Onchocerciasis(River Blindness)

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

blindness.

A Short History

1875: John O’Neill first reports the presence of microfilaria in Onchocerciasis patients in Ghana

1893: Rudolf Leuckhart describes morphology of adult worms in subcutaneous nodules

1917: Rodolfo Robles publishes findings on a “new disease” which includes subcutaneous nodules, anterior ocular lesions, dermatitis, and microfilariae

1995: WHO establishes The African Program for Onchocerciasis Control (APOC)

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

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

RashesLesionsIntense itchingDepigmentation of the skinLymphadenitisGeneral debilitationSerious visual impairmentBlindness

River Blindness primarily affects the tropics of Africa and the Americas

•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

99 percent of River Blindness cases occur in Africa

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

Ivermectin doesn’t kill adult worms, but prevents themfrom 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

APOC: African Programme for Onchocerciasis Control (1995)

The Carter Center (1996)

IDP: Ivermectin Distribution Program (1989-1994)

Mectizan Donation Program (1987)

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