Reduced prevalence of onchocerciasis in Uganda following either deforestation or vector control with DDT
Fischer, P.; Garms, R.; Buttner, D.W.; Kipp, W.; Bamuhiiga, J.; Yocha, J.
East African Medical Journal 74(5): 321-325
1997
ISSN/ISBN: 0012-835X PMID: 9337013 Document Number: 479238
To determine the prevalence of onchocerciasis in western Uganda following deforestation and vector control, three foci were re-examined 20 years after previous surveys. In the Ruteete focus Simulium neavei had apparently disappeared and the prevalence of onchocerciasis declined in adults from about 70% in 1971 to a standardized prevalence of 12% in 1992. An increase of population density together with extended deforestation was assumed as cause of this strong reduction. In Bugoye, a S. damnosum s.l. focus, the standardized prevalence of microfilaria carriers declined from 62% in 1972 to 4.7% in 1992. Entomological data indicated the absence of man biting blackflies in the nineties. It can be suggested that the vector control using DDT performed during the seventies had lead to a change of the species composition from anthropophilic to non-anthropophilic S. damnosum s.l. In the focus Kicheche environmental changes were insignificant, deforestation was not progressive and S. neavei was abundant. Here the standardized prevalence of microfilaria carriers was still high (61%).