Onchocerciasis (River Blindness)

River Blindness, a parasitic disease, is the second leading infectious cause of blindness .

A Short History

1893: Rudolf Leuckhart describes morphology of adult worms in subcutaneous nodules 1875: John O’Neill first reports the presence of microfilaria in Onchocerciasis patients in Ghana 1917: Rodolfo Robles publishes findings on a “new disease” which includes subcutaneous nodules, anterior ocular lesions, dermatitis, and microfilariae 1975: Fungus that produces chemical toxic to parasitic worms discovered in Japanese soil sample, from which scientists develop avermectins 2009: First evidence that Onchocerciasis can be eliminated with Ivermectin published in the journal Neglected Tropical Diseases 1995: WHO establishes The African Program for Onchocerciasis Control (APOC) 1987: Merck & Co agrees to donate Ivermectin to all countries where River Blindness is endemic

-

River blindness is caused by a round worm,

Onchocerca volvulus

River blindness is transmitted to humans by the blackfly.

Life Cycle

Symptoms

 Rashes  Lesions  Intense itching  Depigmentation of the skin  Lymphadenitis  General debilitation  Serious visual impairment  Blindness

River Blindness primarily affects the tropics of Africa and the Americas

99 percent of River Blindness cases occur in Africa

• 36 countries • 29 in sub-Saharan Africa • 6 in Latin America • Yemen • 120 million people at risk • 96 percent in Africa • Estimated 18 million infected • 99 percent in Africa

Ivermectin is a broad-spectrum antiparasitic that can be used to treat River Blindness

Ivermectin doesn’t kill adult worms, but prevents them from producing additional offspring

• Drug binds to and activates glutamate-gated chloride channels • By activating channels, drug causes inhibitory postsynaptic potential • Microfilaria experience paralysis and then death

What is Being Done

Mectizan Donation Program (1987) IDP: Ivermectin Distribution Program (1989-1994) APOC: African Programme for Onchocerciasis Control (1995) The Carter Center (1996)

APOC countries:

Angola, Burundi, Cameroon, Central African Republic, Chad, Congo, Democratic Republic of Congo, Ethiopia, Equatorial Guinea, Gabon, Kenya, Liberia, Malawi, Mozambique, Nigeria, Rwanda, Sudan, Tanzania and Uganda.

http://www.who.int/blindness/partnerships/onchocerciasis_disease_information/en/index.html

http://emedicine.medscape.com/article/217776-overview http://www.irishhealth.com/article.html?id=285 http://news.bbc.co.uk/2/hi/health/6753003.stm

http://www.stanford.edu/class/humbio103/ParaSites2006/Onchocerciasis/history%20of%20discovery.html

http://www.cartercenter.org/health/river_blindness/index.html

http://www.cartercenter.org/health/river_blindness/index.html

http://www.mectizan.org/onchocerciasis-maps http://www.dpd.cdc.gov/dpdx/html/frames/af/filariasis/body_Filariasis_o_volvulus.htm

http://emedicine.medscape.com/article/224309-overview