Review article: hepatitis E-a concise review of virology, epidemiology, clinical presentation and therapy

Cross-species transmission and histopathological variation in specific-pathogen-free minipigs infected with different hepatitis E virus strains

Hepatitis E virus (HEV) is a major cause of viral hepatitis worldwide. Pigs are the natural host of HEV genotype 3 and the main reservoir of HEV. As the host range of HEV genotype 3 expands, the possibility that HEV from various species can be transmitted to humans via pigs is increasing. We investigated the potential cross-species transmission of HEV by infecting minipigs with swine HEV (swHEV), rabbit HEV (rbHEV), and human HEV (huHEV) and examining their histopathological characteristics and distribution in various organs. Fifteen specific-pathogen-free Yucatan minipigs were infected with swHEV, rbHEV, huHEV, or a mock control. In the present study, we analysed faecal shedding, viremia, and serological parameters over a seven-week period. Our results indicated that swHEV exhibited more robust shedding and viremia than non-swHEVs. Only swHEV affected the serological parameters, suggesting strain-specific differences. Histopathological examination revealed distinct patterns in the liver, pancreas, intestine, and lymphoid tissues after infection with each HEV strain. Notably, all three HEVs induced histopathological changes in the pancreas, supporting the association of HEVs with acute pancreatitis. Our results also identified skeletal muscle as a site of HEV antigen presence, suggesting a potential link to myositis. In conclusion, this study provides valuable insights into the infection dynamics of different HEV strains in minipigs, emphasizing the strain-specific variations in virological, serological, and histological parameters. The observed differences in infection kinetics and tissue tropism will contribute to our understanding of HEV pathogenesis and the potential for cross-species transmission.

Preliminary investigation of hepatitis E virus detection by a recombinase polymerase amplification assay combined with a lateral flow strip

Hepatitis E virus (HEV) is a zoonotic pathogen that is a significant public health problem. Detecting HEV relies mainly on conventional PCR, which is time-consuming and requires sophisticated instruments and trained staff. We aimed to establish a reverse-transcription (RT)-recombinase polymerase amplification (RPA) assay (RT-RPA) combined with a lateral flow strip (LFS; RT-RPA-LFS) to rapidly detect HEV RNA in human and rabbit samples. With the optimal reaction conditions (37°C for 30 min), our assay detected as few as 1.0 × 102 copies/mL of HEV and showed no cross-reactivity with other hepatitis viruses. We tested 28 human samples (4 fecal and 24 serum samples) and 360 rabbit samples (180 fecal and 180 serum samples) with our RT-RPA-LFS assay and compared our assay to an RT-qPCR method. There was no significant difference (p > 0.05) in the test results between the 2 assays. Our RT-RPA-LFS assay detected both HEV3 and HEV4 genotypes. Our rapid, sensitive, and specific RT-RPA-LFS assay for the detection of HEV may provide a useful detection tool for limited-resource areas.

Acute Liver Failure Guidelines

Acute liver failure (ALF) is a rare, acute, potentially reversible condition resulting in severe liver impairment and rapid clinical deterioration in patients without preexisting liver disease. Due to the rarity of this condition, published studies are limited by the use of retrospective or prospective cohorts and lack of randomized controlled trials. Current guidelines represent the suggested approach to the identification, treatment, and management of ALF and represent the official practice recommendations of the American College of Gastroenterology. The scientific evidence was reviewed using the Grading of Recommendations, Assessment, Development and Evaluation process to develop recommendations. When no robust evidence was available, expert opinions were summarized using Key Concepts. Considering the variety of clinical presentations of ALF, individualization of care should be applied in specific clinical scenarios.

Decreased expression of HBV surface antigen (HBsAg) with sK122R and sV96A co-mutation is associated with an ineffective antibody response in a chronic hepatitis B patient

BACKGROUND

Emergence and predominance of hepatitis B virus (HBV) variants carrying S gene mutations frequently occur in HBV-infected individuals. Here, coexistent serum anti-HBsAg antibody (HBsAb) and HBV surface antigen (HBsAg) were detected in a chronic HBV patient. The patient's HBsAg proteins possessed amino acid substitutions sK122R and sV96A. We reported this case and conducted relevant studies to investigate differences in expression levels and antibody neutralization of HBsAg proteins bearing sK122R and sV96A amino acid substitutions to explore causes of antigen-antibody coexistence in a chronic hepatitis B patient.

