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.