The glutamate receptor antagonist ifenprodil inhibits hepatitis E virus infection.

Infection with hepatitis E virus (HEV) represents a global problem, with over 20 million people infected annually. No specific antiviral drugs are available for treating HEV infection, necessitating the development of novel targeted therapeutics. Here, we report that the N-methyl-D-aspartate receptor (NMDAR) antagonist ifenprodil, a clinically approved drug used to treat idiopathic pulmonary fibrosis (IPF), is an HEV inhibitor in liver-derived cells. In vitro investigation demonstrates that ifenprodil suppresses viral protein expression in a dose-dependent manner in human hepatoma cells by inhibiting early stages of viral infection. We also found that ifenprodil modulates host cell intrinsic biological processes distinct from virus-induced innate immunity, inhibiting HEV RNA accumulation in primary human hepatocytes. Finally, the inhibitory effect of ifenprodil in vivo was also tested in rabbits challenged with the HEV-3ra CHN-BJ-R14 strain. Fecal virus shedding was below the limit of detection in two animals for both ribavirin-treated and ifenprodil-treated rabbits compared to vehicle-treated control animals. Our data demonstrate that ifenprodil is an effective anti-HEV compound with potential as a therapeutic candidate for the treatment of HEV infection.

Hepatitis E virus infection during pregnancy: Advances in animal models.

Hepatitis E virus (HEV) is one of the major pathogens causing acute viral hepatitis worldwide, which usually causes acute self-limited diseases in general individuals. However, it can lead to high mortality and adverse pregnancy outcomes in pregnant women. Due to the lack of effective and stable cell culture models for HEV, the establishment of suitable animal models for HEV infection during pregnancy is necessary. An electronic search of the relevant database was conducted to identify eligible articles. Main animal models for the study of HEV infection during pregnancy include rabbits, swine, nonhuman primates and Mongolian gerbils. These animal models have been used to study the prevention, treatment and possible mechanisms of HEV infection during pregnancy. Studies using these animal models have investigated the potential pathogenesis of HEV infection during pregnancy. It has been found that immune mechanism (changes in the CD4/CD8 ratio and cytokines), hormonal changes (increase in pregnancy-related hormones) and viral factors (different genotypes and genome structures) can lead to HEV-related adverse pregnancy outcomes in animal models. In this review, we aimed to comprehensively present the characteristics of different animal models and the pathogenesis of HEV-related adverse pregnancy outcomes.

Incidence and risk factors of de novo hepatitis E virus infection after receiving liver transplantation.

Organ transplant recipients with hepatitis E virus (HEV) infection bears high risk to develop chronic hepatitis, which is generally associated with immunosuppressive therapies. This study aimed to identify the incidence and predictors of de novo HEV infection in patients after receiving transplantation. We performed a large retrospective study to investigate the prevalence of anti-HEV at baseline, incidence of de novo HEV infection after transplantation, and the risk factors of HEV infection among patients with liver transplant in China. A total of 407 liver transplant recipients were examined for the presence of anti-HEV immunoglobulin G, IgM antibodies, and HEV RNA in serum. Basal indexes in individuals with evidence of post-transplant HEV infection were compared with those without evidence of that, and risk factors associated with HEV infection were assessed. The prevalence of anti-HEV at pretransplant in liver transplant recipients was 25.8% (105/407). Serum-negative conversion occurred in 34 (32.38%) of 105 liver transplant patients. Sixty-five out of 302 patients had de novo HEV infection after transplantation, with a cumulative incidence of 42.74% during follow-up. After transplantation, HEV infection was associated with liver failure (p = 0.012), hypoproteinemia (p = 0.030) and higher level of r-glutamyl transferase (GGT) (p = 0.022) before transplantation. Graft rejection (OR = 0.075; p = 0.045) was negatively associated with serum-negative conversion in patients who had positive anti-HEV antibody before transplantation. The incidence of de novo HEV infection after transplantation were higher in China. Liver failure, hypoproteinemia, and GGT elevation may be associated with HEV infection after liver transplantation. This study suggests that prevention and control of HEV infection after liver transplantation should be paid attention in patients bearing these risk factors.