STUDY DESIGN

We first sequenced the S gene from HBV present within the patient's serum. Based on the S gene sequence, we cloned wild-type and mutated S gene sequences via site-directed mutagenesis to construct expression plasmids pJW4303-WT (wild-type), pJW4303-sV96A, pJW4303-sK122R, and pJW4303-sV96A-sK122R. Plasmids were transfected into HEK 293 T cells then culture supernatants and cells were collected. Collected cells and supernatants were next subjected to a series of quantitative and functional tests to assess expression and neutralization characteristics of wild-type and mutant HBsAg proteins.

RESULTS

Based on quantification of HBsAg expression in cells transfected with the four plasmids, HBsAg-sK122R-sV96A was more intracellularly retained and less secreted than HBsAg-sV96A single-mutant protein and WT. Neutralization ability of serum from chronic HBV patient against culture supernatants containing recombinant HBsAg proteins were ranked from highest to lowest as HBsAg-sV96A, HBsAg-sV96A-sK122R, and HBsAg-sK122R. However, no significant differences of neutralization efficiency by high-potency antibodies from HBV-vaccinees against these three mutant proteins were observed.

CONCLUSIONS

The levels of HBsAg proteins with amino acid substitutions sV96A-sK122R were greatly reduced in culture supernatants but were apparently increased in the intracellular fraction. This may account for the higher levels of HBV replication in patients. HBsAg neutralization by HBsAb in this patient may have been compromised by the HBsAg sK122R amino acid substitution, suggesting that antibodies produced by the patient had lost their HBV-neutralizing effect.

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.

Hepatitis E case series: A UK experience

The incidence of hepatitis E continues to increase and in immunocompromised patients can lead to chronic infection. Management of hepatitis E has evolved over time, with the first step being a reduction of immunosuppression followed by treatment with ribavirin. The European Association for the Study of Liver guidelines support treatment with ribavirin although the optimum dose and regime is unknown. This series reviews eight chronically infected cases treated between 2018 and 2021 in two UK centres (Ipswich Hospital and Addenbrooke's Hospital). Treatment response was defined primarily as sustained virological response at 12 weeks (SVR12) following the cessation of treatment and secondly as sustained virological response at 24 weeks (SVR24). The median dose of ribavirin given daily was 600 mg. The management of five of the eight cases was in line with the guidelines, and treatment was stopped after 12 weeks. Two of these five patients achieved SVR (40%). The remaining three cases were given a 24-week course based on clinical judgement, and all achieved SVR (100%). The three patients who relapsed received a second 24-week course of treatment and achieved SVR. Therefore, with a 24-week course, a 100% treatment success rate was attained. In chronic hepatitis E, a 24-week course of ribavirin would achieve optimum clearance rates with a single course of treatment. Ensuring the highest dose of ribavirin as possible (aiming to reach 800 mg daily) and attempts to reduce immunosuppressive therapy safely may also be relevant to achieving SVR.

Hepatitis E Diagnosis and Management After Liver, Kidney, or Heart Transplant: A Single-Center Experience

BACKGROUND

Transplant-related hepatitis E virus (HEV) infection is a rarely recognized phenomenon with significant clinical importance given its potential to result in chronic hepatitis posttransplant.

METHODS

We retrospectively evaluated HEV diagnosis and treatment after liver, kidney, and heart transplant in a single center. We identified patients diagnosed with HEV by serologic testing and evaluated their treatment regimens.

RESULTS

Fifteen transplant recipients (12 liver, 2 kidney, and 1 heart) presented with elevated liver enzymes and were positive for HEV IgM antibody. Liver enzymes normalized in 4 patients after being treated with ribavirin. One of the 4 patients had 2 recurrences with positive HEV RNA results following ribavirin treatment but recovered after 12 months of ribavirin therapy. After treatment with reduction in immunosuppression without antiviral treatment, 6 of 8 patients' liver enzymes normalized. One of these patients died of acute pancreatitis 2 months after testing positive for HEV IgM antibody.

CONCLUSIONS

The potential for complications related to active HEV infections in transplant recipients necessitates prompt diagnosis and treatment to prevent irreversible damage. Diagnosis with HEV reverse transcriptase-polymerase chain reaction should follow a positive HEV IgM antibody test. This manuscript provides evidence that ribavirin antiviral therapy and reducing immunosuppression are effective treatments for HEV infections in liver, kidney, and heart transplant recipients, which has not been sufficiently investigated in the population of the United States. Larger multicenter studies are needed to confirm the risks and benefits of using ribavirin antiviral therapy as first-line therapy of HEV posttransplant.

