Cross-sectional Seroprevalence and Genotype of Hepatitis E Virus in Humans and Swine in a High-density Pig-farming Area in Central China

Seroprevalence survey of Hepatitis E Virus in Domestic Pigs in Guangdong, China

The Hepatitis E virus (HEV) causes acute and chronic Hepatitis E and is a global public health concern. HEV genotypes 3 (HEV-3) and 4 (HEV-4) are common to humans and animals, and domestic pigs and wild boars have been identified as the main reservoirs. However, limited information is available on the status of HEV infection in pigs, particularly in the Guangdong Province, China. This study aimed to investigate the seroprevalence of HEV in pig farms within the Guangdong Province. A total of 1568 serum samples were collected from 25 farms and tested for anti-HEV IgG antibodies. Enzyme-linked immunosorbent assay (ELISA) results revealed that 57.53% (902/1568) of serum samples from 24 farms (24/25, 96%) were positive for anti-HEV IgG antibodies. Year, season, region, and age were all linked risk factors for HEV in Guangdong, with season and region showing more significant impacts. The results showing a high seroprevalence of HEV confirmed its circulation among domestic pigs in the Guangdong Province, China. The presence of this antibody indicates that HEV infection was or is present on farms, posing a risk of zoonotic transmission of HEV from pigs to exposed workers and from pork or organs to consumption.

Association of Common Zoonotic Pathogens With Concentrated Animal Feeding Operations

Animal farming has intensified significantly in recent decades, with the emergence of concentrated animal feeding operations (CAFOs) in industrialized nations. The congregation of susceptible animals in CAFOs can lead to heavy environmental contamination with pathogens, promoting the emergence of hyper-transmissible, and virulent pathogens. As a result, CAFOs have been associated with emergence of highly pathogenic avian influenza viruses, hepatitis E virus, Escherichia coli O157:H7, Streptococcus suis, livestock-associated methicillin-resistant Staphylococcus aureus, and Cryptosporidium parvum in farm animals. This has led to increased transmission of zoonotic pathogens in humans and changes in disease patterns in general communities. They are exemplified by the common occurrence of outbreaks of illnesses through direct and indirect contact with farm animals, and wide occurrence of similar serotypes or subtypes in both humans and farm animals in industrialized nations. Therefore, control measures should be developed to slow down the dispersal of zoonotic pathogens associated with CAFOs and prevent the emergence of new pathogens of epidemic and pandemic potential.

Identifying Circular RNAs in HepG2 Expressing Genotype IV Swine Hepatitis E Virus ORF3 Via Whole Genome Sequencing

Swine hepatitis E (SHE) is a new type of zoonotic infectious disease caused by swine hepatitis E virus (SHEV). Open reading frame 3 (ORF3) is a key regulatory and virulent protein of SHEV. Circular RNAs (circRNAs) are a special kind of non-coding RNA molecule, which has a closed ring structure. In this study, to identify the circRNA profile in host cells affected by SHEV ORF3, adenovirus ADV4-ORF3 mediated the overexpression of ORF3 in HepG2 cells, whole genome sequencing was used to investigate the differentially expressed circRNAs, GO and KEGG were performed to enrichment analyze of differentially expressed circRNA-hosting gene, and Targetscan and miRanda softwares were used to analyze the interaction between circRNA and miRNA. The results showed adenovirus successfully mediated the overexpression of ORF3 in HepG2 cells, 1,105 up-regulation circRNAs and 1,556 down-regulation circRNAs were identified in ADV4-ORF3 infection group compared with the control. GO function enrichment analysis of differentially expressed circRNAs-hosting genes classified three main categories (cellular component, biological process and molecular function). KEGG pathway enrichment analysis scatter plot showed the pathway term of top20. The circRNAs with top10 number of BS sites for qRT-PCR validation were selected to confirmed, the results indicated that the up-regulated hsa_circ_0001423 and hsa_circ_0006404, and down-regulated of hsa_circ_0004833 and hsa_circ_0007444 were consistent with the sequencing data. Our findings first preliminarily found that ORF3 protein may affect triglyceride activation (GO:0006642) and riboflavin metabolism (ko00740) in HepG2 cells, which provides a scientific basis for further elucidating the effect of ORF3 on host lipid metabolism and the mechanism of SHEV infection.

