Hepatitis E: An update on One Health and clinical medicine

Molecularly generated rat hepatitis E virus strains from human and rat show efficient replication in a human hepatoma cell line

The hepatitis E virus (HEV) can cause acute and chronic hepatitis in humans. Whereas HEV genotypes 1-4 of species Paslahepevirus balayani are commonly found in humans, infections with ratHEV (species Rocahepevirus ratti) were previously considered to be restricted to rats. However, several cases of human ratHEV infections have been described recently. To investigate the zoonotic potential of this virus, a genomic clone was constructed here based on sequence data of ratHEV strain pt2, originally identified in a human patient with acute hepatitis from Hongkong. For comparison, genomic clones of ratHEV strain R63 from a rat and of HEV genotype 3 strain 47832mc from a human patient were used. After transfection of in vitro-transcribed RNA from the genomic clones into the human hepatoma cell line HuH-7-Lunet BLR, virus replication was shown for all strains by increasing genome copy numbers in cell culture supernatants. These cells developed persistent virus infections, and virus particles in the culture supernatant as well as viral antigen within the cells were demonstrated. All three generated virus strains successfully infected fresh HuH-7-Lunet BLR cells. In contrast, the human hepatoma cell lines HuH-7 and PLC/PRF/5 could only be infected with the genotype 3 strain and to a lesser extent with ratHEV strain R63. Infection of the rat-derived hepatoma cell lines clone 9, MH1C1 and H-4-II-E did not result in efficient virus replication for either strain. The results indicate that ratHEV strains from rats and humans can infect human hepatoma cells. The replication efficiency is strongly dependent on the cell line and virus strain. The investigated rat hepatoma cell lines could not be infected and other rat-derived cells should be tested in future to identify permissive cell lines from rats. The developed genomic clone can represent a useful tool for future research investigating pathogenicity and zoonotic potential of ratHEV.

Global burden and trends of acute viral hepatitis among children and adolescents from 1990 to 2019: a systematic analysis of the Global Burden of Disease Study 2019

BACKGROUND

Children and adolescents are at high risk for acute viral hepatitis (AVH), but epidemiological research focusing on them has been overshadowed by adult chronic B and C. We provide global, regional, and national estimates of the AVH burden and their trends on people under 20 years from 1990 to 2019.

METHODS

AVH data from Global Burden of Disease Study (GBD) 2019 was used. Incidence and disability-adjusted life years (DALYs) were calculated, analyzing trends with estimated annual percentage change (EAPC) and Joinpoint regression.

RESULTS

In 2019, 156.39 (95% uncertainty interval 145.20-167.16) million new cases of AVH were reported among children and adolescents globally, resulting in 1.98 (1.50-2.55) million DALYs. Incidence rates for young children (< 5 years), older children (5-9 years), and adolescents (10-19 years) were 12,799 (11,068-14,513), 5,108 (4829-5411), and 3020 (2724-3339) per 100,000 population, respectively. The global AVH incidence displayed a linear decline with an EAPC of - 0.66 (- 0.68 to - 0.65). High-incidence regions included sub-Saharan Africa, Oceania, South Asia, and Central Asia, with India, Pakistan, and Nigeria facing the greatest burden. Leading causes were hepatitis A, followed by hepatitis E, B, and C. All hepatitis types showed declining trends, especially hepatitis B. Furthermore, we confirmed the association between the AVH incidence and the socioeconomics, vaccine, and advanced liver diseases.

CONCLUSION

Effective vaccines and treatments for hepatitis B and C offer eradication opportunities. Broadening diagnostic and therapeutic coverage is vital to address disparities in service provision for children and adolescents.

Kinetics of Hepatitis E Virus Infections in Asymptomatic Persons

To determine the kinetics of hepatitis E virus (HEV) in asymptomatic persons and to evaluate viral load doubling time and half-life, we retrospectively tested samples retained from 32 HEV RNA-positive asymptomatic blood donors in Germany. Close-meshed monitoring of viral load and seroconversion in intervals of ≈4 days provided more information about the kinetics of asymptomatic HEV infections. We determined that a typical median infection began with PCR-detectable viremia at 36 days and a maximum viral load of 2.0 × 104 IU/mL. Viremia doubled in 2.4 days and had a half-life of 1.6 days. HEV IgM started to rise on about day 33 and peaked on day 36; IgG started to rise on about day 32 and peaked on day 53. Although HEV IgG titers remained stable, IgM titers became undetectable in 40% of donors. Knowledge of the dynamics of HEV viremia is useful for assessing the risk for transfusion-transmitted hepatitis E.

Hepatitis E Seroprevalence and Detection of Genotype 3 Strains in Domestic Pigs from Sierra Leone Collected in 2016 and 2017

Hepatitis E virus (HEV) is the main cause of acute hepatitis in humans worldwide and is responsible for a large number of outbreaks especially in Africa. Human infections are mainly caused by genotypes 1 and 2 of the genus Paslahepevirus, which are exclusively associated with humans. In contrast, viruses of genotypes 3 and 4 are zoonotic and have their main reservoir in domestic and wild pigs, from which they can be transmitted to humans primarily through the consumption of meat products. Both genotypes 3 and 4 are widespread in Europe, Asia, and North America and lead to sporadic cases of hepatitis E. However, there is little information available on the prevalence of these genotypes and possible transmission routes from animal reservoirs to humans in African countries. We therefore analysed 1086 pig sera collected in 2016/2017 in four districts in Sierra Leone for antibodies against HEV using a newly designed in-house ELISA. In addition, the samples were also analysed for HEV RNA by quantitative real-time RT-PCR. The overall seroprevalence in Sierra Leone was low with only 44 positive sera and a prevalence of 4.0%. Two serum pools were RT-PCR-positive and recovered partial sequences clustered into the genotype 3 (HEV-3) of the order Paslahepevirus, species Paslahepevirus balayani. The results are the first evidence of HEV-3 infection in pigs from Sierra Leone and demonstrate a low circulation of the virus in these animals to date. Further studies should include an examination of humans, especially those with close contact with pigs and porcine products, as well as environmental sampling to evaluate public health effects within the framework of a One Health approach.

Evaluation of Food Homogenates on Cell Survival In Vitro

A critical review on the approaches to assess the infectivity of the Hepatitis E virus (HEV) in food recommended that a cell culture-based method should be developed. Due to the observations that viral loads in food may be low, it is important to maximise the potential for detection of HEV in a food source in order to fully assess infectivity. To do so, would require minimal processing of any target material. In order to proceed with the development of an infectivity culture method that is simple, robust and reproducible, there are a number of points to address; one being to assess if food homogenates are cytotoxic to HEV susceptible target cells. Food matrices previously shown to have detectable HEV nucleic acid were selected for analysis and assessed for their effect on the percentage survival of three cell lines commonly used for infectivity assays. Target cells used were A549, PLC/PRF/5 and HepG2 cells. The results showed that, as expected, various food homogenates have differing effects on cells in vitro. In this study, the most robust cell line over a time period was the A549 cell line in comparison to HepG2, with PLC/PRF/5 cells being the most sensitive. Overall, this data would suggest that FH can be left in contact with A549 cells for a period of up to 72 h to maximise the potential for testing infection. Using food homogenates directly would negate any concerns over losing virus as a result of any additional processing steps.

The molecular epidemiology of hepatitis E virus genotype 3 in Canada

Autochthonous hepatitis E virus (HEV) infection is increasingly reported in industrialized countries and is mostly associated with zoonotic HEV genotype 3 (HEV-3). In this study, we examined the molecular epidemiology of 63 human clinical HEV-3 isolates in Canada between 2014 and 2022. Fifty-five samples were IgM positive, 45 samples were IgG positive and 44 were IgM and IgG positive. The majority of the isolates belong to the subtypes 3a, 3b, and 3j, with high sequence homology to Canadian swine and pork isolates. There were a few isolates that clustered with subtypes 3c, 3e, 3f, 3h, and 3g, and an isolate from chronic infection with a rabbit strain (3ra). Previous studies have demonstrated that the isolates from pork products and swine from Canada belong to subtypes 3a and 3b, therefore, domestic swine HEV is likely responsible for the majority of clinical HEV cases in Canada and further support the hypothesis that swine serve as the main reservoirs for HEV-3 infections. Understanding the associated risk of zoonotic HEV infection requires the establishment of sustainable surveillance strategies at the interface between humans, animals, and the environment within a One-Health framework.

