# Meta-analysis of global prevalence of hepatitis E virus infection in deer

## TL;DR

This study estimates how common hepatitis E virus is in deer worldwide, showing big differences by region and testing method, which is important for preventing human infections.

## Contribution

A global meta-analysis of HEV prevalence in deer with subgroup analyses by region, development status, and diagnostic methods.

## Key findings

- North America had the highest HEV prevalence in deer, with Mexico reporting the highest national estimate.
- Developing countries showed higher HEV prevalence in deer compared to developed countries.
- Molecular methods detected higher active HEV infection rates than serological tests.

## Abstract

Hepatitis E virus (HEV) is an important zoonotic pathogen, and deer serve as a potential wildlife reservoir capable of contributing to human infections through wildlife–livestock–human transmission pathways. Accurate estimates of HEV prevalence in deer are essential for understanding zoonotic risks and informing surveillance strategies.

We conducted a systematic search across five major databases. Among 134 publications screened, 33 studies met the inclusion criteria for meta-analysis. Pooled prevalence estimates were calculated, and subgroup analyses were performed by region, development status, time period, age, sex, and diagnostic method. Serological assays (ELISA) and molecular assays (RT-PCR and RT-qPCR) were evaluated separately.

Significant geographical and demographic variation in HEV prevalence was observed. North America showed the highest pooled prevalence (29.57%, 95% CI: 0.00–89.25), with Mexico reporting the highest national estimate (62.68%, 95% CI: 54.54–70.47). Developing countries exhibited higher prevalence (21.45%, 95% CI: 7.12–40.63) than developed countries (5.01%, 95% CI: 2.40–8.43). HEV infection decreased over time, with lower prevalence after 2010 (4.92%, 95% CI: 1.57–9.83) compared with before 2010 (13.17%, 95% CI: 6.01–22.45). Adults had higher infection rates (23.02%, 95% CI: 9.04–41.06) than juveniles (10.11%, 95% CI: 5.83–15.41), and females slightly exceeded males (6.25% vs. 5.07%). Serology indicated past exposure (10.48%, 95% CI: 4.29–18.92), while molecular methods reflected active infection, with pooled rates of 8.58% for RT-PCR and 5.22% for RT-qPCR.

Our findings reveal substantial heterogeneity in HEV prevalence among deer and highlight the importance of standardized diagnostic protocols. These results underscore the need for harmonized surveillance to better assess zoonotic risks and support public health strategies targeting HEV transmission at the wildlife–human interface.