Serological survey on Hepatitis E virus in Namibian dogs, cats, horses, and donkeys.

The present study investigated the seropositivity rate of Hepatitis E virus (HEV) in domestic and working animals in Namibia, which included dogs, cats, horses, and donkeys. HEV poses a growing threat as a significant cause of human hepatitis globally and has several genotypes of varying zoonotic potential. As epidemiological data on the seroprevalence of HEV in Namibia is scarce, a serosurvey was conducted on archived serum samples of 374 dogs, 238 cats, 98 horses, and 60 donkeys collected between 2018 and 2022 from different regions, to assess the potential of these animals as sources of HEV infection. The findings revealed that 10.43% (n = 39/374) canine and 5.88% (n = 14/238) feline samples tested positive for HEV antibodies, whereas no seropositivity was detected in horses and donkeys. The study further examined the risk factors associated with HEV seropositivity, including animal sex, age, and geographical region, and noted a higher prevalence in dogs living in areas with intensive pig farming. Although there is no direct evidence indicating that these animals served as major reservoirs for HEV transmission to humans, the study underscores the importance of preventive measures to minimize contact exposure with pets considering the potential zoonotic risk, especially for susceptible risk groups. Further research is needed to explore the zoonotic potential of domestic animals and the epidemiological links between animal and human HEV transmissions in Namibia.

Biosecurity measures to control hepatitis E virus on European pig farms.

Hepatitis E virus (HEV) genotype 3 is a prevalent zoonotic pathogen in European pig farms, posing a significant public health risk primarily through the foodborne route. The study aimed to identify effective biosecurity measures for controlling HEV transmission on pig farms, addressing a critical gap in current knowledge. Utilizing a cross-sectional design, fecal samples from gilts, dry sows, and fatteners were collected on 231 pig farms of all farm types across nine European countries. Real-time RT-PCR was employed to test these samples for HEV. Simultaneously, a comprehensive biosecurity questionnaire captured data on various potential measures to control HEV. The dependent variable was HEV risk, categorized as lower or higher based on the percentage of positive pooled fecal samples on each farm (25% cut-off). The data were analyzed using generalized linear models (one for finisher samples and one for all samples) with a logit link function with country and farm type as a priori fixed factors. The results of the final multivariable models identified key biosecurity measures associated with lower HEV risk, which were the use of a hygienogram in the breeding (OR: 0.06, p = 0.001) and/or fattening area after cleaning (OR: 0.21, p = 0.019), the presence of a quarantine area (OR: 0.29, p = 0.025), testing and/or treating purchased feed against Salmonella (OR: 0.35, p = 0.021), the presence of other livestock species on the farm, and having five or fewer persons in charge of the pigs. Contrary to expectations, some biosecurity measures were associated with higher HEV risk, e.g., downtime of 3 days or longer after cleaning in the fattening area (OR: 3.49, p = 0.005) or mandatory handwashing for farm personnel when changing barn sections (OR: 3.4, p = 0.026). This novel study unveils critical insights into biosecurity measures effective in controlling HEV on European pig farms. The identification of both protective and risk-associated measures contributes to improving strategies for managing HEV and underscores the complexity of biosecurity in pig farming.

Corrigendum: Biosecurity measures to control hepatitis E virus on European pig farms.

[This corrects the article DOI: 10.3389/fvets.2024.1328284.].

Hepatitis E Virus in the United States and Canada: Is It Time to Consider Blood Donation Screening?

Hepatitis E virus (HEV) is the most common cause of acute viral hepatitis in the world and can lead to severe complications in immunocompromised individuals. HEV is primarily transmitted through eating pork, which has led to an increased in anti-HEV IgG seropositivity in the general population of Europe in particular. However, it can also be transmitted intravenously, such as through transfusions. The growing evidence of HEV contamination of blood products and documented cases of transmission have given rise to practice changes and blood product screening of HEV in many European countries. This review covers the abundant European literature and focuses on the most recent data pertaining to the prevalence of HEV RNA positivity and IgG seropositivity in the North American general population and in blood products from Canada and the United States. Currently, Health Canada and the Food and Drug Administration do not require testing of HEV in blood products. For this reason, awareness among blood product prescribers about the possibility of HEV transmission through blood products is crucial. However, we also demonstrate that the province of Quebec has a prevalence of anti-HEV and HEV RNA positivity similar to some European countries. In light of this, we believe that HEV RNA blood donation screening be reevaluated with the availability of more cost-effective assays.