Prevalence and risk factors for hepatitis E virus infection in blood donors: a nationwide survey in Italy, 2017 to 2019

Background

In high-income countries, hepatitis E virus (HEV) infection is mainly a zoonosis. However, it is also transfusion-transmissible and some countries, but not Italy, have introduced HEV screening for blood donations.

Aim

We assessed HEV infection prevalence and risk factors in a nationwide sample of Italian blood donors.

Methods

We selected 107 blood establishments (BE) distributed in the 20 Italian regions by a stratified two-stage design and invited them to participate in the study. Donors were tested for anti-HEV IgG and IgM and HEV RNA. Sociodemographic data and risk factors were collected through a questionnaire.

Results

Overall, 60 BE from 60 provinces in 19 Italian regions joined the study. We assessed HEV markers in 7,172 blood donors, of whom 6,235 completed the questionnaire. Overall crude and adjusted anti-HEV IgG prevalences were 8.3% and 5.5%, respectively. Overall anti-HEV IgM prevalence was 0.5%, while no blood donor was HEV RNA-positive. Anti-HEV IgG prevalence varied widely among regions (range: 1.3%–27.20%) and hyperendemic prevalences (> 40%) were detected in some provinces in two regions. Older age (AOR = 1.81; 95% CI: 1.36–2.41), foreign nationality (AOR = 2.77; 95% CI: 1.06–7.24), eating raw pork liver sausages (AOR = 2.23; 95% CI: 1.55–3.20) and raw homemade sausages (AOR = 3.63; 95% CI: 2.50–5.24) were independent infection predictors.

Conclusion

Italian blood donors showed a low to moderate HEV seroprevalence. High levels in some regions and/or provinces were mainly attributable to eating habits. Prevention should include avoiding consumption of raw or undercooked meat and safe production of commercial pork products.

Therapeutic Advances in Viral Hepatitis A-E

Viral hepatitis remains a significant global health problem. All forms of viral hepatitis A through E (A-E) can lead to acute symptomatic infection, while hepatitis B and C can lead to chronic infection associated with significant morbidity and mortality related to progression to cirrhosis, end-stage-liver disease, and liver cancer. Viral hepatitis occurs worldwide, though certain regions are disproportionately affected. We now, remarkably, have highly effective curative regimens for hepatitis C, and safe and tolerable medications to suppress hepatitis B activity, and to prevent liver damage and slow disease progression. We have effective vaccines for hepatitis A and B which provide long-lasting immunity, while improved sanitation and awareness can curb outbreaks of hepatitis A and E. However, more effective and available preventive and curative strategies are needed to achieve global eradication of viral hepatitis. This review provides an overview of the epidemiology, transmission, diagnosis, and clinical features of each viral hepatitis with a primary focus on current and future therapeutic and curative options.

Risk assessment of hepatitis E transmission through tissue allografts

Hepatitis E virus (HEV) is a small non-enveloped single stranded RNA virus whose genotypes 3 and 4 have been associated with zoonotic transmission in industrialized countries. HEV infection is considered the main cause of acute hepatitis worldwide. In some cases, transfusion of blood components or organ transplantation have been reported as the source of infection. We have conducted a literature review on the risk of transmission through cell and tissue allografts. Although no case was found, measures to control this risk should be taken when donor profile (based upon geographical and behavioural data) recommended it. Issues to be considered in donor screening and tissue processing to assess and to reduce the risk of HEV transmission are approached.

Study of Hepatitis E Virus-4 Infection in Human Liver-Chimeric, Immunodeficient, and Immunocompetent Mice

The hepatitis E virus (HEV) is responsible for 20 million infections worldwide per year. Although, HEV infection is mostly self-limiting, immunocompromised individuals may evolve toward chronicity. The lack of an efficient small animal model has hampered the study of HEV and the discovery of anti-HEV therapies. Furthermore, new HEV strains, infectious to humans, are being discovered. Human liver-chimeric mice have greatly aided in the understanding of HEV, but only two genotypes (HEV-1 and HEV-3) have been studied in this model. Moreover, the immunodeficient nature of this mouse model does not allow full investigation of the virus and all aspects of its interaction with the host. Recent studies have shown the susceptibility of regular and nude Balb/c mice to a HEV-4 strain (KM01). This model should allow the investigation of the interplay between HEV and the adaptive immune system of its host, and potential immune-mediated complications. Here, we assess the susceptibility of human liver-chimeric and non-humanised mice to a different HEV-4 strain (BeSW67HEV4-2008). We report that humanised mice could be readily infected with this isolate, resulting in an infection pattern comparable to HEV-3 infection. Despite these results and in contrast to KM01, non-humanised mice were not susceptible to infection with this viral strain. Further investigation, using other HEV-4 isolates, is needed to conclusively determine HEV-4 tropism and mouse susceptibility.

