Transcript River Blindness

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