[Nutritional Status Of Children Under Five During Seasonal Malaria Chemoprevention In 2018 At Kita, Mali: Household Survey]

INTRODUCTION

Malaria and malnutrition are among the major causes of morbidity and mortality in children under five in Mali. This study is part of the analysis of the association between both in children under five after a seasonal malaria chemoprevention distribution campaign.

METHODS

We carried out a cross-sectional household survey in rural areas after a seasonal malaria chemoprevention distribution campaign to determine the prevalence of malnutrition and parasitaemia in children under five who had passed the season of high transmission of malaria in the health district of Kita. After obtaining written consent, each child was given a physical examination, hemoglobin testing using the Hemocue machine, a thick drop and a thin smear. , A rapid diagnostic test was performed in febrile children. The data was analyzed with ENA 2020 and Stata software version 15.0. Measures of association were made using the chi-square test and a multiple logistic regression model. Odds ratios were used with a 95% confidence interval and a significance level of 0.05.

RESULTS

We selected 308 children aged 6 to 59 months. The prevalence of malaria was 13.6%, it was 15%, 17% and 25% respectively for wasting, underweight and stunting. The susceptibility to malaria increased with age and that of wasting decreased with age. There was no significant relationship between malaria disease and nutritional status.

CONCLUSION

There is no significant association between malaria and malnutrition in our study.

[Spatio-temporal analysis of the incidence of morbidity and mortality from severe malaria in the Sélingué health district, Mali]

AIMS/OBJECTIVES/ASSUMPTION

In Mali, malaria is the leading cause of death and consultations in health facilities. The objective of this study was to examine trends in morbidity and mortality among children aged 0 to 15 years and to establish accurate mapping of the distribution of cases in health areas of the Sélingué health district.

MATERIALS AND METHOD

A retrospective analysis of hospital records at the Sélingué district reference health center from 2010 to 2013 was conducted. Trend Chi2 and logistic regression were used, respectively, to compare changes in trends between health areas and to identify risk factors associated with malaria mortality.

RESULTS

Among the 1282 cases of malaria, the incidence of severe malaria gradually decreased from 96.75 ‰ (671 cases) in 2010 to 34.23 ‰ (291 cases) in 2011, 19.76 ‰ (168 cases) in 2012 and 19.43 ‰ (152 cases) in 2013. From 2010 to 2013, there was an average monthly variation in October of 26, 6% cerebralmalaria and 23.3% malaria anemia by the month of July of the same year. Spatial variation of anemic forms of malaria between health areas (p < 0.001) was observed from 2010 to 2013. From 2012 to 2013, there was an overall decrease in the frequency of hospitalizations, incidence and death rate for severe malaria. In multivariate analysis, in the final model, malaria lethality was associated with the duration of hospitalization for more than three days (OR = 0.124); the year of hospitalization from 2010 to 2012 (OR = 0.813); the absence of blood transfusion of the patient (OR = 0.282); at the age of the patient in children under one year (OR = 0.356) and at the emergency anti-malarial treatment instituted with artemether (OR = 3.006) adjusting for the form of malaria. On the other hand, malaria lethality was not related to the form of malaria (p = 0.072), sex (p = 0.390), residence (p = 0.308), prior treatment before hospitalization (p = 0.949). at fever in children (p = 0.153) adjusting for other variables in the model.

CONCLUSION

Hospital case fatality remains high with a drop in the incidence of morbidity and mortality; a monthly variation in morbidity and mortality with two peaks, July - August and October-November and the emergency treatment instituted with artemether, the length of hospital stay could be identified as associated factors.

The extent of chloroquine underdosing in adult patients with malaria by Plasmodium vivax from an endemic area of the Brazilian Amazon basin

OBJECTIVES

To evaluate the extent of chloroquine underdosing and to measure the concentrations of chloroquine and desethylchloroquine in adult patients with P. vivax malaria in the Brazilian Amazon basin.

METHODS

Prospective study of cases in male adult patients with malaria by Plasmodium vivax treated with a total dose of 1500 mg chloroquine over three days and a short course of primaquine. Patients were weighed at admission, and the dose per mg/kg was determined. Blood samples were collected at 24 and 168 h after enrolment, and the concentrations of chloroquine and desethylchloroquine were measured in plasma by high-performance liquid chromatography with fluorescence detection.

RESULTS

Of 61 patients were included in the study, and 60% received a total dose of chloroquine below 25 mg/kg. Plasma chloroquine concentrations ranged from 90 to 184 ng/ml and from 175 to 827 ng/ml at 24 and 168 hours. For desethylchloroquine, the values ranged from 32 to 144 ng/ml and from 90 to 440 ng/ml at 24 and 168 h. There were no significant correlations between the plasma levels of chloroquine and the doses administered (mg/kg) at 24 and 196 h. Similar results were found for desethylchloroquine.

CONCLUSION

There is widespread suboptimal dosing of chloroquine that is probably due to the dosing regimen based on patient age, which reduces the drug exposure with a possible influence on parasite clearance.

Potential distribution of main malaria vector species in the endemic Colombian Pacific region

OBJECTIVE

To assess the existing fundamental niche, potential distribution and degree of niche overlap for the three main Colombian malaria vectors Anopheles albimanus, Anopheles darlingi and Anopheles nuneztovari in the major malaria endemic Pacific region.

METHODS

We used models based on presence records and Normalised Difference Vegetation Index (NDVI) data, created using the maximum entropy algorithm.

RESULTS

The three vector species occupied heterogeneous environments, and their NDVI values differed. Anopheles albimanus had the largest niche amplitude and was distributed mainly on coastal areas. Environmentally suitable areas for An. albimanus and An. nuneztovari were the dry forest of inter-Andean Valleys in south-western Colombia, as confirmed for An. albimanus during model validation. There was a slight degree of niche overlap between An. darlingi and An. nuneztovari, and the species co-occurred in humid forests, predominantly in riparian zones of the San Juan and Atrato rivers.

CONCLUSION

The information obtained may be used for the implementation of vector control interventions in selected priority areas to reduce malaria risk in this region while optimising resources.

Effect of adding azithromycin to the antimalarials used for seasonal malaria chemoprevention on the nutritional status of African children

OBJECTIVES

Mass administration of azithromycin has reduced mortality in children in sub-Saharan Africa but its mode of action is not well characterised. A recent trial found that azithromycin given alongside seasonal malaria chemoprevention was not associated with a reduction in mortality or hospital admissions in young children. We investigated the effect of azithromycin on the nutritional status of children enrolled in this study.

METHODS

A total of 19 578 children in Burkina Faso and Mali were randomised to receive either azithromycin or placebo alongside seasonal malaria chemoprevention with sulfadoxine-pyrimethamine plus amodiaquine monthly for three malaria transmission seasons (2014-2016). After each transmission season, anthropometric measurements were collected from approximately 4000 randomly selected children (2000 per country) at a cross-sectional survey and used to derive nutritional status indicators. Binary and continuous outcomes between treatment arms were compared by Poisson and linear regression.

RESULTS

Nutritional status among children was poor in both countries with evidence of acute and chronic malnutrition (24.9-33.3% stunted, 15.8-32.0% underweight, 7.2-26.4% wasted). There was a suggestion of improvement in nutritional status in Burkina Faso and deterioration in Mali over the study period. At the end of each malaria transmission season, nutritional status of children did not differ between treatment arms (seasonal malaria chemoprevention plus azithromycin or placebo) in either the intention-to-treat or per-protocol analyses (only children with at least three cycles of SMC in the current intervention year).

