Onchocerciasis (River Blindness)
Travel Health

From: Travel Health Information and Advice

Onchocerciasis (River Blindness)
Onchocerciasis is a parasitic infection caused by the roundworm Onchocerca volvulus with infection causing blindness.

Cause of Onchocerciasis
Infection is caused when a black fly takes a blood meal on an infected human and ingests minute larvae of the roundworm.

These larvae develop within the fly and are then released back into the bloodstream during another blood meal on a human.

Once inside the larvae migrate and further mature within the subcutaneous tissue layer of the skin and when they are adults they mate and produce minute larvae which are subsequently ingested by a black fly during a blood meal which starts the process of infection again.

Symptoms of Onchocerciasis
Symptoms often appear around one year after being initially bitten by an infected black fly and can include:

Preventing Onchocerciasis
Prevention is best achieved through avoiding being bitten by the black fly, such as by wearing insect repellent and covering over exposed skin, especially when close to rivers and water sources in endemic countries.

Diagnosis of Onchocerciasis
Diagnosis of Onchocerciasis is achieved through blood tests and/or skin biopsy.

Treatment for Onchocerciasis
Treatment often involves the use of the drug Ivermectin.

Most At Risk
Anyone in endemic areas.

Affected Areas
Sub Saharan Africa is a particularly affected area.