Tsetse distribution in Tanzania: 2012 status

Abstract

Tsetse flies and the trypanosomoses they transmit are of great economic importance in terms of preventing use of arable and grazing land and hence causing food insecurity. Annually 40,000 -50,000 people suffer from sleeping sickness (Human African Trypanosomosis; HAT) and three million cattle deaths can be attributed to Nagana (African Animal Trypanosomosis; AAT) a disease which necessitates use of approximately 35 million doses of trypanocidal drugs for treatment. Nagana has a severe impact on  agriculture in sub-Saharan Africa with economic losses in cattle production alone being in the range of US$ 1.0 - 1.2 billion. Despite huge losses attributed to the presence of tsetse and trypanosomosis, the distribution of tsetse flies in many African countries is not known precisely. Limited resources have prevented systematic updating of tsetse distribution for the continent, thus relying on outdated late 1960’s and early 1970’s   information. Recently, Tanzania undertook a survey to map out tsetse distribution countrywide whereby categorization of different levels of risk areas has been outlined in each region with the overall trends showing a decrease in tsetse infested areas. The current infestation rate is about 33% (1/3) against the earlier documented 60% infestation. Results further show that the seven species of Glossina that had been recorded earlier still occur in Tanzania, although unevenly distributed due to different ecological features, climatic change, human development activities and tsetse control interventions. This paper highlights current status of tsetse distribution in Tanzania and advocates effective control measures based on this up-to date information.

Keywords: tsetse, Glossina, surveys, trypanosomosis, distribution,  Tanzania