The African Programme for Onchocerciasis Control: impact on onchocercal skin disease

OBJECTIVES To assess the long-term impact of the African Programme for Onchocerciasis Control on itching and onchocercal skin disease (OSD). METHODS Seven study sites in Cameroon, Sudan, Nigeria and Uganda participated. Two cross-sectional surveys were conducted of communities meso- and hyper-endemic for onchocerciasis before and after 5 or 6 years of community-directed treatment with ivermectin (CDTI). Individuals were asked about any general health symptoms including itching and underwent full cutaneous examinations. Onchocercal skin lesions were documented according to a standard classification. RESULTS Five thousand one hundred and ninety three people were examined in phase I and 5,180 people in phase II. The presence of onchocercal nodules was a strongly significant ( P < 0.001) risk factor for all forms of onchocercal skin disease: APOD (OR 1.66); CPOD (OR 2.84); LOD (OR 2.68); reactive skin lesions (OR 2.38) and depigmentation (OR 3.36). The effect of community-directed treatment with ivermectin was profound. At phase II, there were significant (P < 0 001) reductions in the odds of itching (OR 0.32), APOD (OR 0.28); CPOD (OR 0.34); reactive skin lesions (OR 0.33); depigmentation (OR 0.31) and nodules (OR 0.37). Reduction in the odds of LOD was also significant (OR 0.54, P < 0.03). CONCLUSIONS This first multi-country report of the long-term impact of CDTI reveals a substantial reduction in itching and OSD. APOC operations are having a major effect in improving skin health in poor rural populations in Africa.