onchocerciasis


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onchocerciasis

 [ong″ko-ser-ki´ah-sis]
infection with worms of the genus Onchocerca. Human infection is caused by O. volvulus, with heavy infestations usually being characterized by subcutaneous nodules (onchocercomas) containing tangled masses of adult worms, a persistent dermatitis, lymphadenitis, and ocular lesions related to the invasion and death of microfilariae, which may progress to optic neuritis, optic atrophy, and blindness. The condition is also known by many local and regional names (craw-craw, Robles' disease) and by various names descriptive of the manifestations of the disease (coast erysipelas, river blindness, blinding filarial disease).

on·cho·cer·ci·a·sis

(ong'kō-ser-kī'ă-sis),
Infection with Onchocerca (especially O. volvulus, a filarial nematode transmitted from person to person by black flies of the genus Simulium), marked by nodular swellings forming a fibrous cyst enveloping the coiled parasites (onchocercoma); microfilariae move freely out of the nodule and escape into the intercellular lymph in the dermis. Dermatologic changes often develop in those affected, especially in patients in Africa, resulting in intense pruritus, scaly or lichenoid skin, depigmentation, and destruction of elastic fibers. Most important are the ocular complications that may develop after a long chronic course, with blindness frequently occurring in advanced cases, caused by the presence of living or dead microfilariae seen by slitlamp biomicroscopy.

onchocerciasis

(ŏng′kō-sər-kī′ə-sĭs)
n.
Any of several diseases caused by infestation with filarial worms of the genus Onchocerca, especially a disease of humans caused by O. volvulus and characterized by nodular swellings on the skin and eye lesions that can result in blindness. Transmitted by black flies of the genus Simulium, the disease occurs in tropical regions of Africa and Central and South America. Also called river blindness.
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ONCHOCERCIASIS: Cutaneous nodules of onchocerciasis
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ONCHOCERCIASIS

onchocerciasis

(ong?ko-ser?ki'a-sis) (-sez?) plural.onchocerciases [ Onchocerca + -iasis]
Infection with Onchocerca volvulus.
Synonym: onchocercosis; river blindness See: illustrationillustration

onchocerciasis

A tropical parasitic disease, mainly of West Africa, caused by the microfilarial worm Onchocerca volvulus . The filarial forms of the worm are spread by the biting blackfly Simulium damnosum , which breeds only in turbulent rivers-hence the alternative term river blindness. Onchocerciasis causes lumps or nodules under the skin, each containing at least one male and one female adult worm. After impregnation, the female worm releases millions of microscopic microfilaria which migrate under the skin and enter the eyes where, on dying they set up a severe and destructive inflammation that leads to irremediable blindness. The microfilaria also often block lymph channels and cause ELEPHANTIASIS. Treatment is with drugs such as diethylcarbamazine and suramin to kill the worms. This may cause severe reactions.

Onchocerciasis

Parasitic infestation caused by filamentous worms of the genus Onchocerca, especially O. volvulus, that is found in tropical America and is transmitted by several types of blackflies.
Mentioned in: Antihelminthic Drugs

onchocerciasis 

A disease caused by infestation with the filarial worm (Onchocerca volvulus) spread by blackflies. It is common in tropical Africa and Central America, especially in areas near rivers. Large numbers of microfilariae are present on the skin and often enter the eye. The patient initially complains of itching, but blindness occurs as a result of chorioretinitis and optic neuritis. The disease is treated successfully with ivermectin. Syn. onchocercosis; river blindness.
References in periodicals archive ?
In the roadmap of the WHO for the elimination of onchocerciasis, the prevalence of the infective stage of O.
Mass drug treatment for lymphatic filariasis and onchocerciasis. Trends Parasitol., 2003; 19: 516-522.
Onchocerciasis, or river blindness, is an infectious disease endemic in 31 sub-Saharan African countries, which is estimated to have infected 26 million people.2 It is caused by the parasitic worm Onchocerca volvulus.
[3.] Gnedina MP (1949) Cattle skin onchocerciasis of and combating.
(1) With a much broader distribution range, Onchocerca volvulus is transmitted by Simulium species black flies and causes onchocerciasis with chronic skin and eye infections in about 37 million people in endemic areas of Mexico, Central and South America, West and Central Africa, and the Arabian Peninsula (Yemen).
guianense immatures in the onchocerciasis area of Venezuela.
They conducted a pilot study in Cameroon, where health officials have been battling the filarial, or parasitic worm, diseases onchocerciasis (river blindness) and lymphatic filariasis.
And there is onchocerciasis, also known as "river blindness," which has infected 37 million people.
Other tropical diseases that are also infectious and thrive in hot, humid areas are malaria, onchocerciasis and dengue.
for example, Malaria, Dengue Fever, Japanese encephalitis, Lymphatic disease, Schistosomiasis, Yellow fever, Leishmaniasis, Chagas disease, Chikungunya, Crimean-Congo hemorrhagic fever, Human African trypanosomiasis, Onchocerciasis Vector-Borne Diseases in Palestine Due to the efforts of the Palestinian Ministry of Health and it's preventive procedures; Palestine is completely free of all vector-borne diseases listed above with the exception of the disease leishmaniasis, which still recorded injuries in the West Bank , while the Gaza Strip free of it as a result of the different nature of the environment.
Colombia has become the first nation to eliminate onchocerciasis, more commonly known as river blindness, according to the World Health Organization.