Specification of blood meals ingested by female sand flies caught in Palestinian foci and identification of their concomitant leishmanial infections

Author summary Leishmaniases are vector-borne tropical diseases caused by more than twenty species belonging to the protozoan genusLeishmaniaand transmitted to humans and some other mammalian species by the bites of female phlebotomine sand flies. In the Palestinian Authority, cutaneous leishmaniasis (CL) is the most common leishmaniasis. This study investigated the Palestinian sand fly fauna, their infection rates and feeding preference determined by applying a kDNA-PCR and an ITS1-PCR. Twenty phlebotomine species were shown to be circulating in the study area. The most abundant species wasPh.papatasi(33.7%), followed byPh.sergenti(21%). Infection by parasites ofL.tropicawas confirmed in 6.4%, using an ITS1-PCR. Meals of human blood were the most abundant (78.1%) and those of hyrax blood were identified in the cases of six sand flies, fivePh.sergentiand onePh.papatasi Since leishmaniases are zoonotic vector-borne diseases transmitted through the bites of infected female sand flies, identification of the sources of imbibed blood meals and the detection and identification of leishmanial DNA in them are important in discerning animal reservoirs, clarifying the epidemiology and facilitating control of local leishmaniases. CDC light traps, aspirators and sticky paper traps were used to collect sand flies in four Palestinian foci of both, CL and VL. Phlebotomine species identification was based on morphological keys. Female specimens were screened to detect and identify leishmanial infections, using a kDNA-PCR and ITS1-PCR, and engorged female specimens were analyzed to identify the origin of their blood meals, using an RDB blood meal assay based on the amplification of the cytochrome b gene (cytb) of vertebrate mitochondrial DNA (mtDNA). Twenty sand fly species, 11 of the genusPhlebotomusand nine of the genusSergentomyia, were identified. The most abundant species wasPh.papatasi(33.7%), followed byPh.sergenti(21%). Among the 691 female sand fly specimens, 18.5% (128/691) were positive for leishmanial DNA, using the kDNA-PCR and 6.4% (44/691) were positive using the ITS1-PCR. DNA from parasites of the genusLeishmaniawas identified in only 1.5% of the infected sand flies. That ofLeishmania tropicaparasites was detected in six female specimens ofPh.sergentiand that ofL.majorparasites in two female specimens ofPh.papatasi. Interestingly, two engorged females of the speciesSe. (Neophlebotomus) sp. were positive forL.tropicaDNA. Ninety engorged female sand flies ofPh.papatasiand 104 ofPh.sergentihad fed on a large variety of vertebrate hosts such as humans, hyraxes, rats, cows, goats and birds. Regarding blood-meals showing a mixture from different species of animal host, hyrax and rat blood was revealed in 8/104 (7.7%) females ofPh.sergenti. Detection of hyrax blood in engorged female sand flies of the speciesPh.sergentisupports the role of hyraxes being a potential reservoir ofL.tropicain Palestinian regions. Rat blood meals might be significant since a few strainsL.tropicaandL.infantumwere isolated from rats. Further studies must be undertaken before conclusions could be drawn.