Hepatitis E Virus (HEV) Infection Among Immunocompromised Individuals: A Brief Narrative Review

Hepatitis E virus (HEV) is a single-stranded positive-sense RNA virus that belongs to Hepeviridae family. HEV is the most common cause of acute viral hepatitis worldwide. According to the World Health Organization (WHO), there are estimated 20 million HEV infections worldwide every year, leading to estimated 3.3 million symptomatic cases of HEV infection. The WHO estimates that HEV infection caused approximately 44,000 deaths in 2015, which represents 3.3% of mortality rates due to viral hepatitis. In low-income (LI) countries and lower-middle-income (LMI) countries, HEV is a waterborne infection induced by HEV genotype (gt) 1 and HEV gt 2 that cause large outbreaks and affect young individuals with a high mortality rate in pregnant women from South Asian countries and patients with liver diseases. HEV gt 3, HEV gt 4, and HEV gt 7 are responsible for sporadic infections with zoonotic transmission mainly through the consumption of raw or undercooked meat from different animals. Acute HEV infection is relatively asymptomatic or mild clinical form, in rare cases the disease can be moderate/severe clinical forms and result in fulminant hepatitis or acute liver failure (ALF). Furthermore, HEV infection is associated with extrahepatic manifestations, including renal and neurological clinical signs and symptoms. Pregnant women, infants, older people, immunocompromised individuals, patients with comorbidities, and workers who come into close contact with HEV-infected animals are recognized as major risk groups for severe clinical form of HEV infection and fatal outcome. Chronic HEV infection can occur in immunocompromised individuals with the possibility of progression to cirrhosis.

Heat stability of foodborne viruses - Findings, methodological challenges and current developments

Heat treatment of food represents an important measure to prevent pathogen transmission. Thus far, evaluation of heat treatment processes is mainly based on data from bacteria. However, foodborne viruses have gained increasing attention during the last decades. Here, the published literature on heat stability and inactivation of human norovirus (NoV), hepatitis A virus (HAV) and hepatitis E virus (HEV) was reviewed. Data for surrogate viruses were not included. As stability assessment for foodborne viruses is often hampered by missing infectivity assays, an overview of applied methods is also presented. For NoV, molecular capsid integrity assays were mainly applied, but data from initial studies utilizing novel intestinal enteroid or zebrafish larvae assays are available now. However, these methods are still limited in applicability and sensitivity. For HAV, sufficient cell culture-based inactivation data are available, but almost exclusively for one single strain, thus limiting interpretation of the data for the wide range of field strains. For HEV, data are now available from studies using pig inoculation or cell culture. The results of the reviewed studies generally indicate that NoV, HAV and HEV possess a high heat stability. Heating at 70-72 °C for 2 min significantly reduces infectious titers, but often does not result in a >4 log10 decrease. However, heat stability greatly varied dependent on virus strain, matrix and heating regime. In addition, the applied method largely influenced the result, e.g. capsid integrity assays tend to result in higher measured stabilities than cell culture approaches. It can be concluded that the investigated foodborne viruses show a high heat stability, but can be inactivated by application of appropriate heating protocols. For HAV, suggestions for safe time/temperature combinations for specific foods can be derived from the published studies, with the limitation that they are mostly based on one strain only. Although significant improvement of infectivity assays for NoV and HEV have been made during the last years, further method development regarding sensitivity, robustness and broader applicability is important to generate more reliable heat inactivation data for these foodborne viruses in future.

Long-term efficacy of a recombinant hepatitis E vaccine in adults: 10-year results from a randomised, double-blind, placebo-controlled, phase 3 trial

BACKGROUND

Hepatitis E virus (HEV) is a frequently overlooked causative agent of acute hepatitis. Evaluating the long-term durability of hepatitis E vaccine efficacy holds crucial importance.

METHODS

This study was an extension to a randomised, double-blind, placebo-controlled, phase-3 clinical trial of the hepatitis E vaccine conducted in Dontai County, Jiangsu, China. Participants were recruited from 11 townships in Dongtai County. In the initial trial, a total of 112 604 healthy adults aged 16-65 years were enrolled, stratified according to age and sex, and randomly assigned in a 1:1 ratio to receive three doses of hepatitis E vaccine or placebo intramuscularly at month 0, month 1, and month 6. A sensitive hepatitis E surveillance system including 205 clinical sentinels, covering the entire study region, was established and maintained for 10 years after vaccination. The primary outcome was the per-protocol efficacy of hepatitis E virus vaccine to prevent confirmed hepatitis E occurring at least 30 days after administration of the third dose. Throughout the study, the participants, site investigators, and laboratory staff remained blinded to the treatment assignments. This study is registered with ClinicalTrials.gov (NCT01014845).

FINDINGS

During the 10-year study period from Aug 22, 2007, to Oct 31, 2017, 90 people with hepatitis E were identified; 13 in the vaccine group (0·2 per 10 000 person-years) and 77 in the placebo group (1·4 per 10 000 person-years), corresponding to a vaccine efficacy of 83·1% (95% CI 69·4-91·4) in the modified intention-to-treat analysis and 86·6% (73·0 to 94·1) in the per-protocol analysis. In the subsets of participants assessed for immunogenicity persistence, of those who were seronegative at baseline and received three doses of hepatitis E vaccine, 254 (87·3%) of 291 vaccinees in Qindong at the 8·5-year mark and 1270 (73·0%) of 1740 vaccinees in Anfeng at the 7·5-year mark maintained detectable concentrations of antibodies.

INTERPRETATION

Immunisation with this hepatitis E vaccine offers durable protection against hepatitis E for up to 10 years, with vaccine-induced antibodies against HEV persisting for at least 8·5 years.

FUNDING

National Natural Science Foundation of China, Fujian Provincial Natural Science Foundation, Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences, and the Fundamental Research Funds for the Central Universities.

Hepatitis E virus infections among patients with acute febrile jaundice in two regions of Cameroon: First molecular characterization of hepatitis E virus genotype 4

BACKGROUND

Febrile jaundice is a common indicator of certain infectious diseases, including hepatitis E. In Cameroon, the yellow fever virus is the only pathogen that is monitored in patients who present with this symptom. However, more than 90% of the samples received as part of this surveillance are negative for yellow fever. This study aimed to describe the prevalence and hepatitis E virus (HEV) genotype among yellow fever-negative patients in the Far North and West regions of Cameroon.

METHODS

In a cross-sectional study, yellow fever surveillance-negative samples collected between January 2021 and January 2023 were retrospectively analyzed. Anti-HEV IgM and IgG antibodies were tested using commercially available ELISA kits. Anti-HEV IgM and/or IgG positive samples were tested for HEV RNA by real-time RT-PCR, followed by nested RT-PCR, sequencing and phylogenetic analysis.

RESULTS

Overall, 121 of the 543 samples (22.3%, 95% CI: 19.0% - 26.0%) were positive for at least one anti-HEV marker. Amongst these, 8.1% (44/543) were positive for anti-HEV IgM, 5.9% (32/543) for anti-HEV IgG, and 8.3% (45/544) for both markers. A total of 15.2% (12/79) samples were positive for HEV RNA real-time RT-PCR and 8 samples were positive for HEV RNA by nested RT-PCR. Phylogenetic analysis showed that the retrieved sequences clustered within HEV genotypes/subtypes 1/1e, 3/3f and 4/4b.

CONCLUSION

Our results showed that HEV is one of the causes of acute febrile jaundice in patients enrolled in the yellow fever surveillance program in two regions of Cameroon. We described the circulation of three HEV genotypes, including two zoonotic genotypes. Further studies will be important to elucidate the transmission routes of these zoonotic HEV genotypes to humans in Cameroon.

Drug repurposing screen identifies vidofludimus calcium and pyrazofurin as novel chemical entities for the development of hepatitis E interventions

Hepatitis E virus (HEV) infection can cause severe complications and high mortality, particularly in pregnant women, organ transplant recipients, individuals with pre-existing liver disease and immunosuppressed patients. However, there are still unmet needs for treating chronic HEV infections. Herein, we screened a best-in-class drug repurposing library consisting of 262 drugs/compounds. Upon screening, we identified vidofludimus calcium and pyrazofurin as novel anti-HEV entities. Vidofludimus calcium is the next-generation dihydroorotate dehydrogenase (DHODH) inhibitor in the phase 3 pipeline to treat autoimmune diseases or SARS-CoV-2 infection. Pyrazofurin selectively targets uridine monophosphate synthetase (UMPS). Their anti-HEV effects were further investigated in a range of cell culture models and human liver organoids models with wild type HEV strains and ribavirin treatment failure-associated HEV strains. Encouragingly, both drugs exhibited a sizeable therapeutic window against HEV. For instance, the IC50 value of vidofludimus calcium is 4.6-7.6-fold lower than the current therapeutic doses in patients. Mechanistically, their anti-HEV mode of action depends on the blockage of pyrimidine synthesis. Notably, two drugs robustly inhibited ribavirin treatment failure-associated HEV mutants (Y1320H, G1634R). Their combination with IFN-α resulted in synergistic antiviral activity. In conclusion, we identified vidofludimus calcium and pyrazofurin as potent candidates for the treatment of HEV infections. Based on their antiviral potency, and also the favorable safety profile identified in clinical studies, our study supports the initiation of clinical studies to repurpose these drugs for treating chronic hepatitis E.

