Definitions for onchocerciasis
This page provides all possible meanings and translations of the word onchocerciasis
onchocerciasis, river blindness(noun)
infestation with slender threadlike roundworms (filaria) deposited under the skin by the bite of black fleas; when the eyes are involved it can result in blindness; common in Africa and tropical America
A disease caused by a worm of the genus Onchocerca, especially as transmitted to humans by flies and often causing blindness; common in tropical Africa.
Origin: From scientific Onchocerca (a genus of parasitic worms, from ‘barb’ + ‘tail’) + -iasis.
Onchocerciasis, also known as river blindness and Robles disease, is a parasitic disease caused by infection by Onchocerca volvulus, a nematode. Onchocerciasis is second in the world only to trachoma as an infectious cause of blindness. It is not the nematode, but its endosymbiont, Wolbachia pipientis, that causes the severe inflammatory response that leaves many blind. The parasite is transmitted to humans through the bite of a black fly of the genus Simulium. The larval nematodes spread throughout the body. When the worms die, their Wolbachia symbionts are released, triggering a host immune system response that can cause severe itching, and can destroy optical tissue in the eye. Most infections occur in sub-Saharan Africa, although cases have also been reported in Yemen and isolated areas of Central and South America. As of 2001, an estimated 18 million people suffered from onchocerciasis, with approximately 270,000 cases of blindness related to the infection. In 1915, Dr. Rodolfo Robles Valverde's study on patients with river blindness in Guatemala led to the discovery that the disease is caused by filaria of O. volvulus, and sheds light on the life cycle and transmission of the parasite. Using case studies of coffee plantation workers in Guatemala, Robles hypothesized the vector of the disease is a day-biting insect, and more specifically, two anthropophilic species of Simulium flies found to be endemic to the areas. He published his findings on a “new disease” from Guatemala associated with subcutaneous nodules, anterior ocular lesions, dermatitis, and microfilariae in 1917.
U.S. National Library of Medicine
Infection with nematodes of the genus ONCHOCERCA. Characteristics include the presence of firm subcutaneous nodules filled with adult worms, PRURITUS, and ocular lesions.
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"onchocerciasis." Definitions.net. STANDS4 LLC, 2014. Web. 10 Mar. 2014. <http://www.definitions.net/definition/onchocerciasis>.