Abstract:
BACKGROUND: In the 1980s and 1990s, great strides were taken towards the elimination of tsetse and animal African
trypanosomiasis (AAT) in Zimbabwe. However, advances in recent years have been limited. Previously freed areas
have been at risk of reinvasion, and the disease in tsetse-infested areas remains a constraint to food security. As part
of ongoing control activities, monitoring of tsetse and AAT is performed regularly in the main areas at risk. However, a centralized digital archive is missing. To fll this gap, a spatially explicit, national-level database of tsetse and
AAT (i.e. atlas) was established through systematic data collation, harmonization and geo-referencing for the period
2000–2019.
METHODS: The atlas covers an area of approximately 70,000 km2
, located mostly in the at-risk areas in the north of
the country. In the tsetse component, a total of 33,872 entomological records were assembled for 4894 distinct trap
locations. For the AAT component, 82,051 samples (mainly dry blood smears from clinically suspicious animals) were
collected at 280 diptanks and examined for trypanosomal infection by microscopy.
RESULTS: Glossina pallidipes (82.7% of the total catches) and Glossina morsitans morsitans (17.3%) were the two tsetse
species recorded in the north and northwest parts of the country. No fy was captured in the northeast. The distribution of AAT follows broadly that of tsetse, although sporadic AAT cases were also reported from the northeast, apparently because of transboundary animal movement. Three trypanosome species were reported, namely Trypanosoma
brucei (61.7% of recorded infections), Trypanosoma congolense (28.1%) and Trypanosoma vivax (10.2%). The respective
prevalences, as estimated in sentinel herds by random sampling, were 2.22, 0.43 and 0.30%, respectively.
DISCUSSION: The patterns of tsetse and AAT distributions in Zimbabwe are shaped by a combination of bioclimatic
factors, historical events such as the rinderpest epizootic at the turn of the twentieth century and extensive and
sustained tsetse control that is aimed at progressively eliminating tsetse and trypanosomiasis from the entire country.
The comprehensive dataset assembled in the atlas will improve the spatial targeting of surveillance and control activities. It will also represent a valuable tool for research, by enabling large-scale geo-spatial analyses.
