Leishmaniases in the Lower Omo plains, south-western Ethiopia: The sandflyfauna

Sandfly entomological surveys were conducted between November 1990 and Nove mber 1993 in six localities of south-western Ethiopia known to be endemic f or visceral and cutaneous leishmaniasis. Center for Disease Control light t raps, sticky traps and suction aspirators were used to explore potential ha bitats such as termite hills, soil cracks, animal burrows, rock cliffs, tre e holes, human huts and latrines. No sandflies were found in the latter thr ee. A total of 16,575 sandflies comprising 7 species of Phlebotomus and 16 species of Sergentomyia were collected and identified. Phlebotomus oriental is, a suspected vector of visceral leishmaniasis in Ethiopia, represented 3 .5% of all collections and was the predominant Phlebotomus species (53.9%). In Gisma, a locality of the Woitu plains, P. alexandri outnumbered P. mart ini, P. celiae and P. duboscqi. There were very few P. saevus and P. rodhai ni. Most of the Phlebotomus species are new records for the area. Phlebotom us martini and P.celiae, known vectors of visceral leishmaniasis in south-w estern Ethiopia, were found in most of the study localities. Among the Serg entomyia, S. antenna, S. schwetzi and S.clydei were the most abundant follo wed by S. squamipleuris, S. affinis, S. bedfordi and S. africana. Based on sandfly species composition and abundance, the present study suggests that P. orientalis, P. martini and P.celiae might play a role in the transmissio n of visceral leishmaniasis in the Lower Omo plains whereas P. alexandri co uld be of focal importance in the transmission of either visceral or cutane ous leishmaniasis. This conjecture needs, however, to be tested by means of detailed further epidemiological and entomologucal studies.