Molecular epidemiological investigation of swine hepatitis e virus (sHEV) in Guangdong Province, China: prevalence, genotypic characteristics, and zoonotic risk.
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Abstract
Background: Hepatitis E virus (HEV) is a major zoonotic foodborne pathogen causing human acute hepatitis, with genotype 4 endemic in China and swine as its main reservoir. Guangdong has a large intensive swine industry, yet stratified molecular epidemiological data on swine HEV are lacking. This study explored the prevalence, risk factors and genetic traits of swine HEV in Guangdong to support zoonotic disease control.
Methods: A total of 1280 pig fecal samples from farms and abattoirs were tested for HEV RNA via RT-nPCR targeting ORF2. All positive samples underwent Sanger sequencing, and partial isolates were amplified for near-full-length genomes. Phylogenetic trees were built using the maximum likelihood method with 1000 bootstraps. Samples were grouped by region, season and sampling site; subgroup detection rates were compared via χ² and Fisher's exact tests, and binary logistic regression identified independent risk factors (P < 0.05).
Results: The overall HEV positive detection rate was 2.66% (34/1280, 95% CI: 1.85-3.69). Detection rates differed markedly by region (P < 0.001) and season (P < 0.05), with no discrepancy between farms and abattoirs (P > 0.05). Region and season were independent risk factors. All isolates were HEV genotype 4, dominated by subtype 4a plus minor 4b and 4d strains, with consistent genotyping results from ORF2 and full-length genomes. Wide genetic divergence existed among local strains, and amino acid mutations concentrated in the ORF1 hypervariable region.
Conclusion: Swine HEV prevalent in Guangdong Province mainly belongs to genotype 4 and exhibits obvious regional and seasonal distribution characteristics. Continuous and targeted surveillance in high-risk regions and peak epidemic seasons is recommended to reduce the zoonotic transmission risk of swine HEV and ensure public health safety.
期刊介绍：
BMC Veterinary Research is an open access, peer-reviewed journal that considers articles on all aspects of veterinary science and medicine, including the epidemiology, diagnosis, prevention and treatment of medical conditions of domestic, companion, farm and wild animals, as well as the biomedical processes that underlie their health.
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