Where the River Bites Back: A Heat Map of Blackfly and River Blindness Hotspots in Nigeria

This educational public health article presents a schematic heat map of river blindness (onchocerciasis) hotspots in Nigeria, highlighting areas where blackfly breeding and infection persist despite decades of community ivermectin treatment. Drawing on WHO/ESPEN (2025) and Babalola et al. (2026), it identifies remaining high-concern clusters in Enugu-Ebonyi, Abia-Cross River, Osun, Oyo-Ogun, and Taraba, and notes that risk follows rivers rather than state boundaries. The piece also summarizes the 2024 stop-treatment decisions in four southeastern states and the subsequent return of infection in parts of Enugu, emphasizing that surveillance matters as much as treatment. The heat map is schematic and shows relative concern, not case counts. This article is for education only and is not medical advice.