Global molecular diversity of Hepatitis E virus in wild boar and domestic pig

Our study aim was to describe and characterize the global Hepatitis E virus (HEV) molecular and genotype geographical distribution in domestic pig and wild boar, which could facilitate the traceability of human cases. We performed a systematic sequence search for HEVs identified in domestic pig and wild boar from the available data in GenBank. Only sequences with lengths greater than 300 nt were included. For all sequences, the sequence length, host (i.e., domestic pig or wild boar), country of origin, and HEV genotype/subtype were recorded. Genotypes were assigned by the HEVnet typing tool. The genotype distributions were described by country and host. In countries with sequences available for both species, the genotype coincidences between both animal populations were analyzed. A total of 1404 viral sequences were included: 32.6% from wild boar and 67.4% from domestic pig. Most sequences were consistent with HEV genotype 3 (n = 1165). Genotype 4 was represented by 193 sequences, while genotypes 5 and 6 were represented by only 6 sequences. Sequences were identified in 39 countries, which included all continents except Antarctica. The genotypes with a wide distribution were 3a and 3f. Twenty-five countries had sequences that were found only in domestic pig, three countries only in wild boar, and 11 countries had sequences in both populations. In all countries with available sequences in both populations, the same viral genotype was identified. Our study shows that the number of swine HEV sequences is small, which limits direct comparisons with the sequences identified in humans. The global distribution of genotype 3, together with the wide distribution of genotype 4 in Asia, strongly limits the interpretation of the molecular analysis in the absence of an epidemiological survey of the cases. Increased HEV sequencing in swine should be a priority.

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Our study shows that the number of swine HEV sequences is small.

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The global distribution of genotype 3 strongly limits the interpretation of the molecular analysis.

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Increased HEV sequencing in swine should be a priority.

Hepatitis E virus in professionally exposed: A reason for concern?

The zoonotic risk of hepatitis E virus (HEV) is well established. The HEV seroprevalence rates vary according to geographical region, assays used, and study cohorts. HEV infection is still underdiagnosed, implying the need to evaluate the disease's burden in the general population and specific risk groups, such as professionally exposed. Close contact with various animal reservoirs such as pigs, rabbits, sheep, dogs, wild boars, and deer has been associated with higher anti-HEV seroprevalence as a part of occupational exposure. While exact transmission routes remain to be determined, some general preventive measures such as proper hand hygiene, the usage of personal protective equipment, and the thermal processing of food before consumption should be followed. A “One-Health” multisectoral approach should be implemented to achieve optimal health and well-being outcomes, recognizing the interconnections between humans, animals, plants, and their shared environment, in which a vaccine against the zoonotic genotypes 3 and 4 and swine vaccination should be considered as a possible public health measure. This opinion review comprehensively addresses the HEV burden of professional exposure for butchers, slaughterhouse workers, veterinarians, farmers, hunters, and forestry workers delineates the current limits of protective work measures, and tackles future directions.

Deep Insight Into Long Non-coding RNA and mRNA Transcriptome Profiling in HepG2 Cells Expressing Genotype IV Swine Hepatitis E Virus ORF3

Swine hepatitis E (swine HE) is a new type of zoonotic infectious disease caused by the swine hepatitis E virus (swine HEV). Open reading frame 3 (ORF3) is an important virulent protein of swine HEV, but its function still is mainly unclear. In this study, we generated adenoviruses ADV4-ORF3 and ADV4 negative control (ADV4-NC), which successfully mediated overexpression of enhanced green fluorescent protein (EGFP)-ORF3 and EGFP, respectively, in HepG2 cells. High-throughput sequencing was used to screen for differentially expressed long non-coding RNAs (lncRNAs) and messenger RNAs (mRNAs). The cis-target genes of lncRNAs were predicted, functional enrichment (Gene Ontology [GO] and Kyoto Encyclopedia of Genes and Genomes [KEGG]) was performed, and 12 lncRNAs with statistically significant different expressions (p ≤ 0.05 and q ≤ 1) were selected for further quantitative real-time reverse transcription (qRT-PCR) validation. In HepG2 cells, we identified 62 significantly differentially expressed genes (DEGs) (6,564 transcripts) and 319 lncRNAs (124 known lncRNAs and 195 novel lncRNAs) that were affected by ORF3, which were involved in systemic lupus erythematosus, Staphylococcus aureus infection, signaling pathways pluripotency regulation of stem cells, the peroxisome proliferator-activated receptor (PPAR) signaling pathway, and platinum drug resistance pathways. Cis-target gene prediction identified 45 lncRNAs corresponding to candidate mRNAs, among which eight were validated by qRT-PCR: LINC02476 (two transcripts), RAP2C-AS1, AC016526, AL139099, and ZNF337-AS1 (3 transcripts). Our results revealed that the lncRNA profile in host cells affected by ORF3, swine HEV ORF3, might affect the pentose and glucuronate interconversions and mediate the formation of obstructive jaundice by influencing bile secretion, which will help to determine the function of ORF3 and the infection mechanism and treatment of swine HE.

