onchocerciasis “river blindess ”
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 PresentationTRANSCRIPT
![Page 1: Onchocerciasis “River Blindess ”](https://reader034.vdocument.in/reader034/viewer/2022050806/56815d68550346895dcb71f7/html5/thumbnails/1.jpg)
Onchocerciasis“River Blindess”
the world's second leading infectious cause of blindness
Pooja Makam
![Page 2: Onchocerciasis “River Blindess ”](https://reader034.vdocument.in/reader034/viewer/2022050806/56815d68550346895dcb71f7/html5/thumbnails/2.jpg)
Prevalence!
95% + of cases occur within 30 African countries!17.7 Million INFECTED!
40% of cases are in Nigeria!!!300, 000 people are blind
![Page 3: Onchocerciasis “River Blindess ”](https://reader034.vdocument.in/reader034/viewer/2022050806/56815d68550346895dcb71f7/html5/thumbnails/3.jpg)
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!!
![Page 4: Onchocerciasis “River Blindess ”](https://reader034.vdocument.in/reader034/viewer/2022050806/56815d68550346895dcb71f7/html5/thumbnails/4.jpg)
Causative Agent
Black fly- Simulium
Onchocerca volvolus
Causative
Agent!Vector!
![Page 5: Onchocerciasis “River Blindess ”](https://reader034.vdocument.in/reader034/viewer/2022050806/56815d68550346895dcb71f7/html5/thumbnails/5.jpg)
How do we get sick from a fly?
![Page 6: Onchocerciasis “River Blindess ”](https://reader034.vdocument.in/reader034/viewer/2022050806/56815d68550346895dcb71f7/html5/thumbnails/6.jpg)
Death of Microfilaria Inflammatory Response
![Page 7: Onchocerciasis “River Blindess ”](https://reader034.vdocument.in/reader034/viewer/2022050806/56815d68550346895dcb71f7/html5/thumbnails/7.jpg)
DiagnosisPresence of microfilaria in blood, urine and
eyes
![Page 8: Onchocerciasis “River Blindess ”](https://reader034.vdocument.in/reader034/viewer/2022050806/56815d68550346895dcb71f7/html5/thumbnails/8.jpg)
TreatmentMedication= Ivermectin
Kills by paralyzing microfilariae(larvae)
NO Reproduction
NO Inflammatory Resonse- No Lesions
![Page 9: Onchocerciasis “River Blindess ”](https://reader034.vdocument.in/reader034/viewer/2022050806/56815d68550346895dcb71f7/html5/thumbnails/9.jpg)
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
![Page 10: Onchocerciasis “River Blindess ”](https://reader034.vdocument.in/reader034/viewer/2022050806/56815d68550346895dcb71f7/html5/thumbnails/10.jpg)
Repeated Ivermectin exposure Resistance!Due to genetic changes in parasitegenetic marker = â-tubulin gene
Roger Prichard (McGill University, Canada) and colleagues
![Page 11: Onchocerciasis “River Blindess ”](https://reader034.vdocument.in/reader034/viewer/2022050806/56815d68550346895dcb71f7/html5/thumbnails/11.jpg)
No Vaccinations!!Currently no safe drug available to cure this
disease or prevent it!FUTURE??
Research: Some Cattle develop natural immunity to disease
![Page 12: Onchocerciasis “River Blindess ”](https://reader034.vdocument.in/reader034/viewer/2022050806/56815d68550346895dcb71f7/html5/thumbnails/12.jpg)
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 !
![Page 13: Onchocerciasis “River Blindess ”](https://reader034.vdocument.in/reader034/viewer/2022050806/56815d68550346895dcb71f7/html5/thumbnails/13.jpg)
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
![Page 14: Onchocerciasis “River Blindess ”](https://reader034.vdocument.in/reader034/viewer/2022050806/56815d68550346895dcb71f7/html5/thumbnails/14.jpg)
Treatment Span OCP= (green)
APOC=(yellow)
![Page 15: Onchocerciasis “River Blindess ”](https://reader034.vdocument.in/reader034/viewer/2022050806/56815d68550346895dcb71f7/html5/thumbnails/15.jpg)
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