First detection of Hepatitis E virus (Rocahepevirus ratti) in French urban wastewater: Potential implications for human contamination.

Hepatitis E virus (HEV) is considered as an emerging zoonotic pathogen circulating in a wide range of animals. In recent decades, the genus Paslahepevirus frequently isolated in pigs were the most involved in human clinical practice. In addition, the genus Rocahepevirus have been isolated in rodents, and transmission to humans is increasingly reported worldwide, although gaps remain regarding the exposure factors. In this study, the presence of HEV was investigated in urban wastewater, swine slaughterhouse wastewater and river waters, in a geographical area where its circulation had previously been reported. In addition to the expected detection of Paslahepevirus in almost all waters samples collected, Rocahepevirus strains were detected with the same frequencies in urban and river waters, at concentrations up to 40-fold higher. No Rocahepeviruses were detected in swine slaughterhouse wastewater. This is the first study demonstrating the presence of Rocahepevirus in French wastewater. Although no evidence of transmission was reported among patients followed for a suspected HEV infection in the same area between April 2019 and October 2023 (i.e. 135/3078 serological tests positive for anti-HEV IgM detection; 46/822 blood samples positive for Paslahepevirus genome detection but none for Rocahepevirus), the circulation of Rocahepevirus in waters in such concentrations raises the question of the possible zoonotic transmission to human. Indeed, the waterborne transmission of HEV is now well documented in industrialized countries, and the exploration of the growing number of human infections in Europe involving Rocahepevirus has not until now made it possible to clarify the transmission routes.

Strain- and Subtype-Specific Replication of Genotype 3 Hepatitis E Viruses in Mongolian Gerbils.

Since Mongolian gerbils are broadly susceptible to hepatitis E virus (HEV), including genotypes 1, 4, 5, and 8 (HEV-1, HEV-5, HEV-5, and HEV-8) and rat HEV, they are a useful small animal model for HEV. However, we have observed that the subtypes HEV-3k and HEV-3ra in genotype 3 HEV (HEV-3) were not infected efficiently in the gerbils. A small-animal model for HEV-3 is also needed since HEV-3 is responsible for major zoonotic HEV infections. To investigate whether gerbils can be used as animal models for other subtypes of HEV-3, we injected gerbils with five HEV-3 subtypes (HEV-3b, -3e, -3f, -3k, and -3ra) and compared the infectivity of the subtypes. We detected viral RNA in the gerbils' feces. High titers of anti-HEV IgG antibodies in serum were induced in all HEV-3b/ch-, HEV-3f-, and HEV-3e-injected gerbils. Especially, the HEV-3e-injected animals released high levels of viruses into their feces for an extended period. The virus replication was limited in the HEV-3b/wb-injected and HEV-3k-injected groups. Although viral RNA was detected in HEV-3ra-injected gerbils, the copy numbers in fecal specimens were low; no antibodies were detected in the sera. These results indicate that although HEV-3's infectivity in gerbils depends on the subtype and strain, Mongolian gerbils have potential as a small-animal model for HEV-3. A further comparison of HEV-3e with different genotype strains (HEV-4i and HEV-5) and different genera (rat HEV) revealed different ALT elevations among the strains, and liver damage occurred in HEV-4i- and HEV-5-infected but not HEV-3e- or rat HEV-infected gerbils, demonstrating variable pathogenicity across HEVs from different genera and genotypes in Mongolian gerbils. HEV-4i- and HEV-5-infected Mongolian gerbils might be candidate animal models to examine HEV's pathogenicity.