Hepatitis E Virus Genotype 3 among Hemodialysis Patients in Mexico: First Identification of Chronic Infection.

The global distribution of hepatitis E virus (HEV) is attributed to its capacity to spread through several routes of transmission; hemodialysis has gained increased amounts of attention in recent years. Although Mexico is considered a hyperendemic region for hepatitis E, no HEV surveillance is performed in the country. The frequency of HEV in hemodialysis (HD) patients has not been determined. Herein, we conducted a cross-sectional single-center analytical study including 67 serum samples from HD patients. Anti-HEV IgG and IgM antibodies and the viral genome were determined; partial regions within the HEV genome were sequenced for further phylogenetic analysis. Globally, 14.9% of the tested patients exhibited reactivity for IgG antibodies against HEV, and none showed reactivity to IgM. A total of 5.9% of the samples showed HEV genome amplification, and sequencing confirmed the identity of genotype 3; subsequent analysis of positive cases revealed two acute cases and chronic hepatitis E infection in one patient. Notably, the chronic patient was negative for anti-HEV IgG antibodies. Our findings highlight the importance of viral genome testing in HD patients and the need to establish guidelines for HEV detection in Mexico.

Oxysterol binding protein (OSBP) contributes to hepatitis E virus replication.

Hepatitis E virus (HEV) is a positive-sense, single-stranded RNA virus and causes primarily acute self-limiting infections. The ORF1 of the HEV genome encodes a polyprotein around 190 kDa, which contains several putative domains, including helicase and RNA-dependent RNA polymerase. The HEV-encoded helicase is a member of the superfamily 1 helicase family and possesses multiple enzymatic functions, such as RNA 5'-triphosphatase, RNA unwinding, and NTPase, which are thought to contribute to viral RNA synthesis. However, the helicase interaction with cellular proteins remains less known. Oxysterol binding protein (OSBP) is a lipid regulator that shuffles between the Golgi apparatus and the endoplasmic reticulum for cholesterol and phosphatidylinositol-4-phosphate exchange and controls the efflux of cholesterol from cells. In this study, the RNAi-mediated silencing of OSBP significantly reduced HEV replication. Further studies indicate that the HEV helicase interacted with OSBP, shown by co-immunoprecipitation and co-localization in co-transfected cells. The presence of helicase blocked OSBP preferential translocation to the Golgi apparatus. These results demonstrate that OSBP contributes to HEV replication and enrich our understanding of the HEV-cell interactions.

Integrated hepatitis e virus monitoring in central Argentina: a six-year analysis of clinical surveillance and wastewater-based epidemiology.

Wastewater-based epidemiology (WBE) has gained prominence worldwide as a powerful tool in public health. This study aimed to monitor the circulation of Hepatitis E Virus (HEV) from wastewater samples collected during a six-year period and compare these results with clinical surveillance in the central region of Argentina. From 2017 to 2022, 1008 raw wastewater samples were analyzed, including four wastewater treatment plants from four cities (n=319), and 7 local neighborhood collector sewers in Córdoba city (n=689). Serum and/or stool samples from patients suspected of HEV infection were also analyzed (n=48). HEV molecular detection and viral load quantification were performed by real time RT-qPCR, and genetic characterization by two RT-Nested PCRs (targeting partial ORF-1 and ORF-2 genomic regions), sequencing and phylogenetic analysis. Fifty-three (5.3%) wastewater samples were RNA-HEV positive by real time RT-qPCR, with variations according to the location and year (0.0% - 21.6%). Out of these, ORF-2 genomic region was amplified in 20 samples (37.7%) and ORF-1 partial region in 12 (22.6%), and eighteen sequences were obtained. Throughout the study period, two (4.2%) HEV confirmed infections were reported, and one sequence was obtained. Phylogenetic analyses for both genomic regions showed that all the isolates were genotype HEV-3 clade abchijklm. Our study detected HEV in wastewater over a six-year period, despite a low number of clinical cases, emphasizing WBE as a valuable tool that complements clinical surveillance, by detecting pathogens' presence; identifying their transmission, circulation dynamics and excretion hotspots; and revealing changes in their genomic diversity.

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.

Characterization of zoonotic hepatitis E virus in domestic pigs and wild boar in Vietnam: Implications for public health.

