Spatiotemporal dynamics and environmental drivers of listeriosis hospitalizations in Spain (2016-2024): A One Health perspective

Background: Listeria monocytogenes causes invasive infections with high mortality. However, ecological studies linking human incidence to livestock and weather remain scarce. This retrospective study analyzed the geographical distribution of human listeriosis in Spain using nationwide hospitalization data, livestock censuses, and meteorological records. Methods: Negative binomial regression models, spatial autocorrelation (Moran's Index), and bivariate local indicators of spatial association (LISA) analysis were applied. Results: Between 2016 and 2024, 4,391 hospital admissions were recorded. The national mean incidence was 1.03 per 100,000 inhabitants, peaking in 2019. Bovine density was the primary environmental driver, with an 11% increased risk per 10 heads/km2. Weather-livestock synergies were observed: bovine-associated risk increased exponentially at higher temperatures ([~]21 C) and lower humidity (53%), whereas caprine-associated incidence peaked at cooler temperatures ([~]13 C). Spatial mapping revealed northern clusters for bovine reservoirs and southern segregation for caprine reservoirs, with no associations for ovine or porcine livestock. Conclusions: Zoonotic risk is environmentally conditioned, with weather acting as a biological trigger. This study highlights the critical role of ruminant farming practices and the need for a "One Health" surveillance approach that integrates meteorological and farming data to predict seasonal outbreaks and optimize food chain safety.