Onchocerciasis, also known as river blindness and Robles disease, is caused by infection with the parasitic worm Onchocerca volvulus. Symptoms include severe itching, bumps under the skin, and blindness.
The parasite worm is spread by the bites of a black fly of the Simulium type. Usually many bites are required before infection occurs. These flies live near rivers therefore the name of the disease. Once inside a person the worms create larva that make their way out to the skin.
“The control of onchocerciasis, or river blindness, in West Africa has been hailed worldwide as a public health and economic development success. The World Health Organization (WHO) and the World Bank estimate that because of The Onchocerciasis Control Programme (OCP) in West Africa 40 million people have been protected from river blindness and an estimated 600,000 cases of blindness have been prevented in the 11 participating countries, 25 million hectares of arable land in previously infected river valleys have been open to resettlement and cultivation, and food resources for an estimated 17 million people are now being produced.
OCP achieved its success by controlling the vector of this disease, a Simulium black fly that transmits the disease-causing filarial worm, through application of insecticides to vast stretches of rivers (>50,000km at the peak of control activities) spread over large geographical areas (1,235,000 km2). Applications were frequent (near-weekly during 10-12 months each year) and, in some cases, lasted for 20 years.”
Authors: Resh, V. H., et al.
Affiliation: Department of Environmental Science, University of California, Berkeley.
Title: Long-Term, Large-Scale Biomonitoring of the Unknown: Assessing the Effects of Insecticides to Control River Blindness (Onchocerciasis) in West Africa.
Source: Annu. Rev. Entomol. 2004. 49:115-139.