River blindness

Onchocerciasis (River Blindness) is endemic in over 25 nations in Africa. Small endemic foci are also present in the Arabian peninsula, (Yemen and Saudia Arabia) and in Latin America (Southern Mexico, Guatemala, Colombia, Venezuela, Ecuador, Brazil).

The disease is a parasitic worm infestation transmitted by the bite of the black fly that bites by day and is found near rapidly flowing rivers and streams.

Symptoms include dermatitis, itchy rash, subcutaneous nodules, lymphadenitis, and eye lesions which can cause visual impairment, including blindness.

Short-term travelers to onchocerciasis-endemic regions, such as most tourists, appear to be at low risk for this condition. However, temporary residents and others who visit endemic regions for 3 months or more and live or work near black fly habitats are at increased risk for infection. Infections tend to occur in expatriate groups such as missionaries and their families, field scientists, and Peace Corps volunteers. Most reported cases have been acquired in Sierra Leone, Liberia, Zaire, and Cameroon.

No vaccine is available, nor is there effective chemoprophylaxis. Protective measures include avoidance of black fly habitats and the use of personal protection measures against biting insects such as those for malaria.

Diseases