Risk assessment of West Nile fever in equines in Europe based on an ecological niche model

West Nile fever is a zoonotic viral disease transmitted by Culex mosquitoes, capable of causing severe neurological illness in humans, equines, and birds. Over the past dozen years, Europe has experienced numerous WNF outbreaks of varying severity, leading to significant public health and economic impacts. Consequently, WNF has emerged as a major concern for both public health and veterinary sectors. In this study, we employed spatiotemporal analysis techniques alongside an optimized ecological niche model to investigate the spatiotemporal distribution patterns of historical WNF outbreaks, predict high-risk areas for equine WNF occurrence in Europe, and identify associated risk factors. The spatiotemporal analysis revealed a distinct seasonal pattern, with most outbreaks occurring in September. Between 2010 and 2023, the overall spread direction of equine WNF outbreaks in Europe trended from southeast to northwest, forming seven statistically significant spatiotemporal clusters. Ecological niche modeling indicated that southern Portugal, southern and eastern coastal regions of Spain, southwestern and southeastern regions of France, most parts of Italy, northeastern Germany, western Poland, southwestern coastal regions of Croatia, southwestern coastal regions of Bosnia and Herzegovina, southwestern coastal regions of Montenegro, western coastal regions of Albania, most parts of Greece, southwestern regions of Bulgaria, and Tekirdağ Province in Turkey are high-risk areas for WNF occurrence in equines in Europe. Isothermality, mean temperature of the warmest quarter, mean precipitation of the warmest quarter, elevation, and NDVI are important variables affecting WNF occurrence in equine. This study provides valuable insights to support targeted West Nile virus surveillance and optimized resource allocation across Europe.