Abstract
The bank vole Myodes glareolus is the main reservoir of hantavirus Puumala (PUUV)responsible of the nephropathia epidemica (NE) in Europe. This work aims to describe theresistance/tolerance variability of M. glareolus to PUUV and to explore its role in the distribution andtransmission of the virus. We hypothesized that tolerance to PUUV favours its persistence andtransmission, which could increase the NE emergent risk.We developed candidate gene approach to determine the role of three immune genes inresistance / tolerance to PUUV. The existence of positive association between Drb gene allele andPUUV infection in one hand and the negative relationship detected between the Tnf-_ expression leveland PUUV prevalence in the other hand corroborates the evolution of tolerance in NE endemic area. Itcould be selected in response to the cost of inflammatory response which is activated againstPUUV.The population genetic approach demonstrated the role of population dynamic of reservoir inPUUV epidemiology. The comparison of Drb and Tnf-_ polymorphism and neutral genetic patternseems to indicate a weak influence of selection in the polymorphism of these immune genes. Thisresult suggests a potential important effect of phenotypic plasticity in the levels of resistance/toleranceobserved. The study of helminth communities confirmed this hypothesis showing the impact ofparticular species on the risk of PUUV infection.