Vietnam's unprecedented demand for meat from livestock, including pigs and farmed wildlife, underscores the importance of understanding zoonotic reservoirs for hepatitis E virus (HEV). This study aimed to identify and characterize circulating zoonotic HEV in domestic pigs and wild boar to understand genotype frequencies, transmission dynamics, and associated human health burdens. Rectal swabs, feces, and liver samples from 415 pigs and 102 wild boars were collected across various farms and slaughterhouses in central and southern Vietnam and screened for HEV RNA using nested PCR. HEV RNA-positive samples underwent sanger sequencing and genotyping. Overall, 10% (n = 54/517) of samples were HEV RNA-positive, with wild boars exhibiting the highest HEV positivity rate at 25%, followed by domestic pigs at 7%. Southern Vietnam showed a higher HEV RNA positivity rate (20%) compared to central Vietnam (7%). Notably, rectal swabs demonstrated the highest positivity rate (15%), followed by feces (8%) and liver (4%). HEV-3a was the predominant genotype at 85%, followed by HEV-4b at 9% and HEV-3f at 6%. While HEV-3a was distributed across both central and southern Vietnam, HEV-3f was exclusively detected in central Vietnam, and HEV-4b was identified in wild boar in southern Vietnam. These findings underscore the substantial prevalence of HEV in wild boars, emphasizing their potential as crucial zoonotic reservoirs alongside domestic pigs. Further investigations involving occupationally exposed individuals in high-prevalence areas are warranted to evaluate the human health impact of zoonotic hepatitis E and inform preventive measures. Regular epidemiological studies are imperative for assessing the prevalence and transmission of zoonotic HEV infections among common reservoirs, thereby aiding in the prevention of spillover events within the community.

Multiple Functions of Hepatitis E Virus ORF3.

Hepatitis E (Hepatitis E, HE) is an acute and chronic infectious hepatitis caused by hepatitis E virus (Hepatitis E Virus, HEV) infection, which is responsible for most acute hepatitis in the world and is a significant public health problem. The pathogen, HEV, has three Open Reading Frames (ORFs) ORF1, ORF2, and ORF3, each of which has a different function. Most of the current research is focused on ORF1 and ORF2, while the research on ORF3 is still relatively small. To provide more ideas for the study of HEV pathogenesis and the prevention and treatment of HE, this paper reviews the effects of ORF3 on the ERK pathway, growth factors, immune response, and virus release.

Progress and Challenges to Hepatitis E Vaccine Development and Deployment.

Hepatitis E is a significant cause of acute hepatitis, contributing to high morbidity and mortality rates, and capable of causing large epidemics through fecal-oral transmission. Currently, no specific treatment for hepatitis E has been approved. Given the notably high mortality rate among HEV-infected pregnant women and individuals with underlying chronic liver disease, concerted efforts have been made to develop effective vaccines. The only licensed hepatitis E vaccine worldwide, the HEV 239 (Hecolin) vaccine, has been demonstrated to be safe and efficacious in Phase III clinical trials, in which the efficacy of three doses of HEV 239 remained at 86.6% (95% confidence interval (CI): 73.0-94.1) at the end of 10 years follow-up. In this review, the progress and challenges for hepatitis E vaccines are summarized.

Seroprevalence of Hepatitis-E Virus-Immunoglobulin G and its association with Chronic Liver Disease.

Background & Objective: Viral hepatitis is a major public health concern in low-middle income countries. Hepatitis-E infection (HEV) is found globally but most prevalent in low-income countries especially those with poor sanitation systems, access to clean drinking water and health services. Superinfection with HEV in patients with chronic liver disease (CLD) can cause severe hepatic decompensation leading to increased morbidity and mortality. To determine the frequency of seroprevalence of Hepatitis-E virus Immunoglobulin g (IgG) and its association with chronic liver disease. Methods: A cross-sectional study was conducted in Asian Institute of Medical Sciences, Hyderabad, Pakistan from January till May 2022. A total of 196 patients of aged ≥ 18 years, presenting in gastroenterology clinics were included in the study after informed consent. Result: Among 196 patients, one third of patient were male (73.5%). Out of which 162 (82.7%) had liver disease and 34 (17.3%) were without liver disease. The median age of patient was 45 (33-51) years. The overall seroprevalence of HEV IgG among study population was 69.4%. HEV IgG was present in 114 and 22 in CLD and non CLD patients respectively. Multivariable regression shows no association between seroprevalence of HEV in CLD and non-CLD patient (AOR 1.02, 95% CI 0.45-2.313). Conclusion: Our study showed high frequency of HEV seropositivity. No difference was observed in HEV seropositivity among CLD and non-CLD patients.

