Hepatitis E virus and chronic hepatitis in organ-transplant recipients

Stable HEV IgG seroprevalence in Belgium between 2006 and 2014

Recent European studies suggest an emergence of hepatitis E virus (HEV) infection. We evaluated trends in birth cohort-specific HEV seroprevalence and regional differences in Belgium. HEV IgG seroprevalence was analysed on national serum banks (1579 and 2087 samples for 2006 and 2014, respectively. Hepatitis E virus antigen was tested on positive samples. Observed data were modelled using a generalized additive model with a complementary log-log link. No significant differences between birth cohorts or sexes were found. Modelling identified the individual's age and province as relevant factors. The probability of HEV seropositivity increases significantly with age. An estimated total of 434 819 (yearly rate of 54,352) (sero-)infections were found between 2006 and 2014. Overall, HEV IgG seroprevalences were 4.1% (64/1579, 95% CI 3.1-5.1) and 5.8% (121/2087, CI 4.8-6.9) in 2006 and 2014, respectively. Observed HEV antigen seroprevalence was 0.027% (1/3666) for the entire cohort. These results show stable HEV IgG seroprevalence in Belgium.

Drug screening identified gemcitabine inhibiting hepatitis E virus by inducing interferon-like response via activation of STAT1 phosphorylation

Exposure to hepatitis E virus (HEV) bears a high risk of developing chronic infection in immunocompromised patients, including organ transplant recipients and cancer patients. We aim to identify effective anti-HEV therapies through screening and repurposing safe-in-human broad-spectrum antiviral agents. In this study, a safe-in-human broad-spectrum antiviral drug library comprising of 94 agents was used. Upon screening, we identified gemcitabine, a widely used anti-cancer drug, as a potent inhibitor of HEV replication. The antiviral effect was confirmed in a range of cell culture models with genotype 1 and 3 HEV strains. As a cytidine analog, exogenous supplementation of pyrimidine nucleosides effectively reversed the antiviral activity of gemcitabine, but the level of pyrimidine nucleosides per se does not affect HEV replication. Surprisingly, similar to interferon-alpha (IFNα) treatment, gemcitabine activates STAT1 phosphorylation. This subsequently triggers activation of interferon-sensitive response element (ISRE) and transcription of interferon-stimulated genes (ISGs). Cytidine or uridine effectively inhibits gemcitabine-induced activation of ISRE and ISGs. As expected, JAK inhibitor 1 blocked IFNα, but not gemcitabine-induced STAT1 phosphorylation, ISRE/ISG activation, and anti-HEV activity. These effects of gemcitabine were completely lost in STAT1 knockout cells. In summary, gemcitabine potently inhibits HEV replication by triggering interferon-like response through STAT1 phosphorylation but independent of Janus kinases. This represents a non-canonical antiviral mechanism, which utilizes the innate defense machinery that is distinct from the classical interferon response. These results support repurposing gemcitabine for treating hepatitis E, especially for HEV-infected cancer patients, leading to dual anti-cancer and antiviral effects.

Hepatitis E Virus Infection: Circulation, Molecular Epidemiology, and Impact on Global Health

Infection with hepatitis E virus (HEV) represents the most common source of viral hepatitis globally. Although infecting over 20 million people annually in endemic regions, with major outbreaks described since the 1950s, hepatitis E remains an underestimated disease. This review gives a current view of the global circulation and epidemiology of this emerging virus. The history of HEV, from the first reported enteric non-A non-B hepatitis outbreaks, to the discovery of the viral agent and the molecular characterization of the different human pathogenic genotypes, is discussed. Furthermore, the current state of research regarding the virology of HEV is critically assessed, and the challenges towards prevention and diagnosis, as well as clinical risks of the disease described. Together, these points aim to underline the significant impact of hepatitis E on global health and the need for further in-depth research to better understand the pathophysiology and its role in the complex disease manifestations of HEV infection.

Hepatitis E in Sub Saharan Africa - A significant emerging disease

Hepatitis E is an emerging endemic disease found across the African continent, but there are clear differences in epidemiology between North Africa and countries south of the Sahara. In this systematic review, Google scholar and PubMed databases were searched for peer-reviewed articles on HEV epidemiology. Publications meeting our inclusion criteria were critically reviewed to extract consistent findings and identify knowledge gaps. Hepatitis E has been reported in 25 of the 49 countries in Sub Saharan Africa.

Mortality rates of 1–2% in the general population and ~ 20% in pregnant women. Outbreaks were closely linked to refugees and Internally Displaced Persons in camps which accounted for 50% of reported outbreaks. There was very little research and concrete evidence for sources of contamination and transmission routes. There are indications of zoonotic transmission of Hepatitis E Virus infection but further research in these fields is required.

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No data from 50% of African countries

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Outbreaks closely linked to refugee and IDP camps

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Little data on sources of HEV contamination

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Indications but little evidence of zoonotic transmission

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Low awareness amongst health professionals and general public

Phylogenetic analysis of two new complete genomes of the hepatitis E virus (HEV) genotype 3 from Thailand

Hepatitis E virus (HEV) is a causative agent of acute viral hepatitis globally. Evolutionary phylogeny classifies the HEV into eight genotypes that correlate with the viral transmission. Only four genotypes have been proven to be responsible for transmission in humans. However, there has been no report on the genomics and genotyping of HEV in Thailand during the past ten years. Here, we identified the genotype distributions of the Thai isolates of HEV and we sequenced two HEV genomes. We screened for 18 Thai isolates of HEV from Siriraj Hospital in Bangkok, from 2014–2016. The HEV genomes were sequenced from the serum and feces of a patient. The results showed that all Thai isolates of HEV were identified as genotype 3 (HEV-3). The ORF2 and genome phylogenies suggested two subgenotypes, called 3.1 and 3.2. The Thai isolates of HEV were frequently found in the subgenotype 3.1. The genome sequences of the two Thai isolates of HEV from the serum and fecal samples of the same patient showed 91% nucleotide similarity with the HEV genotype 3. Comparisons between the HEV genome and the ORF2 phylogenies illustrated that the ORF2 tree can be used to identify HEV genotypes, but it has less phylogenetic power for the HEV evolution. The two new genome sequences of HEV-3 from Thailand could contribute valuable information to the HEV genome study. (226 words)

Hepatitis E virus: Epidemiology, diagnosis, clinical manifestations, and treatment

The hepatitis E virus (HEV) is the fifth known form of viral hepatitis and was first recognized as the cause of an epidemic of unexplained acute hepatitis in the early 1980s. Globally, it is one of the most frequent causes of acute viral hepatitis. The majority of HEV infections are asymptomatic and lead to the spontaneous clearance of the virus. Among the eight different genotypes identified to date, HEV genotype 1 (HEV1), HEV2, HEV3, and HEV4 are the most frequent genotypes causing infections in humans. HEV1 and HEV2 are prevalent in developing regions and able to result in large-scale outbreaks originating from contaminated water supplies. They are also responsible for severe hepatitis in pregnant patients and infants. In contrast, HEV3 and HEV4 are zoonotic, and the transmission of these genotypes to humans occurs mainly through the fecal contamination of water and consumption of contaminated meat from infected animals. Their main reservoir is the pig, and they are mostly encountered in developed countries. The major risk groups for HEV infection and its ensuing adverse consequences are pregnant women, infants, older people, immunocompromised individuals, patients with underlying chronic liver diseases, and workers that come into close contact with HEV-infected animals. In the clinical perspective, HEV infections have diverse clinical manifestations including acute and self-limiting hepatitis, acute-on-chronic liver disease, chronic hepatitis, cirrhosis, and liver failure. Although HEV mainly results in acute self-limiting infection, chronic HEV infection may occur among immunocompromised patients (e.g., solid-organ transplant recipients). Additionally, HEV-associated extrahepatic manifestations involving various organs have been reported in the last decade, although the causal link for many of them still needs to be proven. Ribavirin and interferon-alpha are the most widely used agents for the treatment of HEV infections with a certain level of success. However, ribavirin is contraindicated in pregnant patients, and interferon-alpha cannot be used in most transplant recipients. Therefore, there is an urgent need for novel antiviral compounds that are safe and effective particularly for patients having contraindications for ribavirin or interferon-alpha and infected by the ribavirin-resistant HEV. In this review article, a literature search using PubMed and MEDLINE databases was performed, up to March 2020. Only the articles published in English were reviewed.

