Increased prevalence of human cutaneous leishmaniasis in Israel and the Palestinian Authority caused by the recent emergence of a population of genetically similar strains of Leishmania tropica

Abstract

Twelve unlinked microsatellite markers were used to determine the microsatellite profiles of 50 newly and 46 previously typed strains of L. tropica from various Israeli and Palestinian foci. Their microsatellite profiles were compared to those of 99 previously typed strains of L. tropica from 15 countries. Israeli and Palestinian strains of L. tropica fell into three different groups, one of which contained 75 of the 96 Israeli and Palestinian strains. This population separated from all the others at the first hierarchical level by Bayesian statistics and formed a distinct monophyletic group on applying genetic distance and allele frequency analyses. The second cluster contained ten Israeli strains from a specific focus north of the Sea of Galilee, which were previously shown to differ from all other strains of L. tropica in their serological, biochemical and molecular biological parameters. This cluster was closely related to clusters comprising strains of L. tropica from Africa. Four Israeli and five Palestinian strains fell into different genetic entities mostly related to strains from Asian foci of CL. Importation during numerous migrations of humans and, perhaps, infected reservoir animals in the past and, now, through modern travel is the most likely explanation for the existence of so many locally encountered genetic variants of L. tropica in the Israeli-Palestinian region. Geographical and ecological variation may play a role in expanding the genetic heterogeneity once given importations had become established in different foci. Currently, one population is expanding in the area comprising almost all of the Palestinian and Israeli strains of L. tropica isolated since 1996 and investigated in this study, which differ clearly from all other strains of whatsoever origin. This population seems to result from the re-emergence of a previously existing genotype owing to environmental changes and human activities.

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

“…Previous epidemiological studies undertaken in the Palestinian Authority, especially in the Jenin District, were focused on improving the diagnosis of human cases and the identification of the infective agent. Three species of Leishmania: L. major, L. tropica and L. infantum, were identified as causative agents of CL in Palestinian foci [20][21][22][23][24][25]. Here, data are presented on the distribution of phlebotomine sand flies from areas where sporadic human cases of CL continue to occur every year, giving their rates of infection with leishmanial parasites and their blood feeding preferences.…”

Gene Expression in Leishmania Is Regulated Predominantly by Gene Dosage

“…Leishmania tropica is a species that has been recently linked to massive epidemics of CL in refugee camps in Syria and neighboring areas of the Middle East, including Iraq, Jordan, Israel, Palestine, and Afghanistan, due to ongoing armed conflict and civil unrest in the region (2)(3)(4). This species is highly prevalent in this geographic region and follows an anthroponotic, or human-to-human, transmission cycle, which sets this species apart from the zoonotic and coendemic species Leishmania major.…”

Cutaneous Leishmania tropica in children: report of three imported cases successfully treated with liposomal amphotericin B

“…Since 2014, L. tropica has been increasingly recorded in Errachidia 3 as well as in some Middle East countries. 4 Determining the specific species is important because treatment and prognosis vary for each species. The appraisal of fast and reliable molecular techniques such as PCR has made species-directed treatment feasible; however, no standardized therapeutic regimen for L. tropica exists, and the choice of the optimal therapy remains challenging for the clinician.…”