Dams are important to ensure food security and promote economic development in sub-Saharan Africa. However, a poor understanding of the negative public health consequences from issues such as malaria could affect their intended advantages. This study aims to compare the malaria situation across elevation and proximity to dams. Such information may contribute to better understand how dams affect malaria in different eco-epidemiological settings.Plasmodium falciparum sporozoites was done using enzyme-linked immunosorbent assay (ELISA). Five years of monthly malaria case data (2010–2014) were also collected from health centers in the study villages.Larval and adult mosquitoes were collected from dam and non-dam villages around the Kesem (lowland), Koka (midland), and Koga (highland) dams in Ethiopia between October 2013 and July 2014. Determination of blood meal sources and detection of Anopheles arabiensis, Anopheles pharoensis, and Anopheles funestus s.l. were the most common species, largely collected from lowland and midland dam villages. Larvae of these species were mainly found in reservoir shoreline puddles and irrigation canals. The mean adult anopheline density was significantly higher in the lowland dam village than in the midland and highland dam villages. The annual entomological inoculation rate (EIR) of An. arabiensis, An. funestus s.l., and An. pharoensis in the lowland dam village was 129.8, 47.8, and 33.3 infective bites per person per annum, respectively. The annual EIR of An. arabiensis and An. pharoensis was 6.3 and 3.2 times higher in the lowland dam village than in the midland dam village.Mean monthly malaria incidence was two- and ten-fold higher in the lowland dam village than in midland and highland dam villages, respectively. The total surface area of anopheline breeding habitats and the mean larval density was significantly higher in the lowland dam village compared with the midland and highland dam villages. Similarly, the mean monthly malaria incidence and anopheline larval density was generally higher in the dam villages than in the non-dam villages in all the three dam settings. This study found that the presence of dams intensifies malaria transmission in lowland and midland ecological settings. Dam and irrigation management practices that could reduce vector abundance and malaria transmission need to be developed for these regions. The sub-Saharan Africa region is ranked lowest in the world for average water withdrawal , suggestAnopheles gambiae, were indicated to underpin the increased malaria incidence [Ninety percent of the global malaria burden occurs in sub-Saharan Africa, resulting in transmission and disease management being a leading public health challenge . With thncidence .A number of environmental factors determine the degree of intensity of malaria transmission in Africa. Elevation has long been known for its effect on malaria transmission, mainly due to its influence on ecological and climatic drivers. A study in Tanzania found that malaria prevalence decreases by 21% in every 100 m increase in elevation [Although dams can increase malaria in unstable areas , it is not clear whether the impact of dams on malaria varies in different ecological settings. As Africa is experiencing a new era of dam building, with numerous dams planned or currently under construction , understThe present study assessed the link between three dams and malaria at different eco-epidemiological settings in Ethiopia. The objective of this study was to identify mosquito breeding sites and compare adult and larval abundances around three dams in highland, midland, and lowland settings of Ethiopia. This study aims to compare the malaria situation across elevations and proximity to dams. Such information may contribute to better understand how dams affect malaria in different eco-epidemiological settings.This study was carried out around three dams in Ethiopia Fig. : Kessem 3, and the primary use of its water is for irrigation of sugarcane crops that cover 20,000 hectares of floodplain downstream of the dam. The region is classified as arid with long-term average rainfall between 500 and 600 mm per year and a mean annual temperature of 26 °C . Sabure (932 m asl), hereafter referred as the lowland dam village, is the nearest settlement (<1 km) to the dam with a population of 3608 in 2012 . Inhabitants live close to their irrigated fields. Meli (936 m asl), hereafter referred as lowland non-dam village, is located 15 km from the Kesem reservoir shoreline and was selected as a control village (beyond the vector impact range of the reservoir). Most of the inhabitants of both villages were agrarians, but only dam villages practiced irrigation. According to the local health center, malaria is a serious health problem in this region with intensive seasonal malaria transmission .Kesem Dam , hereafter referred to as the lowland dam, is located on the Awash River in the Ethiopian Rift Valley in east-central Ethiopia, 220 km from Addis Ababa. Its capacity is 500 million m3. Ejersa , hereafter referred to as the midland dam village, is a rural village located adjacent (<1 km) to the Koka Reservoir shoreline. No irrigation was practiced around Koka. Dubsi , hereafter referred as the midland non-dam village, is located about 10 km from Koka Reservoir, and was used as a control village. The inhabitants of both villages are largely agrarians. Malaria is common in both villages, with the main transmission season occurring from September to November, immediately following the long rainy season (June–August).Koka Dam , hereafter referred as the midland dam, is located 100 km south-east of Addis Ababa, in the midland region of Central Ethiopia. The area is classified as semi-arid with 600 to 800 mm of annual rainfall, a mean annual temperature of 20 °C, and unstable/seasonal malaria transmission . Commissioned in 1969, Koka Dam was constructed to provide 46 MW of hydro-electricity to Addis Ababa and has a capacity of 1850 million m3 with the reservoir inundating an area of 17.5 km2. Commissioned in 2009, Koga Dam was constructed to provide water security for 7000 ha of irrigated land growing wheat, corn, and teff downstream of the dam. Endemir (1955 m asl), hereafter referred as the highland dam village, is located adjacent (<1 km) to the reservoir shoreline and had a population of 2907 in 2013 . Sira Behibret (1942 m asl), hereafter referred as the highland non-dam village, is located 12 km from the reservoir shoreline and had a population of 3241 in 2013 . The inhabitants of both villages are agrarians, and cattle herding is also common. Only dam villages use irrigation.Koga Dam , hereafter referred as the highland dam, is located on the Koga River, one of the major tributaries of the Blue Nile River in northwest Ethiopia, 556 km from Addis Ababa. The area is classified as a highland with an average annual rainfall of 1500 mm and has a mean annual temperature of 18 °C . Koga Dam has a storage capacity of 83.1 million mPlasmodium falciparum is the most common malaria parasite species, causing between 60 and 80% of malaria cases in the study area, with Plasmodium vivax causing the remaining malaria illnesses [Anopheles arabiensis (the most widely distributed An. gambiae sensu lato species in Ethiopia) is the major malaria vector species, while An. pharoensis plays a secondary role [An. gambiae s.l. collected were An. arabiensis based on previous PCR identifications [Vector control that involves use of bed nets and indoor residual spraying is commonly practiced in all study villages. No socioeconomic or intervention differences was observed among study villages. llnesses . Anophelary role . In thisications , 23.To assess the risk of malaria around dams, monthly data of retrospective microscope-confirmed malaria cases were obtained from health centers in each of the three dam sites (2010–2014). Inhabitants of the study area commonly visit these government health facilities for medical consultation since they provide medical services free of charge. The malaria dataset was sorted for each of the six villages (three dam and three non-dam villages) and species of malaria parasite as confirmed by microscopy.2), and sampling was undertaken at a rate of six dips per m2 [2). Larval anopheline samples were then counted and stored in vials by direct pipetting, killed by gentle heating, and preserved in 70% alcohol for later taxonomic identification. Larval samples from each mosquito habitat were placed in separate vials. Preserved larval anophelines were identified to species by microscope in the laboratory using morphological characteristics [Larval and adult mosquitoes were sampled every 3 weeks in each of the study villages from October 2013 to July 2014. Larval stages were sampled from any water body such as rain pools, man-made pools, reservoir shoreline puddles, irrigation canals, and irrigated field paddies. During each survey, all potential mosquito breeding habitats within a 1-km radius of the study village were sampled using 350 mL standard dippers . First, s per m2 . At leaseristics .Adult mosquitoes were collected using CDC light traps . In each study village, a total of ten light traps were deployed for overnight mosquito collection from 1800 to 0630 h. Five of the light traps were deployed inside human homesteads and the other five were installed outdoors. Houses for light trap mosquito collection were randomly selected, and sampling was conducted in the same houses throughout the period of the study. Each indoor light trap was placed in a bedroom, near a wall, with the bulb about 50 cm above a person sleeping under an untreated bed net . The outP. falciparum circumsporozoite antigens using enzyme-linked imminosorbent assay (ELISA) [The head-thorax portion of each dried female anopheline was processed to detect  (ELISA) . To dete (ELISA) .Monthly malaria incidence was express as the number of microscope-confirmed malaria cases in a given month per 1000 population . Larval Plasmodium sporozoites from the total number of mosquitoes of a species tested by ELISA. Human biting rates were derived from light trap catches by dividing adult anopheline density by a factor of 1.5 to match light trap catches with human landing catches, as determined by Yohannes et al. [Anopheles species, the human blood index (HBI) was determined as the proportion of samples positive for human blood from the total samples tested by blood meal ELISA. All analyses were done using Microsoft Excel 2010 and SPSS statistical software version 22 . The level of significance used for all tests was 0.05.The sporozoite rate was expressed as the proportion of mosquitoes positive for s et al. . The humP < 0.05) . The peak period of malaria incidence at all study sites was between September and November.The mean monthly malaria incidence was generally higher in the dam villages than in the non-dam villages in all three study dam sites (degree of freedom (df) = 2; n = 271) than in the non-dam village (n = 22). At the midland, the number of positive anopheline breeding sites was nearly nine times higher in the dam village (n = 115) than in the non-dam village (n = 16). Similarly, the number of anopheline breeding sites was six times higher in the dam village (n = 68) than in the non-dam village (n = 11).A total of 1838 potential mosquito larval sites were surveyed during the study period  were sampled from the lowland dam while the rest 23% (n = 430) and 13% (n = 239) were