Epidemiological evaluation of onchocerciasis along Ogun River System, southwest Nigeria

Background & objective: Epidemiological studies were carried out to assess the prevalence and communitymicrofilarial load (CMFL) of onchocerciasis after repeated annual treatment with ivermectin along Ogun riverSystem, southwest Nigeria.Method: Skin snips were taken from consented participants in 11 selected communities along the River system.The microfilarial load of the community was estimated.Results: The prevalence and CMFL varied significantly in the communities (p <0.05). The prevalence ofonchocerciasis ranged from 19.1 to 45.6%, while the CMFL ranged from 0.11 to 1.03 microfilariae per skinsnip. The CMFL recorded was <5 microfilariae per skin snip, i.e. recognized by WHO as threshold value incertifying the communities to be free of onchocerciasis as public health problem, thus, signifying the possibilityof onchocerciasis elimination in the study area.Conclusion: Efforts should therefore be intensified to achieve improved ivermectin coverage and compliance inannual ivermectin treatment in order to completely eliminate onchocerciasis as a public health problem in thestudied communities.