Onchocerca volvulus David Meyer

Brief Review… Helminthes worm Commonly called river blindness Blackfly vector

Life Cycle Quickie

Historical Accounts Microfilariae of a river blindness mentioned in ancient Egyptian text. 2nd millennium BC. Also mentioned in African account of river blindness in 1st millennium BC.

The Road to Discovery John O’Neill in 1874 (microfilaria) “I was induced to bestow much time on its microscopic examination, and succeeded length in discovering a filaria which I believe to be the immediate cause of the complaint.” Unnamed German Doctor in 1890 (adult worm) Leuckart in 1890 (adult worm) Robles in 1917 (blackfly vector) Donald Blacklock in 1923 (transmission)

Cultural Practices Farming techniques in Africa (Nigeria) Living near open running water Cultural fishing practices Clothing options

Human Migrations Migration of population after village becomes infected with Onchocerciasis Blackfly migration Bantu Expansion/Nomadic tribes Prevalence: 35 countries total. 28 in tropical Africa where 99% of infected people live. 17.7 million infected

Infrastructure Lack of knowledge/education Location of communities close to blackfly breeding grounds Poor medical attention for those who are infected Agricultural/Cultural practices expose humans to vector

Response of Health Care Treatments Ivermectin Albendazole Corticosteroids Control Using protective netting Pesticides

Anthropogenic Changes Deforestation Economic Development Education

Resources www.dpd.cdc.gov www.who.int/tdr/diseases/oncho/ www.emedicine.com/med/topic1667.htm ucdnema.ucdavis.edu/imagemap/nemmap/ent156html/nemas/onchocercavolvulus en.wikipedia.org/wiki/Onchocerciasis