Extending the reach of Seasonal Malaria Chemoprevention in Sub-Saharan Africa: A microplanning model to improve door-to-door health service delivery

Background Malaria incidence has plateaued in Sub-Saharan Africa despite Seasonal Malaria chemoprevention introduction. Community health workers use a door-to-door delivery strategy to treat children with SMC drugs, but for SMC to be as effective as in clinical trials, coverage must be high over successive seasons. Methods We used a microplanning model that utilizes raster to estimate population size, generates optimal households visit itinerary, and quantifies SMC coverage based on CHWs time investment. CHWs performance under current SMC deployment mode was assessed and compared to microplanning. Results Estimates showed that microplanning significantly reduces CHWs walking distance by 25%, increases visited households by 36% (p < 0.001) and increases SMC coverage by 21% (37.3% under current SMC deployment mode up to 58.3% under microplanning, p < 0.001). Optimal visit itinerary alone increased SMC coverage up to 100% in small villages whereas in larger or hard-to-reach villages, filling the gap additionally needed an optimization of the CHW ratio. Conclusion We estimate that for a pair of CHWs, the daily optimal number of visited children and walking distance should not exceed 45 and 5km respectively. Our work contributes to extend SMC coverage by 21-63% and may have broader applicability for other community health programs.