Hepatitis E virus is circulating widely among pigs raised in Beijing, China, according to a new study published in BMC Microbiology on 26 October 2026. Researchers tested 1,018 serum samples collected from 21 swine farms and found that 21.81 percent of the animals carried antibodies against the virus, indicating prior exposure. Seroprevalence varied across the 21 surveyed farms, with the study reporting variation in anti-HEV antibody prevalence among the farms included in the survey.
The team also examined 991 bile samples taken from slaughtered pigs for the presence of viral genetic material. Hepatitis E virus RNA was detected in 4.74 percent of these bile samples, confirming active viral shedding in a smaller but notable fraction of the animals. Sequence data were successfully obtained from 41 of the positive samples, allowing the researchers to characterize the viral strains circulating in the region.
Genetic analysis revealed that genotype 4, known as HEV-4, was the predominant genotype among the sampled pigs. Within this genotype, subtype 4a accounted for the majority of the sequenced samples, followed by subtype 4d. The genotype 3a strain, HEV-3a, was detected at a lower frequency.
To investigate the evolutionary relationships among the circulating strains, the researchers performed sequencing of the ORF1 and ORF2 regions of the viral genome, followed by phylogenetic analysis. For selected samples, they generated near-complete genome sequences and examined amino acid-level variation. No clear recombination signals were observed among the three near-complete genomes when compared with the selected reference sequences, indicating that genetic exchange between viral lineages was not a prominent feature of the sampled strains.
The amino acid characterization identified genotype-associated variation at residue 1634 of the RNA-dependent RNA polymerase, an enzyme central to viral genome replication. In addition, the analysis uncovered one substitution, designated T497I, within a reported neutralizing epitope of the ORF2 protein.
Hepatitis E virus is a major zoonotic pathogen, meaning it can be transmitted between animals and humans. Swine are recognized as an important reservoir for the virus, and the study’s authors note that contemporary data on the molecular epidemiology of the virus in Beijing’s swine populations had been limited prior to this investigation. The findings help fill that gap by documenting both the exposure rate among pigs and the genetic identity of the strains present in the city’s production system.
The study’s authors state that their findings characterize the seroepidemiological and molecular features of hepatitis E virus in swine sampled in Beijing and support continued genotype-resolved molecular surveillance. Because the samples were drawn from a defined set of 21 farms at a specific time, the results represent a snapshot of the situation in Beijing’s swine population rather than a long-term trend, and the authors frame ongoing monitoring as a priority for tracking how the virus evolves in this reservoir.
Subject of Research: Seroprevalence and genetic diversity of zoonotic hepatitis E virus in swine in Beijing, China
Article Title: Seroprevalence and genetic characterization of zoonotic hepatitis E virus among swine in Beijing, China
Article References: Guo, Z., Bi, J., Sun, Y., Wang, Q., Cheng, M., Mei, L., Zhang, R., Zhang, Q., Ou, Y., Hu, Y., Xu, K., Yin, W., Yang, L., & Tian, J. (2026). Seroprevalence and genetic characterization of zoonotic hepatitis E virus among swine in Beijing, China. BMC Microbiology. https://doi.org/10.1186/s12866-026-05861-4
Image Credits: AI Generated
DOI: 10.1186/s12866-026-05861-4
Keywords: hepatitis E virus, swine, zoonotic disease, Beijing, seroprevalence, HEV-4, molecular epidemiology, phylogenetics, ORF2, surveillance, genetic, characterization
News Source: Kristina Jarvis. (October 29, 2026). Research report: Seroprevalence and genetic characterization of zoonotic hepatitis E virus among swine in Beijing, China. Scienmag.