Development of a Sensitive and Specific Quantitative RT-qPCR Method for the Detection of Hepatitis E Virus Genotype 3 in Porcine Liver and Foodstuff

As an international and zoonotic cause of hepatitis, hepatitis E virus (HEV) poses a significant risk to public health. However, the frequency of occurrence and the degree of contamination of food of animal origin require further research. The aim of this study was to develop and validate a highly sensitive quantitative RT-qPCR assay for the detection and quantification of HEV contamination in porcine liver and food. The focus was on genotype 3, which is most common as a food contaminant in developed countries and Europe. The selected assay has its target sequence in the open reading frame 1 (ORF1) of the HEV genome and showed good results in inclusivity testing, especially for HEV genotype 3. The developed assay seems to show high efficiency and a low intercept when compared to other assays, while having a comparable limit of detection (LOD). In addition, a standard curve was generated using artificially spiked liver to provide more accurate quantitative results for contamination assessment and tracking in this matrix. Application of the assay to test 67 pig livers from different origins resulted in a positivity rate of 7.5%, which is consistent with the results of numerous other prevalence studies. Quantitative detection of the viral genome in the food chain, particularly in pig livers, is essential for understanding the presence and evolution of HEV contamination and thus ensures consumer safety.

Detection of hepatitis E virus genotype 3 in an Algerian mouse (Mus spretus) in Portugal

Virus monitoring in small mammals is central to the design of epidemiological control strategies for rodent-borne zoonotic viruses. Synanthropic small mammals are versatile and may be potential carriers of several microbial agents. In the present work, a total of 330 fecal samples of small mammals were collected at two sites in the North of Portugal and screened for zoonotic hepatitis E virus (HEV, species Paslahepevirus balayani). Synanthropic small mammal samples (n = 40) were collected in a city park of Porto and belonged to the species Algerian mouse (Mus spretus) (n = 26) and to the greater white-toothed shrew (Crocidura russula) (n = 14). Furthermore, additional samples were collected in the Northeast region of Portugal and included Algerian mouse (n = 48), greater white-toothed shrew (n = 47), wood mouse (Apodemus sylvaticus) (n = 43), southwestern water vole (Arvicola sapidus) (n = 52), Cabrera's vole (Microtus cabrerae) (n = 49) and Lusitanian pine vole (Microtus lusitanicus) (n = 51). A nested RT-PCR targeting a part of open reading frame (ORF) 2 region of the HEV genome was used followed by sequencing and phylogenetic analysis. HEV RNA was detected in one fecal sample (0.3%; 95% confidence interval, CI: 0.01-1.68) from a synanthropic Algerian mouse that was genotyped as HEV-3, subgenotype 3e. This is the first study reporting the detection of HEV-3 in a synanthropic rodent, the Algerian mouse. The identified HEV isolate is probably the outcome of either a spill-over infection from domestic pigs or wild boars, or the result of passive viral transit through the intestinal tract. This finding reinforces the importance in the surveillance of novel potential hosts for HEV with a particular emphasis on synanthropic animals.

Exploring Disease Management and Control through Pathogen Diagnostics and One Health Initiative: A Concise Review

The "One Health" initiative is a critical strategy that recognizes the interconnectedness between human, animal, and environmental health in the spread and containment of infectious pathogens. With the ease of global transportation, transboundary disease outbreaks pose a significant threat to food safety and security, endangering public health and having a negative economic impact. Traditional diagnostic techniques based on genotypic and phenotypic analyses are expensive, time-consuming, and cannot be translated into point-of-care tools, hindering effective disease management and control. However, with advancements in molecular methods, biosensors, and new generation sequencing, rapid and reliable diagnostics are now available. This review provides a comprehensive insight into emergent viral and bacterial pathogens and antimicrobial resistance, highlighting the importance of "One Health" in connecting detection and effective treatment. By emphasizing the symbiotic relationship between human and animal health, this paper underscores the critical role of "One Health" initiatives in preventing and controlling infectious diseases.

Emergence of resistance-associated variants during sofosbuvir treatment in chronically infected hepatitis E patients

BACKGROUND AND AIMS

Chronic HEV infections remain a serious problem in immunocompromised patients, as specifically approved antiviral drugs are unavailable. In 2020, a 24-week multicenter phase II pilot trial was carried out, evaluating the nucleotide analog sofosbuvir by treating nine chronically HEV-infected patients with sofosbuvir (Trial Number NCT03282474). During the study, antiviral therapy reduced virus RNA levels initially but did not lead to a sustained virologic response. Here, we characterize the changes in HEV intrahost populations during sofosbuvir treatment to identify the emergence of treatment-associated variants.

APPROACH AND RESULTS

We performed high-throughput sequencing on RNA-dependent RNA polymerase sequences to characterize viral population dynamics in study participants. Subsequently, we used an HEV-based reporter replicon system to investigate sofosbuvir sensitivity in high-frequency variants. Most patients had heterogenous HEV populations, suggesting high adaptability to treatment-related selection pressures. We identified numerous amino acid alterations emerging during treatment and found that the EC 50 of patient-derived replicon constructs was up to ~12-fold higher than the wild-type control, suggesting that variants associated with lower drug sensitivity were selected during sofosbuvir treatment. In particular, a single amino acid substitution (A1343V) in the finger domain of ORF1 could reduce susceptibility to sofosbuvir significantly in 8 of 9 patients.

CONCLUSIONS

In conclusion, viral population dynamics played a critical role during antiviral treatment. High population diversity during sofosbuvir treatment led to the selection of variants (especially A1343V) with lower sensitivity to the drug, uncovering a novel mechanism of resistance-associated variants during sofosbuvir treatment.

Viral Biology and Immune Privilege in the Development of Extrahepatic Manifestations During Hepatitis E Virus Infection

Hepatitis E virus (HEV) exhibits tropism toward hepatocytes and thus affects the liver; however, HEV may also affect other tissues, including the heart, kidneys, intestines, testicles, and central nervous system. To date, the pathophysiological links between HEV infection and extrahepatic manifestations have not yet been established. Considering that HEV infects multiple types of cells, the direct effects of virus replication in peripheral tissues represent a plausible explanation for extrahepatic manifestations. In addition, since the immune response is crucial in the development of the disease, the immune characteristics of affected tissues should be revisited to identify commonalities explaining the effects of the virus. This review summarizes the most recent advances in understanding the virus biology and immune-privileged status of specific tissues as major elements for HEV replication in diverse organs. These discoveries may open avenues to explain the multiple extrahepatic manifestations associated with HEV infection and ultimately to design effective strategies for infection control.

Co-circulation of Hepatitis E Virus (HEV) Genotype 3 and Moose-HEV-Like Strains in Free-Ranging-Spotted Deer (Axis axis) in Uruguay

Hepatitis E caused by hepatitis E virus (HEV) is considered an emerging foodborne zoonosis in industrialized, non-endemic countries. Domestic pigs and wild boars are considered the main reservoir of HEV. However, HEV can also infect an ever-expanding host range of animals, but they exact role in transmitting the virus to other species or humans is mostly unknown. In this work, we investigated the spread of HEV in free-living and captive spotted deer (Axis axis) from Uruguay in a 2-year period (2020-2022) and examined the role of this invasive species as a new potential reservoir of the virus. In addition, with the aim to gain new insights into viral ecology in the context of One Health, by using camera trapping, we identified and quantified temporal and spatial coexistence of spotted deer, wild boars, and cattle. In free-living animals, we detected an anti-HEV seropositivity of 11.1% (6/54). HEV infection and viral excretion in feces were assessed by RT-PCR. Thirteen of 19 samples (68.4%) had HEV RNA. Six samples were amplified using a broadly reactive RT-PCR and sequenced. No captive animal showed evidence of HEV infection. Additionally, HEV RNA was detected in a freshwater pond shared by these species. Phylogenetic and p-distance analysis revealed that zoonotic HEV genotype 3 strains circulate together with unclassified variants related to moose HEV whose potential risk of transmission to humans and other domestic and wild animals is unknown. The data presented here suggest that spotted deer (A. axis) may be a novel host for zoonotic HEV strains.

The burden of HEV-related acute liver failure in Bangladesh, China and India: a systematic review and meta-analysis

BACKGROUND

Hepatitis E can potentially progress to HEV-related acute liver failure (HEV-ALF). East and South Asia bear a substantial burden of HEV infection, with Bangladesh, China, and India facing the most severe threat in this region. Therefore, we conducted a systematic review and meta-analysis to evaluate the burden of HEV-ALF in these three high-risk countries.

METHODS

A systematic literature search was performed utilizing PubMed, the Cochrane Library, Medline, Embase, and Web of Science databases. Studies in English or Chinese that reported data on the burden of HEV-ALF in Bangladesh, China and India were included. Outcomes were pooled with meta-analysis utilizing R software. Estimates were calculated with random-effects models, and subgroup analysis and sensitivity analysis were conducted to address heterogeneity. Egger's test and Begg's test were performed to assess publication bias.

RESULTS

A total of 20 eligible studies were included in this study. The pooled HEV-attributable proportion of viral-related acute liver failure was estimated to be 40.0% (95% CI: 0.28-0.52), 30.0% (95% CI: 0.18-0.44), and 61.0% (95% CI: 0.49-0.72) among non-pregnant individuals in India, China and Bangladesh, while in Indian pregnant females, it was 71.0% (95% CI: 0.62-0.79). The combined prevalence among non-pregnant HEV-infected participants was 28.0% (95% CI: 0.20-0.37) and 10.0% (95% CI: 0.01-0.28) in India and China, and it was 34.0% (95% CI: 0.27-0.42) in Indian pregnant females with HEV infection. The overall mortality of HEV-ALF was estimated to be 32.0% (95% CI: 0.23-0.42) and 64.0% (95% CI: 0.50-0.77) among the non-pregnant and the pregnant participants in India, and it was 23.0% (95% CI: 0.14-0.34) in Chinese non-pregnant participants.

