Onchocerciasis is commonly known as River Blindness. It is caused by a parasitic worm carried by a tiny black fly. These flies breed along fast-moving rivers. When the fly bites a human the larvae of a parasitic worm, Onchocerca volvulus, enters the human. These worms can grow to more than two feet in length in the body. This results in nodules in the skin. When the adult worms reproduce, they release millions of microscopic offspring known as microfilariae. The microfilariae cause the real harm. As they move through body tissue they cause terrible itching of the skin. After several years, the microfilariae can cause depigmentation of the skin. Eventually they invade the eyes, often causing blindness.
In attempts to escape the flies, villages would abandon fertile areas near rivers, and would be forced to move to poorer soil. This contributed to food shortages and more hardships for these villages. (Donaldson 216)
The World Health Organization (WHO) describes Onchocerciasis as a serious health and socioeconomic problem. In 1978, 85 million people throughout Africa, the Middle East, and Latin America were affected. Also, 340,000 people were blind and about a million suffered from some visual impairment. The majority of those that were blind were over the age of 45. It still remains the second leading infectious cause of blindness.
The World Health Organization, Division of Control of Tropical Diseases has collected the following facts about Onchocerciasis:
Infection:
Disease:
Risk Factors:
