Human onchocerciasis is an infection caused by the filarial nematode Onchocerca volvulus transmitted by Simulium blackflies. The disease is endemic in sub-Saharan African countries, the Arabian peninsula, and small parts of Latin America. Persons with onchocerciasis may develop skin diseases such as pruritus, lichenification, and depigmentation, as well as ocular manifestations. Onchocerca volvulus contain Wolbachia bacteria as mutualistic symbionts, and these Wolbachia affects the nematode survival.
