Bat rabies in France: Analysis of national surveillance data reveals contrasting bioclimatic preferences between EBLV-1a and EBLV-1b of the common serotine (Cnephaeus (Eptesicus) serotinus) bats.

Bat rabies in mainland France is mainly caused by European bat lyssavirus 1 (EBLV-1; Lyssavirus hamburg), which is almost exclusively associated with the common serotine bat, Cnephaeus (Eptesicus) serotinus. Two variants, EBLV-1a and EBLV-1b, circulate in France and display largely distinct, parapatric distributions. Because bats are highly sensitive to climatic conditions due to their physiological characteristics, including heterothermy, we investigated the relationship between climate and the geographical distribution of these two variants. Using generalized linear models and species distribution models, we assessed the influence of temperature and precipitation on EBLV-1 occurrence. The distribution of EBLV-1 cases was significantly associated with climatic variables, particularly minimum temperatures during the coldest month, maximum temperatures during the warmest month, and precipitation during the driest period. EBLV-1a was more frequently associated with areas characterized by milder winters and warmer, more humid conditions, whereas EBLV-1b was linked to colder and drier environments. Habitat suitability models predicted limited overlap between the two variants, supporting the existence of distinct climatic niches. These findings suggest that climatic factors contribute to shaping the spatial distribution of EBLV-1 variants and highlight the need for broader scale studies to better understand their ecology and potential response to future climate change.