CONCLUSIONS

The addition of azithromycin to seasonal malaria chemoprevention did not result in an improvement of nutritional outcomes in children in Burkina Faso and Mali.

Environmental and anthropogenic factors associated with increased malaria incidence in South-Kivu Province, Democratic Republic of the Congo

OBJECTIVE

To examine environmental and human factors that affect the spatial and temporal dynamism of malaria in DRC's South-Kivu province.

METHODS

In a cross-sectional study conducted between 1 January 2010 and 31 December 2015, spatial distribution was determined through thematic maps of malaria attack rate. SatScan ™ software and Monte Carlo test were used to identify spatial risk clusters. Temporal evolutions were analysed using the Cleveland algorithm. Generalized Additive Models for Location Scale and Shape and negative binomial regression were used to assess the independent human and environmental factors associated with incident malaria.

RESULTS

The cumulative annual incidence of malaria increased from 10 968/100 000 in 2013 to 15 501/100 000 in 2015 (P for trend ˂0.001); malaria lethality increased from 0.1% in 2013 to 0.3% in 2015 (P for trend = 0.62). Between 2010 and 2015, 18 of 34 health zones consistently reported the highest attack rates, which ranged from 25 000 to 50 000/100 000. Four risk clusters areas were identified, with relative risk (RR) of 1.2 to 3.0, from which malaria was reported continuously during each year. Factors significantly associated with malaria cases were agro-pisciculture practices (Incidence Risk Ratio [IRR]: 1.96; 95% CI: 1.23-3.13) and the presence of a lake in the health zone (IRR: 2.48, 95% CI: 1.51-4.42).

CONCLUSIONS

Malaria control in this setting must be intensified in peri-lacustrine areas and those in which the population is intensively engaged in standing water-associated activities.

Ivermectin for causal malaria prophylaxis: a randomised controlled human infection trial

OBJECTIVE

Ivermectin is safe and widely used for treating helminth infections. It also kills arthropods feeding on treated subjects, including malaria vectors. Thus, ivermectin mass drug administration as an additional tool for malaria control is being evaluated by WHO. As in vitro data, animal experiments and epidemiological observations suggest that ivermectin has a direct effect on the liver stages of the malaria parasite, this study was designed to assess the prophylactic effect of ivermectin on Plasmodium falciparum controlled human malaria infection.

METHODS

A total of 4 volunteers were randomised to placebo, and 8 volunteers were randomised to receive ivermectin 0.4 mg/kg, orally, once 2 h before being experimentally infected intravenously with 3200 P. falciparum sporozoites. The primary endpoint was time to parasitaemia detected by positive thick blood smear; RT-qPCR was performed in parallel.

RESULTS

All but one volunteer became thick blood smear positive between day 11 and day 12 after infection, and there was no significant effect of ivermectin on parasitaemia.

CONCLUSION

Ivermectin - at the dose used - has no clinically relevant activity against the pre-erythrocytic stages of P. falciparum.

Tuberculosis and malaria walk side by side in the Brazilian Amazon: an ecological approach

OBJECTIVE

To assess the spatial distribution of TB and malaria incidence, as well as their spatial association with each other, regardless of environmental and socio-economic factors commonly reported as determinants of both disease rates among the municipalities of Amazonas State, Brazil between 2012 and 2015.

METHODS

Through an ecological approach considering municipalities of Amazonas, Brazil, as unit of analysis, a negative binomial regression model was used to assess association between malaria and TB rates, in which the dependent variable was the average municipal tuberculosis incidence rate.

RESULTS

Positive associations of overall malaria (β = 0.100 [CI = 0.032, 0.168], P = 0.004), P. vivax malaria (β = 0.115 [CI = 0.036, 0.195], P = 0.005), and P. falciparum malaria (β = 0.389 [CI = -0.0124, 0.791], P = 0.057) with TB rates were found, regardless of the sociodemographic factors included in the study.

CONCLUSION

In the Brazilian Amazon, TB and malaria are spatially associated. Therefore, it is very likely that co-infections also occur in this region, regardless of the HIV status.

Genetic diversity and population structure of Plasmodium falciparum in Kenyan-Ugandan border areas

Kenya has, in the last decade, made tremendous progress in the fight against malaria. Nevertheless, continued surveillance of the genetic diversity and population structure of Plasmodium falciparum is required to refine malaria control and to adapt and improve elimination strategies. Twelve neutral microsatellite loci were genotyped in 201 P. falciparum isolates obtained from the Kenyan-Ugandan border (Busia) and from two inland malaria-endemic sites situated in western (Nyando) and coastal (Msambweni) Kenya. Analyses were done to assess the genetic diversity (allelic richness and expected heterozygosity, [H_e ]), multilocus linkage disequilibrium ( I S A ) and population structure. A similarly high degree of genetic diversity was observed among the three parasite populations surveyed (mean H_e  = 0.76; P > 0.05). Except in Msambweni, random association of microsatellite loci was observed, indicating high parasite out-breeding. Low to moderate genetic structure (F_ST   = 0.022-0.076; P < 0.0001) was observed with only 5% variance in allele frequencies observed among the populations. This study shows that the genetic diversity of P. falciparum populations at the Kenyan-Ugandan border is comparable to the parasite populations from inland Kenya. In addition, high genetic diversity, panmixia and weak population structure in this study highlight the fitness of Kenyan P. falciparum populations to successfully withstand malaria control interventions.

A population-based study of the prevalence and risk factors of low-grade Plasmodium falciparum malaria infection in children aged 0-15 years old in northern Tanzania

OBJECTIVES

Northern Tanzania experiences significant malaria-related morbidity and mortality, but accurate data are scarce. We update the data on patterns of low-grade Plasmodium falciparum malaria infection among children in northern Tanzania.

METHODS

Plasmodium falciparum malaria prevalence (pfPR) was assessed in a representative sample of 819 children enrolled in 94 villages in northern Tanzania between October 2015 and August 2016, using a complex survey design. Individual- and household-level risk factors for pfPR were elicited using structured questionnaires. pfPR was assessed using rapid diagnostic tests (RDTs) and thick film microscopy (TFM). Associations with pfPR, based on RDT, were assessed using adjusted odds ratios (aOR) and confidence intervals (CI) from weighted survey logistic regression models.

RESULTS

Plasmodium falciparum malaria prevalence (pfPR) was 39.5% (95% CI: 31.5, 47.5) by RDT and 33.4% (26.0, 40.6) by TFM. pfPR by RDT was inversely associated with higher-education parents, especially mothers (5-7 years of education: aOR 0.55; 95% CI: 0.31, 0.96, senior secondary education: aOR 0.10; 95% CI: 0.02, 0.55), living in a house near the main road (aOR 0.34; 95% CI: 0.15, 0.76), in a larger household (two rooms: aOR 0.40; 95% CI: 0.21, 0.79, more than two rooms OR 0.35; 95% CI: 0.20, 0.62). Keeping a dog near or inside the house was positively associated with pfPR (aOR 2.01; 95% CI: 1.26, 3.21). pfPR was not associated with bed-net use or indoor residual spraying.

CONCLUSIONS

Nearly 40% of children in northern Tanzania had low-grade malaria antigenaemia. Higher parental education and household metrics but not mosquito bed-net use were inversely associated with pfPR.

