Epidemiological evaluation of onchocerciasis along Ogun River System, southwest Nigeria.

BACKGROUND & OBJECTIVE Epidemiological studies were carried out to assess the prevalence and community microfilarial load (CMFL) of onchocerciasis after repeated annual treatment with ivermectin along Ogun river System, 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 of onchocerciasis ranged from 19.1 to 45.6%, while the CMFL ranged from 0.11 to 1.03 microfilariae per skin snip. The CMFL recorded was <5 microfilariae per skin snip, i.e. recognized by WHO as threshold value in certifying the communities to be free of onchocerciasis as public health problem, thus, signifying the possibility of onchocerciasis elimination in the study area. CONCLUSION Efforts should therefore be intensified to achieve improved ivermectin coverage and compliance in annual ivermectin treatment in order to completely eliminate onchocerciasis as a public health problem in the studied communities.