Hepatitis E Virus Infection in Patients with Systemic and Cutaneous Lupus Erythematosus.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by a multifactorial etiology in which genetic and environmental factors interplay. An exclusively cutaneous condition has been described and defined as cutaneous lupus erythematosus (CLE). In Italy, a nationwide blood donor survey found an overall HEV prevalence of 8.7%, with an interregional variation from 2.2% to 22.8%. In this study, we aimed to estimate HEV seroprevalence in a cohort of patients affected by SLE and CLE attending the Lupus Clinic, Sapienza University of Rome. Serum samples were tested for anti-HEV immunoglobulin Ig G and M antibodies using commercial enzyme-linked immunosorbent assay (ELISA) kits. Statistical analysis was performed. In total, 138 patients were enrolled, 92 (67%) affected by SLE and 46 by CLE. The prevalence of HEV infection was 23.9% in the CLE group and 7.6% in the SLE group. The anti-HEV+ prevalence was significantly more frequent in CLE. Some mechanisms may be linked to increased susceptibility to HEV such as a molecular mimicry associated with the CLE condition or with the skin compartment/skin self-antigens, as well as the involvement of the genetic background. Regarding the possible risk factors, no association was found, although, of note, the odds of HEV+ relative to contact with animals and to eating raw seafood were strongly higher than the unit in the CLE group.

Phosphorylation of Ser711 residue in the hypervariable region of zoonotic genotype 3 hepatitis E virus is important for virus replication.

Hepatitis E virus (HEV) is distinct from other hepatotropic viruses because it is zoonotic. HEV-1 and HEV-2 exclusively infect humans, whereas HEV-3 and HEV-4 are zoonotic. However, the viral and/or host factors responsible for cross-species HEV transmission remain elusive. The hypervariable region (HVR) in HEV is extremely heterogenetic and is implicated in HEV adaptation. Here, we investigated the potential role of Serine phosphorylation in the HVR in HEV replication. We first analyzed HVR sequences across different HEV genotypes and identified a unique region at the N-terminus of the HVR, which is variable in the human-exclusive HEV genotypes but relatively conserved in zoonotic HEV genotypes. Using predictive tools, we identified four potential phosphorylation sites that are highly conserved in zoonotic HEV-3 and HEV-4 genomes but absent in human-exclusive HEV-1 strains. To explore the functional significance of these putative phosphorylation sites, we introduced mutations into the HEV-3 infectious clone and indicator replicon, replacing each Serine residue individually with alanine or aspartic acid, and assessed the impact of these substitutions on HEV-3 replication. We found that the phospho-blatant S711A mutant significantly reduced virus replication, whereas the phospho-mimetic S711D mutant modestly reduced virus replication. Conversely, mutations in the other three Serine residues did not significantly affect HEV-3 replication. Furthermore, we demonstrated that Ser711 phosphorylation did not alter host cell tropism of zoonotic HEV-3. In conclusion, our results showed that potential phosphorylation of the Ser711 residue significantly affects HEV-3 replication in vitro, providing new insights into the potential mechanisms of zoonotic HEV transmission.IMPORTANCEHEV is an important zoonotic pathogen, causing both acute and chronic hepatitis E and extrahepatic manifestation of diseases, such as neurological sequelae. The zoonotic HEV-3 is linked to chronic infection and neurological diseases. The specific viral and/or host factors facilitating cross-species HEV infection are unknown. The intrinsically disordered HVR in ORF1 is crucial for viral fitness and adaptation, both in vitro and in vivo. We hypothesized that phosphorylation of Serine residues in the HVR of zoonotic HEV by unknown host cellular kinases is associated with cross-species HEV transmission. In this study, we identified a conserved region within the HVR of zoonotic HEV strains but absent in the human-exclusive HEV-1 and HEV-2. We elucidated the important role of phosphorylation at the Ser711 residue in zoonotic HEV-3 replication, without altering the host cell tropism. These findings contribute to our understanding the mechanisms of cross-species HEV transmission.

Increasing trends in hepatitis E hospitalisations in Spain, 1997 to 2019.