Differential contribution of interleukin-10 promoter variants in malaria and schistosomiasis mono- and co-infections among Nigerian children

OBJECTIVE

Interleukin-10 (IL-10) is an anti-inflammatory cytokine produced by Th1 cells and macrophages. The rationale of this study was to examine and validate possible contributions of IL-10 promoter polymorphisms in sub-Saharan Africa in children infected with either Plasmodium falciparum or Schistosoma haematobium and in children co-infected with both parasites.

MATERIALS AND METHODS

A total of 309 Nigerian children aged 4-15 years were recruited. The study group consisted of individuals infected either with P. falciparum (n = 76) or S. haematobium (n = 94) in mono-infections, a group of children co-infected with both P. falciparum and S. haematobium (n = 62) and matched healthy controls (n = 77). The IL-10 promoter polymorphisms -1082G/A, -819C/T and -592C/A were genotyped by direct sequencing.

RESULTS

The frequencies of the IL-10 -1082GG genotype, the -1082G allele and haplotype GCC (positions -1082, -819 and -592) were higher in children infected with P. falciparum than in healthy controls, indicating that the -1082GG genotype and the -1082G allele and the GCC haplotype are associated with increased susceptibility to malaria infection (OR = 3.4, 95% CI = 1.2-10.8, P = 0.02; OR = 2.5, 95% CI = 1.1-3.4, P = 0.02; OR = 3.8, 95% CI = 2.0-7.2, P = 0.0001, respectively). Children with the -1082GG genotype had a higher parasitaemia than children with the -1082AA or -1082AG genotypes (P = 0.0017). Haplotype GCC occurred more frequently in children infected with S. haematobium, while haplotype GTA was less frequent than in controls (OR = 2.2, 95% CI = 1.2-4.4, P = 0.017 and OR = 0.1, 95% CI = 0.02-0.5, P = 0.0004, respectively). No differences in the frequencies of IL-10 promoter polymorphisms were observed between children with P. falciparum-S. haematobium co-infections and healthy controls.

CONCLUSION

Although IL-10 promoter polymorphisms are not associated with P. falciparum and S. haematobium co-infection, variant -1082G/A and haplotype GCC are associated with malaria, whereas the IL-10 haplotypes GCC and GTA are associated with schistosomiasis.

Malaria exacerbates inflammation-associated elevation in ferritin and soluble transferrin receptor with only modest effects on iron deficiency and iron deficiency anaemia among rural Zambian children

OBJECTIVE

In 4- to 8-year-old Zambian children (n = 744), we evaluated the effects of adjusting for inflammation (α1-acid glycoprotein >1 g/l), with or without additional adjustment for malaria, on prevalence estimates of iron deficiency (ID) and iron deficiency anaemia (IDA) during low malaria (LowM) and high malaria (HighM) transmission seasons.

METHODS

To estimate adjustment factors, children were classified as: (i) reference (malaria negative without inflammation), (ii) inflammation without malaria (I), (iii) malaria without inflammation (M) and (iv) inflammation with malaria (IM). We estimated the unadjusted ID or IDA prevalence, and then adjusted for inflammation alone (ID_I or IDA_I ) or inflammation and malaria (ID_IM or IDA_IM ).

RESULTS

Mean ferritin was 38 (reference), 45 (I), 43 (M) and 54 μg/l (IM) in LowM, increasing to 44, 56, 96 and 167 μg/l, respectively, in HighM. Corresponding mean sTfR was 6.4, 6.9, 7.9 and 8.4 mg/l in LowM, increasing to 8.2, 9.2. 8.7 and 9.7 mg/l in HighM. Ferritin-based ID, ID_I and ID_IM were 7.8%, 8.7% or 9.1%, respectively, in LowM and 4.6%, 10.0% or 11.7%, respectively, in HighM. Corresponding soluble transferrin receptor (sTfR)-based estimates were 27.0%, 24.1% and 19.1%, respectively, in LowM, increasing to 53.6%, 46.5% and 45.3%, respectively, in HighM. Additional adjustment for malaria resulted in a ~1- to 2-percentage point change in IDA, depending on biomarker and season.

CONCLUSIONS

In this population, malaria substantially increased ferritin and sTfR concentrations, with modest effects on ID and IDA prevalence estimates.

Genetic diversity of Plasmodium falciparum merozoite surface protein-1 (block 2), glutamate-rich protein and sexual stage antigen Pfs25 from Chandigarh, North India

OBJECTIVE

To elucidate the genetic diversity of Plasmodium falciparum in residual transmission foci of northern India.

METHODS

Clinically suspected patients with malaria were screened for malaria infection by microscopy. 48 P. falciparum-infected patients were enrolled from tertiary care hospital in Chandigarh, India. Blood samples were collected from enrolled patients, genomic DNA extraction and nested PCR was performed for further species confirmation. Sanger sequencing was carried out using block 2 region of msp1, R2 region of glurp and pfs25-specific primers.

RESULTS

Extensive diversity was found in msp1 alleles with predominantly RO33 alleles. Overall allelic prevalence was 55.8% for RO33, 39.5% for MAD20 and 4.7% for K1. Six variants were observed in MAD20, whereas no variant was found in RO33 and K1 alleles. A phylogenetic analysis of RO33 alleles indicated more similarity to South African isolates, whereas MAD20 alleles showed similarity with South-East Asian isolates. In glurp, extensive variation was observed with eleven different alleles based on the AAU repeats. However, pfs25 showed less diversity and was the most stable among the targeted genes.

CONCLUSION

Our findings document the genetic diversity among circulating strains of P. falciparum in an area of India with low malaria transmission and could have implications for control strategies to reach the national goal of malaria elimination.

Effect of cotrimoxazole prophylaxis on malaria occurrence among HIV-infected adults in West Africa: the MALHIV Study

INTRODUCTION

Cotrimoxazole (CTX) should be given to all HIV-infected adults with mild or severe HIV-disease or those with CD4 counts below 350/mm³ according to 2006 WHO guidelines. We assessed the impact of CTX prophylaxis on the risk of malaria episodes in HIV-1-infected adults from four West African countries with different patterns of malaria transmission.

METHOD

Multicentric cohort study, conducted between September 2007 and March 2010 in four West African cities. Antiretroviral therapy (ART) naïve HIV-infected adults started CTX at enrolment (CTX group) if they had CD4 < 350 cells/mm³ or were at WHO clinical stage ≥2. For patients who did not start CTX at enrolment (non-CTX group) and started CTX afterwards, follow-up was censored at CTX initiation. We used Cox's proportional hazard model to compare the risk of malaria between CTX groups.

RESULTS

A total of 514 participants (median CD4 count 238 cells/mm³ ) were followed for a median of 15 months. At enrolment, 347 started CTX, and 261 started ART. During the follow-up, 28 started CTX. The incidence of malaria was 8.7/100 PY (95%CI 6.3-11.5) overall, 5.2/100 PY (95%CI 3.1-8.3) in the CTX group and 15.5/100 PY (95%CI 10.3-22.1) in the non-CTX group. In multivariate analysis, CTX led to a 69% reduction in the risk of malaria (aHR 0.31, 95%CI 0.10-0.90).

CONCLUSION

Patients in the CTX group had an adjusted risk of malaria three times lower than those in the non-CTX group. The prolonged large-scale use of CTX did not blunt the efficacy of CTX to prevent malaria in this region.

Submicroscopic malaria infections in pregnant women from six departments in Haiti

OBJECTIVES

To describe the epidemiology of malaria in pregnancy in Haiti.

