Severe and Cerebral Malaria Investigated Through Host Metabolomics
Severe MalariaThe aim is to describe disease mechanisms of severe and cerebral malaria and identify new targets for adjunctive therapies. Despite treatment between 10-30% of patients with severe malaria die. Metabolic acidosis and cerebral malaria are major complications associated with mortality across all age groups. Still, their underlying pathogenesis remains incompletely understood. Using a metabolomics approach, this study aims to characterise the spectrum of acids accumulating during acidosis, and investigate patterns of metabolic dysregulation associated with coma and seizures.
Frequency and Distribution of Mixed Falciparum-vivax Infections in French Guiana
MalariaMalaria is still endemic in the interior of French Guiana. mixed infections by 2 or more different malaria parasites lead to complex and potentially harmfull therapeutic problems. The aim of the study was to look at malaria smears between 2000 and 2008 and determine using PCR the frequency of mixed infections, and their distribution in the terrtory of French Guiana. Overall 10.75% of 400 smears showed mixed infection with P. falciparum and P. vivax. The Maroni river where Duffy negative populations live was largely devoid of vivax infections. These results suggest that mixed infections are frequent in french guiana except on the Maroni river which leads to practical implications for clinicians facing a patient with clinical malaria.
Insecticide Resistance Management in Burkina Faso and Côte d'Ivoire
MalariaThis study evaluates the benefit to use 1) insecticidal paints, 2) larvicides, 3) Ivermectin for both human and domestic animals and 4) strengthened Information, Education and Communication (IEC) strategy to complement the universal coverage with LLINs through a cluster randomized trial.
Drug Resistance Among Asymptomatic Infection
Drug Resistant MalariaAsymptomatic Infections1 moreA cross-sectional study will be conducted in selected 2 sentinel sites for assessment of drug resistance falciparum and vivax among asymptomatic infection in migrant workers in Myanmar.
Molecular Diagnostic Methods for Detection of Plasmodium Knowlesi
Plasmodium Knowlesi InfectionThis study aims to determine the sensitivity, specificity, and practical value of two new molecular diagnostic assays compared to a more classical nested molecular diagnostic assay and the routine microscopy (both of which are the current gold standard) in detection of P. knowlesi.
Household-level Impact of IPT of Malaria in Schoolchildren
MalariaThe study will evaluate the household-level impact of IPT for malaria in schoolchildren on malaria transmission, using a randomized trial design. Two schools in Busia district will be randomly selected and randomize to either IPT with dihydroartemisinin piperaquine (DP, IPT arm), or standard of care (no intervention). A single dose/round of IPT with DP (40mg/320mg tabs, Fosun Pharmaceuticals) will be given to the children in the intervention arm. The full dose will be given as oral tablets once a day for 3 consecutive days to all eligible children in the intervention school. Surveys will be conducted in households of 100 randomly selected children in each of the study arms at baseline, one month and three months following the intervention. The target population will include all household members of the selected households.
Baseline Cohort Malaria Morbidity Study
MalariaThe BLOOMy study is a longitudinal prospective cohort study of healthy children to assess the incidence of clinical malaria over the main transmission season. Participants will undergo baseline clinical and biological assessments then will receive a curative dose of either artesunate or dihydroartemisinin-piperaquine to clear any existing parasitemia. Clearance of parasites will be confirmed 3 weeks later by Polymerase chain reaction (PCR) and only participants with negative PCR will be definitively enrolled for the longitudinal follow up. Both active and passive case detection will be used to ensure that capture of a high proportion of infections in the cohort is achieved. Blood samples for immunological assessments will be obtained at Day 0 of each positive blood smear episode before treatment and at Weeks 4 post treatment. Participants will be followed for a minimum of six months throughout the malaria peak transmission season.
