achieving this aim.There are important implications for malaria control programmes based on the current findings that PCR confirmed P. vivax infection, upcoming well designed prospective studies are needed to substantiate vivax related SM in other epidemiological settings.Because different parasites need to be treated differently, the ability to diagnose the clinical manifestation of vivax malaria at the healthcare provider level must be strengthened. The subsequent appropriate and effective treatment of vivax malaria and monitoring of clinical course and complications can be life-saving. Although the current review has provided evidence of severity of Figure S1P. vivax and P. falciparum mixed infections.Forest plot showing a comparison of mortality between (PDF)Click here for additional data file.Figure S2P. vivax and mixed infections.Forest plot showing a comparative incidence of severe malaria between (PDF)Click here for additional data file.Figure S3P. vivax and mixed infections.Forest plot showing a comparative incidence of severe anaemia between (PDF)Click here for additional data file.Figure S4Forest plot showing a comparative incidence of severe anaemia between severe vivax and non-severe vivax malaria.(PDF)Click here for additional data file.Figure S5P. vivax and P. falciparum infections.Forest plot showing a comparative incidence of cerebral malaria between (PDF)Click here for additional data file.Figure S6Sensitivity analysis showing a comparative incidence of severe malaria in the 5–15 year-age group.(PDF)Click here for additional data file.Table S1The characteristic of the included studies.(RTF)Click here for additional data file.Table S2The methodological quality of the included studies.(RTF)Click here for additional data file.Checklist S1PRISMA checklist.(RTF)Click here for additional data file.


Plasmodium vivax malaria has been observed in Germany. The majority of cases was seen in Eritrean refugees.Since 2014, a considerable increase in P. vivax malaria admitted to the University Medical Centre Hamburg-Eppendorf Germany from 2011 until August 2015 were retrospectively identified by the hospital coding system and data was matched with records from the laboratory diagnostics unit of the Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.All patients with Between May 2014 and August 2015, 37 cases were reported in newly-arrived Eritrean refugees at the University Medical Centre Hamburg-Eppendorf, Germany. Relapses occurred due to difficulties in procurement of primaquine.Countries hosting Eritrean refugees need to be aware of vivax malaria occurring in this group and the risk of autochthonous cases due to local transmission by indigenous, vector competent Anopheles species. Plasmodium falciparum malaria, almost exclusively imported from West Africa [Plasmodium vivax infections, predominantly in refugees from Eritrea. Plasmodium vivax infections are characterized by relapses of malaria due to persistent liver stages of the parasite (hypnozoites). Those relapses can be prevented currently only by 8-aminoquinoline anti-malarials, such as primaquine [Around 500–600 annual cases of malaria were reported in Germany in the years before 2013. 80 % were In Europe, the number of asylum seekers status is continuously climbing with more than 200,000 applications in the European Union in 2014, most of them in Germany , 4. In tIn this report, the impact of these recent migration trends on the epidemiology of malaria cases seen in a large referral and teaching hospital in Germany is described.P. vivax malaria from 2011 until August 2015 were retrospectively identified by the “International Statistical Classification of Diseases and Related Health Problems” (ICD) and matched the data with records from the laboratory diagnostics unit of the Bernhard Nocht Institute for Tropical Medicine, Hamburg, which is the national reference laboratory for tropical pathogens in Germany. Diagnosis of malaria was performed by reading thin and thick blood films. In cases of low parasitaemia, blood was subjected to species-specific polymerase chain reaction (PCR) for species differentiation. The success of subsequent primaquine therapy after initial anti-malarial chemotherapy was evaluated by telephone interviews of patients or their legal guardians and by reviewing hospital documents.The study was performed at the University Medical Centre Hamburg-Eppendorf (UKE), a 1600-bed tertiary-care referral and teaching hospital with a specialist tropical medicine unit, in Hamburg, northern Germany. For tropical diseases the catchment area of this hospital is northern Germany. All patients admitted to the hospital with Statistical analysis was performed using SPSS software .This study has been granted an exemption from requiring ethics approval as it is an retrospective study and all patient information have been directly anonymised. The exemption was granted by be ethics committee of the physician Chamber