Hepatitis E virus in Saudi Arabia: more surveillance needed

Hepatitis E virus (HEV) is a small quasi-enveloped ssRNA causing acute hepatitis. HEV is the leading cause of intermittent acute hepatitis and fulminant hepatic failure. Risk factors include drinking contaminated water in developing countries and consumption of infected animal products in developed countries. Previous reports on HEV prevalence in Saudi Arabia had small sample sizes. Nationwide systematic seroprevalence studies are needed to investigate risk factors and annual incidence. Camels play a cultural and economic role in the life of Saudi citizens with frequent human contact and potential role in zoonotic transmission. Future research needs to include larger sample-sizes and nationwide studies. Future studies should also focus on raising awareness of HEV infection and the need for wider population testing and screening.

Production of a Hepatitis E Vaccine Candidate Using the Pichia pastoris Expression System

Hepatitis E virus (HEV) is associated with acute hepatitis disease, which may lead to chronic disease in immunocompromised individuals. The disease is particularly severe among pregnant women (20-30% mortality). No vaccine is available to combat the HEV except Hecolin, which is available only in China. Virus-like particle (VLP) generated from the capsid protein (ORF2) of HEV is known to be a potent vaccine antigen against HEV. Hecolin consists of 368-606 amino acid (aa) region of the capsid protein of HEV, which forms a VLP. It is expressed and purified from the inclusion bodies of E. coli. Here, we describe a method to express the 112-608aa region of the capsid protein (ORF2) of genotype-1 HEV in Pichia pastoris (P. pastoris) and purify VLPs from the culture medium. 112-608aa ORF2 VLPs are secreted into the culture medium in a methanol inducible manner. The purified VLPs are glycosylated and induce robust immune response in Balb/c mice. Further, 112-608aa ORF2 VLPs are bigger than the 368-606 VLP present in Hecolin, which may help them in inducing a superior immune response. P. pastoris offers a robust and economical heterologous expression system to produce large quantities of glycosylated 112-608aa ORF2 VLP, which appears to be a promising vaccine candidate against the HEV.

Transfusion-transmitted hepatitis E: What we know so far?

Hepatitis E virus (HEV) is a major cause of viral hepatitis globally. There is growing concern about transfusion-transmitted HEV (TT-HEV) as an emerging global health problem. HEV can potentially result in chronic infection in immunocompromised patients, leading to a higher risk of liver cirrhosis and even death. Between 0.0013% and 0.281% of asymptomatic blood donors around the world have HEV viremia, and 0.27% to 60.5% have anti-HEV immunoglobulin G. HEV is infectious even at very low blood concentrations of the virus. Immunosuppressed patients who develop persistent hepatitis E infection should have their immunosuppressant regimen reduced; ribavirin may be considered as treatment. Pegylated interferon can be considered in those who are refractory or intolerant to ribavirin. Sofosbuvir, a nucleotide analog, showed modest antiviral activity in some clinical studies but sustained viral response was not achieved. Therefore, rescue treatment remains an unmet need. The need for HEV screening of all blood donations remains controversial. Universal screening has been adopted in some countries after consideration of risk and resource availability. Various pathogen reduction methods have also been proposed to reduce the risk of TT-HEV. Future studies are needed to define the incidence of transmission through transfusion, their clinical features, outcomes and prognosis.

Present and future management of viral hepatitis

Viral hepatitis can result in important morbidity and mortality, with its impact on health conditioned by the specific type of hepatitis, the geographical region of presentation and the development and access to new drugs, among other factors. Most acute presentation forms are self-limiting and may even go unnoticed, with just a small percentage of cases leading to acute liver failure that may necessitate transplantation or even cause the death of the patient. However, when they become chronic, as in the case of hepatitis B virus and C virus, unless they are diagnosed and treated adequately they may have severe consequences, like cirrhosis or hepatocarcinoma. Understanding of the mechanisms of transmission, the pathogenesis, the presence of vaccinations and the development over recent years of new highly-efficient, potent drugs have meant that we are now faced with a new scenario in the management of viral hepatitis, particularly hepatitis B virus and hepatitis C virus. The spectacular advances in hepatitis C virus treatment have led the World Health Organization to propose the objective of its eradication by 2030. The key aspect to achieving this goal is to ensure that these treatments reach all the more vulnerable population groups, in whom the different types of viral hepatitis have a high prevalence and constitute a niche that may perpetuate infection and hinder its eradication. Accordingly, micro-elimination programs assume special relevance at the present time.