METHODS

Cross-sectional study among pregnant women in six departments of Haiti. After obtaining informed consent, whole blood samples and demographic surveys were collected to investigate malaria prevalence, anaemia and socio-behavioural risk factors for infection, respectively. A total of 311 pregnant women were screened for Plasmodium falciparum infection using a rapid diagnostic test (RDT), microscopy and a novel, quantitative reverse transcriptase polymerase chain reaction method (qRT-PCR).

RESULTS

Overall, 1.2% (4/311) of pregnant women were tested positive for malaria infection by both microscopy and RDT. However, using the qRT-PCR, 16.4% (51/311) of pregnant women were positive. The prevalence of malaria infection varied with geographical locations ranging between 0% and 46.4%. Additionally, 53% of pregnant women had some form of anaemia; however, no significant association was found between anaemia and submicroscopic malaria infection. The socio-behavioural risk factors identified to be protective of malaria infection were marital status (P < 0.05) and travel within one month prior to screening (P < 0.05).

CONCLUSION

This study is the first to document the high prevalence of submicroscopic malaria infections among pregnant women in Haiti and identify social and behavioural risk factors for disease transmission.

Triggering receptor expressed on myeloid cells 1 (TREM-1) and cytokine gene variants in complicated and uncomplicated malaria

BACKGROUND

Malaria elicits inflammatory responses, which, if not well regulated, may exert detrimental effects. When activated, triggering receptor expressed on myeloid cells 1 (TREM-1) enhances inflammatory responses by increasing secretion of IL-8 and other Th1 cytokines. In contrast, TREM-like transcript 1 (TREML-1) promotes anti-inflammatory responses by binding to TREM-1 ligands and competing with TREM-1, thus antagonizing TREM-1 activation to reduce inflammation. Endothelial protein C receptor (EPCR) also mediates anti-inflammatory responses by activating endothelial protein C (PC). Upon microbial stimulation, soluble forms of TREM-1 (sTREM-1) and soluble EPCR (sEPCR) are released. Their plasma levels reflect the degree of inflammation and the severity of infection.

METHODS

In a cross-sectional study comparing patients with severe with uncomplicated malaria, sTREM-1, soluble TREML-1 (sTREML-1) and sEPCR plasma levels as well as plasma levels of sEPCR derived from convalescent patients were quantified. Samples were collected on admittance of paediatric patients infected with Plasmodium falciparum to hospitals in Accra, Ghana. Distinct genetic regions of the genes encoding TREM-1, EPCR, interleukin (IL)-8 and IL-18 encompassing known genetic polymorphisms that influence plasma levels underwent DNA sequencing.

RESULTS

Higher sTREM-1 levels were observed among children suffering from severe malaria compared to those with uncomplicated malaria (P = 0.049). Low TREM-1 to TREML-1 ratios were associated with uncomplicated malaria (P = 0.033). The TREM1 rs2234237T variant causing the amino acid exchange Thr25Ser, which has been associated with higher TREM-1 plasma levels, was significantly more frequent among patients with severe malaria than in those with uncomplicated malaria (P = 0.036). Low levels of sEPCR were observed in severe and uncomplicated malaria, while variant genotypes of IL8, IL18 and EPCR did not show any association.

CONCLUSION

Higher plasma levels of sTREM-1 alone or relative to sTREML-1 during malaria predispose to the phenotype of severe malaria. Carriage of the TREM1 rs2234237T allele appears to be a risk factor for the development of severe malaria.

Rapid diagnostic test for G6PD deficiency in Plasmodium vivax-infected men: a budget impact analysis based in Brazilian Amazon

OBJECTIVE

The aim of this study was to estimate the incremental budget impact (IBI) of a rapid diagnostic test to detect G6PDd in male patients infected with Plasmodium vivax in the Brazilian Amazon, as compared with the routine protocol recommended in Brazil which does not include G6PDd testing.

METHODS

The budget impact analysis was performed from the perspective of the Brazilian health system, in the Brazilian Amazon for the years 2013, 2014 and 2015. The analysis used a decision model to compare two scenarios: the first consisting of the routine recommended in Brazil which does not include prior diagnosis of dG6PD, and the second based on the use of RDT CareStart™ G6PD (CS-G6PD) in all male subjects diagnosed with vivax malaria. The expected implementation of the diagnostic test was 30% in the first year, 70% the second year and 100% in the third year.

RESULTS

The analysis identified negative IBIs which were progressively smaller in the 3 years evaluated. The sensitivity analysis showed that the uncertainties associated with the analytical model did not significantly affect the results.

CONCLUSION

A strategy based on the use of CS-G6PD would result in better use of public resources in the Brazilian Amazon.

El Niño-based malaria epidemic warning for Oromia, Ethiopia, from August 2016 to July 2017

OBJECTIVE

Tropical highland malaria intensifies and shifts to higher altitudes during exceptionally warm years. Above-normal temperatures associated with El Niño during boreal winter months (December-March) may intensify malaria in East African highlands. We assessed the malaria risk for Oromia, the largest region of Ethiopia with around 30 million inhabitants.

METHODS

Simple linear regression and spatial analyses were used to associate sea surface temperatures (SST) in the Pacific and surface temperatures in Ethiopia with annual malaria risk in Oromia, based on confirmed cases of malaria between 1982 and 2005.

RESULTS

A strong association (R² = 0.6, P < 0.001) was identified between malaria and sea surface temperatures in the Pacific, anticipating a 70% increase in malaria risk for the period from August 2016 to July 2017. This forecast was quantitatively supported by elevated land surface temperatures (+1.6 °C) in December 2015. When more station data become available and mean March 2016 temperatures from meteorological stations can be taken into account, a more robust prediction can be issued.

CONCLUSION

An epidemic warning is issued for Oromia, Ethiopia, between August 2016 and July 2017 and may include the pre-July short malaria season. Similar relationships reported for Madagascar point to an epidemic risk for all East African highlands with around 150 million people. Preparedness for this high risk period would include pre-emptive intradomestic spraying with insecticides, adequate stocking of antimalarials, and spatial extension of diagnostic capacity and more frequent reporting to enable a rapid public health response when and where required.

Cost of microbial larviciding for malaria control in rural Tanzania

OBJECTIVE

Microbial larviciding may be a potential supplement to conventional malaria vector control measures, but scant information on its relative implementation costs and effectiveness, especially in rural areas, is an impediment to expanding its uptake. We perform a costing analysis of a seasonal microbial larviciding programme in rural Tanzania.

METHODS

We evaluated the financial and economic costs from the perspective of the public provider of a 3-month, community-based larviciding intervention implemented in twelve villages in the Mvomero District of Tanzania in 2012-2013. Cost data were collected from financial reports and invoices and through discussion with programme administrators. Sensitivity analysis explored the robustness of our results to varying key parameters.

RESULTS

Over the 2-year study period, approximately 6873 breeding sites were treated with larvicide. The average annual economic costs of the larviciding intervention in rural Tanzania are estimated at 2014 US$ 1.44 per person protected per year (pppy), US$ 6.18 per household and US$ 4481.88 per village, with the larvicide and staffing accounting for 14% and 58% of total costs, respectively.

CONCLUSIONS

We found the costs pppy of implementing a seasonal larviciding programme in rural Tanzania to be comparable to the costs of other larviciding programmes in urban Tanzania and rural Kenya. Further research should evaluate the cost-effectiveness of larviciding relative to, and in combination with, other vector control strategies in rural settings.

Minimising invasiveness in diagnostics: developing a rapid urine-based monoclonal antibody dipstick test for malaria

OBJECTIVE

To generate monoclonal antibodies (MAbs) for developing a rapid malaria diagnostic urine-based assay (RUBDA), using Plasmodium-infected human urinary antigens.