from the midland and highland dam sites, respectively. Anopheline larval abundance was generally higher in the dam villages than in the non-dam villages at all study dam sites. The mean larval density (larvae per square meter) was significantly higher in the lowland dam village  than in the midland  and highland  dam villages. Overall, controlling for elevation differences, the variation in mean larval density among the three dam sites was significant .A total of 1860 anopheline larvae were sampled during the period of the study (Table Anopheles species were identified as larvae across the study area: An. gambiae s.l. (hereafter referred as An. arabiensis), An. pharoensis, An. funestus s.l., An. coustani s.l., and An. cinereus  of total larval collections, followed by An. pharoensis , An. coustani s.l. , and An. funestus s.l. . Larvae of An. funestus s.l. were found only in the lowland dam village, predominantly in the shoreline puddles and irrigation canals. In the lowland setting, An. arabiensis was predominantly found in irrigation canals and shoreline puddles, contributing to 56 and 37% of the total larval collection from these habitats, respectively. Shoreline puddles accounted for 70.1% of this species’ larvae in the midland dam village, while irrigation canals and shoreline puddles accounted for 49.5 and 12.6% in the highland dam village, respectively. Similarly, An. pharoensis larvae were primarily found within irrigation canals and/or shoreline puddles at each of the dam villages. In control villages, larval An. arebiensis was predominant, commonly found in rain pools and man-made pools. Overall, while anopheline larvae at the midland dam village were collected mainly from shoreline puddles, both shoreline puddles and irrigation canals were the dominant larval habitats at the lowland and highland dam villages.Five us Table . Among tAnopheline larval density peaked between October and November, dropping during the dry season, and building up to the wet season in all study villages Fig. . Howevern = 3503), 29% (n = 1506), and 3% (n = 131) were from lowland, midland, and highland study sites, respectively , followed by An. funestus s.l. (9.4%), An. coustani s.l. (6.4%), and An. cinereus (0.2%).A total of 5140 adult anopheline mosquitoes were collected during the study period. Of these, 68% n = 503, 29% F = 23.89; P < 0.001) and was generally higher at the dam villages than at the non-dam villages in all three study areas. The highest density was recorded at the lowland dam village  and the lowest at the highland non-dam village . Similarly, the overall mean adult anopheline density at the lowland dam village was 2.2 times higher than at the midland dam village and 22 times higher than at the highland dam village.Similar to larvae, anopheline adult density peaked between October and November, fell during the dry season, and increased again in June with the commencement of the wet season in all study villages Fig. . OverallAn. arabiensis predominantly indoors in all study villages  = 87.2%) and An. arabiensis (HBI = 82.4%) were the most anthropophagic species in the lowland dam village  to midland (34%) and highland (36%). An. pharoensis preferred human blood meals over bovine sources, while An. coustani s.l. preferred bovine over human blood in all study villages.ELISA results indicated that ge Table . SlightlP. falciparum sporozoite infections  of An. arabiensis and 1.2% (3/251) of An. pharoensis tested positive for P. falciparum sporozoites. In the midland dam village, the sporozoite rate of An. arabiensis and An. pharoensis was 2% (11/541) and 1.4% (6/421), respectively, while only a single female An. arabiensis  tested positive for P. falciparum sporozoite in the midland non-dam village. All sporozoite-infected anophelines were collected during the main transmission season. None of the samples from the highland dam villages tested positive for P. falciparum sporozoites.A total of 4848 female anophelines were tested for ns Table . The higAn. arabiensis, An. funestus s.l., and An. pharoensis at the lowland dam village was found to be 129.8, 47.8, and 33.3 infective bites per person per year (ib/p/y), respectively  for ly Table . In contAnopheles arabiensis and An. pharoensis were the major malaria vectors, occurring in higher abundance at lowland and midland dam villages than at the highland dam villages.The present study indicates the link between dams and malaria in different eco-epidemiological settings in Ethiopia. At the lowland and midland settings, reservoir shoreline puddles and irrigation canals were the major malaria vector breeding habitats, contributing to 70–80% of the anopheline larval breeding sites. Anopheles arabiensis and An. pharoensis were primarily breeding in shoreline puddles and irrigation canals in the lowland, midland, and highland dam villages, although their abundance differed among villages. The abundance of these vector species peaked between October and November when the water level started receding following peak water level between July and August: this creates breeding sites at the shorelines. A previous study around the Koka Dam indicated that while An. arabiensis prefers shallow sunlit shoreline puddles, An. pharoensis breeds in semi-permanent and partly covered large water pools [er pools . A prefeer pools , around er pools  and elseer pools , 32.Larval and adult vector densities decreased from the lowland to midland to highland dam villages. Climate variables such as temperature are the major factors that determine rates of mosquito breeding, adult longevity, and malaria parasite development at different elevation settings . Dams inAn. arabiensis, An. pharoensis, and An. funestus s.l.) with a combined annual EIR of 210 per person per year around the Kesem Dam highlights the pressing need to devise vector control strategies around lowland dams. Nevertheless, the annual EIR of An. arabiensis (129.8) and An. funestus s.l. (47.4) in the lowland dam village was lower than those reported  from the Lower Moshi irrigation area of northern Tanzania for the same species [An. funestus s.l. in the lowland dam village and An. pharoensis in the midland dam village since the current malaria intervention strategies entirely target indoor mosquitoes.A higher vector density along with a high HBI and EIR in the lowland dam village revealed the serious potential negative impact of dams on malaria in lowland Ethiopia. Moreover, the presence of three vector species  in the lowland dam village was comparable to that reported from Uganda (5.3%) [An. funestus s.l. was 25-fold higher in the irrigated sites as compared to that in non-irrigated sites in the sub-Saharan Africa. The present study documented the link between An. funestus s.l. and irrigation dams in the lowland areas of Ethiopia which otherwise would not have been identified.The present study has documented for the first time in four decades the role of  changes . The prea (5.3%)  but lowea (5.3%) . Krafsura (5.3%)  reporteda (5.3%)  reportedMalaria incidence and vector density peaked in all study villages between October and November immediately after the main wet season. The impact of the dams was to intensify the malaria transmission instead of extending the period of transmission. Similar findings were documented in the Gilgel-gibe Dam in south Ethiopia , the BemAn. funestus complex in the lowland regions of Ethiopia.This study did not include data for all months of a year. For instance, September lies in the peak malaria transmission season and its inclusion would improve the seasonality of malaria transmission in each eco-epidemiological settings. Future longitudinal research is required to verify the results of this study and assess interannual water level variations on malaria transmission across dams in different ecological settings. Similarly, molecular work is needed to provide the taxonomic resolution for the species of the The link between dams and malaria must be considered while planning, designing, and operating large dams in sub-Saharan Africa where malaria is a primary public health challenge. The present study confirmed that dams in semi-arid lowland and midland areas intensify malaria transmission due to mosquito vector breeding in associated shoreline and irrigation habitats. However, such an effect was not detected at the highland dam area. Proper management of dams and associated shallow shoreline and canal habitats is thus essential to reduce malaria vector breeding around these economically important water infrastructures. Such environmental management techniques along with conventional vector interventions should be targeted to reduce malaria transmission around these critical infrastructures.


Plasmodium falciparum cause an accumulation of specific responses against various antigens that correlate with a decreased risk of clinical malaria episodes. However, small effect sizes and the often polymorphic nature of immunogenic parasite proteins make the robust identification of the true targets of protective immunity ambiguous. Furthermore, the degree of individual-level protection conferred by elevated responses to these antigens has not yet been explored. Here we applied a machine learning approach to identify immune signatures predictive of individual-level protection against clinical disease. We find that commonly assumed immune correlates are poor predictors of clinical protection in children. On the other hand, antibody profiles predictive of an individual’s malaria protective status can be found in data comprising responses to a large set of diverse parasite proteins. We show that this pattern emerges only after years of continuous exposure to the malaria parasite, whereas susceptibility to clinical episodes in young hosts (< 10 years) cannot be ascertained by measured antibody responses alone.Antibodies are thought to play an essential role in naturally acquired immunity to malaria. Prospective cohort studies have frequently shown how continuous exposure to the malaria parasite  P. falciparum malaria is of fundamental importance for malaria control and elimination efforts. The identification of parasite antigens that could potentially be considered as vaccine targets often relies on prospective cohort studies where observed infection rates are related to measured immune responses. However, what is unknown, is how these population-level associations between antibody titres and protection from severe malaria can predict the risk of an infection for an individual. We therefore analysed three sets of cohort-based immune profiles using a machine learning approach in order to identify distinct immune signatures that are predictive of protection at the individual-level. Our results show that even statistically significantly associated responses fail to provide robust information about an individual’s risk of malaria and that machine learning approaches should be considered more prominently alongside traditional methods for analysing these complex and high dimensional datasets.Understanding naturally acquired immunity against  P. falciparum endemic areas develop protection against clinical and symptomatic infections over years of repeated exposure. Since the first experimental evidence demonstrating how passively transferred immunoglobulins from immune adults can dramatically reduce parasitaemia in infected recipients P. falcip(PDF)Click here for additional data file.S1 Script(R)Click here for additional data file.


