Epidemiology of Leishmania infantum, Toxoplasma gondii, and Neospora caninum in Rattus rattus in absence of domestic reservoir and definitive hosts

Isolated environments are privileged settings to study transmission of infection. Montecristo is a small island where no wild or domestic carnivores are present. Invasive Black rats Rattus rattus (n=78) were captured and tested by PCR for Leishmania infantum, Toxoplasma gondii and Neospora caninum. We wanted to test, for these parasites, the existence of a sylvatic cycle independent of reservoir or definitive hosts. None of the rats tested positive by PCR for either T. gondii or N. caninum. We recorded a 15.5% prevalence (CI95% 8-26%) of L. infantum in the rats and Phlebotomus mascittii was captured in Montecristo, leading us to identify it as possible vector of the parasite.