Validation of reports of nodules dissolution after repeated ivermectin treatment of onchocerciasis in southeastern Nigeria.

OBJECTIVE: To ascertain the validity of the claims by villagers in endemic communities in southeastern Nigeria that repeated ivermectin treatment cause disappearance or dissolution of onchocercal nodules. DESIGN: From baseline epidemiological data, four communities (Amuro, Aku, Nzerem Ikpem and Awuchinimo) were randomly chosen as the study sites. A total of 324 adults (hitherto had onchocercal nodules), aged > or = 20 years from these communities were enlisted in the study. After clinical examination, each of the villager was interviewed with structured, pre-tested questionnaire. Also personal and focus group discussion was held. RESULTS: Sixty nine (21.30%) respondents; 16.67% from Amuro, 32.26% from Aku, 19.05% from Nzerem Ikpem and 15% from Awuchnimo claimed that their nodules gradually dissolved or disappeared. A significant (p < 0.05) proportion (82.61%) attributed this phenomenon to repeated doses of ivermectin; 4.35% claimed it was not due to ivermectin therapy while 13.04% were not sure of the cause. CONCLUSION: The results have opened challenges in our understanding of the role of ivermectin therapy in endemic communities and calls for further studies of nodule dissolution in other onchocerciasis endemic communities.