# Hepatitis E in Wildlife: Emerging Threats to Human Health

## TL;DR

Wild animals, especially wild boars, play a key role in spreading Hepatitis E virus, posing risks to human health through contaminated game meat and environmental exposure.

## Contribution

This review highlights the role of wildlife in HEV transmission and emphasizes the need for improved surveillance to protect public health.

## Key findings

- Wild boars are the primary wildlife reservoir for HEV in Europe, with high seroprevalence reported in the Balkans.
- HEV RNA has been detected in game meats like deer and rabbit, indicating food safety risks.
- Rodents may spread HEV by contaminating the environment, increasing indirect transmission risks.

## Abstract

Hepatitis E virus is a cause of liver disease in people and is increasingly recognized as a zoonotic infection that can be shared between animals and humans. While domestic pigs are the main source of human infection, many wild animals also carry the virus and help it persist in nature. This narrative review examines the role of wildlife, especially wild boars, deer, hares, rabbits, rodents, and carnivores, in maintaining and spreading hepatitis E virus. Studies show that wild boars are the most important wildlife source, with high levels of infection reported in several European regions, including the Balkans, which represent an epidemiologically diverse subregion of Europe. The virus has also been found in the meat and organs of other game animals, which means that eating raw or undercooked game meat can pose a risk to people. In areas where hunting and handling of wild game are common, these practices may further increase human exposure to the virus. Small mammals such as rodents may further spread the virus by contaminating the environment. By summarizing current knowledge from Europe, with contextual reference to findings from other parts of the world, this review highlights existing gaps in wildlife surveillance and explains why monitoring wildlife is essential for food safety and public health. Better inclusion of wildlife in disease surveillance can help reduce infection risks and support a coordinated approach to protecting human, animal, and environmental health.

Hepatitis E virus (HEV) is a significant public health concern and a leading cause of acute viral hepatitis worldwide. In recent years, HEV has been increasingly recognized as a wildlife-associated zoonotic pathogen, with numerous free-ranging species contributing to its maintenance and transmission. While domestic pigs remain the primary reservoir for human infection globally, growing evidence indicates that wild animals, particularly wild boars, cervids, lagomorphs, rodents, and carnivores, play a critical role in the ecology of HEV. Wild boars are the principal wildlife reservoir, with HEV seroprevalence in Europe ranging from less than 5% to more than 50%, including some of the highest levels reported in the Balkans. In addition to the frequent detection of HEV RNA in wild boar liver and muscle, viral RNA has also been identified in several other game species, most consistently in red deer, roe deer, and, in some regions, hares and wild rabbits, highlighting food safety risks associated with the consumption of raw or undercooked game meat. In regions such as the Balkans, where hunting activities and handling of wild game are widespread, these practices may further increase occupational and dietary exposure to HEV. Rodents may further complicate the epidemiological landscape through environmental contamination of water, soil, and farm surroundings, thereby facilitating indirect transmission pathways. As wildlife populations expand and human–animal interfaces intensify, understanding HEV dynamics in free-ranging species is essential for assessing zoonotic risks and implementing a strengthened One Health approach. This narrative review synthesizes and critically examines current evidence on HEV prevalence, molecular characteristics, and transmission pathways in wildlife, with particular emphasis on Europe and focused consideration of the Balkans as an epidemiologically heterogeneous and underrepresented subregion; examines associated public health implications; and highlights the importance of integrating wildlife into food safety and One Health surveillance frameworks. Existing knowledge gaps and limitations in wildlife surveillance are also discussed.