Characteristics of the villages.

aper km2. bPopulation according to the national census 2004 [21]. cProportion of people in each village who reported to visit the Agogo hospital, data from Community Survey. dPopulation of children <15 years of age estimated as a proportion of 42% of the population counted at national census 2004 [22] and an additional proportion of 70% due to inclusion into the study at hospital admittance and by taking into account hospital access. eStudy period from May 2007 to November 2008 (18 months). fIncidence in children <15 years (per year and 1,000 children <15 years). Formula: incidence = 1,000*cases/(total_population*0.42*0.70*hospital_access*1.5).