Streptocerciasis is form of human filariasis caused by the nematode Mansonella streptocerca transmitted by Culicoides biting midges. The disease is endemic in countries along the Central and West African coast from Ghana to Zaire.

Mansonella streptocerca infection occurs when a midge takes a blood meal from a human, which allows the transfer of filarial larvae to the bite wound. The filarial larvae develop into adults in the skin, where they produce microfilariae. When a midge takes a blood meal from an infected host, the microfilariae are ingested and develop into larvae in the midge's gastrointestinal tract.

Infection by M streptocerca is usually asymptomatic. Patients may develop pruritus, especially over the thorax and shoulders. Cutaneous signs include hypopigmented macules, excoriations, and lichenification. Patients may also develop axillary or inguinal lymphadenopathy. This disease is slightly more prevalent in males after age 39. Individuals younger than 24 years are seldom affected.

Related topics: Mansonella ozzardi infection, Mansonella perstans infection