Containing Infectious Diseases and Its Consequences on the Environment in the Angar- Dhidhessa Valley, Western Ethiopia, 1965-1998

Abstract

This article seeks to explain how development agencies controlled pathogens to make the Angar-Dhidhessa River Valley viable for cultivation from 1965-1998. The valley is one of the extensive plains following the Dhidhessa and Angar Rivers that join the Blue Nile River. Evidences for the study came from feasibility studies, veterinary reports, archives on state farms and settlement projects as well as land lease for large-scale agricultural investments. Herders' and hunters' descriptions and personal records are also helpful to trace a history of valley environment, including diseases. By using sources that describe the valley environment for the precise periods, the article tries to show the process how development agencies used to fight against diseases in the valley and its effects on the environment. The most prevalent endemic human and livestock diseases in the valley were malaria and trypanosomiasis. The study depicts that continuous removal of savanna vegetation where mosquito and tsetse fly breed, and the plantation of exotic trees contained malaria and trypanosomiasis. In addition to the above mechanisms, trypanosomiasis appeared to be contained following the elimination of buffalo and other games as well as the wide use of chemicals such as DDT (Dichloro-Diphenyl-Trichloroethane) to eradicate the tsetse fly that spread the infection from immune wildlife to susceptible livestock. The lost tropical vegetation and wild animals cannot be easily replaced. However, land use and conservation measures that would involve the local society could mitigate the worst environmental crisis and agricultural failure that might be anticipated in the region.