METHODS

Plasmodium-infected human urinary (PAgHU) and cultured parasite (CPfAg) antigens were used to generate mouse MAbs. The reactivity and accuracy of the MAbs produced were then evaluated using microplate ELISA, SDS-PAGE, Western blotting assay, microscopy and immunochromatographic tests.

RESULTS

Ninety-six MAb clones were generated, of which 68.8% reacted to both PAgHU and CPfAg, 31.3% reacted to PAgHU only, and none reacted to CPfAg only. One promising MAb (UCP4W7) reacted in WBA, to both PAgHU and CPfAg, but not to Plasmodium-negative human urine and blood, Schistosoma haematobium and S. mansoni antigens nor measles and poliomyelitis vaccines.

CONCLUSION

MAb UCP4W7 seems promising for diagnosing Plasmodium infection. Urine is a reliable biomarker source for developing non-invasive malaria diagnostic tests. SDS-PAGE and MAb-based WBA appear explorable in assays for detecting different levels of Plasmodium parasitaemia.

Effect of deploying community health assistants on appropriate treatment for diarrhoea, malaria and pneumonia: quasi-experimental study in two districts of Zambia

OBJECTIVE

A critical shortage of human resources for health in Zambia remains a great challenge. In response, the Zambian Ministry of Health developed a national community health assistant (CHA) programme, aiming to create a well-trained and motivated community-based health workforce. This study assessed whether CHAs increased treatment rates for diarrhoea, confirmed malaria or pneumonia in the first programme year.

METHODS

This study used a quasi-experimental difference-in-difference design, comparing changes in the catchment areas of health posts with CHAs to those without. Baseline and end line household surveys were conducted to measure the proportion of children under 5 years treated for diarrhoea, malaria or pneumonia in the 2 weeks before the survey and immunisation rates and malaria rapid diagnostic test rates.

RESULTS

We surveyed 2330 women with children under five from the intervention area and 2314 from comparison areas at baseline and end line. Treatment for diarrhoea, malaria or pneumonia increased by 18.0% (P < 0.01) and 23.5% (P < 0.01) in the intervention and comparison groups, respectively, but DID analysis was not significant (P = 0.27). The proportion of fully immunised children grew by 7.5% in the intervention, but shrank by 7.5% in the comparison group (DID: 0.14; 95% CI 0.12-0.16, P < 0.01).

CONCLUSION

Although we observed no significant difference between the intervention and comparison groups in the DID estimates for the primary outcome, there were significant increases after one year in treatment for all three diseases in the intervention group from baseline to end line and in the proportion of fully immunised children.

Aetiologies of non-malaria febrile episodes in children under 5 years in sub-Saharan Africa

OBJECTIVES

To provide an overview of the most frequent aetiologies found in febrile episodes of children under 5 years from sub-Saharan Africa.

METHODS

MEDLINE and EMBASE were searched for publications in English and French on non-malaria fever episodes in African children under 5 years of age, which were published between January 1990 and July 2015. Case reports and conference abstracts were excluded.

RESULTS

In total, 3851 titles and abstracts were reviewed, and 153 were selected for full screening of which 18 were included in the present review. Bloodstream infection (BSI) was most commonly investigated (nine of 18) followed by urinary tract infection (UTI) (four of 18) and respiratory tract infection (RTI) (two of 18). Few studies investigated BSI and UTI in the same children (two of 18), or BSI and gastrointestinal infection (GII) (one of 18). As for BSI, the most frequently isolated bacteria were E. coli (four of 12), Streptococcus pneumonia (four of 12), Salmonella spp (three of 12) and Staphylococcus aureus (two of 12) with a positive identification rate of 19.7-33.3%, 5.2-27.6%, 11.7-65.4% and 23.5-42.0%, respectively. As for UTI, the main bacteria isolated were E. coli (six of six) and Klebsiella spp (six of six) with a positive rate of 20.0-72.3% and 10.0-28.5%, respectively. No bacterium was isolated in RTI group, but Human influenzae A and B were frequently found, with the highest positive identification rate in Tanzania (75.3%). Dengue virus (two of 12) was the most frequently reported viral infection with a positive identification rate of 16.7-30.8%. Finally, only rotavirus/adenovirus (69.2% positive identification rate) was found in GII and no bacterium was isolated in this group.

CONCLUSIONS

The high prevalence of treatable causes of non-malaria fever episodes requires a proper diagnosis of the origin of fever followed by an appropriate treatment, thereby reducing the under-5 mortality in sub-Saharan Africa and preventing the overprescription of antibiotics and thus circumventing the rise of antibiotic resistance.

Environmental factors and population at risk of malaria in Nkomazi municipality, South Africa

OBJECTIVE

Nkomazi local municipality of South Africa is a high-risk malaria region with an incidence rate of about 500 cases per 100 000. We examined the influence of environmental factors on population (age group) at risk of malaria.

METHODS

r software was used to statistically analyse data. Using remote sensing technology, a Landsat 8 image of 4th October 2015 was classified using object-based classification and a 5-m resolution. Spot height data were used to generate a digital elevation model of the area.

RESULTS

A total of 60 718 malaria cases were notified across 48 health facilities in Nkomazi municipality between January 1997 and August 2015. Malaria incidence was highly associated with irrigated land (P = 0.001), water body (P = 0.011) and altitude ≤400 m (P = 0.001). The multivariate model showed that with 10% increase in the extent of irrigated areas, malaria risk increased by almost 39% in the entire study area and by almost 44% in the 2-km buffer zone of selected villages. Malaria incidence is more pronounced in the economically active population aged 15-64 and in males. Both incidence and case fatality rate drastically declined over the study period.

CONCLUSION

A predictive model based on environmental factors would be useful in the effort towards malaria elimination by fostering appropriate targeting of control measures and allocating of resources.

Reduction in symptomatic malaria prevalence through proactive community treatment in rural Senegal

OBJECTIVES

We piloted a community-based proactive malaria case detection model in rural Senegal to evaluate whether this model can increase testing and treatment and reduce prevalence of symptomatic malaria in target communities.

METHODS

Home care providers conducted weekly sweeps of every household in their village throughout the transmission season to identify patients with symptoms of malaria, perform rapid diagnostic tests (RDT) on symptomatic patients and provide treatment for positive cases. The model was implemented in 15 villages from July to November 2013, the high transmission season. Fifteen comparison villages were chosen from those implementing Senegal's original, passive model of community case management of malaria. Three sweeps were conducted in the comparison villages to compare prevalence of symptomatic malaria using difference in differences analysis.

RESULTS

At baseline, prevalence of symptomatic malaria confirmed by RDT for all symptomatic individuals found during sweeps was similar in both sets of villages (P = 0.79). At end line, prevalence was 16 times higher in the comparison villages than in the intervention villages (P = 0.003). Adjusting for potential confounders, the intervention was associated with a 30-fold reduction in odds of symptomatic malaria in the intervention villages (AOR = 0.033; 95% CI: 0.017, 0.065). Treatment seeking also increased in the intervention villages, with 57% of consultations by home care providers conducted between sweeps through routine community case management.

CONCLUSIONS

This pilot study suggests that community-based proactive case detection reduces symptomatic malaria prevalence, likely through more timely case management and improved care seeking behaviour. A randomised controlled trial is needed to further evaluate the impact of this model.

Association between recent internal travel and malaria in Ugandan highland and highland fringe areas

OBJECTIVE

To examine the association between travel (recency of travel, transmission intensity at destination compared to origin and duration of travel) and confirmed malaria in Uganda.