BackgroundHepatitis E, a viral hepatitis caused mainly by the ingestion of raw or undercooked food, is not a notifiable disease in Spain.AimTo analyse the temporal trends, epidemiological characteristics and factors associated with severe disease from hepatitis E hospitalisations in Spain from 1997 to 2019.MethodsHospitalisation records were obtained from the Spanish National Hospital Discharge Database. Temporal trends and seasonality were analysed by Poisson regression in years 1997-2015 and 2016-19, given changes in hospital discharge databases. Multivariate logistic regression was used to identify factors associated with severe disease.ResultsHepatitis E hospitalisation incidence increased from 0.22 cases per 1,000,000 inhabitants in 1997 to a maximum of 2.95 in 2018. Seasonality was observed during 2016-19 period, with more cases in the second and third quarters of the year. The incidence was higher in men vs women, and in the population aged over 40 years. Factors independently associated with death were age ≥ 50 years (adjusted odds ratio (aOR): 2.43), chronic liver disease (aOR: 4.29), HIV infection (aOR: 3.00) and hepatitis B/C (aOR: 2.11).ConclusionsHepatitis E hospitalisations have increased in Spain in recent years, being more severe in cases with older age, chronic hepatic diseases and HIV infection. A greater incidence in men over 40 years and a possible seasonality were observed. Further studies are needed to assess the seasonality, geographical distribution and impact of the disease to guide public health actions for prevention and control.

First Detection of Hepatitis E Virus RNA in Ovine Raw Milk from Herds in Central Italy.

HEV mainly enters animal and human hosts through the orofecal route, which presents a critical health concern alongside the associated environmental variable. Among products of animal origin, milk (both ovine and bovine) can harbor HEV RNA, which can potentially be transmitted to consumers. In this study, a total of 220 raw ovine milk samples were collected from Apennine breed subjects farmed (transhumance method) in three different Italian provinces, L'Aquila, Pescara, and Teramo, located in the Abruzzo region (Central Italy). All the specimens were screened using one-step real-time RT-qPCR and nested RT-PCR assays. Among them, 5/220 or 2.27% harbored HEV RNA fragments belonging to the ORF1 and ORF2 codifying regions of the genotype 3c. The average viral amount discovered was 102 GE/mL. These subjects represented 2/57 or 3.51% of the Pescara herd, and 3/105 or 2.86% of the Teramo herd. Although HEV RNA was discovered in sheep fecal samples, the original data obtained in the present study represent the first HEV RNA detection in ovine raw milk from Italy.

Assessment of Hepatitis E virus transmission risks: a comprehensive review of cases among blood transfusion recipients and blood donors.

Background: Hepatitis E Virus is a major cause of acute and fulminant hepatitis, particularly in developing countries. While the virus is commonly spread through the fecal-oral route, numerous cases of transfusion transmitted Hepatitis E Virus (TT-HEV) have been reported, raising concerns about its transmission via blood transfusions, especially in industrialized countries. The high prevalence of antibodies and viremia among asymptomatic blood donors further heightens the risk of transfusion-related transmission. However, there is still debate about the best strategy to minimize TT-HEV. Objective: The review was conducted to Summarize the literature on TT-HEV infection cases and the prevalence of HEV among blood donors. Methods: The databases PubMed, Scopus, Web of Science, Embase, and CINAHL were searched for relevant studies from 2000 to 2022.Serological and molecular screening data of HEV in blood donors were used to gather prevalence and incidence rates.TT-HEV cases were reviewed by examining evidence of HEV infection before and after transfusion. Results: A total of 121 manuscripts reports the prevalence and incidence of HEV among blood donors and cases of TT-HEV. Twenty-six articles reported confirmed cases of TT-HEV and 101 articles reported on HEV prevalence or incidence among blood donors. Conclusion: TT-HEV transmission through blood products is a real concern, especially for immunocompromised patients.The risk and severity of infection could vary between immunocompetent and immunosuppressed patients.To increase transfusion safety, the evaluation recommends HEV screening protocols, especially in endemic region.

HEV in Blood Donors in Switzerland: The Route to Safe Blood Products.