Hamburg, Germany.P. falciparum. Plasmodium vivax accounted for only one or two cases per year, imported from Afghanistan and Benin (2011), Pakistan and Brazil (2012) or Vanuatu (2013). In 2014, a sharp increase was recognized and 23 cases of vivax malaria were diagnosed, of which 22 occurred in Eritrean refugees and one case in a refugee from Syria. In 2015, until August, there were 16 cases of vivax malaria, 15 cases in Eritrean refugees and one case in a returning traveller from Indonesia. One additional case was an unspecified tertian malaria from Uganda . Therefore, a relative increase of vivax malaria from only 2 % of all cases in 2013 to 26 % in 2014 and 34 % in 2015 was observed . All reported migration through Ethiopia and/or Sudan before embarking from Libya to Europe on the “Central Mediterranean Route” [Of the 37 Eritrean patients seen in the institution since 2014 , artemether-lumefantrine (4 cases) or chloroquine (3 cases). For all patients subsequent primaquine therapy was recommended. One patient had glucose-6-phosphate dehydrogenase (G6PD) deficiency. In 18 cases it was possible track down if the therapy with primaquine was taken: In 14 of these (78 %) primaquine was administered as recommended. The remaining patients were lost to follow up.P. vivax. This changed considerably in 2014, when more than a quarter of cases were diagnosed as vivax malaria; the trend currently continues in 2015 and was also observed on a national level [Until 2013, only very few malaria cases seen at our University Medical Centre were due to infection with Data from Sweden, where Eritrean refugees were the third largest group of refugees in 2014 also, indicate a similar development . InteresP. ovale. Unfortunately, a specimen diagnosis by PCR was not possible, since no blood sample was left in this case. Another P. ovale infection imported from East Africa seen at another hospital was, however, confirmed by PCR.It remains unclear if the infection was acquired at home in Eritrea or during the journey. Interestingly, one case of tertian malaria was observed, which was microscopically most likely an infection with Plasmodium falciparum and P. vivax predominate in Eritrea (60 and 39 %), Ethiopia (64 and 36 %) and Sudan  [P. ovale is most often seen in travellers and expatriates returning from West Africa. Nevertheless, data published in 2013 reported P. ovale infections in neighbouring north-west Ethiopia [P. ovale is fairly common and East African migrants both use the route via Libya to come to Europe [ctively) , whereas 60 and 3 %, EthioAnopheles species competent for P. vivax transmission are present in most European countries, such as Anopheles atroparvus in Germany. Thus, the increased introduction of P. vivax into Europe poses the risk for local transmission and the occurrence of autochthonous malaria, as recently reported from Greece [Furthermore, it is important to note that m Greece .It is of concern that there were a number of relapses of vivax malaria in patients with previous inpatient treatment in Germany, despite the fact that subsequent therapy with primaquine had been recommended. Primaquine is currently not licensed in Germany and has to be ordered from abroad. This makes prompt primaquine treatment challenging, especially for patients currently seeking asylum who may not have a fixed place of residence.P. vivax infection in this group of patients and correct diagnosis is of major importance in order to treat the patients effectively by successive primaquine administration. This is of considerable importance to prevent relapses and to minimize the risk of local transmission.A steep rise in vivax malaria in was observed at the University Medical Centre Hamburg-Eppendorf Germany since May 2014, almost exclusively seen in Eritrean refugees. Awareness of possible


The burden of malaria remains high for children in parts of Africa despite the use of insecticide-treated bed nets (ITNs). Chemoprevention has the potential of reducing the malaria burden; however, limited data exist on the efficacy and safety of anti-malarial therapy in the setting of chemoprevention.600 children 4–5 months of age were enrolled in Tororo, Uganda, an area of high transmission intensity. Participants were given ITNs, and caregivers instructed to bring their child to a study clinic whenever they were ill. Starting at six months of age, 579 were randomized to no chemoprevention, monthly sulphadoxine-pyrimethamine (SP), daily trimethoprim-sulphamethoxazole (TS), or monthly dihydroartemisinin-piperaquine (DP). Study drugs were administered unsupervised at home until 24 months of age. Episodes of uncomplicated malaria were treated with artemether-lumefantrine (AL) with active follow-up for 28 days. The cumulative risk of recurrent malaria within 84 days and the risk of adverse events within 28 days were compared across study arms using a Cox proportional hazards model and generalized estimating equations, respectively.A total