METHODS

Health facility-based case-control study in highland (~2200 m), and highland fringe (~1500 m) areas with adjustment for other covariates.

RESULTS

In the highland site, patients who had travelled to areas of higher transmission intensity than their home (origin) areas recently were nearly seven times more likely to have confirmed malaria than those who had not (OR 6.9; P = 0.01, 95% CI: 1.4-33.1). In the highland fringe site, there was also a statistically significant association between travel and malaria (OR 2.1; P = 0.04, 95% CI: 1.1-3.9).

CONCLUSIONS

For highland areas, or areas of low malaria transmission, health authorities need to consider internal migrants when designing malaria control programs. Control interventions should include information campaigns reminding residents in these areas of the risk of malaria infection through travel and to provide additional mosquito nets for migrants to use during travel. Health authorities may wish to improve diagnosis in health facilities in highland areas by adding travel history to malaria case definitions. Where routine monitoring data are used to evaluate the impact of interventions on the malaria burden in highland areas, health authorities and donors need ensure that only cases from the local area and not 'imported cases' are counted.

Effect of cotrimoxazole prophylaxis on malaria occurrence in HIV-infected patients on antiretroviral therapy in sub-Saharan Africa

OBJECTIVE

To systematically review the evidence on the effect of cotrimoxazole (CTX) on malaria in HIV-positive individuals on antiretroviral therapy (ART).

METHODS

Web of Science, PubMed and MEDLINE, EMBASE, Global Health and Cochrane Library databases were searched using terms for malaria, HIV and CTX. Studies meeting the inclusion criteria were reviewed and assessed for bias and confounding.

RESULTS

Six studies (in Uganda, Kenya, Malawi, Zambia and Zimbabwe) had relevant data on the effect of CTX on malaria in patients on ART: four were observational cohort studies (OCS) and two were randomised controlled trials (RCTs); two were in children and one in women only. Samples sizes ranged from 265 to 2200 patients. Four studies compared patients on ART and CTX with patients on ART alone; 2 (RCTs) found a significant increase in smear-positive malaria on ART alone: (IRR 32.5 CI = 8.6-275.0 and HR 2.2 CI = 1.5-3.3) and 2 (OCS) reported fewer parasitaemia episodes on CTX and ART (OR 0.85 CI = 0.65-1.11 and 3.6% vs. 2.4% of samples P = 0.14). One OCS found a 76% (95% CI = 63-84%) vs. 83% (95% CI = 74-89%) reduction in malaria incidence in children on CTX and ART vs. on CTX only, when both were compared with HIV-negative children. The other reported a 64% reduction in malaria incidence after adding ART to CTX (RR = 0.36, 95% CI = 0.18-0.74). The 2 RCTs were unblinded. Only one study reported adherence to CTX and ART, and only two controlled for baseline CD4 count.

CONCLUSION

Few studies have investigated the effect of CTX on malaria in patients on ART. Their findings suggest that CTX is protective against malaria even among patients on ART.

Association between malaria exposure and Kaposi's sarcoma-associated herpes virus seropositivity in Uganda

OBJECTIVE

Unlike other herpes viruses, Kaposi's sarcoma-associated herpes virus (KSHV) is not ubiquitous worldwide and is most prevalent in sub-Saharan Africa. The reasons for this are unclear. As part of a wider investigation of factors that facilitate transmission in Uganda, a high prevalence country, we examined the association between antimalaria antibodies and seropositivity against KSHV.

METHODS

Antibodies against P. falciparum merozoite surface protein (PfMSP)-1, P. falciparum apical membrane antigen (PfAMA)-1 and KSHV antigens (ORF73 and K8.1) were measured in samples from 1164 mothers and 1227 children.

RESULTS

Kaposi's sarcoma-associated herpes virus seroprevalence was 69% among mothers and 15% children. Among mothers, KSHV seroprevalence increased with malaria antibody titres: from 60% to 82% and from 54% to 77%, comparing those with the lowest and highest titres for PfMSP-1 and PfAMA-1, respectively (P < 0.0001). Among children, only antibodies to PfAMA-1 were significantly associated with KSHV seropositivity, (P < 0.0001). In both mothers and children, anti-ORF73 antibodies were more strongly associated with malaria antibodies than anti-K8.1 antibodies.

CONCLUSION

The association between malaria exposure and KSHV seropositivity suggests that malaria is a cofactor for KSHV infection or reactivation.

Effectiveness of insecticide-treated and untreated nets to prevent malaria in India

OBJECTIVES

India is the most malaria-endemic country in South-East Asia, resulting in a high socio-economic burden. Insecticide-treated or untreated nets are effective interventions to prevent malaria. As part of an Indian first-aid guideline project, we aimed to investigate the magnitude of this effect in India.

METHODS

We searched MEDLINE, Embase and Central to systematically review Indian studies on the effectiveness of treated or untreated vs. no nets. Parasite prevalence and annual parasite incidence served as malaria outcomes. The overall effect was investigated by performing meta-analyses and calculating the pooled risk ratios (RR) and incidence rate ratios.

RESULTS

Of 479 articles, we finally retained 16 Indian studies. Untreated nets decreased the risk of parasite prevalence compared to no nets [RR 0.69 (95% CI; 0.55, 0.87) in high-endemic areas, RR 0.49 (95% CI; 0.28, 0.84) in low-endemic areas], as was the case but more pronounced for treated nets [RR 0.35 (95% CI; 0.26, 0.47) in high-endemic areas, risk ratio 0.16 (95% CI; 0.06, 0.44) in low-endemic areas]. Incidence rate ratios showed a similar observation: a significantly reduced rate of parasites in the blood for untreated nets vs. no nets, which was more pronounced in low-endemic areas and for those who used treated nets. The average effect of treated nets (vs. no nets) on parasite prevalence was higher in Indian studies (RR 0.16-0.35) than in non-Indian studies (data derived from a Cochrane systematic review; RR 0.58-0.87).

CONCLUSIONS

Both treated and untreated nets have a clear protective effect against malaria in the Indian context. This effect is more pronounced there than in other countries.

Differences in malaria care seeking and dispensing outcomes for adults and children attending drug vendors in Nasarawa, Nigeria

Objectives

To characterise the differences in care seeking behaviour and dispensing outcomes between adults and children purchasing drugs for malaria at retail shops in Nigeria.

Methods

In Nasarawa State, retail drug shops were enumerated and a subset of those stocking antimalarials were selected as study sites and surveyed. Customers exiting shops after purchasing antimalarial drugs were surveyed and tested with a malaria rapid diagnostic test. Sick adults and caregivers accompanying sick children were eligible, but individuals purchasing drugs for a sick person that was not present were excluded. Multivariate regression analysis was used to identify the correlates of care seeking and the quality of interaction at the shop.

Results

Of 737 participants, 80% were adults and 20% were children (under age 18). Caregivers of sick children were more likely to obtain a prescription prior to attending a drug retailer than adults seeking care for themselves and waited a shorter time before seeking care. Caregivers of sick children were also more likely than sick adults to have been asked about symptoms by the retailer, to have been given an examination, and to have purchased an ACT. Fewer than half of respondents had purchased an ACT. Only 14% of adults, but 27% of children were RDT-positive; RDT-positive children were more likely to have had an ACT purchased for them than RDT-positive adults.

Conclusions

Children with suspected malaria tend to receive better care at drug retailers than adults. The degree of overtreatment and prevalence of dispensing non-recommended antimalarials emphasise the need for routine diagnosis before treatment to properly treat both malaria and non-malaria illnesses.

