Repeated surveys on Onchocerca volvulus infestation in villages Bouzalo, Kemeni and Sagbadai.

The prevalence of O. volvulus microfilariae (mf) in skin biopsies in study populations was determined from before mass drug administration (MDA) of ivermectin and several years with the annually repeated MDA. The mass drug administration (MDA) with ivermectin began in 1988 and continued after Onchocerciasis Control Program (OCP) closure in 2002. In the post-OCP period in the Mô river basin special interventions continued with aerial larvicide application for five additional years (2003–2007) and MDA with ivermectin implemented twice annually. The surveyed years, number of examnied participants and the prevalence of O.volvulus mf in skin biopsies are shown.