The hepatitis E virus (HEV) is an emerging infectious disease with zoonotic potential, causing acute hepatitis in humans. Infections in healthy individuals are often acute, self-limiting and asymptomatic, thus leading to the underdiagnosis of HEV infections. Asymptomatic HEV infections pose a problem for blood transfusion safety by increasing the risk for transfusion-transmitted HEV infections. Here, we describe the journey from determining the HEV seroprevalence among blood donors to the implementation of routine HEV RNA testing of all blood products in Switzerland in 2018 and summarise the HEV cases detected since. In total, 290 HEV-positive blood donations were detected by mini-pool nucleic acid testing (NAT) in Switzerland in the period of October 2018-December 2023, equal to an incidence of 20.7 per 100,000 donations. Thanks to the implemented scheme, no transfusion-transmitted infections occurred in this period. Furthermore, blood donation monitoring has proven to be an effective means of detecting HEV outbreaks in the general population. HEV cases in Swiss blood donors are caused by two major genotypes, the Swiss-endemic subtypes 3h3 and 3c. Interestingly, 11 HEV cases (5%) were of genotype 3ra, a variant found in wild and farmed rabbits. Our results indicate that mini-pool NAT is an efficient method to reduce the risk of transfusion-transmitted HEV infections.

Cell binding tropism of rat hepatitis E virus is a pivotal determinant of its zoonotic transmission to humans.

Classically, all hepatitis E virus (HEV) variants causing human infection belong to the genus Paslahepevirus (HEV-A). However, the increasing cases of rat HEV infection in humans since 2018 challenged this dogma, posing increasing health threats. Herein, we investigated the underlying mechanisms dictating the zoonotic potentials of different HEV species and their possible cross-protection relationships. We found that rat HEV virus-like particles (HEVVLPs) bound to human liver and intestinal cells/tissues with high efficiency. Moreover, rat HEVVLPs and infectious rat HEV particles penetrated the cell membrane and entered human target cells postbinding. In contrast, ferret HEVVLPs showed marginal cell binding and entry ability, bat HEVVLPs and avian HEVVLPs exhibited no binding and entry potency. Structure-based three-dimensional mapping identified that the surface spike domain of rat HEV is crucial for cell binding. Antigenic cartography indicated that rat HEV exhibited partial cross-reaction with HEV-A. Intriguingly, sera of HEV-A infected patients or human HEV vaccine Hecolin® immunized individuals provided partial cross-protection against the binding of rat HEVVLPs to human target cells. In summary, the interactions between the viral capsid and cellular receptor(s) regulate the distinct zoonotic potentials of different HEV species. The systematic characterization of antigenic cartography and serological cross-reactivity of different HEV species provide valuable insights for the development of species-specific diagnosis and protective vaccines against zoonotic HEV infection.

Glucose and glutamine drive hepatitis E virus replication.

Viruses have undergone evolutionary adaptations to tune their utilization of carbon sources, enabling them to extract specific cellular substrates necessary for their replication. The lack of a reliable cell culture system and a small-animal model has hampered our understanding of the molecular mechanism of replication of hepatitis E virus (HEV) genotype 1. Our recent identification of a replicative ensemble of mutant HEV RNA libraries has allowed us to study the metabolic prerequisites for HEV replication. Initial assessments revealed increased glucose and glutamine utilization during HEV replication. Inhibition of glycolysis and glycolysis + glutaminolysis reduced the levels of HEV replication to similar levels. An integrated analysis of protein-metabolite pathways suggests that HEV replication markedly alters glycolysis, the TCA cycle, and glutamine-associated metabolic pathways. Cells supporting HEV replication showed a requirement for fructose-6-phosphate and glutamine utilization through the hexosamine biosynthetic pathway (HBP), stimulating HSP70 expression to facilitate virus replication. Observations of mannose utilization and glutamine dependence suggest a crucial role of the HBP in supporting HEV replication. Inhibition of glycolysis and HSP70 activity or knockdown of glutamine fructose-6-phosphate amidotransferase expression led to a substantial reduction in HEV RNA and ORF2 expression accompanied by a significant decrease in HSP70 levels. This study demonstrates that glucose and glutamine play critical roles in facilitating HEV replication.