Combining malaria control with house electrification: adherence to recommended behaviours for proper deployment of solar-powered mosquito trapping systems, Rusinga Island, western Kenya

OBJECTIVE

To investigate community adherence to recommended behaviours for proper deployment of solar-powered mosquito trapping systems (SMoTS) after 3- to 10-week use.

METHODS

Solar-powered mosquito trapping system, which also provided power for room lighting and charging mobile phones, were installed in houses in Rusinga Island, western Kenya. We used a structured checklist for observations and a semi-structured questionnaire for interviews in 24 homesteads. We also analysed the subject of 224 community calls to the project team for technical maintenance of SMoTS.

RESULTS

Most respondents cared for SMoTS by fencing, emptying and cleaning the trap. Our observations revealed that most traps were fenced, clean and in good working condition. A significantly higher proportion of community calls was lighting-related. Lighting was the main reason respondents liked SMoTS because it reduced or eliminated expenditure on kerosene. However, some respondents observed they no longer heard sounds of mosquitoes inside their houses. All respondents reportedly slept under insecticide-treated nets (ITNs) before receiving SMoTS. After receiving SMoTS, most respondents reportedly continued to use ITNs citing that the project advised them to do so. Some beach residents stopped using ITNs because they no longer heard mosquitoes or due to heat discomfort caused by lights.

CONCLUSION

Electricity-related incentives played a greater role in encouraging adherence to recommended behaviours for proper deployment of SMoTS than the potential health benefits in the early stages of the intervention. Although energy-related financial incentives may play a role, they are insufficient to ensure adherence to health advice, even in the short term. Ongoing community engagement and research monitors and addresses adherence to recommended behaviours including continuation of current malaria control strategies.

The evolution of genomic GC content undergoes a rapid reversal within the genus Plasmodium

The genome of the malarial parasite Plasmodium falciparum is extremely AT rich. This bias toward a low GC content is a characteristic of several, but not all, species within the genus Plasmodium. We compared 4283 orthologous pairs of protein-coding sequences between Plasmodium falciparum and the less AT-biased Plasmodium vivax. Our results indicate that the common ancestor of these two species was also extremely AT rich. This means that, although there was a strong bias toward A+T during the early evolution of the ancestral Plasmodium lineage, there was a subsequent reversal of this trend during the more recent evolution of some species, such as P. vivax. Moreover, we show that not only is the P. vivax genome losing its AT richness, it is actually gaining a very significant degree of GC richness. This example illustrates the potential volatility of nucleotide content during the course of molecular evolution. Such reversible fluxes in nucleotide content within lineages could have important implications for phylogenetic reconstruction based on molecular sequence data.

Investigation of antimalarial activity, cytotoxicity and action mechanism of piperazine derivatives of betulinic acid

OBJECTIVES

To semisynthesise piperazine derivatives of betulinic acid to evaluate antimalarial activity, cytotoxicity and action mechanism.

METHODS

The new derivatives were evaluated against the CQ-sensitive Plasmodium falciparum 3D7 strain by flow cytometry (FC) using YOYO-1 as stain. Cytotoxicity of 4a and 4b was performed with HEK293T cells for 24 and 48 h by MTT assay. The capability of compound 4a to modulate Ca(2+) in the trophozoite stage was investigated. The trophozoites were stained with Fluo4-AM and analysed by spectrofluorimetry. Effect on mitochondrial membrane potential (ΔΨm) was tested for 4a by FC with DiOC6 (3) as stain. For β-haematin assay, 4a was incubated for 24 h with reagents such as haemin, and the fluorescence was measured by FlexStation at an absorbance of 405 nm.

RESULTS

Antimalarial activity of 4a and 4b was IC50 = 1 and 4 μm, respectively. Compound 4a displayed cytotoxicity with IC50 = 69 and 29 μm for 24 and 48 h, respectively, and 4b was not cytotoxic at the tested concentrations. Addition of 4a leads to an increase in cytosolic Ca(2+) . We have measured ΔΨm after treating parasites with the compound. Data on Figure 4a show that mitochondria were not affected. The action mechanism for 4a, inhibition of β-haematin formation (17%), was lower than CQ treatment (83%; IC50 = 3 mm).

CONCLUSION

Compound 4a showed excellent antimalarial activity, and its action mechanism is involved in Ca(2+) pathway(s).

Malaria in school-age children in Africa: an increasingly important challenge

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

Cotrimoxazole prophylactic treatment prevents malaria in children in sub-Saharan Africa: systematic review and meta-analysis

OBJECTIVES

Cotrimoxazole prophylactic treatment (CPT) prevents opportunistic infections in HIV-infected or HIV-exposed children, but estimates of the effectiveness in preventing malaria vary. We reviewed studies that examined the effect of CPT on incidence of malaria in children in sub-Saharan Africa.

METHODS

We searched PubMed and EMBASE for randomised controlled trials (RCTs) and cohort studies on the effect of CPT on incidence of malaria and mortality in children and extracted data on the prevalence of sulphadoxine-pyrimethamine resistance-conferring point mutations. Incidence rate ratios (IRR) from individual studies were combined using random effects meta-analysis; confounder-adjusted estimates were used for cohort studies. The importance of resistance was examined in meta-regression analyses.

RESULTS

Three RCTs and four cohort studies with 5039 children (1692 HIV-exposed; 2800 HIV-uninfected; 1486 HIV-infected) were included. Children on CPT were less likely to develop clinical malaria episodes than those without prophylaxis (combined IRR 0.37, 95% confidence interval: 0.21-0.66), but there was substantial between-study heterogeneity (I-squared = 94%, P < 0.001). The protective efficacy of CPT was highest in an RCT from Mali, where the prevalence of antifolate resistant plasmodia was low. In meta-regression analyses, there was some evidence that the efficacy of CPT declined with increasing levels of resistance. Mortality was reduced with CPT in an RCT from Zambia, but not in a cohort study from Côte d'Ivoire.

CONCLUSIONS

Cotrimoxazole prophylactic treatment reduces incidence of malaria and mortality in children in sub-Saharan Africa, but study designs, settings and results were heterogeneous. CPT appears to be beneficial for HIV-infected and HIV-exposed as well as HIV-uninfected children.

The interaction between malaria and human immunodeficiency virus infection in severely anaemic Malawian children: a prospective longitudinal study

OBJECTIVE

Malaria and human immunodeficiency virus (HIV) infection are co-prevalent in sub-Saharan Africa and cause severe anaemia in children. Interactions between these infections occur in adults, although these are less clear in children. The aim of study was to determine their interaction in a cohort of severely anaemic children.

METHODS

Severely anaemic Malawian children were enrolled, tested for HIV and malaria, transfused and followed for 18 months for malaria incidence. Antiretrovirals were not widely available in Malawi during the study period.

RESULTS

Of 381 children (haemoglobin <5 g/dl), 357 consented for HIV testing, 12.6% were HIV-infected, and 59.5% had malaria parasitaemia. At enrolment, HIV-infected children had similar malaria parasitaemia prevalence (59.1% vs. 58.7%; P = 0.96) and parasite density (geometric mean [parasites/μl] 6903 vs. 12417; P = 0.18) as HIV-negative children. There were no differences in mean CD4%, or prevalence of severe immunosuppression, between those with and without malaria parasitaemia. Plasma viral load correlated negatively with log parasitaemia (r = -0.78; P = 0.01). During follow-up, HIV-infected children did not experience more frequent parasitaemias or symptomatic malaria episodes. Adjusted risk estimates (95% CI) for malaria parasitaemia in HIV-infected children at 6 and 18 months follow-up were 0.39 (0.13-1.14) and 0.40 (0.11-1.51), respectively.