Hepatitis E virus genotyping in Pakistan: a regional study to explore the implications for pregnant females

Aim: Hepatitis E virus (HEV) has different genotypes 1–4, which is generally associated with mild to severe complications among immunocompromised patients and pregnant women. Materials & methods: Immunoglobulin M (IgM) HEV-positive samples were collected from the diagnostic center. HEV infection was further confirmed by RT-based PCR and genotyping was done to affirm the prevailing genotype. Results: This study identified 28 patients from Islamabad who were confirmed to have immunoglobulins type M against HEV showing acute infection, of which 17 were pregnant and 11 were non-pregnant women. All pregnant women were in their third trimester of pregnancy. Conclusion: Genotype-1 is commonly associated with pregnant females presenting with HEV infections in Islamabad. There is a need to further identify both the sources & route of infections.

Antigenic Characterization of ORF2 and ORF3 Proteins of Hepatitis E Virus (HEV)

To evaluate the antigenic properties of Hepatitis E Virus (HEV) Open Reading Frame 2 and 3 (ORF2 and ORF3) codified proteins, we expressed different portions of ORF2 and the entire ORF3 in E. coli, a truncated ORF2, was also expressed in baculovirus. A panel of 37 monoclonal antibodies (MAbs) was raised against ORF2 (1-660 amino acids) and MAbs were mapped and characterized using the ORF2 expressed portions. Selected HEV positive and negative swine sera were used to evaluate ORF2 and ORF3 antigens' immunogenicity. The MAbs were clustered in six groups identifying six antigenic regions along the ORF2. Only MAbs binding to the sixth ORF2 antigenic region (394-608 aa) were found to compete with HEV positive sera and efficiently catch the recombinant antigen expressed in baculovirus. The ORF2 portion from 394-608 aa demonstrated to include most immunogenic epitopes with 85% of HEV positive swine sera reacting against the region from 461-544 aa. Only 5% of the selected HEV sera reacted against the ORF3 antigen.

Hepatitis E Outbreak in the Central Part of Italy Sustained by Multiple HEV Genotype 3 Strains, June-December 2019

In European countries, autochthonous acute hepatitis E cases are caused by Hepatitis E Virus (HEV) genotype 3 and are usually observed as sporadic cases. In mid/late September 2019, a hepatitis E outbreak caused by HEV genotype 3 was recognized by detection of identical/highly similar HEV sequences in some hepatitis E cases from two Italian regions, Abruzzo and Lazio, with most cases from this latter region showing a link with Abruzzo. Overall, 47 cases of HEV infection were finally observed with onsets from 8 June 2019 to 6 December 2019; they represent a marked increase as compared with just a few cases in the same period of time in the past years and in the same areas. HEV sequencing was successful in 35 cases. The phylogenetic analysis of the viral sequences showed 30 of them grouped in three distinct molecular clusters, termed A, B, and C: strains in cluster A and B were of subtype 3e and strains in cluster C were of subtype 3f. No strains detected in Abruzzo in the past years clustered with the strains involved in the present outbreak. The outbreak curve showed partially overlapped temporal distribution of the three clusters. Analysis of collected epidemiological data identified pork products as the most likely source of the outbreak. Overall, the findings suggest that the outbreak might have been caused by newly and almost simultaneously introduced strains not previously circulating in this area, which are possibly harbored by pork products or live animals imported from outside Abruzzo. This possibility deserves further studies in this area in order to monitor the circulation of HEV in human cases as well as in pigs and wild boars.

A Superinfection of Salmonella typhi and Hepatitis E Virus Causes Biphasic Acute Hepatitis

A 47-year-old Japanese man was referred to our hospital because of a sustained high fever with diarrhea 12 days after a flight from India. Liver enzymes were elevated with rose spots, hepatosplenomegaly, relative bradycardia, and acute cholecystitis. A liver biopsy depicted the dense infiltration of lymphocytes and Kupffer cells in sinusoids and the granulomatous formation in the parenchyma. The liver damage was initially resolved with the administration of ceftriaxone for 16 days but flared up 1 week later. Laboratory tests yielded positive reactions for Salmonella typhi and hepatitis E virus RNA. The pathophysiological presentations of concurrent typhoid and type E hepatitis are discussed.