Hepatitis E seroprevalence in a German cohort of patients with inflammatory bowel diseases

BACKGROUND AND AIMS

The incidence of hepatitis E virus (HEV)-infections in industrialized nations has been increasing over the past years. Patients suffering from inflammatory bowel diseases (IBD) may be more prone to transmission. Data on HEV seroprevalence in IBD patients is scarce and has not been reported in German IBD patients. The German Health Examination Survey for Adults 2008-2011, which included 4.422 samples, found a HEV seroprevalence of 16.8%, increasing with age. The aim of the present study was to determine the seroprevalence of anti-HEV IgG in a German cohort of IBD patients, and to explore which parameters have an impact on HEV seroprevalence.

MATERIAL AND METHODS

This is an uncontrolled, cross-sectional, retrospective monocentric study. Among the patients visiting the IBD outpatient clinic between 25 January, 2019 and 24 September, 2019, 328 patients with Crohn's disease (CD) and 150 patients with ulcerative colitis (UC) were included in the study. IgG antibodies against HEV were determined by enzyme-linked immunosorbent assay. Positive antibody titers were verified using immunoblot analysis. Medical records were reviewed for demographic and clinical parameters to identify potential risk factors for HEV infection.

RESULTS

The prevalence of anti-HEV IgG antibodies was 17.4% in CD patients and 24.7% in UC patients. No patient with positive HEV PCR was detected. Greater age of CD und UC patients and longer duration of anti-interleukin 12/23 treatment in CD patients were associated with higher anti-HEV IgG antibody rates.

CONCLUSIONS

In summary, we conclude that patients with UC have a higher anti-HEV IgG antibody prevalence than the general population in Germany, and that immunosuppressive therapy may carry no higher risk for HEV infection.

Viral Hepatitis E and Chronicity: A Growing Public Health Concern

Hepatitis E viral infection recently emerges as a global health concern. Over the last decade, the understanding of hepatitis E virus (HEV) had changed with the discovery of new genotypes like genotype-7 and genotype-8 with associated host and mode of infection. Diversification in the mode of hepatitis E infection transmission through blood transfusion, and organ transplants in contrast to classical feco-oral and zoonotic mode is the recent medical concern. The wide spectrum of infection ranging from self-limiting to acute liver failure is now overpowered by HEV genotype-specific chronic infection especially in transplant patients. This concern is further escalated by the extra-hepatic manifestations of HEV targeting the central nervous system (CNS), kidney, heart, and pancreas. However, with the development of advanced efficient cell culture systems and animal models simulating the infection, much clarity toward understanding the pathogenetic mechanism of HEV has been developed. Also this facilitates the development of vaccines research or therapeutics. In this review, we highlight all the novel findings in every aspect of HEV with special emphasis on recently emerging chronic mode of infection with specific diagnosis and treatment regime with an optimistic hope to help virologists and/or liver specialists working in the field of viral hepatitis.

A Nationwide Survey of Hepatitis E Virus Infection and Chronic Hepatitis in Heart and Kidney Transplant Recipients in Japan

Background.

Recently, chronic hepatitis E has been reported in solid organ transplant (SOT) recipients in European countries. Previously, we clarified the prevalence of hepatitis E virus (HEV) infection in Japanese liver transplant recipients and identified 2 chronic hepatitis E patients infected by blood transfusion. However, the rate of HEV infection in recipients of SOTs other than liver in Japan remains unclear, so we conducted a nationwide survey to clarify the prevalence of chronic HEV infection in Japanese heart and kidney transplant recipients.

Methods.

A total of 99 heart and 2526 kidney transplant recipients in 17 hospitals in Japan were examined for the presence of the IgG class of anti-HEV antibodies as well as for serum HEV RNA.

Results.

The prevalence of anti-HEV IgG among heart and kidney transplant recipients was 7.07% (7/99) and 4.08% (103/2526), respectively. One heart transplant patient (1.01%) and 11 kidney transplant patients (0.44%) were found to be positive for HEV RNA. The HEV isolates from all viremic patients were typed as genotype 3. Four patients developed chronic hepatitis E after transplantation. Three patients were treated with ribavirin; their liver enzymes normalized, and HEV RNA became negative immediately. Sustained virologic response was achieved in all cases.

Conclusions.

This is the first nationwide survey of HEV infection in Japanese heart and kidney transplant recipients. The prevalence of anti-HEV IgG and HEV RNA in heart and kidney transplant recipients in Japan was lower than that in European countries. Of note, 42% of viremic transplant patients developed chronic hepatitis.

Immunization of human hepatitis E viruses conferred protection against challenge by a camel hepatitis E virus

Dromedary camel hepatitis E virus is a novel HEV that belongs to the family Hepeviridae, and is classified as genotype 7 HEV (HEV-7). Since HEV-7 is transmitted from camels to humans and causes acute hepatitis E, this virus is a non-negligible pathogen for zoonosis, and a vaccine against HEV-7 infection is urgently needed. Here, we first intravenously inoculated HEV-7 to rhesus monkeys to explore the susceptibility, and we established an animal model. We then used virus-like particles (VLPs) of HEV-1 (HEV-1 VLPs) and HEV-3 (HEV-3 VLPs), a candidate hepatitis E vaccine, to intramuscularly inoculate rhesus monkeys. The monkeys elicited IgG antibody titers as high as >1:102,400 against heterologous HEV-7 without any adjuvants. The HEV-1 VLPs and HEV-3 VLPs-immunized monkeys were challenged intravenously with HEV-7, and they were protected completely from the infection, demonstrating that these VLPs could be a usable vaccine against HEV-7 infection. We also observed that HEV-7-infected rhesus monkeys did not show any liver damage during these experiments. Further efforts are necessary to establish an animal model for investigation of the pathogenesis of hepatitis E caused by HEV-7 infection.

Hepatitis E Virus and rheumatic diseases: what do rheumatologists need to know?

BACKGROUND

Hepatitis E virus (HEV) represents the most common cause of acute hepatitis and jaundice in the world. About 2 million of infection cases occur each year in Europe, mainly as autochthonous anthropozoonosis, and HEV can be transmitted through undercooked pork meat. This infection has been linked to various extra-hepatic manifestations, while chronic infections with a rapid development of liver failure have been described in heavily immunosuppressed patients undergoing solid organ transplantations (SOTs), in patients with hematological diseases or with immunodeficiency virus infection.

MAIN BODY OF ABSTRACT

The purpose of this review article is to describe rheumatic manifestations related to HEV infection and their implications for rheumatologists in the daily clinical practice. Despite recent accumulating literature in this field, little is known about the course of the infection in patients with rheumatic diseases (RDs) and about the impact of immunosuppressive drugs. Moreover, HEV infection can mimic RDs' manifestations or drugs toxicity. Specific guidelines on management are lacking and the majority of data are referred to SOTs receivers.

CONCLUSIONS

More studies are needed to better understand the real impact of HEV infection in patients with RDs, regarding both clinical outcomes and their management.

Viral infections of pigs used for medical education. A Japanese experience

Infectious viruses pose a threat to all living organisms, including humans, and can cause significant morbidity. Previous experience with pigs in medical education and research, rather than in domestic control settings, has led to a unique perspective on viral infections in swine. In this article, common porcine infectious diseases have been listed, based mainly on the authors' experience thus far. For example, young domestic pigs that were used in surgical training and infected with hepatitis E were subjected to quarantine and isolation treatment, and attempts were made to develop a DNA vaccine for swine influenza arising from swine-to-human transmission. More recent research has focused on preventing infection by the African swine virus, a current threat. We hope that this article of porcine infectious diseases identified at the School of Medicine will help develop a breakthrough with regard to coronavirus disease.

