Onchocerca volvulus David Meyer Brief Review o Helminthes

Onchocerca volvulus David Meyer

Brief Review… o Helminthes worm o Commonly called river blindness o Blackfly vector

Life Cycle Quickie

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

The Road to Discovery o John O’Neill in 1874 (microfilaria) n “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. ” o Unnamed German Doctor in 1890 (adult worm) o Leuckart in 1890 (adult worm) o Robles in 1917 (blackfly vector) o Donald Blacklock in 1923 (transmission)

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

Human Migrations o Migration of population after o o 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 o Lack of knowledge/education o Location of communities close to blackfly breeding grounds o Poor medical attention for those who are infected o Agricultural/Cultural practices expose humans to vector

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

Anthropogenic Changes o Deforestation o Economic Development n Education

Resources o www. dpd. cdc. gov o www. who. int/tdr/diseases/oncho/ o www. emedicine. com/med/topic 1667. htm o ucdnema. ucdavis. edu/imagemap/nemm ap/ent 156 html/nemas/onchocercavolvulu s o en. wikipedia. org/wiki/Onchocerciasis