Download Onchocerciasis (River Blindness)

Onchocerciasis
(River Blindness)
Amanda Kramer
WHAT IS RIVER BLINDNESS?
A neglected tropical diseased caused by
the worm Onchocerca volvulus and
carried by Simulium blackflies that can
result in skin damage and blindness.
DISTRIBUTION
25 million people infected
300,000 blind
800,000 with visual impairment
No reported deaths
99% of cases in sub-Saharan
Africa
Yemen and Americas also
affected
LIFE CYCLE OF ONCHOCERCUS VOLVULUS
RELEASE OF WOLBACHIA CAUSES SYMPTOMS
SYMPTOMS
Skin nodules
Leopard Skin
Blindness
DIAGNOSIS
• Skin snip
• Removal and testing of nodules
• Antibody tests in development
TREATMENT
Ivermectin
Deoxycycline
Primary Treatment
Secondary Treatment
• Binds to glutamate-gated chloride channel
• Hyperpolarizes nerve and muscle cells
• Kills larvae
• Antibiotic protein synthesis inhibitor
• Kills Wolbachia, a necessary symbiotic
bacteria
PREVENTION
• Anti-insect measures
• Covering clothing
• Screens
• Insect repellent
• IVM treatment
REFERENCES
•
Brattig NW, Rathjens U, Ernst M, Geisinger F, Renz A, Tischendorf F. 2000. Lipopolysaccharide-like molecules derived from Wolbachia endobacteria of the filaria Onchocerca
volvulus are candidate mediators in the sequence of inflammatory and anti-inflammatory responses of human monocytes. Microbes and Infection 2: 1147-1157.
•
Center for Disease Control, "Parasites - Onchocerciasis (alson known as River Blindness)." Last modified May 21, 2013. Accessed March 16, 2014.
http://www.cdc.gov/parasites/onchocerciasis/.
•
Convit J, Schuler H, Borges R, Olivero V, Dominguez-Vasquez A, Frontado H, Grillet M. 2013. Interruption of Onchocerca volvulus transmission in Northern Venezuela. Parasites
and Vectors 6: 289.
•
Langworthy NG, Renz A, Mackenstedt U, Henkle-Duhrsen K, Bronsvoort MB, Tanya VN, Donnelly MJ, Trees AJ. 2000. Macrofilaricidal activity of tetracycline against the filarial
nematode Onchocerca ochengi: elimination of Wolbachia precedes worm death and suggests a dependent relationship. Proc R Soc Lond 267: 1063-1069.
•
Osei-Atweneboaan MY, Boakye DA, Awadzi K, Gyapong JO, Prichard RK. 2012. Genotypic analysis of B-tubulin in Oncocerca volvulus from communities and individuals showing
poor parasitological response to ivermectin treatment. International Journal for Parasitology: Drugs and Drug Resistance 2: 20-28.
•
Stanford Human Biology, "Mechanism of Action." Accessed March 16, 2014. http://www.stanford.edu/class/humbio103/ParaSites2005/Ivermectin/mechanism of action.htm.
•
Wikipedia, "Onchocerciasis." Last modified March 20, 2014. Accessed March 16, 2014. http://en.wikipedia.org/wiki/Onchocerciasis.
•
Wilson MD, Osei-Atweneboana M, Boakye DA, Osei-Akoto I, Obuobi E, Wiafe C, Kiszewski A. 2013. Efficacy of DEET and non-DEET-based insect repellents against bites of Similium
damnosum vectors of onchocerciasis. Medical and Veterinary Entomology 27: 226-231.
•
World Health Organization, "Onchocerciasis." Last modified March 2014. Accessed March 16, 2014. http://www.who.int/mediacentre/factsheets/fs374/en/.
•
World Health Organization, "Onchocerciasis (river blindness) disease information." Last modified 2014. Accessed March 16, 2014.
http://www.who.int/blindness/partnerships/onchocerciasis_disease_information/en/.