Summary
Anthroponotic cutaneous leishmaniasis (ACL) due to Leishmania tropica is spreading to new areas. Exposure to the vector,Phlebotomus sergenti , is the only proven risk factor. Our objective was to compare the densities and genetic characteristics ofP. sergenti populations in two nearby localities in Morocco, one within an ACL endemic area (El Borouj) and another undamaged (Sidi Hajjaj). Statistically significant differences were detected betweenP. sergenti densities with a higher density of P. sergentiin the endemic town (p≤ 0.032). A different main P. sergentimitochondrial lineage was evidenced in each one of the 2 localities, and for the first time, the lineage of P. sergenti specimens that are acting as a vector of L. tropica has been identified. Bioclimatic differences were detected between both localities. In conclusion, between an ACL endemic locality and another ACL free there are differences in both the density of P. sergenti and the mitochondrial lineage that may explain the different epidemiological situation. Given that the density of P. sergenti in the locality without ACL cases seems sufficient to allow transmission, the main factor that would justify its ACL undamaged character could be the absence of P. sergenti Lineage IV, which seems to prefer warmer and drier climates.