P < 0.001), leukocytosis , mean hemozoin-containing monocytes >5% , mean hemozoin-containing neutrophils >5% , and high density parasitemia  were associated with severe malaria. Hemozoin-containing leukocytes, leukocytosis, and other identified associated factors should be considered for proper management of children with severe malaria.Hematological parameter changes are the most common complications in malaria. We aimed to determine the hematological parameters and hemozoin-containing leukocytes and their association with disease severity in malaria infected children aged between 1 and 15 years. A facility-based cross-sectional study was conducted at Pawe General Hospital from July 31 to December 30, 2014. Demographic and clinical data were collected using structured questionnaire. Blood specimen was collected from each study participant for hematological investigations. Data were analyzed using SPSS version 20. The overall prevalence of anemia was 40.3%, most of which were mildly anemic. Leukocytosis was found in 15.4% of study participants. More than a fourth (27%) of the children had severe malaria. Hemozoin-containing monocytes and neutrophils were found in 80.1% and 58.9% of the study participants, respectively. Under-five years of age (AOR = 3.01, 95% CI: 1.83–7.39,  Plasmodia. Both circulating and resident phagocytes acquire HZ through phagocytosis of parasitized red blood cells (PRBCs). Free HZ crystals may also be released after schizont rupture. Some studies show acquisition of HZ by circulating monocytes and neutrophils to be associated with malarial severity [Malaria is one of the infectious diseases that may affect hematological parameters. Anemia, thrombocytopenia, leukocytosis, and leukopenia are the most common hematological complications associated with malaria –3. The eseverity , 7. Deteseverity –11.Hematological changes are the most common complications in malaria and play major role in disease outcomes. In malaria endemic areas, severe malarial anemia (SMA) is one of the major factors contributing to anemia resulting in morbidity and mortality among children , 5. HealAlthough there are several factors that increase mortality due to malaria in Ethiopia, the absence of reliable diagnosis and management of SM is the most important. In health facilities in Ethiopia, SM is usually diagnosed by counting the number of asexual parasitaemia in peripheral blood smear of the patients . HoweverA facility-based cross-sectional study was conducted at Pawe General Hospital from July 31 to December 30, 2014. Pawe General Hospital is found in Metekel Zone of Benishangul Gumuz Regional State, located 557 kms northwest of Addis Ababa. The hospital serves an estimated 300,000 people in the region, with bed capacity of 180. The geographical coordinates of the area are approximately 11°19′N latitude and 36°25′E longitude, with altitude range of 1050–1250 meters above sea level. The annual mean rainfall is 1150 mm with average temperature of 32°C. The area is characterized by hot and humid climatic condition with stable, year-round transmission of malaria. Even though there is perennial transmission of malaria in the study area, the transmission peaks from September to December, following the main rainy season from June to September , 26.A total of 377 children diagnosed with malaria by peripheral smear microscopy at the hospital were included in this study. The sample size was estimated using single population proportion formula considering 43% expected prevalence of malarial anemia , 5% margThe following exclusion criteria were considered in this study: (1) positivity for intestinal parasite(s) as screened by microscopic examination of wet mount and formol-ether concentrated stool sample; (2) HIV-1/2-seropositivity as screened by the HIV rapid diagnostic tests ; (3) antimalarial treatment 48 hours prior to data collection; (4) history of chronic illness as responded by the parents/guardians of the children.Demographic and clinical data of the children were collected by a trained public health officer using structured questionnaire. Moreover, laboratory data including complete blood count (CBC), blood film examination for hemoparasites, and HCLs were generated in this study. Approximately 4 mL of venous blood was aseptically collected into ethylene diamine tetra acetic acid- (EDTA-) containing vacationer tube. The blood samples were analyzed for CBC and thin and thick blood smears prepared for microscopic examination of malaria parasites. The CBC was analyzed using CELLDYNE 1800®  within two hours of sample collection. Thick and thin blood films were prepared on single slide for each study participant. Thin blood smears were methanol-fixed before staining. The slides were stained using 10% Giemsa stain (PH 7.2) for 10 minutes, with the Giemsa stain being prepared immediately before use. The blood smears were examined for malaria parasites, and HCLs were enumerated.To ensure quality of the data generated in the study, data collectors were trained prior to commencement of the study. Control samples were utilized to ensure accuracy of outputs of the hematology analyzer. Two independent blinded laboratory technologists examined the blood films. In case of discrepancy between the two readings, a third person was involved in reading the slide. Moreover, 10% of the slides were randomly selected and reexamined by the third laboratory technologist.μL, 1,000–10,000/μL, and >10,000/μL, respectively [9/L and >11.0 × 109/L, respectively. Thrombocytopenia was defined as PLT count <150 × 109/L [Children with at least one of the clinical symptoms: prostration, severe malarial anemia, and hyperparasitemia were classified to have SM . Malariaectively . Childreectively . Leukope × 109/L .P value less than 0.25 were candidates for the multivariable logistic regression in this study. P value < 0.05 was considered significant during the analysis.The collected data were checked for completeness regularly during the course of data collection. The data were entered, cleaned, and analyzed using SPSS version 20.0 . Descriptive statistics including frequency, mean, and standard deviation were utilized to summarize demographic profile of the children and some of the clinical data. Bivariate and multivariable logistic regressions were used to assess association of the independent variables with the dependent variables. Variables with Ethical clearance was obtained from Jimma University Ethical Review Board. Permission was obtained from the Regional Health Bureau. Voluntary participation of the children and their parents/guardians was ensured. Written informed consent was obtained from the parents/guardians of the children before enrollment in the study. Confidentiality of all the clinical information obtained from the children was strictly maintained. All the children who were involved in the study were treated for malaria according to the Malaria Treatment Guidelines . Moreoven = 127) were children between 1 to 5 years. At presentation, 63.9% (n = 241) of the children had fever (axillary temperature ≥ 37.5°C). The majority of malaria cases were due to P. falciparum   .n = 302) and 58.9% (n = 222) of study participants, respectively. On average, 9.7 and 1.7% of the monocytes and neutrophils contained HZ, respectively. The total HCMs and HCNs per microliter of blood of the study participants were 80.6 ± 34.3 and 85.8 ± 37.1, respectively. Children with SM had significantly lower mean Hb concentration, hematocrit value, and RBC count. On the other hand, the children with SM had significantly higher WBC count, mean HCMs count, and HCNs percentages compared to those with uncomplicated malaria. The mean PLT count did not differ significantly between the two groups  were anemic, of whom 87.5% (n = 133), 9.2% (n = 14), and 3.3% (n = 5) had mild, moderate, and severe anemia, respectively. Thrombocytopenia was found in 56.8% (n = 214) of the study participants. Mild, moderate, and severe thrombocytopenia accounted for 41.6% (n = 89), 45.3% (n = 97) and 13.1% (n = 28) of the children with thrombocytopenia, respectively. Leukocytosis and leukopenia were found in 15.4% (n = 58) and 10.3% (n = 39) of the study participants, respectively.Factors associated with severe malaria among the children are demonstrated in After adjusting for all the measured explanatory variables in the multivariable regression model, under-five years of age , leukocytosis , mean HCMs >5% , mean HCNs >5% , and high parasitemia  were associated with SM.The main aim of this study was to determine the common hematological indices and HCLs among the malaria infected children. Accordingly, the overall prevalence of anemia was 40.3%. Anemia is a common complication associated with malaria , 30, 32,In this study, nearly half of the children had moderate to mild thrombocytopenia. Low PLT associated with malaria in malaria endemic areas has also been reported previously , 37–41. Leukocytosis and leukopenia were found in 15.4% and 10.3% of the study participants, respectively. Moreover, children who had leukocytosis were 3 times more likely to have SM. Other studies also show significant association of leukocytosis with SM , 23, 37.In this study, it was also revealed that most of the malaria infected children had HCMs and HCNs in their peripheral blood smear. The interaction of HZ with immune cells may result in upregulation or downregulation of immune mediators –48 affecThe findings of this study should be interpreted in light of the following limitations. As no locally established reference range for hematological parameters in children was obtained, the WHO reference range was utilized. Although certain bacterial infections can profoundly perturb hematological parameters, thereby affecting their diagnostic value in determining severity of malaria, this study did not investigate any bacterial coinfections.Over a quarter of the children with malaria had SM. Demographic and hematological parameters significantly affected the malaria disease outcome among the studied children. The presence and quantities of HCLs and other hematological parameters should be considered in the management of children with malaria in the study area. Further longitudinal studies with larger sample size are needed to determine the association of hematological parameters with SMA.