Evaluation of hepatitis E virus RNA persistence in experimentally contaminated cured pork liver sausages.

Hepatitis E is a disease sustained by RNA viruses, which have four different genotypes, all of which are responsible for acute forms of hepatitis. Genotypes 1 and 2 infect only humans, causing epidemics mainly transmitted by contaminated water, while geno-types 3 and 4 are zoonotic, and the infection is linked to the consumption of raw or undercooked meat or meat products. Hepatitis E virus (HEV) genotypes 3 and 4 have been detected in domestic Suidae, considered the asymptomatic reservoir of HEV, and in wild animals such as wild boar and deer. Despite scientific studies that have highlighted the presence of HEV in cured meat products, such as pork liver sausages, the viral persistence in the different production steps of curing has not been evaluated. Therefore, this study aimed to evaluate the persistence of HEV genotype 3 during the different curing and storage times of experimentally contaminated pork liver sausages using biomolecular methods. The sausages tested positive at all curing and storage times. This study confirms the potential risk attributed to pork liver sausages in HEV transmission. However, to guarantee an efficient risk assessment, future studies will be performed to correlate the presence of HEV RNA with infectious viral particles.

Hepatitis E virus infection upregulates ING5 expression in vitro and in vivo.

Hepatitis E virus (HEV) is the major pathogen of viral hepatitis. Immunocompromised individuals infected by HEV are prone to chronic hepatitis and increase the risk of hepato-cellular carcinoma (HCC). Inhibitor of growth family member 5 (ING5) is a tumor suppressor that is expressed at low levels in cancer tumors or cells. However, the underlying relationship between ING5 and HEV infection is unclear. In the present study, acute and chronic HEV animal models are used to explore the interaction between ING5 and HEV. Notably, the expression of ING5 is significantly increased in both the livers of acute HEV-infected BALB/c mice and chronic HEV-infected rhesus macaques. In addition, the relationship between HEV infection and ING5 expression is further identified in human hepatoma (HepG-2) cells. In conclusion, HEV infection strongly upregulates ING5 expression both in vivo and in vitro, which has significant implications for further understanding the pathogenic mechanism of HEV infection.

Proof of infectivity of hepatitis E virus particles from the ejaculate of chronically infected patients.

Recently, hepatitis E virus (HEV, Paslahepevirus balayani) particles were detected for the first time in the ejaculate of two chronically infected patients. Since then, we have been able to detect HEV in ejaculate in five further patients, and thus in a total of seven out of nine (78%) chronically infected men (age 36-67 years, median 56 years). In five patients, the HEV RNA concentration was more than 100-fold higher compared to the serum, while in two patients, the viral load was more than 10-fold lower. However, it has remained unclear whether viral particles shed in the ejaculate were infectious, as a previous cell culture model had failed to demonstrate the infectivity. In the current study, we employed an optimized HEV cell culture system based on overconfluent PLC/PRF/5 cells to investigate the infectivity of HEV particles from ejaculate and other body fluids. With this approach, we were able to show for the first time that HEV particles in the ejaculate from several patients were infectious. HEV replicated to high viral loads of 1e9 HEV RNA copies per ml. This indicates that HEV-positive ejaculate could bear a risk of infection for sexual partners.

Hepatitis E virus in children and adolescents living in an urban environment in central Argentina: An explorative study.

In Argentina, circulation of hepatitis E virus (HEV) genotype 3 has been described, producing sporadic cases of acute and chronic hepatitis. Limited information is available regarding HEV infection in children, so we aimed to investigate this virus in a pediatric population from the country. Serum samples from Argentine children (0-18 years old) (n = 213) were studied for IgG anti-HEV, IgM anti-HEV and RNA-HEV: 202 samples belonged to individuals attending health-care centers for routine check-ups, and 11 samples from patients with acute hepatitis of unknown etiology. Seropositivity for IgG anti-HEV was 1.49 % (3/202). One sample from an 18-years-old female patient with acute hepatitis tested positive for IgM anti-HEV detection, negative for IgG anti-HEV and RNA-HEV, but also positive for IgM anti-EBV. The HEV prevalence was low and showed circulation among children in central Argentina.

