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 [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 Formula: incidence = 1,000*cases/(total_population*0.42*0.70*hospital_access*1.5).