Chibuzo Odigwe explains the history and current treatment strategies for a disease that has been a large scale problem in Africa since recorded history began
- By: Chibuzo Odigwe
From the beginnings of recorded history, onchocerciasis has been a problem in Africa, as folklore and orally preserved tradition indicate. But it has also been described on the Arabian Peninsula and the Americas. An estimated 18-40 million people are currently affected worldwide, with about 270 000 people having lost their sight as a result. About 99% of the people living with onchocerciasis are in Africa with about half of this population in Nigeria alone.
Onchocerciasis is caused by Onchocerca volvulus, a nematode of the family Filariiadae, whose vector is the blackfly, Simulium damnosum. Because the black fly prefers to lay its eggs in fast flowing rivers, onchocerciasis is endemic in these areas--giving rise to its more familiar name of river blindness.
The early skin related signs include mild pruritus, which may later be followed rash, erosion, and lichenification. Adult worms also lodge in nodules under the skin and releasing large