Hepatitis E (HE) is a zoonotic viral disease caused by hepatitis E virus (HEV). The objective of this study was to investigate the prevalence of HEV infection among dogs and humans exposed to dogs in the south-west region of China. A total of 4,490 dog serum samples and 2,206 relative practitioner serum samples were collected from 18 pet hospitals and dog farms in Yunnan, Sichuan and Guizhou province, and the anti-HEV IgG antibodies were detected by ELISA. The results showed that the total positive rate of anti-HEV antibodies was 36.55% with the highest rate in city stray dogs, and the differences in distinct species and growth phases were significant. The positive rate of anti-HEV antibody in veterinarian and farm staff-related practitioners was significantly higher than the general population. The finding of the present survey suggested that high HEV seroprevalence in dogs and humans exposed to dogs in the south-west area of China poses a significant public health concern. It is urgent to improve integrated strategies to detect, prevent and control HEV infection in dogs and humans exposed to dogs in this area.

Hepatitis E virus (HEV) is responsible for hepatitis E, which represents a global public health problem. HEV genotypes 3 and 4 are reported to be zoonotic, and animals are monitored for HEV infection in the interests of public hygiene and food safety. The development of novel diagnostic methods and vaccines for HEV in humans is thus important topics of research. Opening reading frame (ORF) 2 of HEV includes both linear and conformational epitopes and is regarded as the primary candidate for vaccines and diagnostic tests. We investigated the precise location of the HEV epitopes in the ORF2 protein. We prepared four monoclonal antibodies (mAbs) against genotype 4 ORF2 protein and identified two linear epitopes, G438IVIPHD444 and Y457DNQH461, corresponding to two of these mAbs using phage display biopanning technology. Both these epitopes were speculated to be universal to genotypes 1, 2, 3, 4, and avian HEVs. We also used two 12-mer fragments of ORF2 protein including these two epitopes to develop a peptide-based enzyme-linked immunosorbent assay (ELISA) to detect HEV in serum. This assay demonstrated good specificity but low sensitivity compared with the commercial method, indicating that these two epitopes could serve as potential candidate targets for diagnosis. Overall, these results further our understanding of the epitope distribution of HEV ORF2, and provide important information for the development of peptide-based immunodiagnostic tests to detect HEV in serum.

Recently, a report in Viruses has highlighted the problem of porcine circovirus-like (PCL) virus [...]

In this study, we detected a circular replication-associated protein (Rep)-encoding single-stranded (CRESS) DNA virus [named Po-Circo-like (PCL) virus] in intestinal tissue and fecal samples of pigs. PCL virus contains a single-stranded DNA genome, and ORF1 encodes the Rep and not the typical capsid protein encoded in PCV. The Rep protein may be responsible for viral genome replication. In addition, PCL virus may be one of the pathogens causing diarrhea symptoms in pigs. We identified four strains of PCL virus in two different pig farms with severe diarrhea outbreaks in Hunan Province, China. The strains in this study share 85.7–99.7% nucleic acid identity and 84.7–100% amino acid identity with Rep of the reference strains. A multiple sequence alignment of these PCL viruses and Bo-Circo-like CH showed a identity of 93.2% for the Rep protein, and the nucleotide identity was 86.7–89.3%. Moreover, Bo-Circo-like CH and HN75, HN39-01, HN39-02 had similar stem-loop sequences. In conclusion, the present study is the first detailed report of the PCL virus in Hunan provinces, which is a potential new virus in pigs that might be involved in cross-species transmission. Further investigation is needed to determine the pathogenesis of this virus and its epidemiologic impact.

In this study, we detected a circular replication-associated protein (Rep)-encoding single-stranded (CRESS) DNA virus in intestinal tissue samples and faecal samples of pigs. Some researchers named po-circo-like (PCL) virus. PCL virus contains a single-stranded DNA genome, and ORF1 encodes the Rep and not the typical capsid protein encoded in PCV. The Rep protein may be responsible for viral genome replication. In addition, PCL virus may be one of the pathogens causing diarrhea symptoms in pigs. We identified four strains of PCL virus in two different pig farms with severe diarrhea outbreaks in Hunan Province, China. The strains in this study share 39.4%–94.9% nucleic acid identity and 85.3%–98.4% amino acid identity with Rep of the reference strains. A multiple sequence alignment of these PCL viruses and Bo-Circo-like CH showed a identity of 93.2% for the Rep protein, and the nucleotide identity was 86.7-89.3%. Moreover, Bo-Circo-like CH and HN75, HN39-01, HN39-02 had similar stem-loop sequences. The PCL virus might therefore be transmitted to non-porcine hosts by cross-species transmission routes. Through Recombination Detection Program (RDP), Simplot and phylogenetic analyses, strong evidence for recombination events was found in China field PCL virus strains. In conclusion, the present study is the first detailed report of the PCL virus in HuNan provinces, which is a potential new virus in pigs that might be involved in cross-species transmission. Further investigation is needed to determine the pathogenesis of this virus and its epidemiologic impact.