Hepatitis E 3ra Genotype Infection in People Living With HIV in Spain

Background

The objective of our study was to assess the prevalence and incidence of HEV in people living with HIV (PLWH) in a Spanish national cohort.

Methods

Retrospective longitudinal study including PLWH recruited in the cohort of adult HIV-infected patients of the AIDS Research Network in follow-up at 28 Spanish hospitals with available serum samples in 2014 and 2015. All samples were tested for HEV IgG, IgM, and RNA. Samples with detectable HEV viral loads were genotyped. Prevalence and incidence of HEV infection were calculated.

Results

The study sample comprised 845 PLWH. At baseline, 101 patients were positive for HEV IgG antibodies (11.9%), none had HEV IgM antibodies, and 2 presented detectable HEV RNA (0.23%). Forty-two seroconverted for IgG, supposing a cumulative incidence of 5.7%. One subject was positive for IgM (0.13%), and 2 showed detectable HEV RNA (0.27%). One case was infected by the emergent HEV genotype 3ra.

Conclusion

Our study identifies one case of HEV 3ra genotype infection, the main host of which is rabbit, showing a potential zoonotic role of this emerging genotype in Spain.

Uncovering the Roles of miR-214 in Hepatitis E Virus Replication

Viral pathogenesis is a complex event and its regulation involve dynamic interactions with various host factors, of which microRNAs are the key players. In the current study, we have identified the functional importance of an interplay between hepatitis E virus (HEV) and miR-214. Computational analysis indicated that miR-214 binding site is significantly conserved among HEV and related RNA viruses. Intact miR-214 binding site is imperative for HEV replication. miR-214 is an essential host factor for HEV replication. Herein, we demonstrate that miR-214 interacts directly with HEV RNA to enhance HEV replication and HEV genome translation. Augmented translation results in increased levels of HEV ORF2, which is a factor responsible for upregulation of miR-214. HEV usurps host cellular machinery for improving viral fitness and elevates miR-214 expression for amplifying the expression of proviral host factor intracellular active thrombin. This is because miR-214 represses the expression of the negative regulator of thrombin, i.e., protein C. Another viral factor, HEV ORF3, also contributes to the enhancement of intracellular active thrombin. Furthermore, miR-214 directly targets antiviral host factor 2'-5'-oligoadenylate synthetase. Conclusively, we identified a novel mechanism of positive regulation of HEV replication. miR-214 interacts directly with HEV genome and fine-tunes host factors expression. This results in outweighing the proviral factors on the proviral-antiviral axis probably for generating virus supportive environment.

Transcriptome analysis in rhesus macaques infected with hepatitis E virus genotype 1/3 infections and genotype 1 re-infection

Hepatitis E virus (HEV) genotype 1 (gt1) and gt3 infections have distinct epidemiologic characteristics and genotype-specific molecular mechanisms of pathogenesis are not well characterized. Previously, we showed differences in immune response-related gene expression profiles of HEV gt1 and gt3 infections using qPCR. We hypothesize that HEV gt1 and gt3 infections induce transcriptome modifications contributing to disease pathogenesis. RNAseq analysis was performed using liver biopsy samples of naïve (baseline), HEV gt1, or gt3-infected rhesus macaques, and nine anti-HEV positive rhesus macaques re-inoculated with HEV gt1. All 10 primary HEV gt1/gt3 infected animals exhibited the typical course of acute viral hepatitis and cleared the infection between 27 to 67 days after inoculation. Viremic stages of HEV infection were defined as early, peak, and decline based on HEV RNA titers in daily stool specimens. During early, peak, and decline phases of infection, HEV gt1 induced 415, 417, and 1769 differentially expressed genes, respectively, and 310, 678, and 388 genes were differentially expressed by HEV gt3, respectively (fold change ≥ 2.0, p-value ≤ 0.05). In the HEV gt1 infection, genes related to metabolic pathways were differentially expressed during the three phases of infection. In contrast, oxidative reduction (early phase), immune responses (peak phase), and T cell cytokine production (decline phase) were found to be regulated during HEV gt3 infection. In addition, FoxO and MAPK signaling pathways were differentially regulated in re-infected and protected animals against HEV gt1 reinfection, respectively. Significant differences of hepatic gene regulation exist between HEV gt1 and gt3 infections. These findings reveal a new link between molecular pathogenesis and epidemiological characteristics seen in HEV gt1 and gt3 infections.

Hepatitis E virus: host tropism and zoonotic infection

Hepatitis E virus (HEV), the causative agent of hepatitis E, is an understudied but important pathogen. HEV typically causes self-limiting acute viral hepatitis, however chronic infection with neurological and other extrahepatic manifestations has increasingly become a significant clinical problem. The discovery of swine HEV from pigs and demonstration of its zoonotic potential led to the genetic identification of very diverse HEV strains from more than a dozen other animal species. HEV strains from pig, rabbit, deer, camel, and rat have been shown to cross species barriers and infect humans. Zoonotic HEV infections through consumption of raw or undercooked animal meat or direct contact with infected animals have been reported. The discovery of a large number of animal HEV variants does provide an opportunity to develop useful animal models for HEV. In this mini-review, we discuss recent advances in HEV host range, and cross-species and zoonotic transmission.

Hepatitis E Virus Mediates Renal Injury via the Interaction between the Immune Cells and Renal Epithelium

Renal disorders are associated with Hepatitis E virus (HEV) infection. Progression to end-stage renal disease and acute kidney injury are complications associated with HEV infection. The mechanisms by which HEV mediates the glomerular diseases remain unclear. CD10+/CD13+ primary proximal tubular (PT) epithelial cells, isolated from healthy donors, were infected with HEV. Inflammatory markers and kidney injury markers were assessed in the presence or absence of peripheral blood mononuclear cells (PBMCs) isolated from the same donors. HEV replicated efficiently in the PT cells as shown by the increase in HEV load over time and the expression of capsid Ag. In the absence of PBMCs, HEV was not nephrotoxic, with no direct effect on the transcription of chemokines (Cxcl-9, Cxcl-10, and Cxcl-11) nor the kidney injury markers (kidney injury molecule 1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), and interleukin 18 (lL-18)). While higher inflammatory responses, upregulation of chemokines and kidney injury markers expression, and signs of nephrotoxicity were recorded in HEV-infected PT cells cocultured with PBMCs. Interestingly, a significantly higher level of IFN-γ was released in the PBMCs-PT coculture compared to PT alone during HEV infection. In conclusion: The crosstalk between immune cells and renal epithelium and the signal axes IFN-γ/chemokines and IL-18 could be the immune-mediated mechanisms of HEV-induced renal disorder.

Hepatitis E virus infection in liver transplant recipients: a descriptive literature review

Hepatitis E virus infection has been recognized as a rising hepatotropic viral infection in the developing countries but overlooked in the developed countries, due to its lower prevalence. However, hepatitis E virus prevalence is on rise in the liver transplant recipients due to immunosuppression, which needs prompt recognition by healthcare practitioners. Hepatitis E virus infection is commonly believed to be transmitted via an animal host; but in the post-liver transplant patients, it can also be acquired via blood and blood products transfusion and autochthonous route. Previous studies have shown the significance of hepatitis E virus infection in post-liver transplant, as the patients at a high risk of progressing to chronic hepatitis and cirrhosis. Pediatric patients are at higher risk of hepatitis E virus infection post-liver transplant. Specific hepatitis E virus genotypes have the potential for greater severity. The clinical manifestation of hepatitis E virus can also present as extrahepatic features which need high level of suspicion for early recognition and treatment. Treatment options of hepatitis E virus range from immunosuppressive drug minimization, ribavirin therapy to novel direct-acting antiviral regimens. Herein, we aim to explore epidemiology, prevalence, risk factor, diagnosis, and management of hepatitis E virus infection giving special attention to liver transplant recipients.

Recent data on hepatitis E

PURPOSE OF REVIEW

Hepatitis E virus (HEV) has gained increased global recognition in recent years, particularly in developed countries. We summarized here a selection of the literature published since the 1st of June, 2017.