Prevalence of hepatitis E virus among swine in China from 2010 to 2019: A systematic review and meta-analysis

Hepatitis E virus (HEV) is a zoonotic pathogen that has spread worldwide. The HEV reservoir associated with livestock hepatitis E poses a huge threat to public health. Awareness of the prevalence and spatial distribution of livestock hepatitis E is valuable to prevent and control diseases caused by HEV, especially human hepatitis E infection. Currently, swine, including pigs (Sus scrofa), are recognized as the major reservoir of HEV. Therefore, we conducted a systematic review and meta-analysis to evaluate the pooled prevalence of HEV among swine in China. A total of 71 published papers on HEV infection in swine in China (including data from 49,523 animals) from January 1, 2010 to December 31, 2019 met the standard after searching five databases including the Technology Periodical Database, the Wan Fang Database, the China National Knowledge Infrastructure, PubMed, and ScienceDirect. A random effects model was used to calculate the pooled prevalence of HEV in swine. The results showed that the seroprevalence was 48.0% (95% confidence interval (CI) 39.6-56.9) and the prevalence of HEV RNA was 14.4% (95% CI 10.7-18.5). The estimated overall prevalence was 34.1% (95% CI 27.2-41.4). Central China (68.0%, 95% CI 42.2-89.1) had a significantly higher prevalence than other regions. In the publication year subgroup, the prevalence in 2016 or later (27.2%, 95% CI 19.3-36.0) was significantly lower than that in 2011 or earlier (49.0%, 95% CI 36.2-61.8). The prevalence of IgG (42.9%, 95% CI 31.7-54.6) was significantly higher than that of IgM (4.9%, 95% CI 1.6-9.7). Suckling piglets (15.6%, 95% CI 6.6-27.1) had a lower prevalence compared with that in other age groups. In all sample types, body fluids showed the highest prevalence (50.5%, 95% CI 41.7-59.3). Moreover, the pooled prevalence of HEV in boars was higher than that in sows (35.4% > 17.3%). The analysis suggested that HEV infection is common among swine in China. Further strengthening HEV testing in boars, controlling environmental pollution, and reducing the mixed feeding of different stages could contribute to reducing HEV infection in pigs in China and the risk of porcine HEV infection in humans.

Seroprevalence of AIH-related autoantibodies in patients with acute hepatitis E viral infection: a prospective case-control study in China

The seroprevalenc of autoimmune hepatitis (AIH)-related antibodies in patients, particularly Asians, with acute hepatitis E (AHE) is unclear. In this study, we investigated whether acute hepatitis E virus (HEV) infection is associated with the seroprevalence of AIH-related autoantibodies and assessed their impact on the disease characteristics. AIH-related autoantibodies were detected by indirect immunofluorescence in 198 AHE patients and 50 type 1 AIH patients. The positivity rates of against nuclear antigen (ANA) and smooth muscles antibody (SMA) in AHE patients were 37.4% and 22.7%, and the total positivity rate was 50%. Compared to those in AIH patients, the positivity rates of ANA-H and SMA-AA were significantly lower (35.1% vs. 82.1% and 4.4% vs. 88.4%). Female gender and the ALT level, but not immunosuppressive or antiviral drugs, were independently predictive of the presence of AIH-related autoantibodies in AHE patients. Fifty-two patients positive for AIH-related autoantibodies were followed up for 12 months. During this period, 33 of them became negative and 19 remained positive, albeit with significantly decreased titres. In conclusions, the seroprevalence of AIH-related autoantibodies in AHE patients was elevated, particularly in females, but their subspecificities and titres differed from those of type 1 AIH. Acute HEV infection may be related to AIH.

Abbreviations: AIH: autoimmune hepatitis; AHE: acute hepatitis E; ANA: against nuclear antigen; SMA: smooth muscles antibody; ANA-H: ANA with homogeneous pattern; SMA-AA: SMA with anti-actin pattern; Anti-LKM1: anti- liver-kidney microsomes-1 antibody; ANCA: anti-neutrophil cytoplasmic antibody; AMA: anti-mitochondrial antibody; Anti-SLA: anti-soluble liver antigen; Anti-LC1: anti-liver cytoplasmic type 1 antibody; pANCA: perinuclear antineutrophil cytoplasmic antibody