CONCLUSIONS

The burden of HEV-ALF in Bangladesh, China, and India is non-negligible despite geographic and population heterogeneity. The prevention of HEV infection and early recognition of HEV-ALF are of great significance, especially in high-risk countries and populations.

REGISTRATION

PROSPERO registration ID is CRD42022382101.

Knowledge about Hepatitis E and Influencing Factors among Residents in Qingdao: a Cross-Sectional Study

Hepatitis E infection poses a serious health problem in developing countries. Hepatitis E vaccination is important for prevention, but it is influenced by residents' knowledge. Qingdao residents' knowledge of hepatitis E remains unknown. This study used an online survey on the WeChat platform. The chi-square test was used to compare the hepatitis E influencing factors between the subgroups. Binary logistic regression was used for multiple factor analysis to explore the hepatitis E influencing factors. The total awareness rate of hepatitis E was 60.51%. Females aged between 51 and 60, aged 61 and above, and working in government-affiliated departments were found to have higher awareness rates than other subgroups. Participants with family members infected with hepatitis E had a lower awareness rate. The government and relevant departments should focus on education regarding the hepatitis E vaccination and disease process.

Hepatitis E Virus in Livestock-Update on Its Epidemiology and Risk of Infection to Humans

Hepatitis E virus (HEV) is a public health problem worldwide and an important food pathogen known for its zoonotic potential. Increasing numbers of infection cases with human HEV are caused by the zoonotic transmission of genotypes 3 and 4, mainly by consuming contaminated, undercooked or raw porcine meat. Pigs are the main reservoir of HEV. However, it should be noted that other animal species, such as cattle, sheep, goats, and rabbits, may also be a source of infection for humans. Due to the detection of HEV RNA in the milk and tissues of cattle, the consumption of infected uncooked milk and meat or offal from these species also poses a potential risk of zoonotic HEV infections. Poultry infected by avian HEV may also develop symptomatic disease, although avian HEV is not considered a zoonotic pathogen. HEV infection has a worldwide distribution with different prevalence rates depending on the affected animal species, sampling region, or breeding system.

Prevalence and Risk Factors for Hepatitis E Virus in Wild Boar and Red Deer in Portugal

Hepatitis E virus (HEV) is a zoonotic foodborne virus with an annual infection prevalence of 20 million human cases, which seriously affects public health and economic development in both developed and developing countries. To better understand the epidemiology of HEV in Central Portugal, a cross-sectional study was conducted from 2016 to 2023 with sera samples from wild ungulates. The seroprevalence and risk factors for HEV seropositivity were evaluated in the present study. Specifically, antibodies against HEV were determined by a commercial enzyme-linked immune-sorbent assay (ELISA). Our results show that in the 650 sera samples collected from 298 wild red deer and 352 wild boars in Portugal, 9.1% red deer and 1.7% wild boar were positive for antibodies to HEV. Regarding age, the seropositivity in juvenile wild ungulates was 1.3%, whereas it was 7.2% in adults. Logistic regression models investigated risk factors for seropositivity. The odds of being seropositive was 3.6 times higher in adults than in juveniles, and the risk was 4.2 times higher in red deer than in wild boar. Both wild ungulate species were exposed to HEV. The higher seroprevalence in red deer suggests that this species may make a major contribution to the ecology of HEV in Central Portugal. Further research is needed to understand how wildlife affects the epidemiology of HEV infections in Portugal.

High Hepatitis E Virus (HEV) Seroprevalence and No Evidence of HEV Viraemia in Vietnamese Blood Donors

The prevalence of hepatitis E virus (HEV) in the Vietnamese population remains underestimated. The aim of the present study was to investigate the seroprevalence of HEV IgG/IgM antibodies and the presence of HEV RNA in blood donors as a part of epidemiological surveillance for transfusion-transmitted viruses. Serum samples from blood donors (n = 553) were analysed for markers of past (anti-HEV IgG) and recent/ongoing (anti-HEV IgM) HEV infections. In addition, all serum samples were subsequently tested for HEV RNA positivity. The overall prevalence of anti-HEV IgG was 26.8% (n = 148/553), while the seroprevalence of anti-HEV IgM was 0.5% (n = 3/553). Anti-HEV IgG seroprevalence in male and female donors was similar (27.1% and 25.5%, respectively). A higher risk of hepatitis E exposure was observed with increasing age. None of the blood donors were HEV RNA positive, and there was no evidence of HEV viraemia. Although the absence of HEV viraemia in blood donors from Northern Vietnam is encouraging, further epidemiological surveillance in other geographical regions is warranted to rule out transfusion-transmitted HEV.

Epidemiology Update of Hepatitis E Virus (HEV) in Uruguay: Subtyping, Environmental Surveillance and Zoonotic Transmission

Hepatitis E Virus (HEV) infection is an emergent zoonotic disease of increasing concern in developed regions. HEV genotype 3 (HEV-3) is mainly transmitted through consumption of contaminated food in high-income countries and is classified into at least 13 subtypes (3a-3n), based on p-distance values from complete genomes. In Latin America, HEV epidemiology studies are very scant. Our group has previously detected HEV3 in clinical cases, swine, wild boars, captive white-collared peccaries, and spotted deer from Uruguay. Herein, we aimed to provide novel insights and an updated overview of the molecular epidemiology of zoonotic HEV in Uruguay, including data from wastewater-based surveillance studies. A thorough analysis of HEV whole genomes and partial ORF2 sequences from Uruguayan human and domestic pig strains showed that they formed a separate monophyletic cluster with high nucleotide identity and exhibited p-distance values over the established cut-off (0.093) compared with reference subtypes' sequences. Furthermore, we found an overall prevalence of 10.87% (10/92) in wastewater, where two samples revealed a close relationship with humans, and animal reservoirs/hosts isolates from Uruguay. In conclusion, a single, new HEV-3 subtype currently circulates in different epidemiological settings in Uruguay, and we propose its designation as 3o along with its reference sequence.

A multispecies competitive nanobody-based ELISA for the detection of antibodies against hepatitis E virus

The hepatitis E virus (HEV) is an emergent zoonotic virus causing viral hepatitis worldwide. Clinically, hepatitis E is not easily distinguished from other types of acute viral hepatitis. There is a need for HEV diagnostic assays to detect and prevent interspecies transmission among susceptible populations. Nanobodies (Nbs) are expressed recombinantly in different systems, produced with high yields, and have superior physicochemical properties compared with conventional antibodies (Ab). Several Nbs against ORF2, the capsid protein and main antigen, were selected and produced in E. coli. Nb39 and Nb74 specifically recognized HEV ORF2 (genotypes 3 and 4). A competitive ELISA (cELISA) was developed and validated using a reference panel of human (n = 86) and swine sera (n = 116) tested in comparison with a commercial kit. The optimal cutoff values determined by ROC analysis were 69.16% (human) and 58.76% (swine); the sensitivity and specificity were high: 97.4% (95% CI 86.5-99.5%) and 95.8% (95% CI 86.0-98.8%) for human vs. 100% (95% CI 93.5-100%) and 98.3% (95% CI 91.0-99.7%) for swine. Further, the cELISA detected total anti-HEV antibodies in wild boar, deer, and mice. To our knowledge, this is the first report of production of Nbs against HEV-3 ORF2 for diagnostic purposes.

Hepatitis E Virus in the Iberian Peninsula: A Systematic Review

One of the most frequent causes of acute viral hepatitis is hepatitis E virus (HEV) causing 20 million infections worldwide each year and 44,000 deaths. Studies on HEV in the Iberian Peninsula have been increasing through time with HEV infection being identified in humans and animals. The aim of the present systematic review was to compile and evaluate all the published data on HEV from studies performed in humans, animals and environmental samples in the Iberian Peninsula. The electronic databases Mendeley, PubMed, Scopus, and Web of Science were thoroughly searched, and research published up until February 01, 2023 were included. Resulting in a total of 151 eligible papers by full reading and application of PRISMA exclusion/inclusion criteria. Overall, the present review shows that several HEV genotypes, namely HEV-1, 3, 4, and 6 as well as Rocahepevirus, are circulating in humans, animals, and in the environment in the Iberian Peninsula. HEV-3 was the most common genotype circulating in humans in Portugal and Spain, as expected for developed countries, with HEV-1 only being detected in travelers and emigrants from HEV endemic regions. Spain is the biggest pork producer in Europe and given the high circulation of HEV in pigs, with HEV-3 being primarily associated to zoonotic transmission through consumption of swine meat and meat products, in our opinion, the introduction of an HEV surveillance system in swine and inclusion of HEV in diagnostic routines for acute and chronic human hepatitis would be important. Additionally, we propose that establishing a monitoring mechanism for HEV is crucial in order to gain a comprehensive understanding of the prevalence of this illness and the various strains present in the Iberian Peninsula, as well as their potential impact on public health.

