Onchocerciasis Prevalence in Communities Along the Gurara River, Niger State, North Central Nigeria

Onchocerciasis, or river blindness, caused by Onchocerca volvulus and transmitted by Simulium blackfly species, remains a leading cause of preventable visual impairment in communities near fast-flowing rivers in West Africa. This study surveys the prevalence of onchocerciasis in communities along the Gurara River in Niger State, North Central Nigeria. A cross-sectional descriptive design was employed, enrolling 280 adults from five riverine communities in Gurara Local Government Area. Skin snip biopsies were collected from the iliac crest of consenting participants and incubated in normal saline to detect emerging O. volvulus microfilariae under light microscopy. Clinical examination assessed subcutaneous nodule presence, skin lesions, and visual acuity in participants over the age of 40. Data on participation in annual ivermectin distribution campaigns were collected via structured interviews. Literature from 2020 to 2024 confirms persistent onchocerciasis transmission foci in central Nigeria despite two decades of community-directed treatment with ivermectin. This study generates updated prevalence data to assess programme progress and identify communities lagging behind elimination milestones. Findings will be submitted to the Niger State Ministry of Health and the Carter Center Nigeria Onchocerciasis Programme to guide targeted treatment and vector control operations. Keywords: onchocerciasis, Onchocerca volvulus, Gurara River, Niger State, ivermectin.