Onchocercidae

Onchocercidae is a family of nematodes (roundworms) that includes several important parasites of humans and animals. The most well-known species in this family is Onchocerca volvulus, the causative agent of onchocerciasis, also known as river blindness.

Taxonomy

The family Onchocercidae belongs to the order Spirurida, a large group of parasitic nematodes. Other notable families in this order include the Filariidae, which contains the agents of lymphatic filariasis and elephantiasis.

Life Cycle

The life cycle of Onchocercidae involves two hosts: a definitive host, where the adult worms live and reproduce, and an intermediate host, usually a species of black fly or mosquito, in which the larvae develop. The adult worms live in nodules under the skin or in the eyes of the definitive host. The female worms produce microfilariae, which are released into the host's bloodstream. When a blood-feeding intermediate host takes a blood meal from the infected definitive host, it ingests the microfilariae, which then develop into infective larvae within the intermediate host. These larvae are transmitted to a new definitive host when the intermediate host takes another blood meal.

Diseases

Species in the Onchocercidae family cause several diseases in humans and animals. The most significant of these is onchocerciasis, caused by Onchocerca volvulus. This disease is a major cause of blindness and skin disease in many parts of Africa, Latin America, and Yemen. Other species in the family cause diseases in animals, including heartworm in dogs and river blindness in horses.

Prevention and Control

Control of Onchocercidae diseases involves a combination of strategies, including vector control, mass drug administration, and surveillance. The drug ivermectin is commonly used to treat onchocerciasis and other diseases caused by Onchocercidae.