Hepatitis E virus surveillance in wild ruminants from northwestern Italy: results of a three-year molecular survey.

Hepatitis E virus (HEV) is responsible for emerging foodborne zoonotic infections in Europe, which are primarily associated with genotype 3 and more sporadically to genotype 4. While domestic pigs and wild boars are recognized as the principal reservoirs, the epidemiological role of wild ruminants remains less clearly defined. Knowledge of the health status of wildlife is essential, not only to minimize potential risks to human health associated with the consumption of game meat, but also to study the spread of zoonotic diseases in the territory. This study investigated the presence of HEV infections in wild ruminants from northwestern Italy between 2023 and 2025. A total of 883 liver samples were collected from red deer (Cervus elaphus, n = 256), roe deer (Capreolus capreolus, n = 378), fallow deer (Dama dama, n = 136), and alpine chamois (Rupicapra rupicapra, n = 113) in the regions of Liguria, Piedmont, and Aosta Valley. All samples were tested by one-step real-time RT-PCR. No positive samples were identified, indicating the absence of HEV infections in the investigated populations during the study period. However, the cross-sectional design, the analysis of liver samples only, and the lack of serological data did not allow assessment of previous exposure or temporal patterns of virus circulation. Overall, the results suggest that the investigated wild ruminant species in northwestern Italy are unlikely to play a significant role in HEV epidemiology in this geographic context. Continued integrated surveillance, including both molecular and serological approaches, is recommended to monitor potential changes in virus circulation in wildlife to further clarify their role in HEV epidemiology.