RECENT FINDINGS

Longitudinal studies are increasingly conducted in Europe, to determine trends in HEV prevalence. The spectrum of mammals infected with HEV and potentially capable to transmit it to humans has widened. New virological data on HEV repCon and pathogenicity have been reported and clinical features of HEV infections have been precised or newly described. Finally, there are some new data on the therapeutic management of HEV infections in various clinical settings.

SUMMARY

HEV emergence in developed countries appears to be based on improved diagnosis tools and increased awareness of clinicians that HEV transmission is essentially autochthonous and is a possible cause of life-threatening acute hepatitis, chronic hepatitis, cirrhosis, and extra-hepatic symptoms. In addition, the distribution of HEV strains evolves. Ribavirin remains to date the only specific treatment recommended for HEV infection, being efficient in the majority but not in all cases.

Persistent infection with a rabbit hepatitis E virus created by a reverse genetics system

Rabbit hepatitis E virus (HEV) is a novel zoonotic infectious agent. Although a cell culture system to grow the virus has been established, there is currently no reverse genetics system for generating the virus. In this study, capped genomic rabbit HEV RNAs generated by in vitro transcription were transfected into PLC/PRF/5 cells, and the recovered viruses were subsequently passaged in the cells. The cell culture supernatant was capable of infecting rabbits negative for anti-HEV antibody by intravenous and oral inoculation, indicating that rabbit HEV generated by the reverse genetics system is infectious. Genome-wide analyses indicated that no nucleotide sequence change occurred in the virus genomes that were recovered from the cell culture supernatant after transfection and passaged one time or in the virus genomes recovered from faecal specimens of the infected rabbits. Ribavirin, a broad-spectrum anti-viral inhibitor, efficiently abrogated virus replication ex vivo and transiently suppressed the virus growth in the virus-infected rabbits, suggesting that this reagent is a candidate for therapeutic treatment. In addition, transmission of rabbit HEV to rabbits caused persistent infection, suggesting that the virus-infected rabbit could be an animal model for virus-induced hepatitis. The infectious rabbit HEV produced by a reverse genetics system would be useful to elucidate the mechanisms of HEV replication and the pathogenesis of viral hepatitis.

A Review of the Diagnosis and Management of Hepatitis E

Purpose of review

We aim to provide the readers an up-to-date knowledge of the structure, epidemiology, and transmission followed by a detailed discussion on testing, diagnostics and management of hepatitis E virus infection. We have also included a comprehensive review of hepatitis E in pregnancy.

Recent findings

European Association for the Study of the Liver established clinical practice guidelines for testing and treatment of suspected hepatitis E virus infections in 2018. Evidence suggests chronic hepatitis E may follow a course similar to hepatitis B/C with progression to cirrhosis and possibly hepatocellular carcinoma in immunocompromised patients.

Summary

Hepatitis E virus is the most common cause of acute viral hepatitis worldwide. A combination of serology and nucleic acid amplification testing is the recommended strategy for suspected patients. Ribavirin therapy for a period of 3 months is the drug of choice for severe acute hepatitis, acute-on chronic liver failure, and chronic infections from hepatitis E virus in immunocompromised patients who are unresponsive to decreased immunosuppression. PEGylated interferon α can be used for ribavirin-resistant liver transplant patients with chronic hepatitis E. Further research in therapeutic options is essential considering the stormy course of hepatitis E infection during pregnancy and teratogenicity of all available options.

Seroprevalence of anti-hepatitis E antibodies and antigens among HIV-infected patients in Fars Province, southern Iran

Objective

HIV-infected patients have immunological and clinical features that might affect the pathogenesis, as well as the outcome of the HIV/HEV co-infection. The current study aimed to determine the seroprevalence of anti-HEV antibodies and HEV antigens among HIV-infected patients in Fars Province, Southwest Iran.

Methods

Blood samples (5 mL) were collected from 251 HIV-confirmed patients. Respective data, including patients’ demographic information, were obtained for each patient. The presence of HEV antigens and anti-HEV antibodies (IgG) were assessed by commercial ELISA kits, based on the manufacturers’ instructions.

Results

Out of 251 cases, 158 (62.9%) were male and 91 (36.3%) were female. Patients’ age varied from 14 to 83 (mean: 40 ± 9.7) years. Out of 251 HIV positive cases, 26 (10.4%) were positive for anti-HEV IgG antibodies and 6 (2.4%) were positive for HEV-antigens. Also, 2 (0.8%) of the patients were positive for both anti-HEV IgG antibodies and antigens. Statistical analysis revealed no significant association between sex and seropositivity to either HEV antigen or antibodies. Moreover, no significant association was seen between age and seropositivity to HEV antigen or antibody (P = 0.622 and 0.945, respectively).

Conclusion

Our results showed a relatively low prevalence of HEV-antibodies in HIV-infected patients, indicating that HIV positive patients may not be at greater risk of HEV infection than the general population. Moreover, HEV-antigen was detected in a few cases of HIV-infected individuals which indicate an acute or chronic HEV infection in these patients.

Hepatitis E virus in blood donors in England, 2016 to 2017: from selective to universal screening

Introduction

Hepatitis E virus (HEV), the most common cause of acute hepatitis in many European countries, is transmitted through consumption of processed pork but also via blood transfusion and transplantation. HEV infection can become persistent in immunocompromised individuals.

Aim

We aimed to determine the incidence and epidemiology of HEV infection in English blood donors since the introduction of donation screening in 2016.

Methods

Between March 2016 and December 2017, 1,838,747 blood donations were screened for HEV RNA. Donations containing HEV RNA were further tested for serological markers, RNA quantification and viral phylogeny. Demographics, travel and diet history were analysed for all infected donors.

Results

We identified 480 HEV RNA-positive blood donations during the 22-month period, most (319/480; 66%) donors were seronegative. Viral loads ranged from 1 to 3,230,000 IU/ml. All sequences belonged to genotype 3, except one which likely represents a new genotype. Most viraemic donors were over 45 years of age (279/480; 58%), donors aged between 17 and 24 years had a seven-times higher incidence of HEV infection than other donors between March and June 2016 (1:544 donations vs 1:3,830). HEV-infected blood donors were evenly distributed throughout England. Screening prevented 480 HEV RNA-positive blood donations from reaching clinical supply.

Conclusion

HEV screening of blood donations is a vital step in order to provide safer blood for all recipients, but especially for the immunosuppressed. The unusually high rates of HEV infection in young blood donors may provide some insight into specific risks associated with HEV infection in England.

Performance of Roche qualitative HEV assay on the cobas 6800 platform for quantitative measurement of HEV RNA

BACKGROUND

Hepatitis E virus (HEV) infection is an increasingly recognized cause of acute and chronic hepatitis in high-income countries and is the most frequent cause of acute viral hepatitis in many European countries. Appropriate tools to detect and quantify HEV RNA are needed. This study aimed to evaluate the performance of the Roche cobas® HEV assay and compare it with the Fast Track Diagnostics (FTD) Hepatitis E RNA assay.

METHODS

HEV viral load determination and lower limit of detection (LOD, defined as the lowest amount of viral copies that could be detected in 95 % of repeats) were assessed using a WHO standard dilution panel, testing 240 samples of various concentrations. Reproducibility was tested at three different concentration levels, for different genotypes, and with different sample types (serum, plasma) in 30 samples. Sample stability was analyzed after three freeze/thaw cycles in 25 samples.

RESULTS

Cobas HEV assay showed a strong linear relationship between log of HEV WHO dilution series and Ct values over the reportable range from 200-5000 IU/mL HEV RNA copies. The amplification efficiency was higher than 92 %. LOD was 22 IU/mL (95 % CI: 17.4-31.8) and reproducibility tests showed a 100 % nucleic acid test (NAT) reactivity of cobas HEV for WHO dilution series (range 200-5000 IU/mL, n = 90). Cobas HEV assay detected all different HEV genotypes from biobank samples irrespective of the sample type. NAT reactivity of cobas HEV was not affected by three freeze/thaw cycles.