This study was designed to evaluate the efficacy of exchange transfusion in patients with severe imported falciparum malaria. Twelve patients who met the diagnostic criteria for severe malaria were treated with exchange transfusion 14 times according to a conventional anti-malarial treatment. This study evaluated the efficacy of exchange transfusion for severe imported falciparum malaria.Clinical data of severe imported falciparum malaria patients admitted to the intensive care unit (ICU) of Nantong Third People’s Hospital from January 2007 to December 2016 were investigated in this retrospective study. Patients were divided into the intervention group, which received exchange transfusion, and the control group. This study assessed parasite clearance and outcomes of the two groups, and levels of erythrocytes, haemoglobin, platelets, coagulation, liver function, lactate, C-reactive protein, and procalcitonin, before and after exchange transfusion in the intervention group.There was no significant difference in the severity of admitted patients. Exchange transfusion was successfully applied 14 times in the intervention group. Differences in the levels of erythrocytes, haemoglobin and platelets did not reach statistical significance. Exchange transfusion improved coagulation, liver function, lactic acid, C-reactive protein, and procalcitonin. No differences were observed in parasite clearance, ICU and hospital length of stay, in-hospital mortality, and costs of hospitalization between the two groups.Exchange transfusion as adjunctive therapy for severe malaria was observed to be safe in this setting. Exchange transfusion can improve liver function and coagulation and reduce inflammation, but it failed to improve parasite clearance and the outcomes of severe imported falciparum malaria in this case series. Plasmodium falciparum occurs mainly in the erythrocytes. The high density of Plasmodium in severe malaria patients can lead to multiple organ dysfunction [Many severe malaria patients who are admitted to an intensive care unit (ICU) have suffered from dysfunction in their liver, kidneys and other organs. The incidence of severe malaria was 10% in imported falciparum malaria. Advances in the care of severe imported falciparum malaria, including mechanical ventilation, blood purification and other treatments used to maintain organ function, have resulted in improved outcomes . Asexualfunction . In thisfunction  were treP. falciparum parasitaemia > 10%.The inclusion criteria were: (1) hospital admission from January 2007 to December 2016; (2) a diagnosis of falciparum malaria based on a blood smear performed at the hospital and the centres for disease control and prevention; and, (3) meeting the severe malaria diagnostic criteria , which wPatients were divided into the intervention group, which received exchange transfusion, and the control group. This retrospective study was not random. Patients in the intervention group received exchange transfusion within 24 h of admission to the ICU. Admission clinical status was assessed using the Acute Physiology and Chronic Health Evaluation II score, Glasgow Coma Scale, levels of mean arterial pressure, plasma glucose, haemoglobin, plasma pH, lactate, creatinine, total bilirubin, pulmonary oedema, percutaneous oxygen saturation, respiratory rate and parasitaemia. This study compared the parasite clearance between the two groups and the laboratory values of the intervention group before and after exchange transfusion. Laboratory values were tested 8 h after exchange transfusion. Outcome measures, including length of ICU and hospital stay, in-hospital mortality and costs of hospitalization were compared at the same time.9/L. Heparin was used for systemic anticoagulation. Mechanical ventilation with low tidal volumes was used in patients with acute respiratory distress syndrome.Anti-malarial therapy with artesunate and clindamycin was initiated as soon as possible in all patients with malaria. Internal jugular vein and radial artery catheters were placed to obtain haemodynamic monitoring parameters. Continuous renal replacement therapy was used in patients with acute renal failure. Apheresis platelets were administered to patients with a platelet count < 20 × 10Plasmodium trophozoites found in peripheral blood; pH < 7.25; or, diagnosis of disseminated intravascular coagulation. Similar to prior reports [5 parasite/μL. The exchange procedure ceased when the level of haemoglobin had dropped below 70 g/L. The volume of the exchange was 500–1000 mL in most patients. Mean arterial pressure, pulse rate and oxygen saturation were monitored frequently during the exchange transfusion procedure.Patients were eligible for exchange transfusion when they met one of the following criteria: t test was performed to compare continuous variables. Differences before and after exchange transfusion were assessed using a paired sample t test. Categorical variables were compared using the Fisher’s exact test. A P value of < 0.05 was considered to be the level of significance.Data were analysed using SPSS software for Windows, version 17.0 . Continuous data are presented as the mean ± standard deviation. An independent sample A total of 27 patients (12 control group and 15 intervention group) were eligible according to the inclusion criteria. All the patients were male and had working experience in Africa. No differences were observed in age, APACHE II score, Glasgow Coma Scale and levels of mean arterial pressure, plasma glucose, haemoglobin, plasma pH, lactate, creatinine total bilirubin, pulmonary oedema, percutaneous oxygen saturation, respiratory rate, and parasitaemia between the two groups. There was no significant difference in the severity of admitted patients. The details are shown in Table The parasite clearance is shown in Table Exchange transfusion was safely performed 14 times in the intervention group. No significant changes in white blood cell count, haemoglobin and platelet count were detected. There was no significant difference in the levels of prothrombin time, activated partial thromboplastin time, fibrinogen and antithrombin III after exchange transfusion. Exchange transfusion reduced the levels of fibrin degradation products and D-dimer as well as improving liver function . At the same time, exchange transfusion reduced levels of lactate, C-reactive protein and procalcitonin. The details are shown in Table versus 7.3 ± 4.7 days for the intervention group. The length of hospital stay was 14.7 ± 6.7 days for the control group versus 16.7 ± 7.7 days for the intervention group. No case fatalities were observed in the intervention group, whereas two deaths  were noted in the control group . The costs of hospitalization were 10,6135 ± 54,092 yuan for the control group versus 86,165 ± 37,137 yuan for the intervention group. However, there were no statistically significant differences between the two groups for the lengths of ICU and hospital stays, in-hospital mortality or costs of hospitalization . Exchange transfusion failed to improve outcomes. This result may be biased due to the small sample size.The length of ICU stay was 8.8 ± 5.0 days for the control group Severe malaria is a sub-set of malaria with high mortality rates. Most severe malaria is caused by falciparum malaria. Falciparum malaria is extremely common in Africa. Severe malaria mostly occurs in children and women in endemic areas. In recent years, there are many cases of imported falciparum malaria in China. In the early stages of severe malaria, there are no specific clinical symptoms, which results in delayed diagnosis and incorrect treatments.All the patients in this study had working experience in Africa. They were male and previously healthy. Most patients were haemodynamically stable when admitted to the ICU. One early symptom was an unexplained fever in many patients. Because of delayed diagnosis, many patients had developed hyperbilirubinemia, kidney injury, active coagulation, and haemolysis when malaria was diagnosed.Plasmodium can cause erythrocyte destruction and adherence to endothelial cells, which leads to microcirculatory dysfunction [function . RemovinExchange transfusion was first introduced in 1974 , 9, its This research focused on parasite clearance. In severe malaria, infected red blood cells have decreased deformability and increased adhesiveness, which caused sequestration of these cells in the microvasculature, local hypoxia, ischaemia, and local release of pro-inflammatory cytokines . ExchangIn this study, exchange transfusion was safely applied 14 times. Research involving the role of exchange transfusion in improving liver function and coagulation as well a reducing inflammation in severe imported falciparum malaria patients remains rare. According to this findings, exchange transfusion can improve liver function and coagulation as well as reduce inflammation, but it failed to improve parasite clearance, which is consistent with findings from previous studies . This reThis study suggests that using exchange transfusion as an adjunctive therapy for severe malaria was safe in this setting. Exchange transfusion can improve liver function and coagulation as well as reduce inflammation, but it failed to improve parasite clearance and outcomes of severe imported falciparum malaria in this case series.


Plasmodium parasites, is thought to be one of the strongest selective forces that has shaped the genome of modern humans and was endemic in Europe until recent times. Due to its eradication around mid-twentieth century, the potential selective history of malaria in European populations is largely unknown. Here, we screen 224 ancient European genomes from the Upper Palaeolithic to the post-Roman period for 22 malaria-resistant alleles in twelve genes described in the literature. None of the most specific mutations for malaria resistance, like those at G6PD, HBB or Duffy blood group, have been detected among the available samples, while many other malaria-resistant alleles existed well before the advent of agriculture. We detected statistically significant differences between ancient and modern populations for the ATP2B4, FCGR2B and ABO genes and we found evidence of selection at IL-10 and ATP2B4 genes. However it is unclear whether malaria is the causative agent, because these genes are also involved in other immunological challenges. These results suggest that the selective force represented by malaria was relatively weak in Europe, a fact that could be associated to a recent historical introduction of the severe malaria pathogen.Malaria, caused by  Plasmodium falciparum is one of the main causes of child mortality worldwide, although other species from the same genus, P. vivax, P. malariae and P. ovale are also causative agents of the disease. Therefore, it is not surprising that malaria is one of the strongest known selective pressures that have recently shaped the human genome. Malaria is the evolutionary driving force behind sickle-cell disease (HbS), thalassemia, glucose-6-phosphatase deficiency (G6PD) and other erythrocyte defects that together comprise the most common Mendelian diseases of humankind. Remarkably, populations from different geographical areas have developed different genetic mechanisms adapted to malaria resistance; for instance, the HbS allele at the HBB gene is common in Africa but rare in Southeast Asia, whereas the HbE alelle shows a reversed pattern. Resistance to malaria includes primarily genes involved in immunological response, but also some involved in inflammation and cell adhesion and even genes related to metabolic pathways. The fact that different malaria-resistance alleles have arisen in different places suggests that this adaptation occurred relatively recent in human history, at least well after the Out of Africa migration1.The malaria parasite P. falciparum may have rapidly spread from its African tropical origins to other tropical and subtropical regions of the world only within the last 6,000 years2. The recent origin of the worldwide P. falciparum populations, which are the most malignant of human malarial parasites, may account for its virulence3. Thus, haplotype analysis at the G6PD locus suggests that the African resistance allele to P. falciparum originated within the last 10,000 years4 while a similar analysis at the HbE alleles (variants of the HBB gene) in Southeast Asia yielded an even more recent date, around 5,000 years ago5. These and other estimates associate the resistance to P. falciparum with the onset of agriculture and the emergence of favourable