IL-18 discriminates highly frequent hepatitis E virus positive from negative blood donors in Mexico

INTRODUCTION AND OBJECTIVES

Hepatitis E virus (HEV) is not routinely screened in blood banks in low- and middle-income countries, and no specific biomarkers of exposure to this virus have yet been identified. We aimed to identify HEV seropositivity and detect virus RNA among blood donors from Mexico to further correlate risk factors related to infection and levels of interleukin-18 (IL-18) and interferon-gamma (IFN-γ) as potential biomarkers.

MATERIALS AND METHODS

This cross-sectional, single-center study included 691 serum samples of blood donors obtained in 2019. Anti-HEV IgG and IgM antibodies were detected in sera and the viral genome was screened in pooled samples. A statistical comparison of risk factors for infection, demographic and clinical features was performed; IL-18 and IFN- γ values were tested in sera.

RESULTS

Of all the individuals, 9.4% were positive for anti-HEV antibodies and viral RNA detection was confirmed in one of the pools positive for anti-HEV. From the analysis of risk factors, age and having pets were statistically significant for anti-HEV antibody detection. Seropositive samples showed significantly higher IL-18 concentrations relative to samples from seronegative donors. Interestingly, IL-18 values were similar when HEV seropositive samples were compared to samples from clinically acute previously confirmed HEV patients.

CONCLUSIONS

Our findings highlight the need to follow up on HEV in blood banks in Mexico and underscore that IL-18 could represent a biomarker of HEV exposure.

Analysis of the spatial-temporal distribution characteristics of hepatitis E in Jiangsu province from 2005 to 2020

Objective

This study attempts to analyze the spatial clustering and spatial-temporal distribution characteristics of hepatitis E (HE) at the county (city and district) level in Jiangsu province to provide a scientific basis for the prevention and control of HE.

Method

The information on HE cases reported in the Chinese Center for Disease Control and Prevention Information System from 2005 to 2020 was collected for spatial autocorrelation analysis and spatial-temporal clustering analysis.

Result

From 2005 to 2020, 48,456 HE cases were reported in Jiangsu province, with an average annual incidence rate of 3.87/100,000. Male cases outnumbered female cases (2.46:1), and the incidence was highest in the 30-70 years of age group (80.50%). Farmers accounted for more than half of all cases (59.86%), and in terms of the average annual incidence, the top three cities were all in Zhenjiang city. Spatial autocorrelation analysis showed that Global Moran's I of HE incidence varied from 0.232 to 0.513 for the years. From 2005 to 2020, 31 counties (cities and districts) had high and statistically significant HE incidence, and two clustering areas were detected by spatial-temporal scanning.

Conclusion

HE incidence in Jiangsu province from 2005 to 2020 was stable, with age and gender differences, regional clustering, and spatial-temporal clustering. Further investigation of HE clustering areas is necessary to formulate corresponding targeted prevention and control measures.

Effect of High Hydrostatic Pressure Processing and Holder Pasteurization of Human Milk on Inactivation of Human Coronavirus 229E and Hepatitis E Virus

In preterm infants, sterilized donor milk (DM) is frequently used for feeding when breast milk is lacking. Most human milk banks use the Holder pasteurization method (HoP) to ensure the microbiological safety of DM. However, this method degrades many bioactive factors and hormones. Recently, high hydrostatic pressure (HHP) processing, which preserves bioactive factors in human milk, has been proposed as an alternative method to ensure the safety of DM. Although HHP treatment has been shown to be effective for viral inactivation, the effect of HHP on viruses that may be present in the complex nutritional matrix of human milk has not yet been defined. In the present study, we compared the efficacy of two HHP protocols (4 cycles at 350 MPa at 38 °C designated as 4xHP350 treatment, and 1 cycle at 600 MPa at 20 °C designated as 1xHP600 treatment) with the HoP method on artificially virus-infected DM. For this purpose, we used human coronavirus 229E (HCoV-229E) and hepatitis E virus (HEV) as surrogate models for enveloped and non-enveloped viruses. Our results showed that HCoV-229E is inactivated by HHP and HoP treatment. In particular, the 4xHP350 protocol is highly effective in inactivating HCoV-229E. However, our results demonstrated a matrix effect of human milk on HCoV-229E inactivation. Furthermore, we demonstrated that HEV is stable to moderate pressure HHP treatment, but the milk matrix does not protect it from inactivation by the high-pressure HHP treatment of 600 MPa. Importantly, the complex nutritional matrix of human milk protects HEV from inactivation by HoP treatment. In conclusion, we demonstrated that HHP and HoP treatments do not lead to complete inactivation of both surrogate virus models, indicating that these treatments cannot guarantee total viral safety of donor milk.

Molecular characterisation of a rabbit Hepatitis E Virus strain detected in a chronically HEV-infected individual from Germany

In immunocompromised individuals persisting viremia frequently leads to a chronic hepatitis E virus (HEV) infection. Zoonotic transmission of HEV from pigs and wild boar to humans is proven and sporadic infections with rabbit HEV (raHEV) have recently been reported. Here, the molecular characterisation of a raHEV strain isolated from an immunocompromised, chronically HEV-infected, heart-transplanted patient is described. After successful ribavirin (RBV) treatment of a HEV infection in 2019, the patient was again tested HEV positive in 2021 and received a second RBV therapy cycle. Full-length HEV genome amplification and next generation sequencing was performed on a plasma sample taken between first and second cycle of RBV therapy and a stool sample taken two months after starting the second cycle. The sequence of plasma (raHEV-83) and stool (raHEV-99) derived virus showed the highest nucleotide sequence identity to a Chinese raHEV and a phylogenetic relationship to a raHEV strain isolated from a French patient. Furthermore, sequence analysis revealed the presence of RBV-associated substitutions V1479I and G1634K in the HEV sequences from plasma and additionally K1398R from stool. The results underline the role of rabbits as putative sources of HEV infection and emphasize the need of a one health concept for a better understanding of HEV epidemiology and to develop tools for prevention and control of HEV infection.

EGF receptor modulates HEV entry in human hepatocytes

BACKGROUND AND AIMS

Being the most common cause of acute viral hepatitis with >20 million cases per year and 70,000 deaths annually, HEV presents a long-neglected and underinvestigated health burden. Although the entry process of viral particles is an attractive target for pharmacological intervention, druggable host factors to restrict HEV entry have not been identified so far.

APPROACH AND RESULTS

Here we identify the EGF receptor (EGFR) as a novel host factor for HEV and reveal the significance of EGFR for the HEV entry process. By utilizing RNAi, chemical modulation with Food and Drug Administration-approved drugs, and ectopic expression of EGFR, we revealed that EGFR is critical for HEV infection without affecting HEV RNA replication or assembly of progeny virus. We further unveiled that EGFR itself and its ligand-binding domain, rather than its signaling function, is responsible for the proviral effect. Modulation of EGF expression in HepaRG cells and primary human hepatocytes affected HEV infection.

CONCLUSIONS

Taken together, our study provides novel insights into the life cycle of HEV and identified EGFR as a possible target for future antiviral strategies against HEV.

[Viral zoonoses in Germany: a One Health perspective]

The COVID-19 pandemic and the increasing occurrence of monkeypox (mpox) diseases outside Africa have illustrated the vulnerability of populations to zoonotic pathogens. In addition, other viral zoonotic pathogens have gained importance in recent years.This review article addresses six notifiable viral zoonotic pathogens as examples to highlight the need for the One Health approach in order to understand the epidemiology of the diseases and to derive recommendations for action by the public health service. The importance of environmental factors, reservoirs, and vectors is emphasized, the diseases in livestock and wildlife are analyzed, and the occurrence and frequency of diseases in the population are described. The pathogens selected here differ in their reservoirs and the role of vectors for transmission, the impact of infections on farm animals, and the disease patterns observed in humans. In addition to zoonotic pathogens that have been known in Germany for a long time or were introduced recently, pathogens whose zoonotic potential has only lately been shown are also considered.For the pathogens discussed here, there are still large knowledge gaps regarding the transmission routes. Future One Health-based studies must contribute to the further elucidation of their transmission routes and the development of prevention measures. The holistic approach does not necessarily include a focus on viral pathogens/diseases, but also includes the question of the interaction of viral, bacterial, and other pathogens, including antibiotic resistance and host microbiomes.

Treatment Options for Hepatitis A and E: A Non-Systematic Review

Hepatitis A and hepatitis E are relatively common causes of liver disease. Both viruses are mainly transmitted through the faecal-oral route and, consequently, most outbreaks occur in countries with poor sanitation. An important role of the immune response as the driver of liver injury is also shared by the two pathogens. For both the hepatitis A (HAV) and hepatitis E (HEV) viruses, the clinical manifestations of infection mainly consist of an acute disease with mild liver injury, which results in clinical and laboratory alterations that are self-limiting in most cases. However, severe acute disease or chronic, long-lasting manifestations may occur in vulnerable patients, such as pregnant women, immunocompromised individuals or those with pre-existing liver disease. Specifically, HAV infection rarely results in fulminant hepatitis, prolonged cholestasis, relapsing hepatitis and possibly autoimmune hepatitis triggered by the viral infection. Less common manifestations of HEV include extrahepatic disease, acute liver failure and chronic HEV infection with persistent viraemia. In this paper, we conduct a non-systematic review of the available literature to provide a comprehensive understanding of the state of the art. Treatment mainly consists of supportive measures, while the available evidence for aetiological treatment and additional agents in severe disease is limited in quantity and quality. However, several therapeutic approaches have been attempted: for HAV infection, corticosteroid therapy has shown outcome improvement, and molecules, such as AZD 1480, zinc chloride and heme oxygenase-1, have demonstrated a reduction in viral replication in vitro. As for HEV infection, therapeutic options mainly rely on the use of ribavirin, and some studies utilising pegylated interferon-alpha have shown conflicting results. While a vaccine for HAV is already available and has led to a significant reduction in the prevalence of the disease, several vaccines for HEV are currently being developed, with some already available in China, showing promising results.