Contamination of Hepatitis E Virus in Pig Livers of Different Market Types Collected from Seven Provinces of China.

Foodborne transmission of the Hepatitis E virus (HEV) is becoming an important public health problem in China, but the food associated with the HEV transmission route remains unclear. Pig liver is among the suspected food products involved in HEV transmission. Our research aimed to survey the contamination rate and genotype identification of HEV in pig livers from different types of markets in selected provinces of China. reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to screen for HEV in pig livers, nest RT-PCR was used for partial amplification of opren reading frame (ORF) 2, followed by sequencing, and phylogenetic analysis to determine the genotype of positive samples. A total of 787 pig liver samples from 7 provinces were collected. The average positive rate of HEV was 8.13% (64/787), Inner Mongolia (14.29%, 1/7) and Hebei province (14.29%, 23/161) showed the highest positive rate. There was a significant difference among the provinces (p < 0.01). Three major market types (wholesale market, supermarket, and butcher's shop) were included in this study, and the positive rates were 5.28% (21/398), 15.86% (23/145), and 8.20% (20/244), respectively. There was no significant difference among the three market types. Eleven of the positive samples were partially sequenced and identified genotypes 4a, 4d, and 3a.

The 2023 South Sudanese outbreak of Hepatitis E emphasizes ongoing circulation of genotype 1 in North, Central, and East Africa.

In April 2023, an outbreak of acute hepatitis was reported amongst internally displaced persons in the Nazareth community of South Sudan. IgM serology-based screening suggested the likely etiologic agent to be Hepatitis E virus (HEV). In this study, plasma specimens collected from anti-HEV IgM-positive cases were subjected to additional RT-qPCR testing and sequencing of extracted nucleic acids, resulting in the recovery of five full and eight partial HEV genomes. Maximum likelihood phylogenetic reconstruction confirmed the genomes belong to HEV genotype 1. Using distance-based methods, we show that genotype 1 is best split into three sub-genotypes instead of the previously proposed seven, and that these sub-genotypes are geographically restricted. The South Sudanese sequences confidently cluster within sub-genotype 1e, endemic to northeast, central, and east Africa. Bayesian Inference of phylogeny incorporating sampling dates shows that this new outbreak is not directly descended from other recent local outbreaks for which sequence data is available. However, the analysis suggests that sub-genotype 1e has been consistently and cryptically circulating locally for at least the past half century and that the known outbreaks are often not directly descended from one another. The ongoing presence of HEV, combined with poor sanitation and hygiene in the conflict-affected areas in the region, place vulnerable populations at risk for infection and its more serious effects, including progression to fulminant hepatitis.

HEV-3 subtypes and strains detected in cases of HEV infection in central Italy from 2015 to 2023.

PURPOSE: HEV is an emerging pathogen in Europe and was previously shown to be hyperendemic in areas of Abruzzo and Lazio, Central Italy. No systematic analysis of the HEV strains responsible for human infections over several years in Central Italy has previously been reported. Aim of the study was the molecular characterization of HEV from autochthonous hepatitis E cases occurred in Abruzzo and Lazio between 2015 and 2023. METHODS: Samples from 118 cases collected as part of virological surveillance in Abruzzo and Lazio from 2015 to 2023 were subjected to HEV sequencing and phylogenetic analysis. RESULTS: The main observed subtype was 3f, followed by 3c and 3e. The annual subtype distribution was quite stable over the observation period, but 3f cases tended to concentrate in winter/early spring whereas 3e cases in summer. Phylogenetic clusters of highly related sequences (a) highlighted unrecognized "point source outbreaks", (b) provided molecular support to temporally and/or geographically linked cases and (c) provided evidence for transmission of identical/highly related strains up to months/years following their first detection. CONCLUSIONS: The data provide an overview of the HEV strains responsible for human infections over eight years in Central Italy. The observed subtype distribution appears to agree better with the subtype distribution reported in Italy in pigs rather than in geographically matched wild boars, suggesting pig and its derivate food was a more frequent source of infection than wild boar in Abruzzo and Lazio. Molecular characterization is essential to recognize "point source outbreaks" and to monitor HEV circulation.