CONCLUSIONS

Roche cobas HEV assay is a powerful NAT tool in terms of robustness, reproducibility and linearity. It is a feasible alternative for high-volume testing.

The global epidemiology of hepatitis E virus infection: A systematic review and meta-analysis

BACKGROUND AND AIMS

Hepatitis E virus (HEV), as an emerging zoonotic pathogen, is a leading cause of acute viral hepatitis worldwide, with a high risk of developing chronic infection in immunocompromised patients. However, the global epidemiology of HEV infection has not been comprehensively assessed. This study aims to map the global prevalence and identify the risk factors of HEV infection by performing a systematic review and meta-analysis.

METHODS

A systematic searching of articles published in Medline, Embase, Web of science, Cochrane and Google scholar databases till July 2019 was conducted to identify studies with HEV prevalence data. Pooled prevalence among different countries and continents was estimated. HEV IgG seroprevalence of subgroups was compared and risk factors for HEV infection were evaluated using odd ratios (OR).

RESULTS

We identified 419 related studies which comprised of 1 519 872 individuals. A total of 1 099 717 participants pooled from 287 studies of general population estimated a global anti-HEV IgG seroprevalence of 12.47% (95% CI 10.42-14.67; I²  = 100%). Notably, the use of ELISA kits from different manufacturers has a substantial impact on the global estimation of anti-HEV IgG seroprevalence. The pooled estimate of anti-HEV IgM seroprevalence based on 98 studies is 1.47% (95% CI 1.14-1.85; I²  = 99%). The overall estimate of HEV viral RNA-positive rate in general population is 0.20% (95% CI 0.15-0.25; I²  = 98%). Consumption of raw meat (P = .0001), exposure to soil (P < .0001), blood transfusion (P = .0138), travelling to endemic areas (P = .0244), contacting with dogs (P = .0416), living in rural areas (P = .0349) and receiving education less than elementary school (P < .0001) were identified as risk factors for anti-HEV IgG positivity.

CONCLUSIONS

Globally, approximately 939 million corresponding to 1 in 8 individuals have ever experienced HEV infection. 15-110 million individuals have recent or ongoing HEV infection. Our study highlights the substantial burden of HEV infection and calls for increasing routine screening and preventive measures.

BALB/c Mouse Is a Potential Animal Model System for Studying Acute and Chronic Genotype 4 Hepatitis E Virus Infection

Hepatitis E virus (HEV) is the main pathogen of hepatitis worldwide. However, its infection biology and pathogenesis remain largely unknown. Suitable small-animal models are required to advance the study of HEV infection. Although an efficient model of genotype 1 (gt1) and gt3 HEV infection has been established in human liver chimeric mice, the infectivity of gt4 HEV infection in mice has not been comprehensively characterized. In this study, immunocompromised BALB/c nude, immunocompetent BALB/c, and C57BL/6 mice were inoculated with either gt3 or gt4 HEV (19 HEV strains, including human, swine, macaque-adapted, and cow HEV strains). Infectivity was identified by viral RNA and antigen detection, inflammation, and histopathological analysis. Then, HEV-infected BALB/c mice were treated with antiviral drugs. Acute HEV infection was established in BALB/c mice inoculated with eight gt4 HEV strains. However, gt3 HEV strains failed to achieve active HEV infection. HEV infection was established in BALB/c nude and regular mice inoculated with gt4 HEV but not in C57BL/6 mice. Gt4 HEV infection resulted in rapid viremia and high titers in feces, sera, and replication sites. HEV infection in mice showed no gender preference. Furthermore, chronic gt4 HEV infection was well imitated in BALB/c mice for 32 weeks and caused liver fibrosis.

CONCLUSION

BALB/c mice have a great potential for reproducing the process of gt4 HEV infection. The successful establishment of a gt4 HEV small-animal model provides an opportunity to further understand HEV infection biology and zoonotic transmission and develop anti-HEV vaccine.

Hepatitis E virus infection during pregnancy

BACKGROUND

Hepatitis E virus (HEV) generally causes self-limiting viral hepatitis. However, in pregnant women, HEV infection can be severe and has been associated with up to 30% mortality in the third trimester. Additionally, HEV infection in pregnancy is also associated with high rates of preterm labor and vertical transmission.

MAIN BODY

HEV is now recognized as a global health problem in both developing and industrialized countries. HEV can be transmitted via the fecal-oral route, zoonotic route, and blood transfusion route. An altered immune status, hormonal levels, and viral factors may be related to the severity of the disease. Currently, no established treatment is available for HEV in pregnant women. A Chinese vaccine has been demonstrated to be protective against HEV in the general population and seems to be safe in pregnancy; however, its safety and efficacy in a large population of pregnant women remain to be determined.

CONCLUSION

This review summarizes the current knowledge about HEV infection during pregnancy and focuses on the epidemiology, clinical manifestations, mechanisms underlying severe liver injury, and management and prevention of HEV infection during pregnancy. Considering that HEV infection during pregnancy may result in poor outcomes, screening for and monitoring HEV infection early in pregnancy should be taken into account. In addition, a better understanding of the pathogenesis will help to develop potential treatment strategies targeting HEV infection in pregnancy.

Temporal profile of HEV RNA concentration in blood and stool from patients with acute uncomplicated hepatitis E in a region with genotype 1 predominance

Acute hepatitis E virus (HEV) is associated with viremia and faecal excretion of the virus. The information on duration and temporal pattern of viremia and faecal shedding in HEV infection is important, but is not available. Serial serum and stool specimens were collected from patients with acute hepatitis E (typical clinical picture, serum alanine aminotransferase levels > 5-folds the upper limit of normal and presence of IgM anti-HEV), beginning from within 7 days of the onset of symptoms. HEV RNA concentrations were measured in sera and 10% stool suspensions, using a real-time Taqman-based nucleic acid amplification assay. Seventeen patients (median age 25 [range 19-61] years; all men) were enrolled within a median of 5 (range 3-8) days of the onset of the first symptom and provided 113 serum specimens and 71 stool specimens. The median (range) highest levels of serum bilirubin, alanine aminotransferase and aspartate aminotransferase in the patients were 10.3 (5.9-43.4) mg/dL, 1817 (442-4642) IU/L and 1016 (88-4561) IU/L, respectively. All the 17 patients had demonstrable viremia, and 12 of the 13 patients who were tested had faecal excretion at one or more time points. The HEV RNA titres were the highest in the early phase of disease and declined rapidly with time, becoming nondetectable in the serum by day 20 and in the stool by day 21. In most of the patients with acute uncomplicated acute hepatitis E, the degree of viremia and faecal shedding decline quickly after the onset of clinical illness and rapidly disappear in parallel with each other.

Hepatitis E: Epidemiology, Clinical Course, Prevention, and Treatment

Hepatitis E virus is a common cause of acute hepatitis and acute liver failure in resource-constrained parts of the world. The disease is particularly severe when the infection occurs during pregnancy. In developed countries, human infections occur primarily through zoonotic transmission from animal reservoirs; however, clinical disease is less frequent than in the developing world. The virus strains prevalent in these areas also cause chronic infection in immunocompromised persons, which, if untreated, can progress to cirrhosis; such infection responds well to oral ribavirin. A safe and highly effective recombinant vaccine is available in China, but is not available elsewhere.

Hepatitis E Virus (HEV) Open Reading Frame 2 Antigen Kinetics in Human-Liver Chimeric Mice and Its Impact on HEV Diagnosis

BACKGROUND

Hepatitis E virus infection (HEV) is an emerging problem in developed countries. Diagnosis of HEV infection is based on the detection of HEV-specific antibodies, viral RNA, and/or antigen (Ag). Humanized mice were previously reported as a model for the study of HEV infection, but published data were focused on the quantification of viral RNA. However, the kinetics of HEV Ag expression during infection remains poorly understood.

METHODS

Plasma specimens and suspensions of fecal specimens from HEV-infected and ribavirin-treated humanized mice were analyzed using HEV antigen-specific enzyme-linked immunosorbent assay, reverse transcription-quantitative polymerase chain reaction analysis, density gradient analysis, and Western blotting.