Plasmodium Falciparum Clearance Rates in Response to Artesunate in Eastern Cambodia
MalariaPlasmodium falciparum parasite clearance rates (PCRs) after oral artesunate treatment of patients with uncomplicated malaria were recently found to be significantly slower in Pailin (Western Cambodia) compared to Wang Pha (Eastern Thailand). This difference in PCRs has been attributed to different histories of artesunate drug pressure in the two areas. In Pailin, artesunate monotherapy has been used inappropriately for 30 years and is hypothesized to have selected for artemisinin-resistant parasites (slow PCRs). To investigate the potential contribution of human factors to the artemisinin resistance phenotype, we have identified a study site in Eastern Cambodia where artemisinin-resistant parasites are not believed to be present. The main aims of this study are to 1) determine whether the artemisinin resistance phenotype (i.e., a half-life longer than the 2-hour half-life observed in Wang Pha) is present in Eastern Cambodia, 2) determine whether hemoglobin E affects parasite clearance rates in vivo, 3) determine whether age-associated acquired immunity affects parasite clearance rates in vivo, and 4) identify parasite-heritable traits that are associated with slow parasite clearance rates in vivo. To meet these aims, we are conducting a prospective, longitudinal study to recruit Cambodian residents of Lumphat District in Ratanakiri Province who complain of fever and/or symptoms of malaria. Patients diagnosed with uncomplicated malaria will be treated with weight-based doses of artesunate given orally each day for 3 days followed by mefloquine given orally for 2 days. During this time, finger prick blood smears will be obtained every 6 hours until parasite density is zero. From these data, we will estimate parasite clearance rates using a half-life parameter. We will also collect parasitized red blood cell samples from malaria patients prior to antimalarial drug administration. These parasites will be tested in short-term in vitro culture experiments to determine their susceptibility to artemisinins and other antimalarial drugs.
Assessment of Anaemia Attributable to Schistosomiasis in School Children in Kenya: Mechanisms and...
AnaemiaSchistosomiasis Infection2 moreThe purpose of this study is to determine the extend and the nature of anemia in school children and the correlation between anemia and schistosomiasis infections, malaria infections and/or malnutrition (iron deficiency).
Estivation of Malaria Vector Mosquitoes in the Sahelian Region of Mali
MalariaBackground: P. falciparum, one of the most virulent forms of malaria, causes more than 300 million episodes of malaria and 1 million deaths each year. The spread of drug-resistant parasites, insecticide-resistant mosquitoes, and persistent socioeconomic conditions of poverty compound the difficulties of malaria as a major global health problem. New means of disease and vector control are vitally needed. Several promising strategies rely on targeting mosquito populations when they are most vulnerable, such as during the dry season when mosquitoes find it difficult to reproduce. Large regions of the West African country of Mali have prolonged dry seasons (up to 8 months), during which mosquito populations dramatically decline within a month after the rainfall ceases. Clearly, mosquitoes can survive the dry season (as evident from their robust numbers during the wet season) but the process that enables them to do so remains unknown. Targeting the small and fragile mosquito population at the end of the dry season could reduce or eliminate the numbers of mosquitoes in certain regions, providing great benefits for communities in dry regions. Objectives: To determine if common malaria-carrying mosquitoes survive the dry season in the Mali village of Thierola by estivation (going dormant, or hibernating, during dry periods). To identify and examine mosquitoes that were marked with special paint during a previous protocol, if these marked mosquitoes are captured during the investigation. Eligibility: All activities in this protocol will take place in Thierola village, Banamba district, Koulikoro region, Mall, West Africa. The village was chosen because it is isolated from other communities by at least 6 km and is a small community of less than 300 inhabitants living in 90 houses. Participants will be healthy adult men between 18 and 65 years of age. Design: Thirty adult men who live in Thierola will be recruited to participate as mosquito collectors for the human-baited trapping method and will work in teams of two. The first collector will expose his lower legs to attract human-seeking mosquitoes. Using a mouth aspirator, the second collector will collect the mosquitoes as they land on the first collector's legs. The collections will be conducted both indoors and outdoors from 6 p.m. to 6 a.m. the following morning for 14 consecutive days. All study volunteers will be trained in proper collection technique and supervised throughout the study by a mobile team led by the study investigators. Volunteers will be monitored for signs of malaria and treated accordingly if they develop symptoms of the disease. Researchers will collect mosquito samples at the end of the dry season (April-May) and at the start of the rainy season (May-June). Mosquitoes collected in the study will be analyzed by NIH researchers to learn more about how they survive during the dry season.