Study Population

This study was conducted in the health districts of Kolda and Sedhiou in the south of Senegal (Electronic Supplementary Fig. S1) during the SMC campaign of 2015 (August, September, and October). The population is primarily rural. In 2016, the under-5 mortality rate was estimated to be 100 per 1000 children, and the literacy rate was 55% in men and 41% in women [7].

Malaria is a major cause of severe illness in children. Community case management for malaria is provided in the more remote villages by a community health worker (Distributeur de Soins à Domicile [DSDOM]) working from their home or at a case de santé (health hut). SMC targeted children aged 3 months to 10 years and is delivered door-to-door by the DSDOM and (in villages that do not have a resident health worker) by relais communautaires (community volunteers). In this report, DSDOM and relais communautaires are collectively referred to as community health workers (CHWs). SMC delivery is coordinated by the health post from where CHWs collect drugs each day, with SMC distribution following general WHO recommendations [8]. One dose of SP and the first dose of AQ were administered by the CHW on the first day, and the remaining two doses of AQ were left with the caregiver to administer over the next days. Children who are unwell are referred without treatment, however they may then receive SMC at the health post. CHWs are trained to exclude children with a history of allergy to SMC drugs and any child who had received SP, AQ, or a sulfa-containing antibiotic in the previous month. Treatments administered are recorded on tally sheets that are collated to give monthly totals.