Hepatitis E Virus RNA Presence in Wild Boar Carcasses at Slaughterhouses in Italy

Simple Summary

Hepatitis E virus (HEV) is a worldwide diffused pathogen responsible for acute hepatitis of humans. Transmission of the pathogen is mostly related to the consumption of contaminated food and water. Although initially the disease was contained in developing countries, in recent years autochthonous infections have been reported in several industrialised countries. A different epidemiological pattern of transmission has been highlighted; while in Africa and Asia transmission is mainly due to waterborne outbreaks caused by low sanitation standards, in Europe and other industrialised countries, the disease has mainly spread due to consumption of raw or undercooked meat and seafood. Although HEV has been identified in several domestic and wild animal species, pigs and wild boar, appear to play a distinct role mainly acting as a reservoir of the pathogen. In this study, we monitored the presence of HEV in carcasses and livers of wild boar sampled in Tuscany at the slaughterhouse following hunting activities. Our data indicate the presence of the pathogen in the liver and the carcasses, suggesting cross-contamination. This evidence highlights the importance of maintaining safety control measures to avoid the spreading of HEV infection.

Abstract

Hepatitis E virus (HEV) is a waterborne and foodborne pathogen largely spread around the world. HEV is responsible for acute hepatitis in humans and it is also diffused in domestic and wild animals. In particular, domestic pigs represent the main reservoir of the infection and particular attention should be paid to the consumption of raw and undercooked meat as a possible zoonotic vehicle of the pathogen. Several studies have reported the presence of HEV in wild boar circulating in European countries with similar prevalence rates. In this study, we evaluated the occurrence of HEV in wild boar hunted in specific areas of Tuscany. Sampling was performed by collecting liver samples and also by swabbing the carcasses at the slaughterhouses following hunting activities. Our data indicated that 8/67 (12%) of liver samples and 4/67 (6%) of swabs were positive for HEV RNA. The presence of HEV genome on swabs indicates the possible cross-contamination of carcass surfaces during slaughtering procedures. Altogether, our data indicated that it is essential to promote health education programmes for hunters and consumers to limit the diffusion of the pathogen to humans.

In silico and in vitro screening of licensed antimalarial drugs for repurposing as inhibitors of hepatitis E virus

ABSTRACT

Hepatitis E virus (HEV) infection is emerging in Cameroon and represents one of the most common causes of acute hepatitis and jaundice. Moreover, earlier reports showed evidence of falciparum malaria/HEVcoexistence. Although the Sofosbuvir/Ribavirin combination was recently proposed in the treatment of HEV-infected patients, no specific antiviral drug has been approved so far, thereby urging the search for new therapies. Fortunately, drug repurposing offers a good alternative to this end. In this study, we report the in silico and in vitro activities of 8 licensed antimalarial drugs and two anti-hepatitis C virus agents used as references (Sofosbuvir, and Ribavirin), for repurposing as antiviral inhibitors against HEV. Compounds were docked against five HEV-specific targets including the Zinc-binding non-structural protein (6NU9), RNA-dependent RNA polymerase (RdRp), cryoEM structure of HEV VLP, genotype 1 (6LAT), capsid protein ORF-2, genotype 3 (2ZTN), and the E2s domain of genotype 1 (3GGQ) using the iGEMDOCK software and their pharmacokinetic profiles and toxicities were predicted using ADMETlab2.0. Their in vitro effects were also assessed on a gt 3 p6Gluc replicon system using the luciferase reporter assay. The docking results showed that Sofosbuvir had the best binding affinities with 6NU9 (- 98.22 kcal/mol), RdRp (- 113.86 kcal/mol), 2ZTN (- 106.96 kcal/mol), while Ribavirin better collided with 6LAT (- 99.33 kcal/mol). Interestingly, Lumefantrine showed the best affinity with 3GGQ (-106.05 kcal/mol). N-desethylamodiaquine and Amodiaquine presented higher binding scores with 6NU9 (- 93.5 and - 89.9 kcal/mol respectively vs - 80.83 kcal/mol), while Lumefantrine had the greatest energies with RdRp (- 102 vs - 84.58), and Pyrimethamine and N-desethylamodiaquine had stronger affinities with 2ZTN compared to Ribavirin (- 105.17 and - 102.65 kcal/mol vs - 96.04 kcal/mol). The biological screening demonstrated a significant (P < 0.001) antiviral effect on replication with 1 µM N-desethylamodiaquine, the major metabolite of Amodiaquine. However, Lumefantrine showed no effect at the tested concentrations (1, 5, and 10 µM). The biocomputational analysis of the pharmacokinetic profile of both drugs revealed a low permeability of Lumefantrine and a specific inactivation by CYP3A2 which might partly contribute to the short half-time of this drug. In conclusion, Amodiaquine and Lumefantrine may be good antimalarial drug candidates for repurposing against HEV. Further in vitro and in vivo experiments are necessary to validate these predictions.

