Where is onchocerciasis common in Ethiopia?

Onchocerciasis is found in the western part of Ethiopia, where there are many rapidly flowing rivers and streams, with vegetation along the banks that provide good habitats for the blackflies that transmit the parasite. The most affected areas include Keffa, Illubabor, Gambella and Wollega. Cases of onchocerciasis have been also reported from Pawe, Humera and Metema.