RESULT

Open reading frame 2 (ORF2) Ag was detected in both plasma and stool from HEV-infected mice, and levels increased over time. Contrary to HEV RNA, ORF2 Ag levels were higher in mouse plasma than in stool. Interestingly, ORF2 was detected in plasma from mice that tested negative for HEV RNA in plasma but positive for HEV RNA in stool and was detected after viral clearance in mice that were treated with ribavirin. Plasma density gradient analysis revealed the presence of the noninfectious glycosylated form of ORF2.

CONCLUSION

ORF2 Ag can be used as a marker of active HEV infection and for assessment of the effect of antiviral therapy, especially when fecal samples are not available or molecular diagnostic tests are not accessible.

Replication of Hepatitis E Virus (HEV) in Primary Human-Derived Monocytes and Macrophages In Vitro

HEV is the most causative agent of acute viral hepatitis globally. HEV causes acute, chronic, and extrahepatic manifestations. Chronic HEV infection develops in immunocompromised patients such as organ transplant patients, HIV-infected patients, and leukemic patients. The source of chronic HEV infection is not known. Also, the source of extrahepatic manifestations associated with HEV infection is still unclear. Hepatotropic viruses such as HCV and HBV replicate in peripheral blood mononuclear cells (PBMCs) and these cells become a source of chronic reactivation of the infections in allograft organ transplant patients. Herein, we reported that PBMCs and bone marrow-derived macrophages (BMDMs), isolated from healthy donors (n = 3), are susceptible to HEV in vitro. Human monocytes (HMOs), human macrophages (HMACs), and human BMDMs were challenged with HEV-1 and HEV-3 viruses. HEV RNA was measured by qPCR, the marker of the intermediate replicative form (ds-RNA) was assessed by immunofluorescence, and HEV capsid protein was assessed by flow cytometry and ELISA. HEV infection was successfully established in primary HMOs, HMACs, and human BMDMs, but not in the corresponding cells of murine origin. Intermediate replicative form (ds RNA) was detected in HMOs and HMACs challenged with HEV. The HEV load was increased over time, and the HEV capsid protein was detected intracellularly in the HEV-infected cells and accumulated extracellularly over time, confirming that HEV completes the life cycle inside these cells. The HEV particles produced from the infected BMDMs were infectious to naive HMOs in vitro. The HEV viral load was comparable in HEV-1- and HEV-3-infected cells, but HEV-1 induced more inflammatory responses. In conclusion, HMOs, HMACs, and human BMDMs are permissive to HEV infection and these cells could be the source of chronic and recurrent infection, especially in immunocompromised patients. Replication of HEV in human BMDMs could be related to hematological disorders associated with extrahepatic manifestations.

Identification of functional cis-acting RNA elements in the hepatitis E virus genome required for viral replication

There are approximately 20 million events of hepatitis E virus (HEV) infection worldwide annually. The genome of HEV is a single-strand, positive-sense RNA containing 5’ and 3’ untranslated regions and three open reading frames (ORF). HEV genome has 5’ cap and 3’ poly(A) tail to mimic host mRNA to escape the host innate immune surveillance and utilize host translational machineries for viral protein translation. The replication mechanism of HEV is poorly understood, especially how the viral polymerase distinguishes viral RNA from host mRNA to synthesize new viral genomes. We hypothesize that the HEV genome contains cis-acting elements that can be recognized by the virally encoded polymerase as “self” for replication. To identify functional cis-acting elements systematically across the HEV genome, we utilized an ORF1 transcomplementation system. Ultimately, we found two highly conserved cis-acting RNA elements within the ORF1 and ORF2 coding regions that are required for viral genome replication in a diverse panel of HEV genotypes. Synonymous mutations in the cis-acting RNA elements, not altering the ORF1 and ORF2 protein sequences, significantly impaired production of infectious viral particles. Mechanistic studies revealed that the cis-acting elements form secondary structures needed to interact with the HEV ORF1 protein to promote HEV replication. Thus, these cis-acting elements function as a scaffold, providing a specific “signal” that recruits viral and host factors to assemble the viral replication complex. Altogether, this work not only facilitates our understanding of the HEV life cycle and provides novel, RNA-directed targets for potential HEV treatments, but also sheds light on the development of HEV as a therapeutic delivery vector.

Hepatitis E virus (HEV) is an underestimated pathogen, causing approximately 20 million infections worldwide annually and leading to about 60,000 deaths. There are no direct-acting antivirals for treating HEV, and although significant progress has been made to establish robust HEV cell culture models, the life cycle remains poorly characterized. A better understanding of HEV replication could facilitate the development of new drugs targeting this critical process. Our study found that RNA elements in the HEV genome interact with the HEV replicases to promote viral replication, suggesting that these RNA elements function as a scaffold for recruitment and assembly of the viral replication complex. This work furthers our understanding of HEV replication and could inform the generation of RNA-based therapeutics for treating HEV infection.

Rat Hepatitis E Virus Linked to Severe Acute Hepatitis in an Immunocompetent Patient

Hepatitis E virus (HEV) is a major public health concern in developing countries where the primary transmission is via contaminated water. Zoonotic HEV cases have been increasingly described in Europe, Japan, and the United States, with pigs representing the main animal reservoir of infection. We report an unusual acute hepatitis infection in a previously healthy man caused by a rat HEV with a considerably divergent genomic sequence compared with other rat HEV strains. It is possible that rat HEV is an underrecognized cause of hepatitis infection, and further studies are necessary to elucidate its potential risk and mode of transmission.

Hepatitis E Virus Infection in the United States: Current Understanding of the Prevalence and Significance in the Liver Transplant Patient Population and Proposed Diagnostic and Treatment Strategies

Hepatitis E virus (HEV), of the family Herpesviridae, is a virus that infects nearly 20 million people per year throughout the world. HEV is most commonly transmitted via the fecal-oral route and has long been described as a virus that afflicts only those in resource-poor countries. However, HEV has been detected in numerous animal carriers, various food sources, and even in human blood products in resource-rich regions of the world. HEV is of importance in the transplant patient population because of its ability to cause chronic viral infection in these patients can lead to graft loss and cirrhosis. In this review, we discuss the current knowledge of HEV as it pertains to the liver transplant patient population and discuss diagnosis and treatment of this infection.

Clinical significance of post-liver transplant hepatitis E seropositivity in high prevalence area of hepatitis E genotype 3: a prospective study

High hepatitis E (HEV) seroprevalence has been reported in the general population and in post-liver transplant (LT) cases in several regions, including Thailand, with genotype 3 being a predominant genotype. We hypothesized that HEV might persist at a subclinical level and might pose clinical risks in the post-LT period. We performed a cross-sectional study with 108 post-LT patients and found an IgG seroprevalence of 55.6%. Subsequently, 91 cases without clinical evidence of HEV-related hepatitis were enrolled in 1 year of prospective follow-up to determine clinical status, serologies and serum/feces HEV RNA every 4 months. HEV RNA was detected, indicating subclinical infections in patients with or without seropositivity, with an annual incidence of 7.7%. Our results suggest that subclinical HEV infection exists among LT patients in this high-prevalence area. Thus, clinicians should be aware of the possibility of disease reemergence and HEV viral transmission in LT patients.

Implications of Hepatitis E Virus in Blood Transfusions, Hemodialysis, and Solid Organ Transplants

Hepatitis E Virus (HEV) is emerging as the primary cause of acute viral hepatitis in humans. The virus is commonly transmitted by the fecal-oral route via contaminated water in endemic regions or through the consumption of inadequately cooked swine products or game meats in industrialized regions. HEV genotypes 1 and 2 are predominantly associated with waterborne transmission in developing countries, whereas HEV3 and HEV4 are mainly zoonotically transmitted in industrialized countries. Seroprevalence in populations determined by detecting anti-HEV antibodies and serum HEV RNA is commonly used to analyze the presence of HEV. Although HEV RNA-based detection is now standardized, there is a lack of agreement between the assaying methods used for gathering seroprevalence data. Since 2004, HEV has been considered as a transmissible infectious agent through blood transfusion. Recent seroprevalence studies in European countries indicate an underestimated risk for blood transfusion and hence warrant testing the blood supply. HEV infection is usually self-limiting and spontaneously cleared. However, in about 60% of recipients of solid organ transplants, HEV progresses to chronic hepatitis. Immunosuppressive drugs such as tacrolimus are a major cause of chronic hepatitis and reducing its dosage results in viral clearance in about 30% of patients. In hemodialysis patients, the parenteral route is implicated as an important mechanism of transmission. In this review, we explore the clinical and epidemiological characteristics of various HEV genotypes in blood donors, hemodialysis patients, and transplant recipients.

