Onchocerciasis is a major parasitic disease transmitted through the bite of the small blackfly that breeds along the banks of fast-flowing rivers. Humans acquire the disease during their regular trips to infested rivers for their routine daily activities such as farming, hunting, fishing and fetching water. The microscopic infective larvae, transmitted to humans, mature under the skin into adult worms forming visible nodules throughout the body. Pairs of mature worms produce and release into the body millions of microfilariae during their entire 10-15 year life span. The disease is characterized initially by a rash, severe itching, thickening and depigmentation of the skin, followed by visual impairment and eventually blindness. The microfilariae and not the adult worms are primarily responsible for causing the disease. The disease is endemic in 30 African countries, 6 Latin American countries and Yemen. In addition to the serious health consequences, the economic and social consequences of onchocerciasis are devastating.
With current population in the DRC estimated at 60 million people, approximately 21 million are at risk, 13 million are actually infected and about 70,000 are blind from onchocerciasis. The infection rates in endemic areas range from 20% to over 90%. In 1998, a team from the World Health Organization (WHO) was taken by a small plane to Ebango bango, a remote village in DRC in which over 90% of the inhabitants were blind from this terrible disease.