Susceptibility to Leishmania major of different populations of Phlebotomus papatasi (Diptera: Psychodidae) from endemic and non-endemic regions of Egypt.

The ability of three populations of Phlebotomus papatasi collected from different areas of Egypt (Sinai, Aswan and Delta regions) to acquire successfully and transmit Leishmania major (Sinai sandfly isolate IPAP/EG/89/SI-177) was evaluated in the laboratory. Flies from each population were fed artificially on infected blood suspensions, using a chick-skin-membrane feeding apparatus, and naturally on infected mice. Samples of fed flies were dissected and examined microscopically to determine the infection rate and intensity of parasite infection. The Aswan population had a significantly lower feeding rate (16.2%) than the Sinai (51.2%) and Delta (69.7%) populations (P < 0.0001). The infection rate for the Sinai population was significantly higher (65.9%) than the rate for the Delta (52.3%; P < 0.05) and slightly higher than that for the Aswan (62.5%). No differences were observed in the intensity of L. major infection in the midguts of the sandflies examined from any of the three populations. When flies fr...