Swine hepatitis E virus: Cross-species infection, pork safety and chronic infection

Swine hepatitis E virus (swine HEV) belongs to the species Orthohepevirus A within the genus Orthohepevirus in the family Hepeviridae. Four different genotypes of swine HEV within the species Orthohepevirus A have been identified so far from domesticated and wild swine population: genotypes 3 (HEV-3) and 4 (HEV-4) swine HEVs are zoonotic and infect humans, whereas HEV-5 and HEV-6 are only identified from swine. As a zoonotic agent, swine HEV is an emerging public health concern in many industrialized countries. Pigs are natural reservoir for HEV, consumption of raw or undercooked pork is an important route of foodborne HEV transmission. Occupational risks such as direct contact with infected pigs also increase the risk of HEV transmission in humans. Cross-species infection of HEV-3 and HEV-4 have been documented under experimental and natural conditions. Both swine HEV-3 and swine HEV-4 infect non-human primates, the surrogates of man. Swine HEV, predominantly HEV-3, can establish chronic infection in immunocompromised patients especially in solid organ transplant recipients. The zoonotic HEV-3, and to lesser extent HEV-4, have also been shown to cause neurological diseases and kidney injury. In this review, we focus on the epidemiology of swine HEV, host and viral determinants influencing cross-species HEV infection, zoonotic infection and its associated pork safety concern, as well as swine HEV-associated chronic infection and neurological diseases.

Hepatitis E: an expanding epidemic with a range of complications

BACKGROUND

Hepatitis E virus (HEV) is a common cause of viral hepatitis worldwide. Previously considered a disease of the developing world, it is increasingly recognized that locally acquired HEV infection is common in industrialized countries.

OBJECTIVES

The aim was to highlight the changing epidemiology of HEV infection, particularly in the developed world, and inform clinicians of the diverse clinical presentations and extra-hepatic complications associated with the virus.

SOURCES

References for this review were identified through searches of MEDLINE/PubMed, and Google Scholar, up to January 2020. Searches were restricted to articles published in English.

CONTENT

Hepatitis E virus is an under-recognized, emerging pathogen with important implications for public health in both the developing and developed world. The number of cases reported in resource-rich settings is increasing, in part due to improved case ascertainment but also as a result of increased incidence in some countries. The reasons behind these epidemiological shifts are not currently known. Chronic HEV infection has been reported in immunocompromised patients. A range of extra-hepatic manifestations have also been reported, most notably neurological and renal complications. There is evidence to suggest a causal link with Guillain-Barré syndrome, neuralgic amyotrophy and encephalitis/myelitis. Glomerular disease has been reported in the context of both acute and chronic infection.

IMPLICATIONS

HEV should be included in non-invasive liver screens and considered in the differentials for patients presenting with alanine aminotransferase elevation, suspected drug-induced liver injury or decompensated liver disease. Any patients with acute neurological injury and deranged liver function should be tested for hepatitis E, and all patients presenting with Guillain-Barré syndrome or neuralgic amyotrophy should be tested regardless of liver enzymes. Immunocompromised patients with persistently raised liver enzymes should be tested with molecular techniques and offered annual routine screening.

Prevalence of hepatitis E viraemia among blood donors: a systematic review

BACKGROUND

Hepatitis E virus (HEV) is usually transmitted by faecal-oral route. Recent reports have documented HEV viraemia in donated blood units and HEV transmission through blood transfusion. This systematic review summarizes the available data on prevalence of HEV viraemia in blood donors.

METHODS

Electronic databases were searched on 17 December 2018 to identify full-text English papers reporting original data on prevalence of HEV RNA in donated blood units. Two authors independently extracted the relevant data, which were pooled using simple aggregation as well as a random-effects meta-analysis; heterogeneity was assessed using the I2 method.

RESULTS

In all, 59 data sets from 28 countries were identified. The available data showed marked heterogeneity. Of a total of 2 127 832 units studied, 561 (263·6 [95% confidence intervals = 242·7-286·4] per million units) tested positive for HEV RNA. On random-effects meta-analysis, the pooled prevalence was 60·9 [6·7-155·4] per million units. In the viraemic units, HEV RNA titre varied by nearly one million-fold, and most had genotype 3 HEV. The prevalence was higher in blood units with anti-HEV antibodies or elevated alanine aminotransferase. Only nearly one-fourth of viraemic units had anti-HEV antibodies.

CONCLUSIONS

The prevalence of HEV viraemia among healthy blood donors is low, though the available data had limited geographical representation and marked heterogeneity. There is a need for further data on HEV viraemia in blood donors from areas with non-3 HEV genotype preponderance.

Locally acquired hepatitis E virus in Marche Italy: Clinical/laboratory features and outcome

BACKGROUND AND AIMS

Hepatitis E Virus is endemic in Europe with increasing numbers of cases in recent years, also in Italy where this phenomenon has hitherto been modest. The aim of this study was to document the clinical features/natural history of locally acquired hepatitis E in our territory and explore factors which determine adverse outcome.

METHODS

Retrospective study of patients with locally-acquired HEV (hepatitis E virus) in Marche, Italy (2011-2019).

RESULTS

1189 patients were tested for HEV with 89 confirmed cases. 81 (6.8%) had locally acquired infection; 54 (66%) were male (mean age 55.5 years) and 32 (39.5%) had active co-morbidities. 41 cases were viraemic (all HEV-3 (HEV genotype 1,2,3,4)); acute infection was found in 79 and chronic infection in 2. Forty-five cases (55%) required admission to hospital, for a total of 785 days. 4 patients developed acute on-chronic liver failure, 6 developed acute kidney injury and 8 died: all had active comorbidities. Univariate analysis showed that bilirubin, INR, immunosuppression, cirrhosis and diabetes were associated with death. On multivariant analysis the only predictor of death was the presence of diabetes (p = 0.04).

CONCLUSIONS

Hepatitis E in Marche Italy is mostly locally acquired and caused by HEV-3 that impacts on the morbidity and mortality particularly for fragile patients.

Emerging and neglected zoonoses in transplant population

Zoonoses represent a problem of rising importance in the transplant population. A close relationship and changes between human, animal and environmental health (“One Health” concept) significantly influence the transmission and distribution of zoonotic diseases. The aim of this manuscript is to perform a narrative review of the published literature on emerging and neglected zoonoses in the transplant population. Many reports on donor-derived or naturally acquired (re-)emerging arboviral infections such as dengue, chikungunya, West Nile, tick-borne encephalitis and Zika virus infection have demonstrated atypical or more complicated clinical course in immunocompromised hosts. Hepatitis E virus has emerged as a serious problem after solid organ transplantation (SOT), leading to diverse extrahepatic manifestations and chronic hepatitis with unfavorable outcomes. Some neglected pathogens such as lymphocytic choriomeningitis virus can cause severe infection with multi-organ failure and high mortality. In addition, ehrlichiosis may be more severe with higher case-fatality rates in SOT recipients. Some unusual or severe presentations of borreliosis, anaplasmosis and rickettsioses were also reported among transplant patients. Moreover, toxoplasmosis as infectious complication is a well-recognized zoonosis in this population. Although rabies transmission through SOT transplantation has rarely been reported, it has become a notable problem in some countries. Since the spreading trends of zoonoses are likely to continue, the awareness, recognition and treatment of zoonotic infections among transplant professionals should be imperative.

