Monkeypox virus in relation to the ecological features surrounding human settlements in Bumba zone, Zaire

Since monkeypox virus was discovered in animals in 1958 and in man in 1971, several efforts have been made to identify the reservoir of the virus in nature. In July 1985 a study on human environments and animals suspected to maintain virus transmission was carried out in northern Zaire. The study revealed three well demarcated areas: the human settlement area, the agricultural area and the primary tropical rain forest. The first two were found inhabited by terrestrial and arboreal rodents and bats, while the larger animals have abandoned them. Data on human morbidity collected in the preceding years suggested that most of the patients were infected either in the settlement or in the agricultural area. Isolation of the virus from a squirrel confirmed this suggestion and proved, on the other hand, that the virus could circulate in an area deprived of the larger wild animals, including primates. The virus isolation and results of serologic testing suggest that out of three groups of animals inhabiting the agricultural area, the squirrels Funisciurus anerythrus should be considered a priority candidate to sustain virus transmission.