Children ≥ 6 months to < 10 years of age will be enrolled in a single cohort across 60 clusters (30 clusters per treatment arm). The cohort will be followed for 6 months for baseline covariate measurements and 24 months with intervention. Blood samples will be taken once every 4 weeks from all cohort subjects to test for malaria infection and whenever a subject reports a recent history of fever (within previous 48 hours). During follow up of enrolled subjects, study clinicians will have the option to conduct a Hb test for enrolled subjects when they may present signs of anemia to see if they might need additional treatment beyond malaria ACTs (if malaria infection is indicated). Rapid Diagnostic Tests (RDTs) will be used for point-of-care diagnosis of malaria infection with microscopy used to confirm infection status. All positive malaria infections as indicated by either RDT or microscopy, clinical and asymptomatic, will be treated. If a subject has a RDT negative outcome but a positive microscopy diagnosis, follow up treatment for the malaria infection will be provided to the subject within 72hrs of the microscopy read. Cohort subjects who test positive for malaria by either RDT or microscopy, symptomatic or asymptomatic, during both scheduled and unscheduled visits will be treated with ACTs. The incidence of malaria infection will be measured by microscopy and estimated and compared between treatment arms to determine the benefit of using an SR in an area with high, seasonal transmission of malaria.~Entomological endpoints of exposure risk to mosquitoes will also be measured to identify entomological correlates of SR efficacy that may be useful for the evaluation of new SR products. Twenty clusters (10 SR, 10 placebo) will be randomly selected to estimate the impact of the SR on entomological measures of malaria transmission. Within each cluster, light trap collections will be conducted monthly in 10 randomly selected households to assess the impact of SRs on the density of Anopheles mosquitoes indoors. Human landing catches will be done indoors and outdoors in 6 intervention and 6 control clusters (the 12 clusters will remain fixed throughout the study) in four houses (randomly selected) in each cluster for the period of 2 nights (total of 48 houses across both arms) once every quarter (3 months) to determine the effect of SR on the host seeking behavior of mosquitoes.~The SR will be a new formulation of transfluthrin. This active ingredient (AI) is widely used in mosquito coils and other household pest control products. The new formulation is a passive emanator that will release the AI over a period of up to four weeks. The emanator will consist of a pre-treated piece of cellulose acetate, which will be positioned within consenting households according to manufacturer specifications. The SRs and placebos for this study will be designed and manufactured by S.C. Johnson, Inc. USA.
The primary objective of the study is to demonstrate and quantify the protective efficacy of a single Spatial Repellent (SR) product, in reducing malaria infection in a human cohort. The study design will be a prospective cluster Randomized Control Trial (cRCT).