Ribavirin Treatment Failure-Associated Mutation, Y1320H, in the RNA-Dependent RNA Polymerase of Genotype 3 Hepatitis E Virus (HEV) Enhances Virus Replication in a Rabbit HEV Infection Model

Chronic hepatitis E virus (HEV) infection has become a significant clinical problem that requires treatment in immunocompromised individuals. In the absence of an HEV-specific antiviral, ribavirin (RBV) has been used off-label, but treatment failure may occur due to mutations in the viral RNA-dependent RNA polymerase (RdRp), including Y1320H, K1383N, and G1634R. Chronic hepatitis E is mostly caused by zoonotic genotype 3 HEV (HEV-3), and HEV variants from rabbits (HEV-3ra) are closely related to human HEV-3. Here, we explored whether HEV-3ra, along with its cognate host, can serve as a model to study RBV treatment failure-associated mutations observed in human HEV-3-infected patients. By utilizing the HEV-3ra infectious clone and indicator replicon, we generated multiple single mutants (Y1320H, K1383N, K1634G, and K1634R) and a double mutant (Y1320H/K1383N) and assessed the role of mutations on replication and antiviral activity of HEV-3ra in cell culture. Furthermore, we also compared the replication of the Y1320H mutant with the wild-type HEV-3ra in experimentally infected rabbits. Our in vitro analyses revealed that the effects of these mutations on rabbit HEV-3ra are altogether highly consistent with those on human HEV-3. Importantly, we found that the Y1320H enhances virus replication during the acute stage of HEV-3ra infection in rabbits, which corroborated our in vitro results showing an enhanced viral replication of Y1320H. Taken together, our data suggest that HEV-3ra and its cognate host is a useful and relevant naturally occurring homologous animal model to study the clinical relevance of antiviral-resistant mutations observed in human HEV-3 chronically-infected patients. IMPORTANCE HEV-3 causes chronic hepatitis E that requires antiviral therapy in immunosuppressed individuals. RBV is the main therapeutic option for chronic hepatitis E as an off-label use. Several amino acid changes, including Y1320H, K1383N, and G1634R, in the RdRp of human HEV-3 have reportedly been associated with RBV treatment failure in chronic hepatitis E patients. In this study, we utilized an HEV-3ra from rabbit and its cognate host to investigate the effect of these RBV treatment failure-associated HEV-3 RdRp mutations on viral replication efficiency and antiviral susceptibility. The in vitro data using rabbit HEV-3ra was highly comparable to those from human HEV-3. We demonstrated that the Y1320H mutation significantly enhanced HEV-3ra replication in cell culture and enhanced virus replication during the acute stage of HEV-3ra infection in rabbits. The rabbit HEV-3ra infection model should be useful in delineating the role of human HEV-3 RBV treatment failure-associated mutations in antiviral resistance.

Animal reservoirs for hepatitis E virus within the Paslahepevirus genus

Hepatitis E virus (HEV) is responsible for acute hepatitis in humans. It is a single-stranded, positive-sense RNA virus that belongs to the Hepeviridae family. The majority of concerning HEV genotypes belong to the Paslahepevirus genus and are subsequently divided into eight genotypes. HEV genotypes 1 and 2 exclusively infect humans and primates while genotypes 3 and 4 infect both humans and other mammals. Whereas HEV genotypes 5 and 6 are isolated from wild boars and genotypes 7 and 8 were identified from camels in the United Arab Emirates and China, respectively. HEV mainly spreads from humans to humans via the fecal-oral route. However, some genotypes with the capability of zoonotic transmissions, such as 3 and 4 transmit from animals to humans through feces, direct contact, and ingestion of contaminated meat products. As we further continue to uncover novel HEV strains in various animal species, it is becoming clear that HEV has a broad host range. Therefore, understanding the potential animal reservoirs for this virus will allow for better risk management and risk mitigation of infection with HEV. In this review, we mainly focused on animal reservoirs for the members of the species Paslahepevirus balayani and provided a comprehensive list of the host animals identified to date.

Specific Plasma MicroRNA Signatures Underlying the Clinical Outcomes of Hepatitis E Virus Infection

The pathogenic mechanisms determining the diverse clinical outcomes of HEV infection (e.g., self-limiting versus chronic or symptomatic versus asymptomatic) are not yet understood. Because specific microRNA signatures during viral infection inform the cellular processes involved in virus replication and pathogenesis, we investigated plasma microRNA profiles in 44 subjects, including patients with symptomatic acute (AHE, n = 7) and chronic (CHE, n = 6) hepatitis E, blood donors with asymptomatic infection (HEV BDs, n = 9), and anti-HEV IgG⁺ IgM^- (exposed BDs, n = 10) and anti-HEV IgG^- IgM^- (naive BDs, n = 12) healthy blood donors. By measuring the abundance of 179 microRNAs in AHE patients and naive BDs by reverse transcription-quantitative PCR (RT-qPCR), we identified 51 potential HEV-regulated microRNAs (P value adjusted for multiple testing by the Benjamini-Hochberg correction [P_BH] < 0.05). Further analysis showed that HEV genotype 3 infection is associated with miR-122, miR-194, miR-885, and miR-30a upregulation and miR-221, miR-223, and miR-27a downregulation. AHE patients showed significantly higher levels of miR-122 and miR-194 and lower levels of miR-221, miR-27a, and miR-335 than HEV BDs. This specific microRNA signature in AHE could promote virus replication and reduce antiviral immune responses, contributing to the development of clinical symptoms. We found that miR-194, miR-335, and miR-221 can discriminate between asymptomatic HEV infections and those developing acute symptoms, whereas miR-335 correctly classifies AHE and CHE patients. Our data suggest that diverse outcomes of HEV infection result from different HEV-induced microRNA dysregulations. The specific microRNA signatures described offer novel information that may serve to develop biomarkers of HEV infection outcomes and improve our understanding of HEV pathogenesis, which may facilitate the identification of antiviral targets. IMPORTANCE There is increasing evidence that viruses dysregulate the expression and/or secretion of microRNAs to promote viral replication, immune evasion, and pathogenesis. In this study, we evaluated the change in microRNA abundance in patients with acute or chronic HEV infection and asymptomatic HEV-infected blood donors. Our results suggest that different HEV-induced microRNA dysregulations may contribute to the diverse clinical manifestations of HEV infection. The specific microRNA signatures identified in this study hold potential as predictive markers of HEV infection outcomes, which would improve the clinical management of hepatitis E patients, particularly of those developing severe symptoms or chronic infections. Furthermore, this study provides new insights into HEV pathogenesis that may serve to identify antiviral targets, which would have a major impact because no effective treatments are yet available.

The first reported hepatitis E outbreak in a food manufacturing factory: Korea, 2022

OBJECTIVES

On February 16, 2022, 12 cases of hepatitis E virus (HEV) infection were reported in a food manufacturing factory in Korea. The aim of this study was to identify additional cases and to determine the source of this HEV outbreak.

METHODS

This study was an in-depth investigation of 12 HEV immunoglobulin M (IgM)-positive cases and their demographic, clinical, and epidemiological characteristics. On-site specimens were collected from the environment and from humans, and a follow-up investigation was conducted 2 to 3 months after the outbreak.

RESULTS

Among 80 production workers in the factory, 12 (15.0%) had acute HEV infection, all of whom were asymptomatic. The follow-up investigation showed that 3 cases were HEV IgMpositive, while 6 were HEV IgG-positive. HEV genes were not detected in the HEV IgM-positive specimens. HEV genes were not detected in the food products or environmental specimens collected on-site. HEV was presumed to be the causative pathogen. However, it could not be confirmed that the source of infection was common consumption inside the factory.

CONCLUSIONS

This was the first domestic case of an HEV infection outbreak in a food manufacturing factory in Korea. Our results provide information for the future control of outbreaks and for the preparation of measures to prevent domestic outbreaks of HEV infection.