environments for mosquito proliferation after the clearance of woodlands for farming. Falciparum-like illness (I.e. miasmas) appears to be very recent in Europe. It seems to have spread from India to the West, appearing in ancient Greece only by the 4th century BCE, where it was implicated in the decline of many city-state populations2. The retrieval of the eradicated European P. falciparum from 70-year-old slides from a malaria-endemic region in Spain confirms a recent, phylogenetic link with present-day Indian haplotypes6. Therefore, it seems unlikely that P. falciparum would have had a significant impact on prehistoric European genomes.P. vivax  is likely an ancient parasite that evolved in Africa and spread to the rest of the world with the Out of Africa migration, around 60,000 years ago2. Phylogenetic analyses suggest that P. vivax could have an African origin but has largely disappeared from this continent after the spread of Duffy negative resistance7. The biology of P. vivax that makes it highly adapted to maintain itself in small mobile groups of hosts and its mild effect also supports the idea that it is an ancient human parasite. The limited data available does show that P. vivax and P. falciparum may have had at least partially different effects on the human genome1.On the other hand, 2. However, while there is information of some malaria-resistance alleles from Europe, notably from the Mediterranean area (such as the HBB and the G6PD variants), little is known about the magnitude of selection due to malaria in the continent because of the eradication of the parasite around 1950. The recent retrieval of more than 250 ancient genomes from different moments of the prehistory of Europe11 and the publication of several Genome wide association studies (GWAS) on malaria13 now allows for a genome-wide screening of malaria-resistance alleles along space and time. Using this approach, we aim to understand the role of this disease as a selective force in the shaping of the gene pool of modern Europeans.Malaria was endemic in Europe until very recently. Historical data describe malaria as affecting people as north as England, Scandinavia or RussiaG6PD, HBB, ACKRQ, FCGR2B, TIRAP, ATP2B4, GRK5, IL-10, MARVELD3, CD36, CD40LG and ABO blood group system  were already present prior to the arrival of farming, in Upper Palaeolithic and/or Mesolithic individuals. For other loci, the derived alleles are only seen in very recent periods. For instance, only one of the Iron Age individuals carries the T allele (rs2230345) at GRK5 gene, one individual carries the T allele (rs8176746) at ABO gene and only two individuals (one Bronze Age Russian and one Post-Roman British) carry the C allele (rs1050501) at the FCGR2B gene.Even with such data limitations, we were able to detect a substantial number of carriers of the proposed malaria resistance alleles in our ancient genome dataset Table . It is nFCGR2B) , rs4951074 (ATP2B4)  and rs8176746 (ABO) . The three genes show lower frequencies than expected of the derived alleles in ancient populations as compared to present-day Europeans. Samples with data from these three statistically significant ancient vs modern variants are not geographically clustered, as can be seen in Fig. For three genetic variants, we observed significant frequency differences between ancient and modern European populations from the 1,000 Genomes project, after adjusting for multiple tests: rs1050501 FCGRB  was 34%, statistically significant higher than the 16% of the derived alleles in North-European populations  . This trend cannot be discerned in the ancient samples  .Although the problems of assessing population structure with a dataset of low-coverage, geographically and temporally disparate ancient genomes cannot be overlooked we sought to explore the genetic structure among ancient and modern European with an Fe) Table . The FSTgs Table . A G-tesgs Table . This su15. The “Selection” software estimates a posterior probability of selection coefficients for heterozygous haplotypes  and for homozygous derived haplotypes  for each SNP and also the allelic age. The mean values of the selection coefficients and the likelihood values are shown in Fig. To further explore the possibility that changes in our time series data could be attributed to selection acting on the derived alleles, we used a Bayesian method that estimates the frequency trajectory of the alleles based on observed frequencies and sampling datesIL-10 gene with a favoured derived-homozygous genotype  and rs10900585 SNP at ATP2B4 gene, with a favoured heterozygous genotype ; p is the probability of the selection coefficient to be <0.Two genetic variants showed statistically significant evidence of positive selection on the derived allele: rs1800890 SNP at ABO blood group gene. The age estimates of all alleles , Ovalocytosis (in South East Asian groups) and G6PD deficiency19. The first two have little if any effect on P. falciparum while G6PD seems to have more effect on P. vivax than on P. falciparum. So far, none of the ancient genomes available displays any mutation at the crucial G6PD or Duffy loci. In addition, we do not find a single carrier of the HBB mutation. We don’t know if this is attributable to the rather limited sample size or if their absence reflects a relatively recent origin of these mutations among European populations. The frequencies of these mutations are very low in current populations . However, the sample size for some of the SNPs, such as the rs372091 at the HBB locus, is not that small and currently includes 155 ancient genomes.20. At present, only one complete genome 21 and several Neolithic individuals from the oriental Mediterranean peninsulas (Greece and Anatolia)23 derive from the thermo-Mediterranean zone21. However, a significant number of samples derive from regions that are close to the Mediterranean shores  represents a limitation of our survey. This is partially attributable to the warm environmental conditions in the area, which are unfavourable to DNA preservationTIRAP gene (rs8177374)  Table  that shoFCGR2B, ATP2B4 and ABO) show differences in the allelic frequency between ancient and modern Europeans. This could in principle be the signal of recent events of positive selection acting upon the associated SNPs.Three genes (FCGR2B gene (an ILE > THR change in the 232 residue of the protein) has been proposed to have a strong protective effect against severe malaria  in African populations due to the enhancement of phagocythosis of P. falciparum infected-human erythrocytes25. This could explain the high frequency of this mutation in malaria endemic areas, although the same mutation has also been described as causative of Systemic Lupus Erythematosus26. The only two individuals that carry this mutation are from periods and regions where malaria would be endemic in historical times: one is a Bronze Age individual from southern Russia and the other one an Anglo-Saxon from southern England. However, some older specimens , we consulted a genome browser with information about such signaturesATP2B4 and rs1800890 at IL-10 genes. This suggests that selection acted on these genes, an evidence that should be further explored from a functional point of view. The fact that no previous evidence of selective sweeps on these genes has been reported could be explained if the timing of the selective event was very recent or if the effect was regionally restricted. Nevertheless, it is reasonable to discard large-scale and dramatic selective events such as those seen for the lactase gene9.We have modelled all the SNPs with an approach that rejects neutrality across a time series and found evidence for selection in SNPs rs10900585 at P. vivax or to an undetectable adaptive response related to a very recent arrival to the European continent . We have shown however that, despite the large geographic distribution, malaria was likely not an important selective pressure in ancient European populations and not nearly as important as it is in Africa today. Additionally we demonstrate that the study of the selective effect of malaria on ancient genomes is a feasible approach that will likely provide more information in the future with increasing sample sizes, especially from the Mediterranean area. With additional genomic data, and also the retrieval of DNA from the pathogen directly from ancient bones31, it would be possible to check if local selective events took place and to understand the role of malaria in the shaping of modern European genomes.In conclusion, it seems that most of the screened alleles were equally prevalent in past than in present time; in those alleles were differences are statistically significant, we cannot discard the effect of drift or other selective forces acting upon these immunity genes. This could indicate a weak adaptation to malaria, due to either the benignity of symptoms caused by sensu lato- genomes with a mean sequence coverage >1x published so far39. We have also included those genomes for which only targeted capture data is available42. Our final dataset comprises genome-wide-data from 224 individuals  and Mediterranean G6PD (rs5030868) forms. Additional G6PD mutations associated to malaria resistance have also been included 43.HBB) determines the sequence of two types of polypeptidic chains in adult haemoglobin, HbA. Variants in the HBB gene such as HbC and HbS change the structure of the erythrocytes and confer resistance to P. falciparum in Asian and African populations44. The mutations that cause both HbS (rs334) and HbC (rs33930165) were screened45. Recent studies based on GWAS have found an additional mutation in the HBB gene related to malaria resistance (rs372091)12. HbE caused by rs33950507 mutation) is a mainly Asiatic variant of HBB gene that also confers resistance to the infection of P. falciparum46.Haemoglobin beta locus (ACKR1 gene) confers resistance to P. vivax and P. knowlesi through the mutation rs2814778 that changes the structure of the protein, which is a receptor for Plasmodium in the erythrocytes47. This phenotype is especially present in West African populations were P. vivax originated13.Duffy blood group system, Fy (a-b-) (MARVELD3 (rs2334880), ATP2B4 (rs4951074 and rs10900585) and ABO (rs81767199)12. The MARVELD3 gene encodes for a tight junction-associated transmembrane protein of endothelial cells, a key point in the pathology of malaria infection. This mutation is supposed to confer resistance to P. falciparum malaria although it is not confirmed12. The ABO gene encodes for a glycosyltransferase enzyme. Mutations in this enzyme determine the ABO blood group. The individuals who are homozygous for a single nucleotide deletion (rs8176719) are classified as blood group O48. O blood group is linked with a reduced risk of severe malaria49. However, we note that, besides malaria, the O blood group has been associated to susceptibility to other pathogens such as Helicobacter pylori50 and severe cholera51. We have also analyzed the rs8176746 SNP. This mutation, which is in LD with the rs8176719 variant, determines the production of B antigens48. The presence of the derived allele in this locus is associated with an increased risk of severe malaria28. Evidence of malaria protection has been also described at CD40LG gene in Gambian populations: homozygotes for the derived rs3092945 allele show a reduced risk of suffering severe malaria. However, a significant increase of severe malaria risk was found for the same allele in Kenyan populations28. In the same study, a severe malaria protective effect of the SNP rs201346212 heterozygous genotype (CD36 gene) was described. Other possible evidences on P. falciparum malaria resistance include additional genes such as GRK5, a G protein receptor (mutation rs2230345)52, IL-10 (rs1800890), FCGR2B (rs105050) and TIRAP (rs8177374).Additional mutations have been detected by GWAS analysis at 14 and the Tuscans (TSI) population of the 1,000 Genomes project53 as a reference panel.Due to the low coverage in many ancient samples and gaps associated to the targeted capture data, we performed imputations of SNPs not covered by any DNA read using Beagle-4 softwarepost-mortem DNA degradation54. To control for this confounding factor we have screened the genetic background in which the SNP is located, following the same approach as in ref. Some of the alleles screened involve C to T or G to A changes that could be affected by The genotypes obtained from genome sequence data and validated with Beagle-4 software were used to generate genotype frequencies. The