Onchocerca is a genus of parasitic worms, commonly known as filarial worms. These worms are primarily transmitted to humans through the bites of infected blackflies, particularly those in the genus Simulium. Onchocerca species can cause various diseases, the most notable being river blindness or onchocerciasis, which can lead to severe vision impairment and skin problems. The life cycle of Onchocerca involves both human hosts and insect vectors. Once inside the human body, the larvae develop into adult worms, which can live for many years. The adult worms produce microfilariae, which migrate through the skin and can be picked up by blackflies, continuing the cycle of transmission.