Seasonal
malaria chemoprevention, previously known as intermittent preventive treatment in children, is highly effective in areas with a short
malaria transmission season. Here we assess seasonality in
malaria incidence data and define a predictor of seasonality based on rainfall. We then use spatial rainfall,
malaria endemicity and population data to identify areas likely to have highly seasonal
malaria incidence, and estimate the population at risk and
malaria burden in areas where seasonal
malaria chemoprevention would be appropriate. We estimate that in areas suitable for seasonal
malaria chemoprevention, there are 39 million children under 5 years of age, who experience 33.7 million
malaria episodes and 152,000 childhood deaths from
malaria each year. The majority of this burden occurs in the Sahelian or sub-Sahelian regions of Africa. Our data suggest that seasonal
malaria chemoprevention has the potential to avert several million
malaria cases and
tens of thousands of childhood deaths each year if successfully delivered to the populations at risk.