allelic frequencies were estimated using both validated genome sequence data and targeted capture data. Because of the impossibility to infer genotypes in the case of targeted capture data only one random allele per position was taken into account.The allelic frequencies obtained with validated genotypes and targeted capture data were stratified by geographic position of the samples  and period .To explore potential differences in the genotypic composition between modern South (Iberians and Tuscans) and North Europeans  populations, we tested two different genetic models (codominant and logistic additive models) for each SNP, with a case-control approach. A likelihood ratio test was estimated for each SNP and both models using a Bonferroni correction. A Fisher’s exact test with a case-control approach was used for comparing allele frequencies in ancient versus modern European populations in those SNPs with more than one detected case of derived allele. Due to the assumption that ancient frequencies are directly comparable to the modern ones, the Fisher’s exact test is anti-conservative here; however we have included the p-value in the cases were we found an>1 OR, just as an additional, supporting evidence.55 was calculated. The fixation index was determined performing all the possible pairwise calculations comparing North-South present-day Europeans, the five European populations of 1000 genomes, North-South ancient Europeans and Period-stratified ancient Europeans . Nine SNPs that exhibited variability . The likelihood ratio G-statistic was performed on a contingency table of alleles at one locus x sampling unit; the individual genotypes were randomly permutated among samples and the G-statistic obtained from the original dataset is compared to the G-statistics obtained from the permuted datasets, yielding a P-value of the test.Additionally the G-test was calculated as it is described in Goudet https://github.com/Schraiber/selection) as described in ref. http://cran.r-project.org) software.To test for the presence of selection driving the genotypic frequencies in past-populations and reject neutrality we used a specific software (Supplementary Dataset 1Supplementary Figures


In southern Democratic Republic of the Congo, malaria transmission is stable with seasonal fluctuations. Different measurements can be used to monitor disease burden and estimate the performance of control programmes. Repeated school-based malaria prevalence surveys (SMPS) were conducted from 2007 to 2014 to generate up-to-date surveillance data and evaluate the impact of an integrated vector control programme.Biannual SMPS used a stratified, randomized and proportional sampling method. Schools were randomly selected from the entire pool of facilities within each Health Area (HA). Subsequently, school-children from 6 to 12 years of age were randomly selected in a proportional manner. Initial point-of-care malaria diagnosis was made using a rapid detection test. A matching stained blood film was later examined by expert microscopy and used in the final analysis. Data was stratified and analysed based on age, survey time and location.Plasmodium falciparum malaria was significantly different between rural and urban HAs and between end of wet season and end of dry season surveys. The combined prevalence of single P. falciparum, Plasmodium malariae and Plasmodium ovale infections were 29.9, 1.8 and 0.3% of those examined, respectively. Only 1.8% were mixed Plasmodium species infections. From all microscopically detected infections , P. falciparum represented 88.5%, followed by P. malariae (5.4%) and P. ovale (0.8%). Cases with multiple species represented 5.3% of patent infections. Malaria prevalence was independent of age and gender. Control programme performance contributed to a significant decrease in mean P. falciparum infection density in urban compared to rural locations. Some rural areas remained highly refractory to control measures .The baseline SMPS (pre-control in 2007) prevalence was approximately 77%. From 2009 to 2014, 11,628 school-children were randomly screened. The mean age was 8.7 years with a near equal sex ratio. After exclusion, analysis of 10,493 students showed an overall malaria prevalence ratio of 1.92 in rural compared to urbanized areas. The distribution of The SMPS is a useful longitudinal measurement for estimating population malaria prevalence and demonstrating disease burden and impact of control interventions. SMPS can identify refractory areas of transmission and thus prioritize control strategies accordingly. Plasmodium falciparum cases in sub-Saharan Africa . Malaria cases remain elevated during and immediately following the period of heaviest rainfall (December–February) and during the gradual decrease of rains in March and April. Malaria transmission decreases further into the predominantly dry, cooler period (May–July) with reported infections reaching their lowest number during the warmest and driest months (August–September) of the year.These are cross-sectional surveys repeated twice each year with school children randomly selected each round. A stratified, randomized, proportional sampling method of school children was organized in two stages. First, existing primary grade schools at time of survey were randomly selected from the entire pool of available facilities within each HA under MVCP coverage. No school declined participation if selected. Second, a random sampling from all identified eligible school children was performed within each selected school. The total number of children per school was determined in a proportional manner based on most current student enrollment data.Primary schools (grades 1–6) were randomly selected within each HA. Those schools located near the perimeter of the IRS coverage zone were excluded as a larger percentage of attending children resided outside the control zone.To begin, a list of all primary schools  and the current school enrollment register of each is provided by the local government Inspector of Education. In the 2007 baseline collections, all existing primary schools were included in the survey. As the number of schools increased each succeeding year, the inclusion of additional schools in each HA was combined to derive an average in the coverage area and subsequently used in the selection process. For example, if the average was five schools per HA, all schools within a HA that has five or less schools were included. For an HA with more than five schools, an online random number generated table was used to select only five schools to be surveyed .Plasmodium infection in each HA within 95% confidence limits, with 4% precision and design effect of 1. A non-response rate (students who decline or become unavailable to participate) of 10% was included in the sample size calculations. As the overall malaria prevalence began to decline in 2009 following intervention, the number of enrolled students (and schools) increased in number inside the coverage area, therefore influencing the number of students sampled over time . The October results, more reflective dry period effects showed that risk of being infected was 1.839  greater in rural compared to urbanized localities. Thus, malaria prevalence was higher in rural localities with minimal influence of time of year and prevailing seasonal conditions.Tests for homogeneity between location  and time (May or October) found the distribution of malaria cases was different between rural and urban HAs and between May and October surveys , indicating presence of an interaction between survey time and location. Figure Plasmodium species, covering 11 survey periods during a 6-year intervention phase. The overall prevalence of single infections with P. falciparum, P. malariae and P. ovale were 29.9, 1.8 and 0.3% respectively. Plasmodium vivax was not detected morphologically or using real-time qPCR from a random sampling of P. ovale infections. Multiple species infections  represented 1.8% of all malaria cases, wherein 1.5% were P. falciparum + P. malariae. Infections with all 3 species were also detected. Plasmodium species prevalence by survey period and relative proportions are shown in Table P. falciparum alone represented 88.5% of infections, followed by P. malariae (5.4%) and P. ovale in 0.8%. Overall, multiple species infections  represented 5.3% of infections detected. Over time, the proportion of P. falciparum declined from a peak of 98.7% (May 2010) of infections to 74.5% (October 2014).From a total of 10,493 slides examined, 3545 (33.8%) were found malaria positive for one or more From the 10,493 apparently healthy children attending school the day of the survey, 366 did not have an axillary temperature recorded. From the 10,127 children that did, temperature at time of blood sample ranged from 35.1 to 39.9 °C (mean 36.7 °C SD ± 0.43). Only 325 students (3.2%) had a defined ‘fever’ (elevated temp ≥ 37.5 °C) , there was a significant association between fever and malaria infection in urban localities (p = 0.005) with PR 1.257 (95% CI 1.080–1.463), while showing no relationship (p = 0.144) in rural areas [PR = 1.198 (95% CI 0.972–1.476)]. Fevers due to other possible causes were not investigated.r2 = 0.994 with p = 0.001). These findings indicate that there is a positive correlation and a significant difference between infection in the presence or absence of fever.Figure All sampled children were aged from 6 to 12 years old. Three age groups were analysed: 6–8 years (n = 5276), 9–10 years (n = 2851) and 11–12 years of age (n = 2366). From 2009 to 2014, overall malaria prevalence in these groups were 32.8, 35.4 and 34.0%, respectively. Malaria infection was determined to be independent of age. There was no significant association between malaria infection and age groups  indicating no difference in risk of exposure and transmission. Overall, there was no difference in malaria prevalence by gender (p = 0.0847), although there were slightly more males (54.7%) found infected.P. falciparum density and age groups was analysed by location  and the survey period . When stratified by location, there was no significant association between P. falciparum density and age groups in urban (p = 0.134) or rural areas (p = 0.138). However, a significant association between P. falciparum density and age groups (p = 0.039) was seen with time of survey. When stratified by time, May revealed no significant association (p = 0.648) with parasite density, while the end of dry season October surveys showed a strong association (p < 0.0001).Association between od Table . Based o10P. falciparum densities throughout the intervention period (2009–2014) was examined for urban and rural HAs. Overall, there was an inverse correlation (Spearman rho) between the time of the survey and P. falciparum densities . In rural localities, the correlation was not different to zero , therefore, parasite density appeared independent with time. In urban localities, however the correlation was significantly different to zero , indicting a clear difference over time  with Pf density decreasing in urban localities. By using the multivariate regression log-binomial model, there was an association between survey year and prevalence over the 6-year observation period  inside the FHZ. By providing comparable longitudinal data from a reliable and informative population cohort, this evidence has been used to assist in the timely review and, when necessary, the reorientation in control programme policy and operational activities.Anopheles vector mosquito population to the pyrethroid class compounds being used for indoor residual spraying (IRS) and factory-treated bed nets. This lead to the use of an alternative class compound (carbamate) for IRS  to a dry season low of 21.7%. The prevalence at the end of this intervention reporting interval (October 2014) was 33.5%, an overall 55.8% reduction in malaria since control programme inception.Following the introduction of broad coverage vector control measures, the malaria prevalence decreased rapidly. This result that can be attributed to the first-time introduction of pyrethroid-based IRS in the majority (> 90%) of households combined with mass distribution commercial long-lasting insecticide-treated nets. The pyrethroid active ingredients used  provided +an approximate effective residual life of between 4 and 6 months depending on the type of surface sprayed. Initially, the single annual IRS spray round began just before the rains resumed with the intention of providing protection during the higher malaria transmission period (October to March) of the year. The survey strategy was based on the expectation for natural reduction in transmission between May and October attributed to negative effects on the local vector population during the prolonged dry period.p < 0.001) from 30.6% up to 47% in May 2011. Beginning in May 2010, the MVCP entomology laboratory and insectarium was established and two insecticide susceptibility bioassays were performed: (1) the standard WHO tube contact test using wild-caught larvae reared to the female adults and exposed to insecticide-treated filter-paper according to protocol [An. arabiensis and wild-caught anophelines, primarily An. gambiae s.s. ‘S’ molecular form. Results from 2010 susceptibility assays found conclusive evidence of substantial levels of resistance in An. gambiae to pyrethroids (permethrin and deltamethrin) including cross-resistance against DDT. These tests confirmed that in a period of 2 years from inception of wide scale IRS and LLINs (both using pyrethroids), selection pressure was sufficient to produce operationally relevant resistance (> 20%) against pyrethroids. Thus, in 2011, a change was made from pyrethroid to a carbamate-based insecticide (bendiocarb). As carbamates typically have a shorter residual life of only 3–4 months on most sprayed surfaces, two spray rounds were required to cover the entire high malaria transmission period. In May 2012, a second mass distribution of LLINs was conducted. Together with the IRS, treated bed nets likely contributed to the reduction of malaria from May 2011 to October 2012, a period which witnessed the lowest slide positive rate (21.6% based on adjusted RDT findings) over the 6-year observation  survey, approximately 2 years following IRS introduction. However, from October 2010 onwards, the prevalence increased significantly (protocol  and (2) protocol  on treatAlthough a far greater majority students without fever were found infected with malaria (96%) than the few who presented with fever at time of examination, there was a significant association between those with fever (≥ 37.5 °C axillary temperature) and having a malaria infection  in both survey periods of the year. Students with fever were 1.3 times as likely to be infected with malaria compared to the group without fever. This agrees with other studies showing a strong linear relationship between the percentage of febrile children with malaria and infection prevalence . When daDifferent age groups among school-aged children have been used to estimate the risk of malaria infection in an area. From examples in Uganda , Malawi Malaria infection was aggregated in three age groups: 6–8, 9–10 and 11–12 years of age. Overall, malaria prevalence in these age groups were 32.8, 35.4 and 34.0%, respectively. Malaria infection was independent of age or gender and there was no significant association between presence of malaria infection and age groups. In Kinshasa, Kazadi et al.  examinedIn this current 6-year retrospective analysis of school-based prevalence in DRC, no significant differences in malaria infection between age groups in the sampled population was seen. This may indicate that twice-yearly surveys may not be sensitive enough monitoring to detect a difference, if present. The SPR can be a useful measure of the impact of control interventions when considering several important caveats stressed by Jensen et al. . First, Findings showed no difference in malaria prevalence by gender. Other than apparent equal exposure to malaria risk as there would be no apparent occupational-related risk factor in most children at or below 12 years of age. With this younger age group, parents would be as likely to provide the same level of health care to offspring regardless of gender. Female gender inequality, when present, is generally observed into later adolescence and adulthood , 56.In the SMPS, the overall risk of being infected by location was 1.92 greater in rural compared to urbanized localities, regardless of time of year. These results indicate a strong link between malaria transmission and location. A meta-analysis of entomologic inoculation rates (EIR) from urban, peri-urban and rural studies published between 1977 and 2000 reported a mean annual EIRs of 7.1 in city centers, 45.8 in peri-urban areas and 167.7 in rural areas of sub-Sahara African countries sampled . Other sThe distribution of malaria infections was significantly different between rural and urban HAs and between May and October surveys, thus indicating an interaction between time of year and location. In May 2012, while the overall malaria prevalence in the concession decreased, there was a significant increase in malaria in rural localities and a decrease in urban localities. This suggested that additional interventions to the existing methods to control malaria (IRS and LLINs) were required in rural localities to reduce the malaria burden. In response, a pilot study on community-based malaria diagnostic and treatment was conducted from 2012 to 2013 in 14 rural villages. Results indicated that a scaled-up community-based approach using trained and supervised community health workers could be an effective and promising additional strategy to control malaria and an addition to the integrated MVCP .P. falciparum, P. malariae and P. ovale were 29.9, 1.8 and 0.3%, respectively. P. malariae and P. ovale where consistently detected at low rates compared to P. falciparum, and typically at low density. In another study, Congolese children under the age of five showed a higher prevalence of P. malariae and P. ovale, 12.9 and 8.3%, respectively [The prevalence of single infections seen with ectively . The varectively .P. falciparum density and different age groups (p = 0.039). Additionally, there was an inverse correlation between survey period and P. falciparum densities. However, in rural localities, the correlation was not different to zero while it was significantly different in urban localities, i.e. during intervention the mean P. falciparum density decreased over time in urban localities while showing no changes in rural localities.Overall, there was a significant association, albeit weak, between Lateral flow immunochromatographic parasite protein-detecting assays (known more commonly as rapid diagnostic tests) can provide generally accurate diagnosis for case management, often with a similar analytical accuracy to microscopy when using a high-quality product, in good condition, and prepared and interpreted correctly by a trained operator. RDTs are more amenable for use in remote locations and less dependent on higher skill levels to perform . AlthougPfHRP2-detecting RDTs outperform (better sensitivity) than non-PfHRP2 assays that use either aldolase or Plasmodium lactate dehydrogenase (pLDH) enzymes for detecting infections. As P. falciparum is overwhelmingly the predominant malaria parasite species seen in the FHZ, we deliberately selected high quality PfHRP2 detection RDTs. Greater thermal stability compared to pLDH-based RDTs and product availability also influenced the choice of product [Typically,  product .PfHRP2 and PfHRP3 parasite gene deletions that can result in false negative RDTs [P. falciparum parasitaemias, this is not view as a substantial issue, if any, in the FHZ at this time. If later deemed a problem, it will raise the need for using tests that use non-HRP2 falciparum-specific targets, i.e., pLDH, either pan  or P. falciparum-specific, alone or in combination with HRP2. In future, those cases presenting with high parasitaemias that produce negative RDT results could be tested for possible described gene deletions to explain false negative results. Additionally, hyper-parasitaemia can result in an apparent ‘prozone’ effect due to an antigen overload resulting in a false negative result [PfHRP2 has been shown to persist and can be detectable many days, even weeks after the clinical symptoms of malaria have disappeared and the parasites have apparently been cleared from the host [The recognition of ive RDTs  should be result . Prozonethe host . This wothe host . HRP2-baIn the school-aged population surveyed, the RDT sensitivity  has been a notable limitation as the vast majority of such cases appear to have been the result of low-level parasitaemias/asymptomatic infections . This would be of less clinical significance compared to having greater epidemiological implications as repeat infections due to regular exposure are more likely to become subclinical parasite reservoirs.Many contributing factors and limitations in data collection are acknowledged in the SMPS presented, but many were beyond the scope, practicality, and intention of this routine monitoring exercise. For example, time and resources were not available to follow-up registered children not attending school the day of sampling. Children could have been absent for many reasons, one possibility being illness caused by malaria. The loss of children with malaria would have biased the findings and analysis on factors such as age and fever. However, to what extent is not known. Different school’s attendance rolls the day of survey were not compared to determine percent absence and if differences were significant between locations . Depending on location, local demographics may vary considerably, thus a contributing for likelihood of school attendance. For example, in rural areas, more dependent on subsistence seasonal agriculture, a child’s absence may be the result of having to assist in the field during peak planting or harvesting periods. On the other hand, school absenteeism in the urban area could be due to greater access or more frequent travel outside the area. Lastly, it would have been preferred that two persons independently examine the blood films using light microscopy. However, this was deemed prohibitively expensive and time consuming. Moreover, no matter the number of independent reads, some very low density/sub-patent infections will go undetected nevertheless. Given the level of expertise of the microscopist used for all 11 surveys, the authors are confident the results are accurate enough and comparable across surveys for the intended purposes described herein. Lastly, fever (≥ 37.5 °C) was measured using a digital device placed in the axillary area. Axillary temperatures are usually 0.3–0.6 °C lower than an oral temperature. An axillary temperature is influenced by the temperature on the outer surface of the body. A normal axillary temperature is between 35.9 and 36.7 °C. In other words, ‘fever’ during sampling was likely underestimated. While oral readings are typically more accurate, they can take longer to measure than axillary temperatures and thus impede mass sampling efforts. Although the overall absolute number of fevers may have been lower using the axillary method, as all children were measured in the same way, this should have had no meaningful impact on the statistical comparisons.Gécamines) and the DRC Railway Company , there has remained a large gap in basic epidemiological data and information on malaria in the region [The surveys and findings were solely derived for operational purposes, not as controlled experiments, and thus output has some inherent constraints. The school malaria observations were made as part of an evidenced-based monitoring strategy to provide important metrics  to directly assist the control programme. What is presented is the first known longitudinal set of data on malaria prevalence in school children in a defined, but rapidly expanding, population in southern DRC. To this point, recent information on the malaria burden in rural areas of the Katanga region , has remained fragmented, anecdotal, or non-existent in most instances. Since the cessation of organized malaria control programmes in the area in the 1980s mainly by state-sponsored companies such as the mining operations (e region .Effective malaria control and planning requires accurate measurements and information on both the geographical distribution of malaria risk and the effectiveness of malaria interventions , 71–73. The school-based malaria prevalence survey is a valuable evidence-based estimate for observing changes in the intensity of malaria and assess the impact of malaria control interventions. It can assist in identifying areas requiring additional priority interventions and provides critical information for programme orientation. When well executed and where school participation rates are high, prevalence surveys should be considered a routine and valid malariometric tool to measure malaria transmission in most endemic areas.


