FAQ - Onchocerciasis
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Who knows about the disease Onchocerciasis?


I know that it's from africa, but what are the symptoms? What are the causes, and is there a cure?
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It's also in six countries in Latin America (Brazil, Colombia, Ecuador, Guatemala, Mexico, and Venezuela) but it's almost been eliminated there thanks to a drug called Mectizan (http://mectizan.org).

Onchocerciasis is the second leading cause of blindness of infectious origin.Parasites migrate to the eye, and subsequently die there, cause severe inflammation and scarring that can lead to impaired vision and blindness. The life expectancy of a person who becomes blind may be shortened by about 10 years.

It's also called “river blindness” because of the blindness it causes and its association with communities that live near rivers where black flies breed. The disease is caused by multiple bites of the black fly, which deposits larvae into the skin that breeds and creats offspring that spread throughout the body.

River blindness also causes severe dermatitis that can be extremely distressing and debilitating as it creates intense and relentless itching. Eventually the skin becomes swollen and chronically thickened, a condition often called “lizard skin,” due to the constant scratching. The skin may also become lax due to the destruction of its elastic fibers. And over time the skin may lose some of its pigment, which on dark skin gives rise to an appearance commonly referred to as “leopard skin”.

Over time, nodules that contain adult parasites form in the subcutaneous tissue. The nodules vary in size from one to five centimeters in diameter, and an infected individual may have as many as several hundred. Nodules may be detected over the skull, ribs, elbows, hips, thighs, and knees. Non-palpable nodules may be located within muscles, causing deep-seated pain. The region of the body most affected by nodules varies from one geographic locale to another and is dependent upon the biting habits of the area’s black flies and the clothing worn by inhabitants.

The disease can be treated with an annual or bi-annual administration of Mectizan. The drug is distributed to communities by the communities themselves (with the oversight and support of country partners). Mectizan kills the worm's offspring so that they cannot migrate through the body and cause skin and eye disease. Over time, the drug also interferes with the life cycle of the black fly, which has led to elimination of the disease in Latin America and some parts of Africa.

Probably more than you needed - but there you go.  (+ info)

what are the regional spread of onchocerciasis?


where the disease onchocerciasis has spread regionally
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In the Western Hemisphere onchocerciasis is largely confined to Mexico and Central America, although cases have been reported from Venezuela, Colombia and Dutch Guina. It is widespread in tropical Africa. In the Americas it occurs principally among persons inhabiting the western slope of the Sierras at altitudes of 600 to 2000 meters. Guatemala and the southern states of Mexico constitute the chief endemic centers. In Africa onchocerciasis is found from Sierra Leone and Liberia southward through the Gulf Coast, Dahomey, Nigeria and the Cameroons to the Congo; then east to the southern Sudan, Uganda, Nyasaland, Kenya, Tanzania and Kavirondo. Recently, it has been reported in southern Arabia.  (+ info)

what is onchocerciasis?


http://en.wikipedia.org/wiki/Onchocerciasis  (+ info)

Has anyone used a parasite's genome map to design a genetic control or poison to eradicate the parasite.?


African trypanosomiasis. Commonly called sleeping sickness, this disease is caused by a parasitic microbe transmitted by tsetse flies. If untreated, the parasite migrates to the central nervous system, causing seizures, mental disorders and, ultimately, death. As many as 70,000 people are infected in Central and East Africa.


American trypanosomiasis. Commonly called Chagas disease, this disease is caused by a parasitic microbe transmitted by blood-sucking bugs. It can cause organ damage. The parasite infects about 13 million people, mostly in Latin America.


Hookworm. Human hookworm infection is caused by intestinal worm parasites transmitted to humans from contaminated soil. It causes internal blood loss and is the world's leading cause of anemia and protein malnutrition, particularly in pregnant women and children. More than half a billion people in poverty-stricken areas of Africa, Latin America, Southeast Asia and China are infected.


Leishmaniasis. This disease is caused by a parasitic microbe transmitted by sand flies. It can cause skin lesions and swelling of the spleen and liver. More than 12 million people are infected in Africa, Asia, Europe and the Americas.


Lymphatic filariasis. Commonly called elephantiasis, this parasitic worm disease is spread by mosquitoes. It can lead to disabling swelling of the legs and other body parts. About 120 million people are infected throughout Asia, Africa, the Western Pacific, South America and parts of the Caribbean.


Malaria. This disease is caused by a parasitic microbe spread by mosquitoes. Each year, malaria infects at least 300 million people living in tropical regions. It can cause brain damage or death if red blood cells infected with malaria parasites build up in the brain's blood vessels. The annual death toll is about 1 million people, many of whom are children under age 5 and pregnant women.


Onchocerciasis. Commonly called river blindness, this parasitic worm disease is spread by black flies. It can cause extreme itching, sores on the skin and blindness. The parasite infects about 18 million people, mostly in Africa, but also in Latin America.


Schistosomiasis. Also known as bilharzia or snail fever, this parasitic worm disease is transmitted by snails that live in fresh water. It can impair growth, cause severe anemia and lead to kidney and liver malfunctions. More than 200 million people are infected, mostly in Africa and Asia.
A respectable number of parasite genomes have been mapped.

http://www.genomenewsnetwork.org/resources/sequenced_genomes/genome_guide_p1.shtml

Has anyone yet succeeded in designing a control to from knowledge of the parasite genome?
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As far as Schistosomiasis, it was just completed over the summer. Hopefully drugs to follow. see more here: http://bactiman63.blogspot.com/2009/07/genetic-code-to-schistosomes-complete.html  (+ info)


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