EVALUATION OF ALTERNATE METHODS OF RAPID ASSESSMENT OF ENDEMICITY OF ONCHOCERCA-VOLVULUS IN COMMUNITIES IN SOUTHERN CAMEROON

Potential diagnostic indicators of onchocerciasis (subcutaneous nodule s, depigmentation or leopard skin, microfilaruria, diethylcarbamazine patch test positivity, excoriations, and pruritus) were evaluated in a rain forest region of southern Cameroon for usefulness in rapid asses sment of onchocerciasis endemicity in communities. Thirty-two study vi llages were selected, representing high, intermediate, and low prevale nce levels, and 846 adult male residents of these communities 20 or mo re years of age were examined according to a defined protocol. Skin sn ips (from each iliac crest) served as the reference standard. Skin sni p positivity was 75.5%; the effect of age was minimal. Leopard skin an d nodules showed the strongest correlation with both the skin snip pre valence and community microfilarial load, as reflected by the adult ma le study population. We selected greater than or equal to 20% nodules or greater than or equal to 20% leopard skin as the most appropriate l ocal criteria for assigning a community to high priority for control, which corresponds to a greater than or equal to 90% skin snip prevalen ce in adult males. While this criteria should not be applied to region s with savannah onchocerciasis, we believe the methodology can and sho uld be used to determine appropriate diagnostic indicators for rapid a ssessment of Onchocerca volvulus endemicity in regions with different dynamics of transmission and clinical expression of disease.