Malaria Transmission in Humans and Mosquitoes at the Area of Sabou, Burkina Faso

Overview

Background: Malaria is a disease that affects many people in Burkina Faso. It is caused by germs that are spread by mosquito bites. A vaccine that blocks the spread of malaria is important to get rid of the disease. To see if a vaccine works, researchers need to find out how many malaria infections are happening in the community. Objective: To learn how often people of all ages who live in Sabou, Burkina Faso, get malaria. Eligibility: Healthy people ages 6 months to 65 years who reside in Sabou in a household with adults and children. Design: Participants will be screened with questions about their health. They will have a physical exam. Participants will be asked about any malaria symptoms they are having. They will be asked about the use of bed nets. Their vital signs, like blood pressure and temperature, will be measured. They will have blood taken from their arm with a needle. Participants who have a fever will have a malaria test. Those who test positive for malaria will be referred to the local health facility for treatment. Participants will have monthly study visits. Blood will be taken from a finger. Participants may be invited to take part in 2 mosquito feeding experiments. Mosquitos that do not carry malaria will bite their arm. And a small amount of blood will be fed to mosquitos in a laboratory. Participants' homes will be examined for mosquitoes. Researchers will remove all mosquitoes they collect. Participants' homes will be sprayed with a chemical to kill mosquitoes and other insects. Participation will last for 12 months.

A vaccine that interrupts malaria transmission is critical to eradicate the disease, but improved assays are needed to measure the efficacy of vaccines. Transmission-blocking vaccines (TBVs) work by inducing antibodies in vaccines that inhibit parasite development in the mosquito interrupting transmission. Efficacy of vaccines may be estimated by in vitro membrane feeding assays using immune sera and laboratory mosquitoes, but qualified assays that measure transmission in the field are needed to assess transmission-blocking interventions in natura. Clinical trials of TBV have started elsewhere on the continent in Mali, and we expect to expand TBV studies here in Burkina Faso in the future. This protocol will use a longitudinal cohort to gather information on the rates of blood smear positive individuals by month, season and year at Sabou Health district area, Burkina Faso. Individuals in the villages will be approached first for participation, including permission to contact their household and neighbors of their compound for participation. Households will be identified using census data and individuals will be consented for participation. Malaria smears will be obtained at monthly visits, in conjunction with mosquito collections in/around village residences. Parasite rates in locally caught mosquitoes will be assessed longitudinally for differences by season and year. A total of 600 volunteers from Sabou area will be enrolled. Participants aged 0.5-65 years will have monthly blood sampling and mosquito collection at their household. Participants will be followed for up to 1 year, to collect data that will guide the design of future community-based trials of TBV.