Malaria in a peri-urban area of The Gambia

A clinical and entomological survey of malaria was carried out in Bakau, a peri-urban coastal settlement in The Gambia, from June 1988-May 1989. Only 41 of a cohort of 560 children, aged from three months to nine-years-old, experienced a clinical episode of malaria during the observation period. The majority of cases were identified at clinics and not by regular community surveillance. In Bakau Old Town episodes of malaria were more common on the periphery of the settlement, adjacent to typical anopheline breeding sites, than in the centre. Overall malaria cases were not significantly clustered in space and time, although three pairs of cases among children sleeping in the same room at the same time were identified. A cross-sectional survey in November, at the end of the rainy season, revealed a point prevalence parasitaemia of 2.0% and a spleen rate of 0.3%. All malariometric parameters measured were much lower than any found in comparable studies undertaken in rural areas of the country, reflecting the low number of malaria vectors, Anopheles gambiae complex mosquitoes, found in Bakau. Chloroquine consumption, sleeping under bednets, houses with ceilings, the use of insecticide aerosols and burning traditional mosquito repellents may all have contributed to the low prevalence of malaria in the study area.