Onchocerciasis (redirected from Riverblindness)

river blindness

 or onchocerciasis

Human disease caused by a filarial worm native to Africa but also found in parts of tropical America and transmitted by several blackflies. It is so called because the flies that transmit the disease breed on rivers and mostly affect riverine populations. Blindness is caused by dead microfilariae—the larvae that can be produced for some 15–18 years by adult worms—inside the eye. River blindness is common in savannah areas of Africa and in Guatemala and Mexico. In 1987 the World Health Organization began to distribute the drug ivermectin (originally developed for use against livestock parasites), which eliminates the microfilariae, though it does not kill the adult parasite.

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onchocerciasis [‚äŋ·kō·sər′kī·ə·səs]

(medicine)

Infection with the filariaOnchocerca volvulus; results in skin tumors, papular dermatitis, and ocular complications.

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Onchocerciasis 

a chronic parasitic disease that is caused by nematodes of the genus Onchocerca. Onchocerciasis occurs universally and mainly affects ungulates; the greatest economic damage arises when cattle and horses are affected. The intermediate hosts of Onchocerca are simuliids and ceratopogonids, which are bloodsucking insects. The infestation is most prevalent in pastures during the swarming time of the intermediate hosts. The mature parasites concentrate in the tendons, ligaments, and connective tissue, causing inflammatory foci that are often aggravated by pyogenic microflora.

Onchocerciasis usually occurs without observable symptoms. Diagnosis in the living animal is based on the presence of Onchocerca larvae in skin biopsies and on the results of allergic skin tests. No specific treatment is available. Onchocerciasis is prevented by protecting animals from the bites of simuliids and ceratopogonids and by exterminating these insects during hatching time, from May to August.

REFERENCE

Skriabin, K. I., and A. M. Petrov. Osnovy veterinarnoi nematodologii. Moscow, 1964.