A systematic approach to area-wide tsetse distribution and abundance maps

A raster or grid-based Geographic Information System with data on tsetse, trypanosomosis, animal production, agriculture and land use has recently been developed in Togo. This paper describes the generation of area-wide digital tsetse distribution and abundance maps and how these accord with the local climatic and agro-ecological setting. Results include: (i) a spatial demarcation of ecologically distinct areas, producing a seasonal cluster map based on seasonal weather data and temporal series of satellite derived National Oceanic and Atmospheric Administration (NOAA) AVHRR and METEOSAT variables: (ii) tsetse distribution maps of Glossina tachinoides Westwood, G. palpalis palpalis (Robineau-Desvoidy), G. morsitans submorsitans Newstead, G. longipalpis Wiedemann, G. medicorum Austen and G. fusca fusca (Walker); and (iii) tsetse abundance or 'risk' maps, corrected for within database seasonal fluctuations, for G. tachinoides and G. p. palpalis. It is concluded that grid-based sampling is the ideal method for rapid assessment of the current vector and disease situation within any country or region, and that remote sensing has an important role to play in planning such a sampling system.