Over 90% of deaths attributable to malaria are in African children under 5 years old. Yet, new treatments are often tested primarily in adult patients and extrapolations have proven to be sometimes invalid, especially in dosing regimens. For studies in severe malaria an additional complication is that the decline in severe malaria in adult patients precludes sufficiently powered trials in adults, before the intervention can be tested in the ultimate target group, paediatric severe malaria. In this paper we propose an alternative pathway to the development of drugs for use in paediatric severe malaria. We argue that following the classical phase I and II studies, small safety and efficacy studies using well-chosen surrogate endpoints in adult severe malaria be conducted, instead of larger mortality endpoint trials. If the drug appears safe and promising small pilot studies in paediatric severe malaria using the same endpoints can follow. Finally, with carefully observed safeguards in place to ensure high ethical standards, promising candidate interventions can be taken forward into mortality endpoint, well-powered, large paediatric studies in African children with severe malaria. Given the available research capacity, limited numbers of prudently selected interventions can be studied in phase III trials, and adaptive designs should be considered. This means almost all severe disease is in young children. Over 90% of all malaria attributable deaths are in African children under 5, amounting to about half a million deaths annually, despite recent gains in malaria control and efforts to increase pre-referral treatment.5 Nevertheless, testing of new treatments in the main target group of African children is important, since extrapolation of research findings obtained in adults to children can be problematic. For instance, the antimalarial drugs sulphadoxine-pyramethamine and dihydroartemisinin-piperaquine have been introduced at too low doses in children causing unnecessary treatment failure, which has likely contributed to the development of drug resistance to the latter.7 It is thus clear that testing of new treatments in the main target group of African children is important.The clinical presentation of severe malaria is different between adults and children, with more severe anaemia, convulsions and hypoglycaemia in children, and more severe jaundice, renal failure and pulmonary edema in adult patients. However, the presenting symptoms with most prognostic significance, which are coma depth and severity of metabolic acidosis, have very similar prevalence between adult and paediatric cases.Standard practice for drug development for severe falciparum malaria begins with initial phase I testing in healthy adults, mainly focusing on safety and pharmacokinetics. This phase is followed by phase II studies in adults with uncomplicated malaria, designed primarily for dose finding, safety and initial pharmacokinetic and pharmacodynamic evaluation. These are followed by larger phase III efficacy studies involving several thousand patients, usually performed in adult severe malaria outside Africa. Studies in the ultimate target group of African children under 5 years who have severe malaria are generally only done at the end of this development pathway.8 would, with the current incidence, require 6 years. This problem jeopardises the development of much needed new treatments for severe malaria in African children. In this paper, we propose an alternative pathway to studying new interventions for paediatric severe malaria.The declining incidence of adult severe malaria means that large phase III studies in adults are increasingly problematic. To take one example, the SEAQUAMAT trial, which recruited 1259 adult participants in two years (from 2003 to 2005) when malaria incidence was much higher,Dwindling numbers of adults with severe malaria suggest the need to consider alternative intermediate groups, who are less vulnerable than small children, as study targets in drug development. However, none of the available groups—defined below according to age and the continuum in disease severity from uncomplicated, through moderately severe, to severe and lethal malaria—are suitable for this role.Uncomplicated malaria in children: these children can be treated very effectively with an artemisinin combination therapy (ACT). Because ACTs are very efficacious, there is no additional benefit expected from additional therapies, which renders this group unacceptable to study.Severe malaria in adolescents: this faces similar problems as the adult patient group, including extrapolation of results to children under 5 and challenges meeting the sample size.Moderately severe malaria in adults: like uncomplicated malaria, this can be treated effectively with an ACT with no anticipated direct benefits from the new treatment. Moreover, even with a well-defined risk profile of the drug in this group, corresponding risks in children will be difficult to predict.The absence of a suitable intermediate group suggests the need for an alternative approach. One such approach might be as follows:10 An intervention aiming at improving renal function can have the change in renal function as the primary endpoint.Following the classical phase I and II studies, small safety and efficacy studies using well-chosen surrogate endpoints could be conducted in adults with severe malaria, instead of large mortality endpoint studies. The choice of surrogate endpoints will not only depend on their association with mortality, such as depth of coma and severity of prostration, but also on the pathophysiological target of the new intervention. For instance, adjuvant treatments aiming to improve microcirculatory flow could use the improvement in lactic acidosis as a surrogate endpoint for mortality, although its validity will have to be assessed more formally first.11 A second source might be where data are available on the same compound used in different paediatric diseases. One example is inhaled nitric oxide, currently trialed in African children with cerebral malaria, and which has been studied previously in children with sickle cell crisis.12If a new compound appears safe in adults, initial safety data in children might then be obtained from two sources. The first is where a related compound has been used extensively in the paediatric population. For example the safety of sevuparin, which is a heparinlike compound, can be extrapolated from heparin to a certain extent.Once sufficient prior safety data has been obtained, this could provide a rationale to conduct small pilot studies in children with severe malaria focusing on safety and using surrogate efficacy endpoints.Finally, assuming an acceptable safety profile and a strong suggestion for benefit demonstrated by improvement in surrogate endpoints, a large-scale multi-centre, multi-country study in children with severe malaria with a mortality endpoint (or other appropriate endpoints) could be considered.This paper proposes an alternative drug development pathway that does not involve conducting large mortality endpoint trials in adults with severe malaria as a prelude to paediatric trials.14It is important to note that the proposed strategy does not abandon the important principle that research should be conducted in the least vulnerable relevant group before moving on to more vulnerable groups. The proposal does not suggest bypassing studies in adult severe malaria, although there is precedence for such studies, for example the RTS,S/AS01 malaria vaccine trials in Africa.What are the strengths and limitations regarding the use of the proposed pathway?The proposed pathway may lead to more effective development of new drugs, adjuvant therapies and supportive treatments for paediatric severe malaria. Studies are conducted in the main target group instead of being extrapolated from adult studies. It is time efficient and reduces unnecessary risks to patient groups to whom the exposure may not be necessary.18 These guidelines stress that whilst conducting research involving children is complicated, this should not excuse inaction. Excluding children means depriving them from evidence-based medical care, increasing their vulnerability and, in the case of severe malaria, continued high mortality.Recent international guidelines involving research with children have made a case for the protection of children through research rather than only from research.13 Pathophysiological studies and small trials in African children with severe malaria strongly suggested a benefit from fluid bolus therapy. The results of the FEAST trial showed, quite unexpectedly, a detrimental effect.The risk-benefit balance for the proposed pathway might not be favourable for all possible scenarios. Omitting large trials in adults prior to studies in children cannot always fully exclude unexpected risks for the paediatric population. The Fluid Expansion as Supportive Therapy (FEAST) trial was a large randomised trial on fluid bolus therapy in African children with compensated septic shock, of which 57% had severe malaria.19In addition, the use of variables as surrogate endpoints for mortality can have limitations. As a prerequisite, these variables, and normalisation of such variables, for example plasma lactate, should have been shown to correlate closely with mortality, and should be relevant in the pathophysiological chain of events causing death. The requirement that the variable used as a surrogate should have direct benefit for the patients is difficult to generalise. For instance, metabolic acidosis is difficult to translate to a direct discomfort for the patients, although it will cause shortness of breath. Faster recovery of coma has a clear direct benefit for the patient, but in contrast with metabolic acidosis, has no correlation with improved survival in large mortality endpoint severe malaria antimalarial drug trials.Another possible drawback is that subtle neurological side effects may be more difficult to discern in small children compared to adults, since they may not be able to express certain complaints, such as nightmares. In addition, specific adverse events might be more prominent in children, as seen with hypoglycaemia after treatment with the antimalarial drug, quinine. It is also possible that adverse events in young children may not become apparent until later in life. Neurocognitive development of children may have to be followed up years after the study has been completed. Finally, extrapolation of safety data from paediatric studies of similar compounds or from studies of the investigational product in other paediatric diseases is not always warranted, since there can be disease specific factors. An example is the use of heparin-like substances, tested in children with sickle cell crisis. Bleeding risks could be higher in severe malaria because of the invariable presence of thrombocytopenia.Taken together, these considerations suggest that following careful scientific and ethical review, and the putting in place of measures to ensure high ethical standards, the alternative pathway outlined above may offer an acceptable route for the development of new drugs or other interventions in severe paediatric malaria.It is acknowledged that including children earlier in the drug development process could pose ethical concerns, and assessment of risk benefit balance will remain crucial. This assessment will be more difficult if an intervention has not been used widely yet in adults.Another important concern is the validity of the consent provided by parents or guardians. In the case of a child with severe malaria, the parent or guardian may find themselves in a position of ‘situational incapacity’ where their usual capacity to make these important decisions is compromised by the extreme stress of the situation, the time-critical nature of the intervention and the condition of their child. In some trials, the distress of the parents may be further compounded by the uncertainty of long term side effects and difficult-to-comprehend surrogate endpoints.Additional safeguards should be in place, such as support for parents to make informed decisions on participation of their children in the study. For most trials, it will be important that interim analyses are conducted by an independent committee focusing on relevant safety endpoints in which the safety threshold for stopping the study should be clear and low. Study teams would need to ensure the availability of the best supportive care, which includes nursing care, optimum fluid therapy and setting-adapted intensive care.20 These designs allow interventions in under-performing study arms be dropped in an early stage.Because of limited time and research capacity, innovative adaptive designs rather than conventional randomised controlled trials can be considered, which could accommodate testing several interventions in parallel.Despite important progress, mortality from severe malaria remains unacceptably high. There is an urgent need for research on new drugs and additional interventions in the main target group of African children. This paper suggests an approach that does not include large mortality endpoint trials in adults as a prelude to paediatric studies, yet assures safety and quality of the assessments.