Comorbidities of onchocerciasis and non-communicable diseases, and determinants of continued transmission in Bafut Health District, Cameroon

Background: Despite decades of mass Ivermectin distribution, onchocerciasis transmission in Cameroon still persists. Comorbidities with non-communicable diseases (NCDs) and gaps in treatment uptake may contribute to sustained transmission. This study assessed the prevalence of onchocerciasis, its comorbidity with selected NCDs, and determinants of continued transmission in Bafut Health District, Cameroon. Methods: A hospital-based cross-sectional study was conducted from June to July 2024 among 282 adults aged ≥30 years residing in Bafut for ≥5 years. Data on sociodemographics, NCD history, onchocerciasis knowledge, and ivermectin uptake were collected using a structured questionnaire. Laboratory investigations included skin snip microscopy, nodule palpation, blood pressure measurement, and venous blood tests for diabetes and rheumatoid arthritis. The relationship between categorical variables was analysed using the chi-square test and logistic regression at a significance level of 5%. Results: The overall prevalence of onchocerciasis was 21.3%. Females (aOR = 6.58, 95% CI: 2.30–18.87, p < 0.001), age ≥60 years (aOR = 4.30, 95% CI: 1.42–13.02, p = 0.01), and lack of formal education (aOR = 4.58, 95% CI: 1.24–16.91, p = 0.02) were significantly associated with infection. The prevalence of NCDs was 8.5% in the population but 40.0% among onchocerciasis patients, with hypertension (25.0%) and rheumatoid arthritis (21.7%) most common. Refusal of ivermectin, mainly due to side effects, was significantly associated with infection (p = 0.01). Nearly half of the participants (48.9%) demonstrated poor knowledge of onchocerciasis. Conclusion: Onchocerciasis remains endemic in Bafut, with continuous transmission driven by female sex, older age, low education, NCD comorbidities, poor knowledge, and ivermectin refusal. Integrated NCD management, health education, and improved ivermectin compliance are critical to interrupt transmission.