Risk Assessment of the Role of the Ecotones in the Transmission of Zoonotic Cutaneous Leishmaniasis in Central Tunisia.

Zoonotic cutaneous leishmaniasis (ZCL), endemic in Central and Southern Tunisia, is caused by (Kinetoplastida: Trypanosomatidae), which is transmitted by the sand fly . In Tunisia, the fat sand rat and the desert jird are the principal reservoir hosts of . The presence of the vector of the etiologic agent of ZCL was assessed in the vicinity of villages in endemic areas of Central Tunisia. The study was performed from September through October 2019, a period corresponding to the main peak of activity of . Sand flies were collected from rodent burrows located at the ecotone level, which is the transition zone between the natural environment and human settlement. Sand flies were identified to species level and tested for the presence of by PCR. Our entomological survey showed that is the most abundant sand fly species associated with rodent burrows, and this abundance is even higher in ecotones primarily occupied by in comparison to ecotones occupied by . Infections with were detected only in , with an overall minimum infection rate (MIR) of 2.64%. No significant difference was observed between the MIRs in ecotones of and of . Incidence of ZCL in the studied areas ranged from 200 to 700 cases per 100,000 inhabitants, with a mean incidence of 385.41 per 100,000. Higher ZCL incidence was identified in ecotones of compared to ecotones of . ZCL cases are positively correlated with the MIRs. Considering the short flight range of , increases in its densities associated with burrows of or at the ecotone level expand the overlap of infected vectors with communities and subsequently increase ZCL incidence. Therefore, control measures should target populations at the ecotones.