Onchocerciasis is a research focus of the Coalition for Operational Research on Neglected Tropical Diseases (COR-NTD). According to the U.S. Centers for Disease Control and Prevention (CDC):
"Onchocerciasis, or river blindness, is a neglected tropical disease (NTD) caused by the parasitic worm Onchocerca volvulus. It is transmitted through repeated bites by blackflies of the genus Simulium. The disease is called river blindness because the blackfly that transmits the infection lives and breeds near fast-flowing streams and rivers, mostly near remote rural villages. The infection can result in visual impairment and sometimes blindness. Additionally, onchocerciasis can cause skin disease, including intense itching, rashes, or nodules under the skin. Worldwide onchocerciasis is second only to trachoma as an infectious cause of blindness."