Track topics on Twitter Track topics that are important to you
The purpose of this study is to find new ways to control malaria by looking at mosquitoes infected with the disease. Knowledge of the genetics that affect the spread of malaria by mosquitoes will help in developing control strategies. A small amount of blood from infected humans will be used to infect the mosquitoes. No contact will occur between the human subject and the mosquito. Study participants will be divided into 2 groups of 20, for a total of 40 children, ages 5-10, in Burkina Faso, West Africa. Each subject will be screened by finger-prick once per month, from June through October, until they reach a maximum age of 10. Two positive subjects of the 40 screened will be asked to donate about 1 teaspoon of blood, which will be used to feed and infect the mosquitoes. Study participants will be involved in study related procedures for a maximum of 5 years.
Malaria is a blood-borne human disease, and is transmitted to mosquitoes in the bloodmeal, an obligatory step in human malaria transmission. This is a study of malaria parasites in the major mosquito vector of human malaria in Africa, Anopheles gambiae. The intent of the study is to develop modern forms of vector control that would specifically decrease disease transmission by targeting the vector. Genetic linkage mapping of the mosquito vector (Anopheles gambiae) in Africa has identified a small genomic region in the mosquito that controls most of the natural genetic variation for resistance to mosquito infection with the human malaria parasite (Plasmodium falciparum). In order to study the influence of mosquito vector genetics on transmission of malaria parasites, mosquitoes are exposed to malaria parasites and then the efficiency of parasite development within the mosquito is measured. The goal of the study is to promote and expand this non-transmitting subset of the vector population in order to decrease or interrupt human malaria transmission. The study focuses on the mosquito vector, not the human subjects infected with malaria. The reason for the use of human subjects is that 5cc of blood from human subjects naturally infected with malaria will be used to infect the mosquitoes by an indirect feeding method that involves a membrane feeding device. There will be no contact of human subjects with the mosquitoes. The blood-fed mosquitoes are the primary focus of this study, not human subjects. DNA extracted from mosquitoes that fed on the blood of human study subjects will be analyzed genetically by microsatellites and single-nucleotide polymorphisms (SNPs) to identify mosquito genes that control mosquito resistance to malaria parasites. The genetic analysis is of mosquito DNA, not DNA of the human subjects. At the time mosquitoes are analyzed, one week after the bloodmeal, there is no residual genetic, DNA, cellular, or any material of the human subject remaining within the mosquito, and thus no genetic or other information can derive from the human source, even accidentally. A secondary objective will be to identify naturally-occurring mechanisms of mosquito resistance to malaria infection in Burkina Faso. Mosquitoes that are not infected by malaria parasites do not transmit malaria. Research that identifies these genes for resistance may lead to a method for blocking the transmission of malaria. A total enrollment of 40 healthy volunteers, 5-10 years old, is planned at one site in Burkina Faso, West Africa. Malaria transmission occurs during the rainy season (June through October). There will be 2 experimental cycles per month from June through October (10 cycles per year). There will be two such groups of 20, for a total study size of 40. Each group of 20 will be screened for malaria in an alternating pattern, so each group of 20 is screened no more frequently than once per month during the malaria transmission season, for a total study duration of 5 years. One human subject with mature malaria gametocytes (the transmission stage infective to mosquitoes) will be identified the day before the projected experimental infection of mosquitoes. Blood (5 cc) will be drawn from the subject, which will occur no more frequently than once per month. Twenty subjects are screened for malaria parasites (by standard diagnosis) to insure finding at least one positive donor per cycle. The 5cc of blood is used to feed and infect mosquitoes, which are the subject of this study. Subject participation is approximately 5 months per year, for the total study duration of 5 years. A target sample size of 200 mosquitoes with a set of 150 markers will be analyzed in this study. A successful outcome of this study is genetic identification of mosquito genes controlling resistance and susceptibility to P. falciparum infection of the mosquitoes.
Time Perspective: Prospective
Centre National de Recherche et de Formation sur le Paludisme
National Institute of Allergy and Infectious Diseases (NIAID)
Published on BioPortfolio: 2014-08-27T03:38:50-0400
The purpose of this pilot study is to evaluate the use of (1) 'malaria prevalence', (2) 'malaria incidence' and (3) 'malaria mortality' as a measure of malaria transmission in The Gambia, ...
We wish to understand how resistance to malaria develops and how this affects the growth rate of malaria in individuals who have past exposure to malaria.
Purpose of the study is to determine whether LSA-1/AS02A combination malaria vaccine is effective at preventing malaria.
The goal of this study is to develop a safe, well tolerated, and highly efficacious azithromycin combination treatment for uncomplicated falciparum malaria. Azithromycin is a drug that has...
The purpose of the study is to determine whether LSA-1/AS01B combination malaria vaccine is effective at preventing malaria.
Sick neonates in malaria endemic areas are frequently transfused with donor blood unscreened for malaria parasite. Consequently, they are at risk of transfusional malaria which can lead to increased n...
Rapid and precise diagnosis of malaria is an essential element in effective case management and control of malaria. Malaria microscopy is used as the gold standard for malaria diagnosis, however resul...
Insecticide-treated nets (ITNs) reduce malaria morbidity and mortality in endemic areas. Despite increasing availability, the use of ITNs remains limited in some settings. Poor malaria knowledge is a ...
Although consensus exists that malaria in pregnancy (MiP) increases the risk of malaria in infancy, and eventually nonmalarial fevers (NMFs), there is a lack of conclusive evidence of benefits of MiP ...
Although the malaria burden in the Lao PDR has gradually decreased, the elimination of malaria by 2030 presents many challenges. Microscopy and malaria rapid diagnostic tests (RDTs) are used to diagno...
Malaria caused by PLASMODIUM VIVAX. This form of malaria is less severe than MALARIA, FALCIPARUM, but there is a higher probability for relapses to occur. Febrile paroxysms often occur every other day.
Vaccines made from antigens arising from any of the four strains of Plasmodium which cause malaria in humans, or from P. berghei which causes malaria in rodents.
A protozoan parasite that causes vivax malaria (MALARIA, VIVAX). This species is found almost everywhere malaria is endemic and is the only one that has a range extending into the temperate regions.
Malaria caused by PLASMODIUM FALCIPARUM. This is the severest form of malaria and is associated with the highest levels of parasites in the blood. This disease is characterized by irregularly recurring febrile paroxysms that in extreme cases occur with acute cerebral, renal, or gastrointestinal manifestations.
A protozoan parasite that occurs naturally in the macaque. It is similar to PLASMODIUM VIVAX and produces a type of malaria similar to vivax malaria (MALARIA, VIVAX). This species has been found to give rise to both natural and experimental human infections.
Antiretroviral Therapy Clostridium Difficile Ebola HIV & AIDS Infectious Diseases Influenza Malaria Measles Sepsis Swine Flu Tropical Medicine Tuberculosis Infectious diseases are caused by pathogenic...
Pediatrics is the general medicine of childhood. Because of the developmental processes (psychological and physical) of childhood, the involvement of parents, and the social management of conditions at home and at school, pediatrics is a specialty. With ...