GRAPHIC ABSTRACT

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s40203-021-00093-y.

Acute hepatitis E in an immunocompromised patient with seropositive rheumatoid arthritis on rituximab and long-term methotrexate

We report the case of a 61-year old female with a 20-year history of seropositive rheumatoid arthritis (RA) who developed acute hepatitis. Her arthritis had been treated with methotrexate (MTX) since 2003 and, following an increase in disease activity, Rituximab (RTX) was commenced in January 2017. In May 2020, routine blood tests showed a new elevation in her liver profile, although synthetic function was preserved. A standard liver screen found no cause for her acutely abnormal lab values. Upon additional serological testing, the patient was confirmed to have acute hepatitis E virus (HEV). Her primary complaint at the time was fatigue. Within a month, her liver blood tests spontaneously improved and her symptoms resolved with conservative management.

Full-length genome sequencing of RNA viruses-How the approach can enlighten us on hepatitis C and hepatitis E viruses

Among the five main viruses responsible for human hepatitis, hepatitis C virus (HCV) and hepatitis E virus (HEV) are different while sharing similarities. Both viruses can be transmitted by blood or derivatives whereas HEV can also follow environmental or zoonotic routes. These highly variable RNA viruses can cause chronic hepatitis potentially leading to hepatocarcinoma. HCV and HEV can develop new structures and functions under selective pressure to adapt to host immunity, human tissues, treatments or even various animal reservoirs. Elsewhere, with directly acting antiviral treatments, HCV can be eradicated whereas HEV is an emerging pathogen against which specific treatments have to be improved. As a unique molecular tool able to explore viral genomic plasticity, full-length genome (FLG) sequencing has become easier, faster and cheaper. The present review will show how FLG sequencing can explore these RNA viruses with the aim to investigate key genomics data to improve basic knowledge, patients' healthcare and preventive tools.

Gastrointestinal Bleeding in a Pancreas Transplant Recipient: A Case to Remember

Patient: Male, 51-year-old

Final Diagnosis: Ectopic varix

Symptoms: Bleeding • portal hypertension

Medication:—

Clinical Procedure: —

Specialty: Transplantology

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.

The First Case Report of Acute Symptomatic HEV Genotype 4 Infection in an HIV-positive Patient in Japan

Hepatitis E virus (HEV) is a common cause of acute hepatitis. Four major genotypes of HEV have been studied, with genotype 4 being the predominant genotype across Asia. We herein describe the case of a 50-year-old man with a history of human immunodeficiency virus (HIV) infection who was admitted with acute transaminitis. Serum anti-HEV-IgA and HEV-RNA were detected at the time of presentation and further testing revealed HEV genotype 4. To the best of our knowledge, this represents the first clinical case report of acute symptomatic HEV genotype 4 infection in an HIV-positive patient in Japan.

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.

Resolution by deep sequencing of a dual hepatitis E virus infection transmitted via blood components

Hepatitis E virus (HEV) is a zoonotic infection, with consumption of processed pork products thought to be the major route of transmission in England. The clinical features of HEV infection range from asymptomatic infection to mild hepatitis to fulminant liver failure. Persistent, chronic hepatitis is increasingly recognized in immunocompromised patients. Infection via HEV-containing blood components and organs has been reported and measures to reduce this transmission risk were introduced into the blood service in England in 2016. We report here the sequence and phylogenetic findings from investigations into a transmission event from an HEV-infected donor to two recipients. Phylogenetic analysis of HEV genome sequence fragments obtained by Sanger sequencing showed that, whilst most of the sequences from both recipients' samples grouped with the sequence from the blood donor sample, the relationship of five sequences from recipient 2 were unresolved. Analysis of Illumina short-read deep sequence data demonstrated the presence of two divergent viral populations in the donor's sample that were also present in samples from both recipients. A clear phylogenetic relationship was established, indicating a probable transmission of both populations from the donor to each of the immunocompromised recipients. This study demonstrates the value of the application of new sequencing technologies combined with bioinformatic data analysis when Sanger sequencing is not able to clarify a proper phylogenetic relationship in the investigation of transmission events.

Hepatitis E virus infection prevalence among men who have sex with men involved in a hepatitis A virus outbreak in Italy

BACKGROUND

The routes of hepatitis E virus (HEV) transmission have still not been fully clarified. Here, we evaluated the possibility of sexual transmission of HEV, which remains a highly disputed issue.