Examining the Effect of Organic Acids on Inactivation of Hepatitis E Virus

ABSTRACT

Infection with hepatitis E virus genotype 3 (HEV-3) is an emerging cause of illness in developed countries. In North America and Europe, HEV-3 has been increasingly detected in swine, and exposure to pigs and pork products is considered the primary source of infection. We have previously demonstrated the prevalence of the HEV-3 genome in commercial pork products in Canada. In this study, we investigated the application of citric acid and acetic acid to inactivate HEV-3 on food and on food contact surfaces. For this purpose, plastic, stainless steel, and pork pâté surfaces were inoculated with HEV-3 and were treated with acetic acid or citric acid at 1, 3, or 5%. The infectivity of posttreatment viral particles was determined by cell culture. A greater than 2-log reduction in viral infectivity was observed on plastic and stainless steel treated with the organic acids, but the treatment was less effective on HEV infectivity on pork pâté (average reductions of 0.47 log citric acid and 0.63 log acetic acid). Therefore, we conclude that citric acid and acetic acid have potential application to control HEV-3 on food contact surfaces but are not suitable for food.

HIGHLIGHTS

Monitoring of hepatitis E virus in zoo animals from Spain, 2007-2021

Hepatitis E virus (HEV, family Hepeviridae) is an important emerging and zoonotic pathogen. In recent decades, the number of human cases of zoonotic hepatitis E has increased considerably in industrialized countries and HEV has been detected in an expanding range of mammal species. Although domestic pigs and wild boar are considered the main reservoirs of zoonotic HEV genotypes, the role of other susceptible animals in the epidemiology of the virus is still poorly understood. A large-scale, long-term study was carried out (1) to assess HEV exposure in captive zoo animals in Spain and (2) to determine the dynamics of seropositivity in individuals that were sampled longitudinally during the study period. Between 2007 and 2021, serum samples from 425 zoo animals belonging to 109 animal species (including artiodactyls, carnivores, perissodactyls, proboscideans and rodents) were collected from 11 different zoological parks in Spain. Forty-six of these animals at seven of these zoos were also longitudinally sampled. Anti-HEV antibodies were detected in 36 (8.5%; 95% CI: 5.8-11.1) of 425 sampled zoo animals. Specific antibodies against HEV-3 and HEV-C1 antigens were confirmed in ELISA-positive animals using western blot assay. Two of 46 longitudinally surveyed animals seroconverted during the study period. Seropositivity was significantly higher in carnivores and perissodactyls than in artiodactyls, and also during the period 2012-2016 compared with 2007-2011. HEV RNA was not detected in any of the 262 animals that could be tested by RT-PCR. To the best of the author's knowledge, this is the first large-scale, long-term surveillance on HEV in different orders of zoo mammals. Our results indicate exposure to HEV-3 and HEV-C1 in zoo animals in Spain and confirm a widespread but not homogeneous spatiotemporal circulation of HEV in captive species in this country. Further studies are required to determine the role of zoo species, particularly carnivores and perissodactyls, in the epidemiology of HEV and to clarify the origins of infection in zoological parks.

Predicting incidence of hepatitis E for thirteen cities in Jiangsu Province, China

Hepatitis E has placed a heavy burden on China, especially in Jiangsu Province, so accurately predicting the incidence of hepatitis E benefits to alleviate the medical burden. In this paper, we propose a new attentive bidirectional long short-term memory network (denoted as BiLSTM-Attention) to predict the incidence of hepatitis E for all 13 cities in Jiangsu Province, China. Besides, we also explore the performance of adding meteorological factors and the Baidu (the most widely used Chinese search engine) index as additional training data for the prediction of our BiLSTM-Attention model. SARIMAX, GBDT, LSTM, BiLSTM, and BiLSTM-Attention models are tested in this study, based on the monthly incidence rates of hepatitis E, meteorological factors, and the Baidu index collected from 2011 to 2019 for the 13 cities in Jiangsu province, China. From January 2011 to December 2019, a total of 29,339 cases of hepatitis E were detected in all cities in Jiangsu Province, and the average monthly incidence rate for each city is 0.359 per 100,000 persons. Root mean square error (RMSE) and mean absolute error (MAE) are used for model selection and performance evaluation. The BiLSTM-Attention model considering meteorological factors and the Baidu index has the best performance for hepatitis E prediction in all cities, and it gets at least 10% improvement in RMSE and MAE for all 13 cities in Jiangsu province, which means the model has significantly improved the learning ability, generalizability, and prediction accuracy when comparing with others.

Chronic hepatitis E: Advancing research and patient care

The hepatitis E virus (HEV) was initially thought to exclusively cause acute hepatitis. However, the first diagnosis of chronic hepatitis E in transplant recipients in 2008 profoundly changed our understanding of this pathogen. We have now begun to understand that specific HEV genotypes can cause chronic infection in certain immunocompromised populations. Over the past decade, dedicated clinical and experimental research has substantiated knowledge on the epidemiology, transmission routes, pathophysiological mechanisms, diagnosis, clinical features and treatment of chronic HEV infection. Nevertheless, many gaps and major challenges remain, particularly regarding the translation of knowledge into disease prevention and improvement of clinical outcomes. This article aims to highlight the latest developments in the understanding and management of chronic hepatitis E. More importantly, we attempt to identify major knowledge gaps and discuss strategies for further advancing both research and patient care.

Hepatitis E virus is effectively inactivated by methylene blue plus light treatment

BACKGROUND AND OBJECTIVES

Photodynamic treatment with methylene blue (MB) and visible light is a well-established pathogen inactivation system for human plasma. This technique is routinely used in different countries. MB/light treatment was shown to inactivate several transfusion-transmittable viruses, but its efficiency for the inactivation of the quasi-enveloped hepatitis E virus (HEV) has not yet been investigated.

MATERIALS AND METHODS

Plasma units were spiked with cell culture-derived HEV and treated with the THERAFLEX MB-Plasma system using various light doses (30, 60, 90, and 120 J/cm² ). HEV titers in pre- and post-treatment samples were determined by virus titration and a large-volume plating assay to improve the detection limit of the virus assay.

RESULTS

THERAFLEX MB-Plasma efficiently inactivated HEV in human plasma. Even the lowest light dose of 30 J/cm² inactivated HEV down to the limit of detection, with a mean log reduction factor of greater than 2.4 for the total process.

CONCLUSION

Our study demonstrates that the THERAFLEX MB-Plasma system effectively inactivates HEV in human plasma.

Orthohepevirus C infection as an emerging cause of acute hepatitis in Spain: First report in Europe

BACKGROUND & AIM

Hepatitis E virus (HEV) was considered the only member of the Hepeviridae family with zoonotic potential. Nevertheless, this consideration has been reassessed owing to several reported cases of acute and chronic hepatitis linked to the Orthohepevirus C genus. Because the circulation of Orthohepevirus C in rodents has been described worldwide, the risk of zoonotic transmission is plausibly global.

METHODS

Orthohepevirus C RNA was retrospectively evaluated in 2 cohorts of patients in Spain. The first cohort included patients with acute hepatitis without etiological diagnosis after screening for hepatotropic virus infection. The second cohort included patients diagnosed with acute HEV infection, defined as positivity for anti-HEV-IgM antibodies and/or detectable HEV RNA in serum.

RESULTS

Cohort 1 comprised 169 patients (64.4% male, median age 43 years) and cohort 2 comprised 98 individuals (68.3% male, median age 45 years). Of the individuals included in Cohort 1, two (1.18%; 95% CI 0.2-3.8) had detectable Orthohepevirus C RNA in serum. In Cohort 2, of the 98 included patients, 58 showed detectable HEV RNA, while 40 only showed positivity for IgM antibodies. Among those bearing only IgM antibodies, Orthohepevirus C RNA was detected in 1 (2.5%; 95% CI 0.06-13.1) individual. All strains were consistent with genotype C1. The infection resulted in mild self-limiting acute hepatitis in 2 patients. Infection caused severe acute hepatitis in the remaining patient who died as a result of liver and renal failure.

CONCLUSIONS

We described 3 cases of Orthohepevirus C in patients with acute hepatitis, resulting in the first description of this infection in Europe. The prevalence obtained in our study suggests that Orthohepevirus C could be an emerging disease in Europe.

LAY SUMMARY

We describe the first cases of acute hepatitis related to rat hepatitis E virus in Europe. The prevalence found in our study suggest that rat hepatitis E virus could be considered an emerging disease in Europe.

Co-Circulation of Different Hepatitis E Virus Genotype 3 Subtypes in Pigs and Wild Boar in North-East Germany, 2019

Hepatitis E is a major cause of acute liver disease in humans worldwide. The infection is caused by hepatitis E virus (HEV) which is transmitted in Europe to humans primarily through zoonotic foodborne transmission from domestic pigs, wild boar, rabbits, and deer. HEV belongs to the family Hepeviridae, and possesses a positive-sense, single stranded RNA genome. This agent usually causes an acute self-limited infection in humans, but in people with low immunity, e.g., immunosuppressive therapy or underlying liver diseases, the infection can evolve to chronicity and is able to induce a variety of extrahepatic manifestations. Pig and wild boar have been identified as the primary animal reservoir in Europe, and consumption of raw and undercooked pork is known to pose a potential risk of foodborne HEV infection. In this study, we analysed pig and wild boar liver, faeces, and muscle samples collected in 2019 in Mecklenburg-Western Pomerania, north-east Germany. A total of 393 animals of both species were investigated using quantitative real-time reverse transcription polymerase chain reaction (RT-qPCR), conventional nested RT-PCR and sequence analysis of amplification products. In 33 animals, HEV RNA was detected in liver and/or faeces. In one individual, viral RNA was detected in muscle tissue. Sequence analysis of a partial open reading frame 1 region demonstrated a broad variety of genotype 3 (HEV-3) subtypes. In conclusion, the study demonstrates a high, but varying prevalence of HEV RNA in swine populations in Mecklenburg-Western Pomerania. The associated risk of foodborne HEV infection needs the establishment of sustainable surveillance and treatment strategies at the interface between humans, animals, and the environment within a One Health framework.