of 1007, 919, 736, and 451 episodes of malaria were treated in the no chemoprevention, SP, TS, and DP arms, respectively. Only 19 (0.6%) treatments were for severe malaria. Early response to therapy with AL was excellent with 96.5% fever clearance and 99.4% parasite clearance by day 3. However, over 50% of AL treatments were followed by recurrent parasitaemia within 28 days. Compared to the no chemoprevention arm, the cumulative risk of recurrent malaria within 84 days following treatment of uncomplicated malaria with AL was significantly lower in the DP arm  but not the SP or TS arms. Compared to the no chemoprevention arm, none of the chemopreventive regimens were associated with an increased risk of adverse events following treatment of malaria with AL.The risk of severe malaria was very low in this cohort of young children living in a high transmission setting. In the setting of chemoprevention, treatment of uncomplicated malaria with AL was safe and efficacious, with moderate protection against recurrent malaria among children assigned monthly DP.NCT00948896.ClinicalTrials.gov  The burden of malaria remains unacceptably high in some parts of sub-Saharan Africa despite the scaling up of control interventions including provision of insecticide-treated bed nets (ITNs), indoor residual spraying of insecticide, and prompt malaria case management with artemisinin-based combination therapy (ACT). In 2012, there were an estimated 207 million cases and 627,000 deaths, with 80% of cases and 90% of deaths occurring in Africa, primarily in children under five years of age [The use of anti-malarial drugs for the prevention of malaria in children at high risk has recently received widespread attention as an alternative control strategy. Intermittent preventive therapy in infants (IPTi) with sulphadoxine-pyrimethamine (SP) at the time of routine vaccinations has been recommended by the WHO in certain settings . AlternaTwo parallel randomized control trials were recently completed in cohorts of HIV-unexposed (born to HIV uninfected mothers) and HIV-exposed (born to HIV infected mothers) children aged 6–24 months living in an area of Uganda with high antifolate resistance and intense, year-round transmission . Childre, Uganda) single dose once daily, SP  single dose each month, and DP  once daily for three consecutive days each month. HIV-unexposed children were randomized at six months of age and the HIV-exposed were randomized after cessation of breastfeeding and confirmation of their HIV-negative status (median age 10 months). Chemoprevention drugs were administered unsupervised at home according to weight-based guidelines.Two parallel, open label, randomized control trials of malaria chemoprevention were conducted in Tororo, Eastern Uganda, an area with intense year-round malaria transmission and an entomological inoculation rate (EIR) estimated at 125 infectious bites per person-year in 2011–12 . DetailsThe purpose of this report was to evaluate the safety and efficacy of treatment for malaria in the context of chemoprevention. Participants received all of their medical care at a designated study clinic open every day. Parents/guardians were encouraged to bring their children to the clinic any time they were ill. Children who presented with a documented fever (tympanic temperature ≥38.0°C) or history of fever in the previous 24 hours had blood obtained by finger prick for a thick blood smear. If the smear was positive, the patient was diagnosed with malaria and a complete blood count (CBC) and thin blood smear for parasite speciation were performed. Episodes of uncomplicated malaria were treated with artemether-lumefantrine (AL), the recommended first-line treatment in Uganda. AL was administered twice a day for 3 days, with the first daily dose given with milk and under direct observation in the clinic. The second daily dose was administered at home. Mothers were encouraged to give the second dose with milk or after a meal. Episodes of complicated malaria   or treatThick and thin blood smears were stained with 2% Giemsa for 30 minutes. Parasite density was estimated by counting the number of asexual parasites per 200 white blood cells and assuming a white blood cell count of 8,000 per μL. A thick smear was deemed negative if no parasites were seen in 100 high powered fields. Thin smears were used for species identification. Microscopy quality control included re-reading all blood smears and resolution of any discrepancies by a third microscopist. Haemoglobin levels were measured using a Beckham coulter counter machine or a portable spectrophotometer . Piperaquine (PQ) drug levels were measured from capillary blood collected on filter paper on the day malaria was diagnosed among study participants randomized to monthly DP, as previously described [Data were double-entered and verified in Microsoft Access and statistical analyses performed using Stata, version 12 (Stata-Corp). Efficacy and safety outcomes were assessed at the level of each treatment of uncomplicated malaria with AL. 28-day efficacy outcomes included fever and parasite clearance by day 3, appearance of gametocytes not present on day 0, haemoglobin recovery, and WHO treatment outcomes using a standardized classification system . 