First epidemiological characterization of Leishmania tarentolae in sand flies collected in southern France and Corsica Island.

Leishmania tarentolae, a reptile-associated parasite, is poorly documented in France. This study provides the first molecular survey of L. tarentolae in sand flies across mainland France and Corsica (2023-2024), combining morphological and molecular vector identification with PCR-based parasite detection. A total of 2,731 female sand flies were collected, and 412 unfed pools and 132 blood-fed females were analysed. Sergentomyia minuta was the main carrier, with higher infection rates than Phlebotomus perniciosus. Among unfed females, L. tarentolae was detected in 56 pools, mainly from Corsica, whereas only two positive pools were found in mainland France. One pool from Montpellier in mainland France was positive for L. infantum. Of the 132 blood-fed females analysed, 24 tested positive for L. tarentolae. Blood-meal analyses revealed multi-host feeding, humans, livestock, hares and first evidence of goat feeding in Se. minuta, indicating flexible feeding behaviour. Co-circulation of L. tarentolae and L. infantum complicates diagnostics and epidemiology. These findings expand the known range of Sauroleishmania in Western Europe and provide a framework for entomological and eco-epidemiological surveillance. Integrated monitoring of vectors, reptiles, and domestic animals is essential for assessing transmission risks amid environmental and climatic changes.