The Full-Genome Analysis and Generation of an Infectious cDNA Clone of a Genotype 6 Hepatitis E Virus Variant Obtained from a Japanese Wild Boar: In Vitro Cultivation in Human Cell Lines.

Hepatitis E virus (HEV) can cause self-limiting acute and chronic hepatitis infections, particularly in immunocompromised individuals. In developing countries, HEV is mainly transmitted via drinking contaminated water, whereas zoonotic transmission dominates the route of infection in developed countries, including Japan. Pigs are an important reservoir for HEV infection. Wild boars, which share the same genus and species as domestic pigs, are also an HEV reservoir. During our nationwide study of HEV infection in wild boar populations in Japan, a genotype 6 (HEV-6) strain, wbJHG_23, was isolated in Hyogo Prefecture in 2023. The genomic length was 7244 nucleotides, excluding the poly(A) tract. The wbJHG_23 strain exhibited the highest nucleotide identity throughout its genome with two previously reported HEV-6 strains (80.3-80.9%). Conversely, it displayed lower similarity (73.3-78.1%) with the HEV-1-5, HEV-7, and HEV-8 strains, indicating that, although closely related, the wbJHG_23 strain differs significantly from the reported HEV-6 strains and might represent a novel subtype. The wbJHG_23 strain successfully infected the human-derived cancer cell lines, PLC/PRF/5 and A549 1-1H8 cells, suggesting that HEV-6 has the potential for zoonotic infection. An infectious cDNA clone was constructed using a reverse genetics system, and a cell culture system supporting the efficient propagation of the HEV-6 strain was established, providing important tools for further studies on this genotype. Using this cell culture system, we evaluated the sensitivity of the wbJHG_23 strain to ribavirin treatment. Its good response to this treatment suggested that it could be used to treat human infections caused by HEV-6.

Hepatitis E Virus: What More Do We Need to Know?

Hepatitis E virus (HEV) infection is typically a self-limiting, acute illness that spreads through the gastrointestinal tract but replicates in the liver. However, chronic infections are possible in immunocompromised individuals. The HEV virion has two shapes: exosome-like membrane-associated quasi-enveloped virions (eHEV) found in circulating blood or in the supernatant of infected cell cultures and non-enveloped virions ("naked") found in infected hosts' feces and bile to mediate inter-host transmission. Although HEV is mainly spread via enteric routes, it is unclear how it penetrates the gut wall to reach the portal bloodstream. Both virion types are infectious, but they infect cells in different ways. To develop personalized treatment/prevention strategies and reduce HEV impact on public health, it is necessary to decipher the entry mechanism for both virion types using robust cell culture and animal models. The contemporary knowledge of the cell entry mechanism for these two HEV virions as possible therapeutic target candidates is summarized in this narrative review.

Deregulation of immune response contributing to fulminant hepatitis in HEV infected pregnant women.

Hepatitis E virus (HEV) infection in pregnant women is associated with a wide spectrum of adverse consequences for both mother and fetus. The high mortality in this population appears to be associated with hormonal changes and consequent immunological changes. This study conducted an analysis of immune responses in pregnant women infected with HEV manifesting varying severity. Data mining analysis of the GSE79197 was utilized to examine differentially biological functions in pregnant women with HEV infection (P-HEV) versus without HEV infection (P-nHEV), P-HEV progressing to ALF (P-ALF) versus P-HEV, and P-HEV versus non-pregnant women with HEV infection (nP-HEV). We found cellular response to interleukin and immune response-regulating signalings were activated in P-HEV compared with P-nHEV. However, there was a significant decrease of immune responses, such as T cell activation, leukocyte cell-cell adhesion, regulation of lymphocyte activation, and immune response-regulating signaling pathway in P-ALF patient than P-HEV patient. Compared with nP-HEV, MHC protein complex binding function was inhibited in P-HEV. Further microRNA enrichment analysis showed that MAPK and T cell receptor signaling pathways were inhibited in P-HEV compared with nP-HEV. In summary, immune responses were activated during HEV infection while being suppressed when developing ALF during pregnancy, heightening the importance of immune mediation in the pathogenesis of severe outcome in HEV infected pregnant women.