Production and Characterization of Self-Assembled Virus-like Particles Comprising Capsid Proteins from Genotypes 3 and 4 Hepatitis E Virus (HEV) and Rabbit HEV Expressed in Escherichia coli.

The zoonotic transmission of hepatitis E virus (HEV) genotypes 3 (HEV-3) and 4 (HEV-4), and rabbit HEV (HEV-3ra) has been documented. Vaccination against HEV infection depends on the capsid (open reading frame 2, ORF2) protein, which is highly immunogenic and elicits effective virus-neutralizing antibodies. Escherichia coli (E. coli) is utilized as an effective system for producing HEV-like particles (VLPs). However, research on the production of ORF2 proteins from these HEV genotypes in E. coli to form VLPs has been modest. In this study, we constructed 21 recombinant plasmids expressing various N-terminally and C-terminally truncated HEV ORF2 proteins for HEV-3, HEV-3ra, and HEV-4 in E. coli. We successfully obtained nine HEV-3, two HEV-3ra, and ten HEV-4 ORF2 proteins, which were primarily localized in inclusion bodies. These proteins were solubilized in 4 M urea, filtered, and subjected to gel filtration. Results revealed that six HEV-3, one HEV-3ra, and two HEV-4 truncated proteins could assemble into VLPs. The purified VLPs displayed molecular weights ranging from 27.1 to 63.4 kDa and demonstrated high purity (74.7-95.3%), as assessed by bioanalyzer, with yields of 13.9-89.6 mg per 100 mL of TB medium. Immunoelectron microscopy confirmed the origin of these VLPs from HEV ORF2. Antigenicity testing indicated that these VLPs possess characteristic HEV antigenicity. Evaluation of immunogenicity in Balb/cAJcl mice revealed robust anti-HEV IgG responses, highlighting the potential of these VLPs as immunogens. These findings suggest that the generated HEV VLPs of different genotypes could serve as valuable tools for HEV research and vaccine development.

Seroprevalence of swine hepatitis E virus and the farmers' potential risk of infection in the Province of Bali, Indonesia.

Background and Aims: Hepatitis E virus (HEV) infection formerly and predominantly occurred in rural areas. However, it has recently been spread to urban and peri-urban areas. This study aimed to estimate the seroprevalence of HEV in pigs collected from urban and rural areas in Bali. The potential of the pig farmers' risk level for being exposed to HEV and the virus transmitted to them in association with their pig-rearing practices was also assessed. Materials and Methods: A total of 183 pigs from 68 herds were sampled in this study, with 91 pigs collected from Denpasar as the representative samples of urban areas and 92 pigs from Karangasem Regency as the representative samples from rural areas. Sera from the sampled pigs were collected and immunoglobulin G antibodies against HEV were detected using a commercial enzyme-linked immunosorbent assay. A questionnaire was prepared for interviewing the farmers. Bivariable and multivariable logistic regression analyses were performed to identify the putative factors associated with seropositivity. Meanwhile, the potential risk-incurring practices of the farmers for HEV being transmitted to them from their pig-rearing practices were assessed by scoring their responses from the interview. Results: Overall, 23.5% (43/183) (95% confidence interval [CI]: 17.6-30.3) pig sera tested were detected to have the antibodies against HEV. Among 68 pig herds, 36.8% (25) (95% CI: 25.4-49.3) of them had antibodies in at least one pig sampled from each herd. Pigs sampled from Karangasem were 5 times (Odds ratio [OR] 5.34, 95% CI: 2.27-13.54, p < 0.001) more likely to be seropositive than pigs collected from Denpasar. However, no difference was found in the seropositivity to HEV in pig herds between Denpasar and Karangasem (p = 0.05). In assessing the pig rearing management factors, pig farmers from Denpasar were 3 times (OR 3.0, 95% CI: 1.07-8.52, p = 0.05) more likely to rear pigs for economic investment compared to the farmers from Karangasem. Regarding anticipating pig diseases that can be transmitted to humans, farmers from Denpasar were 6 times (OR 5.72, 95% CI: 1.48-26.7, p = 0.0074) more likely to anticipate zoonotic diseases compared to the farmers from Karangasem. Similarly, pig farmers from Denpasar were 3 times (OR 3.29, 95% CI: 1.08-10.23, p = 0.035) more likely to anticipate pig diseases that could be transmitted to humans than the farmers from Karangasem. Pig farmers from Denpasar had 4 times the odds (OR 4.49, 95% CI: 1.11-18.19, p = 0.03) of washing their hands after going to the pigpens compared to the farmers from Karangasem. All the participants were categorized as being at high risk of HEV exposure and transmission. Conclusion: IgG antibodies against HEV were detected among pigs reared in rural areas of Karangasem and those reared in urban areas of Denpasar. This suggests that the risk of HEV exposure and transmission in these areas is not negligible. To minimize the risk, public education on zoonotic diseases, including HEV infection, transmission, and prevention, needs to be implemented and particularly targeted to local pig farmers.