28-day Ethical approval was obtained from the Uganda National Council for Science and Technology, the Makerere University School of Medicine Research and Ethics Committee, and the University of California, San Francisco Committee on Human Research.P. falciparum) of which 3,058 (98.2%) were treated with AL and 55 were treated with quinine  children were randomized to one of the four chemoprevention arms and 514 (340 HIV-unexposed and 174 HIV-exposed) were followed up to 24 months of age  were significantly associated with an increased hazard of recurrent malaria  episodes treated with AL among children assigned to chemoprevention with monthly DP. PQ levels were < 10 ng/mL on the day malaria was diagnosed in 51.1% of episodes, suggesting that a complete dose of DP was not administered in the previous month despite the fact that 96.0% of caregivers reported administering the prior dose of DP [% episodeCompared to the no chemoprevention arm, none of the chemoprevention arms were associated with an increased risk of common adverse events of any severity following treatment with AL Table . Indeed The use of anti-malarial drugs for the prevention of malaria in children at high risk has been shown to be an effective control intervention and recommended as policy in certain epidemiological settings . In two Data from this study comes from two parallel randomized control trials in young HIV-unexposed and HIV-exposed children living in a holoendemic area where the incidence of malaria was remarkably high despite the provision of long-lasting ITNs to all study participants. Although over three thousand treatments were given for malaria, over 98% were uncomplicated cases treated with AL. The very low rate of treatment for complicated malaria seen in this study can likely be attributed to the high quality of care and provision of prompt and effective therapy in a research setting. AL is the recommended first-line treatment for uncomplicated malaria in a majority of countries in sub-Saharan Africa including Uganda. AL has been shown to be highly effective with PCR-corrected cure rates above 95% in the majority of studies . As the pfmdr1 alleles associated with decreased sensitivity to lumefantrine in subsequent episodes, while recent treatment with DP selected for parasites with the opposite alleles associated with increased sensitivity to lumefantrine [In this study, initial response to AL therapy for uncomplicated malaria was excellent, with rapid clearance of fever and parasitaemia, consistent with other studies from Uganda ,12. Despfantrine . This raPerhaps of equal or greater importance than the efficacy of AL, is its safety and tolerability in the setting of concomitant use of other anti-malarial drugs for chemoprevention. In a previous study from Uganda AL was found to be safe and well tolerated with no increased risk of common adverse events among HIV-infected and HIV-exposed children who were prescribed concomitant therapy with daily TS prophylaxis . In thisThere were several limitations to this study. Foremost was the lack of directly observed therapy, as chemopreventive drugs were administered at home and only the 1st of each daily dose of AL was administered in the study clinic. Additionally, the lack of pharmacokinetic data, with the exception of PQ levels measured at the time malaria was diagnosed in the DP chemoprevention arm, precluded the ability to assess drug-drug interactions and their potential impact on the efficacy and safety of AL. Study investigators, participants, and their parents/guardians were not blinded to assigned chemoprevention regimens, which could have introduced bias, especially with respect to measures of drug safety and tolerability which were largely subjective by nature. Finally, comparisons were made between the three chemoprevention arms and the no chemoprevention arm for multiple efficacy and safety outcomes, resulting in multiple tests of significance, increasing the probability of finding significant differences just by chance.In this study conducted in young children living in a high transmission area, over 3,000 episodes of uncomplicated malaria were treated with AL in the setting of three different chemopreventive regimens. AL was found to be safe and effective, with modest protection against recurrent episodes of malaria among children assigned chemoprevention with monthly DP. The use of drugs for the prevention of malaria offers great promise for high risk populations living in Africa. However, breakthrough episodes of malaria will inevitably occur and a better understanding of the optimal management of such episodes in the setting of chemoprevention is needed.