Molecular epidemiology and genotype-specific disease severity of hepatitis E virus infections in Germany, 2010-2019

Zoonotic hepatitis E virus (HEV) is endemic in Europe. Genotype 3 (HEV-3) is predominant but information on subtype distribution, trends and clinical implications in Germany is scarce. We analysed 936 HEV RNA positive samples of human origin and corresponding national surveillance data from 2010 to 2019. Samples were referred to the National Consultant Laboratory and sequenced in at least one of four genomic regions. Sequences were analysed using bioinformatics methods and compared to the latest HEV reference set. 1,656 sequences were obtained from 300 female, 611 male and 25 of unknown sex aged 3–92 years (median 55 years). HEV-3c was predominant (67.3%) followed by HEV-3f, HEV-3e and HEV-3i(-like) with 14.3%, 9.7% and 4.0% (other subtypes ≤1.1%). The proportion of HEV-3 group 2 (3abchijklm) strains increased over time. Jaundice, upper abdominal pain, fever, hospitalization, and death due to HEV were significantly more often reported for patients infected with HEV-3 group 1 (3efg) compared to group 2. Larger spatio-temporal clusters of identical sequences were not observed. HEV-3 group 1 infections are more severe as compared to the predominant group 2. Detection of group 2 strains increased over the last years, possibly due to more frequent diagnosis of asymptomatic and mild courses. The diversity of strains and the space–time distribution is compatible with a foodborne zoonosis with supra-regional distribution of the infection vehicle (pork products).

Stability of Hepatitis E Virus After Drying on Different Surfaces

The hepatitis E virus (HEV) causes acute and chronic hepatitis in humans. The zoonotic HEV genotype 3 is mainly transmitted by consumption of contaminated food produced from infected animals. However, transmission via contaminated surfaces has also to be considered. Here, the genotype 3c strain 47832c was dried on steel, wood, plastics and ceramics, stored at 23 °C or 3 °C for up to 8 weeks and remaining infectivity was titrated on cell culture. During the drying process, only a mean 0.2 log₁₀ decrease of HEV infectivity was observed. At 23 °C, remaining infectious virus was detected until week 4 on most surfaces, but HEV was completely inactivated (> 4 log₁₀ decrease) after 8 weeks. At 3 °C, HEV was detectable up to 8 weeks on most surfaces, with an average 2.3 log₁₀ decrease. HEV showed the highest stability on plastics, which was lower on ceramics and steel, and lowest on wood. The addition of bovine serum albumin mimicking high protein load had only a slight stabilizing effect. In conclusion, HEV shows a high stability against drying and subsequent storage on different surfaces. Strict application of hygienic measures during food production is therefore crucial in order to prevent HEV persistence on surfaces and subsequent cross-contamination.

Chirohepevirus from Bats: Insights into Hepatitis E Virus Diversity and Evolution

Homologs of the human hepatitis E virus (HEV) have been identified in more than a dozen animal species. Some of them have been evidenced to cross species barriers and infect humans. Zoonotic HEV infections cause chronic liver diseases as well as a broad range of extrahepatic manifestations, which increasingly become significant clinical problems. Bats comprise approximately one-fifth of all named mammal species and are unique in their distinct immune response to viral infection. Most importantly, they are natural reservoirs of several highly pathogenic viruses, which have induced severe human diseases. Since the first discovery of HEV-related viruses in bats in 2012, multiple genetically divergent HEV variants have been reported in a total of 12 bat species over the last decade, which markedly expanded the host range of the HEV family and shed light on the evolutionary origin of human HEV. Meanwhile, bat-borne HEV also raised critical public health concerns about its zoonotic potential. Bat HEV strains resemble genomic features but exhibit considerable heterogeneity. Due to the close evolutionary relationships, bat HEV altogether has been recently assigned to an independent genus, Chirohepevirus. This review focuses on the current state of bat HEV and provides novel insights into HEV genetic diversity and molecular evolution.

Phylogeny and spatio-temporal dynamics of hepatitis E virus infections in wild boar and deer from six areas of Germany during 2013-2017

The hepatitis E virus (HEV) can cause acute and chronic hepatitis in humans. Infections with the zoonotic HEV genotype 3, which can be transmitted from infected wild boar and deer to humans, are increasingly detected in Europe. To investigate the spatio-temporal HEV infection dynamics in wild animal populations, a study involving 3572 samples of wild boar and three deer species from six different geographic areas in Germany over a 4-year period was conducted. The HEV-specific antibody detection rates increased between 2013/14 and 2016/17 in wild boar from 9.5% to 22.8%, and decreased in deer from 1.1% to 0.2%. At the same time, HEV-RNA detection rates increased in wild boar from 2.8% to 13.3% and in deer from 0.7% to 4.2%. Marked differences were recorded between the investigated areas, with constantly high detection rates in one area and new HEV introductions followed by increasing detection rates in others. Molecular typing identified HEV subtypes 3c, 3f, 3i and a putative new subtype related to Italian wild boar strains. In areas, where sufficient numbers of positive samples were available for further analysis, a specific subtype dominated over the whole observation period. Phylogenetic analysis confirmed the close relationship between strains from the same area and identified closely related human strains from Germany. The results suggest that the HEV infection dynamics in wild animals is dependent on the particular geographical area where area-specific dominant strains circulate over a long period. The virus can spread from wild boar, which represent the main wild animal reservoir, to deer, and generally from wild animals to humans. This article is protected by copyright. All rights reserved.

[Epidemiology of viral hepatitis A to E in Germany]

Viral hepatitis A to E describes various infectious inflammations of the liver parenchyma that are caused by the hepatitis viruses A to E (HAV, HBV, HCV, HDV, and HEV). Although the clinical pictures are similar, the pathogens belong to different virus families and differ in terms of pathogenesis, transmission routes, clinical course, prevention, and therapy options. In Germany, there is mandatory reporting according to the Infection Protection Act (IfSG) for direct or indirect laboratory evidence and for suspicion, illness, and death of viral hepatitis. The data are transmitted to the Robert Koch Institute.In this article, on the basis of published studies and notification data, we describe the epidemiology of hepatitis A to E as well as current challenges and prevention approaches. In particular, the latter contains the improvement of existing vaccination recommendations (hepatitis A and B); improvement of access to prevention, testing, and care including therapy with antiviral drugs (hepatitis B, C, and D) and the detection and prevention of foodborne infections and outbreaks; and improvements in the field of food safety (hepatitis A and E).

[Hepatitis E virus-a zoonotic virus: distribution, transmission pathways, and relevance for food safety]

Das Hepatitis-E-Virus (HEV) ist ein Erreger einer akuten Hepatitis beim Menschen. Darüber hinaus treten zunehmend auch chronische Infektionen mit fataler Leberzirrhose bei immunsupprimierten Transplantationspatienten auf. Die Zahl der gemeldeten Hepatitis-E-Fälle in Deutschland hat in den vergangenen Jahren stark zugenommen. Hier kommt vor allem der Genotyp 3 vor, der zoonotisch von Tieren auf den Menschen übertragen werden kann. Haus- und Wildschweine, die ohne die Ausbildung klinischer Symptome infiziert werden, stellen das Hauptreservoir dar. In diesem Artikel werden die Verbreitung von HEV in Tieren in Deutschland, mögliche Übertragungswege des Virus und insbesondere die Bedeutung von Lebensmitteln bei der Übertragung anhand der aktuellen wissenschaftlichen Literatur dargestellt.

HEV ist in Haus- und Wildschweinen in Deutschland stark verbreitet und wird hauptsächlich über direkten Kontakt oder den Verzehr von Lebensmitteln, die aus diesen Tieren hergestellt wurden, auf den Menschen übertragen. Beim HEV-RNA-Nachweis in spezifischen Lebensmitteln bleibt allerdings oft unklar, ob das enthaltene Virus noch infektiös ist oder durch die Herstellungsbedingungen inaktiviert wurde. Neuere Studien weisen auf eine hohe Stabilität des HEV unter verschiedenen physikochemischen Bedingungen hin, wohingegen eine Inaktivierung unter anderem durch Erhitzung erreicht wird. Generell wird deshalb ein ausreichendes Erhitzen von Schweinefleisch und -leber vor dem Verzehr empfohlen und für Risikogruppen zusätzlich der Verzicht auf den Verzehr kurzgereifter Rohwürste.

Weitere Forschungen sind nötig, um relevante Risikolebensmittel zu identifizieren, alternative Übertragungswege zu untersuchen und effiziente Maßnahmen zu entwickeln, die eine zoonotische Virusübertragung zukünftig verringern oder vermeiden.