Abstract:
African Animal Trypanosomiasis (AAT) is among several constraints hindering development of the livestock
sector in Tanzania. A survey was conducted in Liwale district located in southern Tanzania in 2013 to determine
the population density of Glossina species, distribution pattern and Trypanosome species infection rate in tsetse
flies. A total of 200 flies were collected from the study area and three Glossina species were identified. The
proportional abundance of all trapped flies was 90% (180) for Glossina pallidipes, 6% (12) for G. brevipalpis and
4% (8) for G. m. morsitans with apparent densities (fly/trap/day - FTD) of 0.44. Higher density of Glossina
pallidipes was observed in villages closer to than those far from the Selous game reserve. Trypanosomes were
detected and identified by microscopy and ITS1 polymerase chain reaction (PCR) assay on DNA purified from
200 flies. Glossina pallidipes was the only fly found infected by three Trypanosoma species, namely T. vivax (60%),
T. simiae (10%) and T. brucei (30%) with an overall infection rate of 10% (20/200). A higher proportion of
trypanosome infections were observed in female tsetse flies than in males. Results of this study show that G
pallidipes is the major Glossina species harboring pathogenic trypanosomes in Liwale district and that the Selous
game reserve is a potential reservoir of trypanosomes in terms of parasite abundance and species diversity.
