Black Flies and Onchocerciasis Transmission: Knowledge, Attitude and Practices among Inhabitants of Mahenge, South-Eastern Tanzania

Abstract

Background: Onchocerciasis remains a significant public health concern in endemic regions of sub-Saharan Africa. Community knowledge, attitudes, and practices (KAP) regarding the bioecology of black flies (Simulium spp.) are critical determinants of disease burden and the success of control programmes. Aim: This study assessed KAP among inhabitants of Mahenge, south-eastern Tanzania. Methods: A cross-sectional KAP survey was conducted among 114 community members in the Mahenge area. Data on knowledge of blackfly bioecology and onchocerciasis, attitudes towards ivermectin and control interventions, and preventive practices were collected using a structured questionnaire. Knowledge was scored (0–14) and categorised. Descriptive statistics, Mann–Whitney U tests, Kruskal–Wallis tests, Spearman's rank correlations, and logistic regression were employed. Results: Most participants were female (67.9%), farmers (89.2%), and had primary-level education (67.6%). The majority (96.4%) had heard of onchocerciasis, although only 35.7% correctly identified blackfly bites as the cause of onchocerciasis. Knowledge of breeding sites was particularly poor (only 10.6% correct). Overall, 61.4% had moderate knowledge, 22.8% had good knowledge, and 15.8% had poor knowledge. Females had significantly higher knowledge scores than males (U = 966.5, p = 0.032). Consistent adherence to ivermectin was 75.4%. Trust in community distributors was the only significant independent predictor of adherence (OR = 3.90, 95% CI 1.36–11.17, p = 0.011). Conclusion: Although awareness of onchocerciasis is high, critical knowledge gaps remain regarding blackfly ecology and transmission. Targeted health education focusing on vector bioecology, combined with strengthened community distribution networks, is urgently needed.