Hepatitis E Virus Infection in an Italian Cohort of Hematopoietic Stem Cell Transplantation Recipients: Seroprevalence and Infection

Chronic hepatitis E virus (HEV) infection in hematopoietic stem cell transplantation (HSCT) recipients is an emerging threat. The aim of this study was to provide data on the HEV burden in an Italian cohort of HSCT recipients and analyze risk factors for HEV seropositivity. This retrospective study reports data from 596 HSCT recipients compiled between 2010 and 2019. It included patients who underwent transplantation between 2010 and 2015 for whom pretransplantation (n = 419) and post-transplantation (n = 161) serum samples were available and tested retrospectively, as well as patients in whom prospective HEV testing was performed during the standard care: pre-HSCT IgG screening in 144, pre-HSCT HEV-RNA screening in addition to IgG screening in 60, and HEV-RNA testing in case of clinical suspicion of HEV infection in 59 (26 of whom were also included in the IgG screening cohorts). The rate of pre-HSCT HEV-IgG positivity was 6.0% (34 of 563). Older age was an independent risk factor for seropositivity (P = .039). None of the 34 HEV-IgG-positive patients had detectable HEV-RNA. One case of transient HEV-RNA positivity pre-HSCT was identified through screening. Two patients were diagnosed with chronic HEV hepatitis, and 1 patient was successfully treated with ribavirin. The burden of HEV infection in HSCT recipients in Italy is limited, and pre-HSCT screening appears to be of no benefit. Timely diagnosis of HEV infection with HEV-RNA is mandatory in cases of clinical suspicion.

Hepatitis E Is a Rare Finding in Liver Transplant Patients With Chronic Elevated Liver Enzymes and Biopsy-Proven Acute Rejection

BACKGROUND

In past decades, liver transplant (LT) patients were not routinely screened for hepatitis E virus (HEV) infection, and thus it might have been misdiagnosed as an acute rejection episode. Our aim was to analyze a real-world cohort of LT patients who presented with at least 1 episode of biopsy-proven acute rejection (BPAR) and suffered from persistent elevated transaminases, to evaluate the frequency of HEV infection misdiagnosed as a rejection episode.

METHODS

Data from 306 patients transplanted between 1997 and 2017, including 565 liver biopsies, were analyzed. Biopsies from patients suffering from hepatitis C (n = 79; 25.8%) and from patients who presented with a Rejection Activity Index <5 (n = 134; 43.8%) were excluded. A subgroup of 74 patients (with 134 BPAR) with persistently elevated liver enzymes was chosen for further HEV testing.

RESULTS

Positive HEV IgG was detectable in 18 of 73 patients (24.7%). Positive HEV RNA was diagnosed in 3 of 73 patients with BPAR (4.1%). Patients with HEV infection showed no difference in etiology of the liver disease, type of immunosuppression, or median Rejection Activity Index.

CONCLUSION

Few HEV infections were misdiagnosed as acute rejection episodes in this real-world cohort. Thus, HEV infection is an infrequent diagnosis in cases with persistent elevated liver enzymes and BPAR after LT.

THE IMPACT OF POSITIVE ANTI-HBC MARKER ON PERMANENT DEFERRAL OF VOLUNTARY BLOOD DONORS IN EASTERN CROATIA AND ESTIMATION OF OCCULT HEPATITIS B VIRUS INFECTION RATE

Recently an increase has been reported in the number of HBV transmissions from anti-HBc positive blood donors that were repeatedly negative in HBsAg and nucleic acid testing using the most sensitive tests available. The aim of the study was to show the effect of anti-HBc antibody testing performed in 2006 on permanent deferral of voluntary blood donors (VBDs), and to estimate occult hepatitis B infection (OBI) rate in this population after the introduction of mandatory molecular testing in the 2013-2016 period. More than 30,000 blood donations collected during the 2005-2007 period and more than 14,000 VBDs having donated blood during the 2013-2016 period after the introduction of molecular testing from eastern Croatia were included in the study. Serologic testing was performed with HBsAg assay throughout the study period, and anti-HBc assay was only performed in 2006. As part of the confirmatory algorithm testing, all HBsAg positive and unclear results were tested with molecular tests. Anti-HBc prevalence among VBDs in 2006 was 1.5%, with a rate of 1:197, whereas HBsAg prevalence was stable from 2005 to 2007 (0.04%, 0.1% and 0.1%, respectively). The calculated OBI rate from 2013 to 2016 was 1:30,250. Ten of 161 (12.4%) VBDs had serologic anti-HBc-only pattern. Anti-HBc testing in 2006 resulted in statistically more deferrals of VBDs compared to 2005 and 2007, and to the rest of Republic of Croatia. The strategy of universal anti-HBc testing of VBDs in addition to the existing HBsAg and molecular screening could be an additional measure to prevent HBV transmission by blood and blood components.

European Brown hare (Lepus europaeus) as a source of emerging and re-emerging pathogens of Public Health importance: A review

European brown hare (Lepus europaeus, EBH) is probably the most important game animal in Europe throughout its historical distribution. The decline in its populations across its geographic range in Europe have been attributed to factors such as reproductive rate and the ability for adaptation, climate, feed availability, predators, anthropogenic factors and diseases. Apart from common diseases of hares with a high impact on their mortality such as European Brown hare Syndrome, EBH has been involved in the epidemiology of pathogens with zoonotic potential. In this work, the role of EBH as a source of Crimean–Congo haemorrhagic fever virus (CCHFV), Hepatitis E virus (HEV), Yersinia spp., Brucella spp., Francisella tularensis, Toxoplasma gondii and Leishmania infantum is discussed. Hares may significantly contribute to the epidemiology of important emerging zoonotic pathogens through maintenance of high endemicity levels as in the case of CCHFV, as a reservoir of important pathogens such as Yersinia spp., B. suis, F. tularensis and L. infantum and as a potential source of T. gondii for other animals, especially for carnivores but also for humans. However, EBH may also be a host of minor importance as in the case of HEV. The continuous surveillance of hare populations will enable the collection of information on the population health status and the pathogens currently circulating in the area posing risk for wildlife, domestic animals and humans. The possible live animal translocations of infected hares, the fact that this species acts as a host of vectors (fleas, ticks, mosquitoes and sandflies) and the prey of carnivores and omnivores that travel in great distances getting into contact with domestic animals and humans, further highlights the need to be included in surveillance studies. Besides, the hunter‐harvested EBH population is an excellent indicator for recent pathogen transmission due to its short lifespan.

The present review provides an overview of the role of European Brown Hare as a source of Crimean–Congo haemorrhagic fever virus (CCHFV), Hepatitis E virus (HEV), Yersinia spp., Brucella spp., Francisella tularensis, Toxoplasma gondii and Leishmania infantum aiming to highlight the contribution of this species to the epidemiology of important emerging zoonotic pathogens.

Hepatitis E virus is an infrequent but potentially serious infection in allogeneic hematopoietic stem cell transplant recipients

Hepatitis E virus (HEV) can cause chronic infection and liver cirrhosis in immunocompromised individuals. The frequency and clinical importance of HEV was studied retrospectively in a cohort of 236 Swedish allogeneic hematopoietic stem cell transplantation (HSCT) recipients. In blood samples collected at 6 months after HSCT, HEV RNA was identified in 8/236 (3.4%) patients, and 11/236 (4.7%) patients had detectable anti-HEV IgG and/or IgM, eight of whom were HEV RNA negative. Two of the patients with positive HEV RNA died with ongoing signs of hepatitis: one of acute liver and multiple organ failure, the other of unrelated causes. The remaining six patients with HEV RNA had cleared the infection at 7-24 (median 8.5) months after HSCT. HEV infection was associated with elevated alanine aminotransferase at 6 months after HSCT (OR 15, 1.3-174, p = 0.03). Active graft-versus-host disease of the liver at 6 months after HSCT was present in 3/8 (38%) patients with HEV RNA, but was not significantly associated with HEV infection. In conclusion, HEV infection is an important differential diagnosis in patients with elevated liver enzymes after HSCT. Although spontaneous clearance was common, the clinical course may be severe.