Evaluation of novel synthetic peptides of avian hepatitis E virus ORF2 as vaccine candidate in chickens.

Avian hepatitis E virus (HEV) has resulted in significant economic losses in the poultry industry. There is currently no commercial vaccination available to prevent avian HEV infection. Previously, a novel epitope (601TFPS604) was discovered in the ORF2 protein of avian HEV. In this study, peptides were synthesized and assessed for their ability to provide immunoprotecting against avian HEV infection in poultry. Twenty-five Hy-Line Variety Brown laying hens were randomly divided into five groups; groups 1 to 3 respectively immunized with RLLDRLSRTFPS, PETRRLLDRLSR (irrelevant peptide control), or truncated avian HEV ORF2 protein (aa 339-606), while group 4 (negative control) was mock-immunized with PBS and group 5 (normal control) was not immunized or challenged. After the challenge, all hens in groups 2 and 4 showed seroconversion, fecal virus shedding, viremia, alanine aminotransferase (ALT) level increasing, liver lesions and HEV antigen in the liver. There were no pathogenic effects in other groups. Collectively, all of these findings showed that hens were completely protected against avian HEV infection when they were immunized with the peptide containing TFPS of the avian HEV ORF2 protein.

Successful recovery from acute-on-chronic liver failure due to acute hepatitis E virus superinfection in chronic hepatitis B: A case report.

Introduction: Acute hepatitis E virus (HEV) infection is a self-limiting disease, but HEV superinfection in patients with chronic hepatitis B virus (HBV) infection may lead to acute-on-chronic liver failure (ACLF) and significantly increase short-term mortality. Diagnosis and comprehensive management of these patients remain in a dilemma. Case presentation: A 32-year-old man with chronic HBV infection for 8 years received entecavir due to abnormal liver function for 4 months. He was admitted for symptomatic hepatitis flare for nearly 2 weeks. Initial investigations did not reveal a cause other than HBV, but repeated tests showed a progressive increase in his anti-HEV IgM. His condition worsened rapidly. Mid-stage ACLF and spontaneous peritonitis were diagnosed. Entecavir and hepatoprotective drugs were continued. Ribavirin, ceftriaxone, and repeated artificial liver support system (ALSS) therapy were administered. His condition gradually improved and his liver function eventually returned to normal. Conclusions: Repeated HEV screening is important for patients with chronic liver disease and symptomatic hepatitis flare. Negative anti-HEV IgM for the first time can easily lead clinicians to mistakenly rule out HEV infection. A progressive increase in anti-HEV IgM is one of the diagnostic criteria for HEV infection, which is not rare but deserves attention. Additionally, comprehensive management including ribavirin and ALSS would be effective therapies for patients who superinfect with HEV and develop ACLF.