Phlebotomus sergenti (Parrot, 1917) identified as Leishmania killicki host in Ghardaïa, south Algeria

Since 2005, an outbreak of human cutaneous leishmaniasis (CL) in Ghardaïa, south Algeria, was studied and one output of these investigations was the identification of two Leishmania species, Leishmania major and Leishmania killicki, as the CL causative agents. In the present study, we were curious to focus on sand fly fauna present in this area and detection of Leishmania-positive sand fly females. Sand flies (3717) were collected during two seasons using sticky papers and CDC light traps in urban, rural and sylvatic sites. Twelve Phlebotomus species were identified. Phlebotomus papatasi was dominant in the urban site while Phlebotomus sergenti and Phlebotomus riouxi/chabaudi were dominant in the sylvatic site. Out of 74 P. sergenti females captured by CDC light traps in the sylvatic site populated by Ghardaïas' Gundi (Massoutiera mzabi), three ones were hosting Leishmania promastigotes. PCR-RFLP and sequencing of seven single-copy coding DNA sequences identified the promastigotes as L. killicki. Furthermore, laboratory experiments revealed that L. killicki isolate sampled from a CL patient inhabiting the studied region develop well in P. sergenti females. Our findings strongly suggest that the human cutaneous leishmaniases caused by L. killicki is a zoonotic disease with P. sergenti sand flies acting as hosts and vectors and gundi rodents as reservoirs.