onchocerciasis

noun on·cho·cer·ci·a·sis \ ˌäŋ-kō-ˌsər-ˈkī-ə-səs , ˌäŋ-kə- \

|Updated on: 19 Jul 2018

Definition of onchocerciasis

plural onchocerciases play \ˌäŋ-kō-ˌsər-ˈkī-ə-ˌsēz, ˌäŋ-kə-\

: infestation with or disease caused by filarial worms (genus Onchocerca); especially : a human disease marked by subcutaneous nodules, dermatitis, and visual impairment and caused by a worm (O. volvulus) found in Africa and tropical America which is transmitted by the bite of a female blackfly — called also river blindness

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Recent Examples of onchocerciasis from the Web

Fifteen years ago as much as half the population was infected with the worm that causes onchocerciasis, or river blindness (see map).

— The Economist, "How Sierra Leone is beating tropical diseases," 23 June 2018
Yet by 2017 only 2% of people carried the worm, and there had been no new cases recorded of people going blind from onchocerciasis in a decade.

— The Economist, "How Sierra Leone is beating tropical diseases," 23 June 2018
River blindness, or onchocerciasis, is a nasty disease that has burdened Africa for as long as anyone can remember.

— brian rinker, CNN, "New tech revolutionizes fight against ancient diseases in Africa, Asia," 17 Apr. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'onchocerciasis.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Origin and Etymology of onchocerciasis

New Latin, from Onchocerca, genus of worms

NEW! Time Traveler

First Known Use: 1911

in the meaning defined above

See Words from the same year

Medical Dictionary

onchocerciasis

noun on·cho·cer·ci·a·sis \ ˌäŋ-kō-ˌsər-ˈkī-ə-səs \

medical Definition of onchocerciasis

plural onchocerciases play \-ˌsēz\

: infestation with or disease caused by filarial worms of the genus Onchocerca; especially : a human disease marked by subcutaneous nodules, dermatitis, and visual impairment that is caused by a worm (O. volvulus) found in Africa and tropical America and transmitted by the bite of a female blackfly — called also onchocercosis, river blindness ; see craw-craw