Abstract
BACKGROUND: Preliminary assessments have identified blackfly biting activity at Erin-Ijesha and Arinta waterfalls in Southwest Nigeria, predisposing first-line communities to a high risk of onchocerciasis. There is a need to assess knowledge of blackflies, onchocerciasis, and participation in treatment programs among residents of first-line communities near the waterfalls to evaluate onchocerciasis transmission risk. METHODS: A cross-sectional survey was conducted among 236 residents at Erin-Ijesha and Ipole-Iloro, two first-line communities using structured questionnaires. Data were entered into Microsoft Excel and analyzed using the Statistical Package for the Social Sciences (SPSS) software version 21. Relationships between variables were analyzed using t-test and chi-square, with a 95% confidence interval. RESULTS: Majority (73.3%) in Erin-Ijesha and (83.7%) in Ipole-Iloro reported knowledge of blackflies, with 83.3% and 87.0% aware of onchocerciasis, respectively. The majority of participants had no knowledge of how onchocerciasis is transmitted, with only 8.7% and 10.5% in Erin-Ijesha and Ipole-Iloro, respectively, linking the disease to blackfly bites. Ivermectin uptake was relatively high at 75.7% and 76.7% in Erin-Ijesha and Ipole-Iloro, respectively. Willingness to participate in future treatment programs was lower, at 64.7% and 64.0% in Erin-Ijesha and Ipole-Iloro, respectively. Level of education significantly influenced willingness to participate in future mass distribution of ivermectin (p < 0.05). CONCLUSION: The limited understanding of blackfly bioecology and onchocerciasis among residents may lead to increased exposure to bites, thereby raising the risk of transmission. To address this, the federal and state ministries of health, along with treatment implementing partners, should enhance sensitization efforts and public health education during the annual Mass Drug Administration campaigns. Improving knowledge in these high-risk communities will encourage residents to take preventive measures against bites and improve treatment uptake, ultimately reducing the risk of disease transmission.