CONCLUSIONS

Severely anaemic HIV-infected children showed no increased susceptibility to asymptomatic or symptomatic malaria during or following their anaemic episode, although all experienced lower parasite prevalence during follow-up. This contrasts with data in adults and may relate to the malaria immunity of young children which is insufficiently developed to be impaired by HIV. The negative correlation between viral load and malaria parasitaemia remains unexplained.

[Community perceptions of malaria vaccines : qualitative research from the sanitary districts of Kaya and Hounde in Burkina Faso]

Au Burkina Faso, le paludisme est la principale cause de mortalité chez les enfants de moins de 5 ans. L’un des moyens les plus efficaces de prévention des maladies reste la vaccination. Aucun vaccin antipaludique n’existe actuellement, mais la recherche pour développer un vaccin progresse. Si les résultats des essais cliniques sont concluants d’ici 2014, l’Organisation Mondiale de la Santé (OMS) pourrait recommander l’utilisation d’un vaccin anti-paludique dès 2015. C’est dans le but de guider la décision d’introduire éventuellement un vaccin contre le paludisme que cette étude a été menée. Les objectifs étaient de comprendre les perceptions et les expériences des communautés au sujet du paludisme et des vaccins et d’explorer l’acceptabilité éventuelle d’un vaccin antipaludique par ces communautés. Cette étude qualitative s’appuie sur le cadre socioécologique de L. W. Green. Elle s’est déroulée dans les districts sanitaires de Kaya et Houndé, au Burkina Faso. Au total, 30 groupes de discussions dirigées et 29 entretiens individuels ont été réalisés. Tous les participants à l’étude ont reconnu que le paludisme représente la première cause de morbidité et de mortalité au sein de leur communauté. En général, les populations de Kaya et Houndé ont eu des expériences positives avec les programmes de vaccination existant. Les effets bénéfiques que pourrait avoir un futur vaccin sont les motifs d’acceptation. L’avis du chef de ménage, l’interaction entre les prestataires de soins et les usagers des services de santé, et les effets secondaires sont des obstacles potentiels. Les résultats de cette étude fournissent des informations aux décideurs pour l’élaboration d’une stratégie de communication à l’éventuelle introduction d’un vaccin contre le paludisme. Pour surmonter les obstacles à l’introduction d’un nouveau vaccin, une stratégie de communication efficace devra formuler des messages appropriés, et identifier des canaux d’information et les publics cibles en tenant compte du contexte local.

[Politics in the fight against Malaria in Casamance, Senegal: public health activity in the context of conflict and decentralization]

Cet article analyse, à partir d’une ethnographie menée à Oussouye (Casamance), la manière dont s’incarnent et se traduisent les politiques nationales sanitaires, dans des contextes locaux spécifiques. Il discute des contraintes que rencontre une politique globalisante, ou plus exactement des points aveugles de cette politique pas suffisamment à l’écoute du contexte, c’est-à-dire, des spécificités régionales et géopolitiques.

Les résultats indiquent que le contexte de la décentralisation et du conflit casamançais ont eu des effets sur le financement, la gestion des activités promotionnelles et la domestication des recommandations officielles de la lutte contre le paludisme. Par ailleurs, celles antérieures laissent des traces, qui s’expriment dans les discours des acteurs et structurent la façon dont ils pensent la lutte aujourd’hui, alors même que cette dernière est supposée s’inscrire dans un autre paradigme. Enfin la dissonance de la prescription d’antipaludiques à Mlomp et Elinkine fait penser à l’existence de « territoires » locaux de la santé où les recommandations nationales cèdent la place aux spécificités contextuelles et locales. Les politiques de santé ne peuvent faire l’économie ni des acteurs, ni des contextes locaux, cependant la prise en compte de la spécificité ne doit certainement pas se faire au détriment d’une certaine notion de « l’être ensemble ».

How does an Ethiopian dam increase malaria? Entomological determinants around the Koka reservoir

OBJECTIVES

To identify entomological determinants of increased malaria transmission in the vicinity of the Koka reservoir in Central Ethiopia.

METHODS

Larval and adult mosquitoes were collected between August 2006 and December 2007 in villages close to (<1km) and farther away from (>6 km) the Koka reservoir. Adult mosquitoes were tested for the source of blood meal and sporozoites.

RESULTS

In reservoir villages, shoreline puddles and seepage at the base of the dam were the most productive Anopheles-breeding habitats. In villages farther from the dam (control villages), rain pools were important breeding habitats. About five times more mature anopheline larvae and six times more adult anophelines were found in the villages near the reservoir. Anopheles arabiensis and Anopheles pharoensis were the most abundant species in the reservoir villages throughout the study period. The majority of adult and larval anophelines were collected during the peak malaria transmission season (September-October). Blood meal tests suggested that A. arabiensis fed on humans more commonly (74.6%) than A. pharoensis (62.3%). Plasmodium falciparum-infected A. arabiensis (0.97-1.32%) and A. pharoensis (0.47-0.70%) were present in the reservoir villages. No P. falciparum-infected anophelines were present in the control villages.

CONCLUSIONS

The Koka reservoir contributes to increased numbers of productive Anopheles-breeding sites. This is the likely the cause for the greater abundance of malaria vectors and higher number of malaria cases evidenced in the reservoir villages. Complementing current malaria control strategies with source reduction interventions should be considered to reduce malaria in the vicinity of the reservoir.

Mass administration of the antimalarial drug mefloquine to Guantánamo detainees: a critical analysis

Recently, evidence has emerged from an unusual form of mass drug administration practised among detainees held at US Naval Station Guantánamo Bay, Cuba ('Guantánamo'), ostensibly as a public health measure. Mefloquine, an antimalarial drug originally developed by the US military, whose use is associated with a range of severe neuropsychiatric adverse effects, was administered at treatment doses to detainees immediately upon their arrival at Guantánamo, prior to laboratory testing for malaria and irrespective of symptoms of disease. In this analysis, the history of mefloquine's development is reviewed and the indications for its administration at treatment doses are discussed. The stated rationale for the use of mefloquine among Guantánamo detainees is then evaluated in the context of accepted forms of population-based malaria control. It is concluded that there was no plausible public health indication for the use of mefloquine at Guantánamo and that based on prevailing standards of care, the clinical indications for its use are decidedly unclear. This analysis suggests the troubling possibility that the use of mefloquine at Guantánamo may have been motivated in part by knowledge of the drug's adverse effects, and points to a critical need for further investigation to resolve unanswered questions regarding the drug's potentially inappropriate use.

From bark to weed: the history of artemisinin

In the 1970's, in China, some brilliant and courageous scientists carried out a research programme, which lead to the discovery of artemisinin derivatives and new quinoleines that are used today, in combination, as first line treatment of malaria.

[Conclusions and recommendations of a WHO expert consultation meeting on iron supplementation for infants and young children in malaria endemic areas]

This article presents the results of an expert consultation meeting aimed at evaluating the safety and public health implications of administering supplemental iron to infants and young children in malaria-endemic areas. Participants at this meeting that took place in Lyon, France on June 12-14, 2006 reached consensus on several important issues related to iron supplementation for infants and young children in malaria-endemic areas. The conclusions in this report apply specifically to regions where malaria is endemic.