Low prevalence of zoonotic Babesia in small mammals and Ixodes ricinus in Brittany, France.

In order to evaluate the zoonotic risk due to Babesia spp., especially B. microti, we investigated their presence in 597 individuals of five small mammal species and in 2620 questing nymphs of Ixodes ricinus in rural landscapes of Western France (Brittany). Small mammals (rodents and shrews) are indeed suspected to be reservoir hosts for B. microti, and the tick I. ricinus is the vector of the three main zoonotic species in Europe, i.e. B. divergens, B. venatorum and B. microti. Only one bank vole carried B. microti (genotype "Munich") and only 13 and 2 nymphs of Ixodes ricinus ticks carried B. venatorum and B. capreoli respectively. According to these results, prevalences observed for zoonotic Babesia (0.17% for small mammals and 0.50% for ticks), indicate that exposure of humans to this infectious agent is probably low in western France.