Feasibility and effectiveness of tailored interventions for two populations at high-risk of malaria in Senegal: Koranic school children and gold miners

Senegal has made significant progress in reducing the malaria burden over the last decade. However, malaria remains a major cause of morbidity in some regions and key challenges exist among high-risk populations who have high exposure to mosquitos, but low coverage and use of vector control measures and limited access to healthcare. Two identified high-risk populations are goldminers and talibés (Koranic school students). We conducted a controlled pre/post survey to measure the impact of targeted malaria interventions, including expansion of active community case management and distribution of LLINs, on reported LLIN usage and Plasmodium falciparum infection prevalence at mining sites and Koranic schools (daaras) during the high transmission season in Senegal. We randomly assigned four health facility catchment areas in Kaolack (a city with many daaras) and four in Saraya (a district with gold mining sites) to intervention or control groups. Surveys were conducted pre (Oct 2021; n = 1740 talibés and gold miners) and post (Feb 2022; n = 2200) delivery of the intervention package to assess intervention coverage and infection prevalence by rapid diagnostic test and qPCR. We compared infection prevalence and self-reported LLIN usage, by group and arm, between the two time periods using a difference in difference framework with binomial generalized linear mixed models. Among the talibés, the package of interventions was associated with an adjusted 12.6-percentage point relative reduction in RDT-derived malaria prevalence (p < 0.05, adjusted risk difference: -12.6, 95% CI: -2.7, -22.4) and an adjusted 44.0-percentage point increase in reported prior night net use (p < 0.001, aRD: 44.0, 95% CI: 36.3, 51.6) in the intervention group compared to the counterfactual. However, among the gold miners there was no measured association between the package of interventions and these outcomes. While there was high acceptability in both groups, interventions should be tailored to address high mobility amongst gold miners and maximize impact.