Knowledge and Practices of Four Onchocerciasis-Endemic Communities in Cameroon

In onchocerciasis-endemic communities, black fly vectors of Onchocerca volvulus cause annoyance. No vector control was performed in Cameroon to complement ivermectin treatment despite high fly densities in the savannah and forest areas. This study assessed the knowledge and practices of four onchocerciasis-endemic communities in Sudan and the Guinea savannah in Cameroon. We surveyed four communities using a structured questionnaire. We interviewed 452 individuals (Mawong: 136, Befang: 160, Soramboum: 88, and Galim: 68) aged 14-50 years. Most respondents (90%) knew about black flies being a nuisance but had misconceptions about their bite's effect, location, and season. Only 9.3% knew that black fly bites could lead to blindness, whereas 34.1% correctly regarded evenings as the biting period. In Savannah, Sudan, 30.9% of the interviewees stated that black flies bite both outdoors and indoors, and 37.0% of the enrolees believed that black flies bite any exposed body part. In the Guinea savannah, 61.1% of respondents agreed that black flies typically bite during the dry season. Proper clothing can protect against black fly bites, but the transmission mode and vector biology are poorly understood. Implementing community-based vector surveillance can help fight onchocerciasis and reduce black fly nuisance.