Onchocerciasis “River Blindess ”
15
Onchocerciasis “River Blindess” the world's second leading infectious cause of blindness Pooja Makam
description
Onchocerciasis “River Blindess ”. the world's second leading infectious cause of blindness Pooja Makam. Prevalence!. 17.7 Million INFECTED!. 300, 000 people are blind . 95% + of cases occur within 30 African countries!. 40% of cases are in Nigeria!!!. Who’s at Risk??. - PowerPoint PPT Presentation
Transcript of Onchocerciasis “River Blindess ”
Onchocerciasis“River Blindess”
the world's second leading infectious cause of blindness
Pooja Makam
Prevalence!
95% + of cases occur within 30 African countries!17.7 Million INFECTED!
40% of cases are in Nigeria!!!300, 000 people are blind
Who’s at Risk??
West AfricaCentral/South
AmericaYemenPeople living
near fast moving rivers
Fast Moving Water is Well
oxygenated= Great
breeding ground!
78 millon people at risk!!
Causative Agent
Black fly- Simulium
Onchocerca volvolus
Causative
Agent!Vector!
How do we get sick from a fly?
Death of Microfilaria Inflammatory Response
DiagnosisPresence of microfilaria in blood, urine and
eyes
TreatmentMedication= Ivermectin
Kills by paralyzing microfilariae(larvae)
NO Reproduction
NO Inflammatory Resonse- No Lesions
Mechanism of IvermectinGlutamate-gated Chloride Channels- found only in
Invertebrate
Inhibitory Postsynaptic Potential (IPSP)
decreases future action Potential
Paralysis
DEATH
Irreversibly activates channel receptors in worm
Repeated Ivermectin exposure Resistance!Due to genetic changes in parasitegenetic marker = â-tubulin gene
Roger Prichard (McGill University, Canada) and colleagues
No Vaccinations!!Currently no safe drug available to cure this
disease or prevent it!FUTURE??
Research: Some Cattle develop natural immunity to disease
Socioeconomic ImpactBlindness = up to 50% of adults in W. AfricaAbandoned the fertile river -valleys in fear of
contracting the disease + adults were blind and could not work Poverty and famine!!
1974: economic losses =$30 million need for Prevention Programs !
Prevention: VECTOR CONTROLOnchocerciasis Control Programme-OCP in West
Africa(1974) African Program for Onchoceriasis Control APOC- (1997)Pesticide SprayingClear brush/vegetation from the banks of fast
running streams to reduce the number of flies Avoid sleeping outdoors in the day time
Treatment Span OCP= (green)
APOC=(yellow)
References:http://www.who.int/topics/onchocerciasis/en/http://www.utmb.edu/gsbs/microbook/images/fig92_3.JPGhttp://images.google.com/imgres?imgurl=http://
www.stanford.edu/group/parasites/http://www.dpd.cdc.gov/dpdx/HTML/Filariasis.htmhttp://images.google.com/imgres?imgurl=http://
www.mectizan.org/images/onchoafricamap.jpgTRD Wellcome trust
Scientists Step Closer To New Treatments For River Blindness- ScienceDaily (Apr. 16, 2006)
River Blindness Parasite Becoming Resistant To Standard Treatment-ScienceDaily (Sep. 5, 2007)
WHOCDC
