Associations Between Drug Levels and the Risk of Malaria and Drug Resistance in the Setting of Seasonal Malaria Chemoprevention in Bobo-Dioulasso, Burkina Faso

In areas of the Sahel sub-region of Africa with intense seasonal malaria transmission, seasonal malaria chemoprevention (SMC) with sulfadoxine-pyrimethamine and amodiaquine (SP+AQ) has become the standard-of-care for the prevention of malaria in children. Despite the scale-up of SMC across West Africa, the malaria burden remains high. Reasons for this are not well understood, however, it is hypothesized that children eligible for SMC who get malaria may be underdosed or may have not received SP+AQ. Moreover, there are major concerns that the continued use of the SMC strategy may increase selection of AQ and/or SP-resistant Plasmodium falciparum parasites. The overall objective of this observational study are to understand the factors driving malaria among children eligible to receive SMC and whether circulating levels of sulfadoxine (SDX), pyrimethamine (PYR), and AQ are associated with risks of malaria and antimalarial drug resistance. The specific objectives of this study are as follows:

1. To determine associations between the levels of exposure to the components of SP+AQ (SDX, PYR, and AQ) and malaria risk.
2. To determine associations between levels of exposure to the components of SP+AQ and the prevalence of P. falciparum genetic polymorphisms associated with drug resistance.
3. To compare the prevalence of genetic polymorphisms associated with SP+AQ resistance between parasites infecting children eligible to receive SMC and those infecting older children ineligible to receive SMC.
4. To assess whether the prevalence of genetic polymorphisms associated with SP+AQ resistance changes over time.