MATERIALS AND METHODS

Hepatitis E virus sexual transmission risk was assessed by comparing the prevalence of HEV infection in a sample of 196 Italian men who have sex with men (MSM) involved in a multi-country hepatitis A virus (HAV) outbreak, and in 3,912 Italian male blood donors selected from the same regions and provinces as the MSM. Selection of study of participants was motivated by the fact that HEV prevalence among Italian blood donors has been found to vary enormously between different geographical areas.

RESULTS

Anti-HEV IgG prevalence was 14.8% and 5.6% in blood donors and MSM, respectively. Adjusted anti-HEV IgG prevalence was significantly lower in MSM than in blood donors (odds ratio [OR], 0.40; 95% confidence interval [CI]: 0.22-0.75; p<0.01), among residents in northern (OR, 0.45; 95% CI: 0.37-0.55; p<0.01) and southern (OR, 0.45; 95% CI: 0.35-0.58; p <0.01) Italy than among residents in Central Italy, while the prevalence was significantly higher in participants over 50 years of age than in those under 50 years of age (OR, 1.83; 95% CI: 1.48-2.27; p<0.01).

DISCUSSION

Our findings suggest that sexual intercourse does not have a relevant role in HEV transmission. In particular, sexual transmission of HEV is unlikely to influence the prevalence of HEV infection at population level.

Hepatitis E infection is an infrequent cause of acute hepatitis in the metropolitan area of Buenos Aires

Background Argentina is considered a region of low seroprevalence of hepatitis E virus (HEV), however; no studies have evaluated its burden among acute hepatitis cases.

OBJECTIVES

We aimed to estimate the proportion of acute HEV and outcome in a cohort of patients with acute hepatitis from 6 liver units in the Metropolitan area of Buenos Aires (MABA).

STUDY DESIGN

We performed a prospective cohort study including patients ≥18 years with acute hepatitis (increase in transaminases x 5 ULN) fromJuly 2016 to May 2018. Severe hepatitis was defined as acute hepatitis + INR> 1.5 and acute liver failure as severe hepatitis + encephalopathy. In patients in whom other etiologies were excluded, HEV tests were performed: anti-HEV IgM/G and HEV-RNA in serum and feces.

RESULTS

Overall, 268 patients with acute hepatitis were included in the study. The most frequent etiologies of acute hepatitis were hepatitis B (67patients, 25 %), hepatotoxicity (65, 24 %) and autoimmune hepatitis (26, 10 %). Acute HEV infection was confirmed in 8 (2.98 %; 95 %CI 1.25-5.63) patients who tested positive for anti-HEV IgM. A total of 63 (23.5 %) patients were hospitalized and 9 (3.3 %) patients died. Overall, 48 (18 %) patients developed severe hepatitis, 6 (2.2 %) have acute liver failure, 6 (1.9 %) underwent liver transplantation and 9 (3.4 %) patients died.

CONCLUSIONS

the proportion of acute HEV in MABA was low during the period studied. We believe our findings will aid physicians prioritize other etiologies of acute hepatitis over HEV in order to optimize diagnostic resources and offer better care to their patients.

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.

Prophylactic Hepatitis E Vaccines: Antigenic Analysis and Serological Evaluation

Hepatitis E virus (HEV) infection causes sporadic outbreaks of acute hepatitis worldwide. HEV was previously considered to be restricted to resource-limited countries with poor sanitary conditions, but increasing evidence implies that HEV is also a public health problem in developed countries and regions. Fortunately, several vaccine candidates based on virus-like particles (VLPs) have progressed into the clinical development stage, and one of them has been approved in China. This review provides an overview of the current HEV vaccine pipeline and future development with the emphasis on defining the critical quality attributes for the well-characterized vaccines. The presence of clinically relevant epitopes on the VLP surface is critical for eliciting functional antibodies against HEV infection, which is the key to the mechanism of action of the prophylactic vaccines against viral infections. Therefore, the epitope-specific immunochemical assays based on monoclonal antibodies (mAbs) for HEV vaccine antigen are critical methods in the toolbox for epitope characterization and for in vitro potency assessment. Moreover, serological evaluation methods after immunization are also discussed as biomarkers for clinical performance. The vaccine efficacy surrogate assays are critical in the preclinical and clinical stages of VLP-based vaccine development.

Clinical presentations of Hepatitis E: A clinical review with representative case histories

Hepatitis E virus (HEV) typically causes an acute, self-limiting hepatitis and is among the commonest cause of such presentations. Hepatitis E viral infection is also increasingly recognized as a cause of chronic hepatitis amongst the immunocompromised, particularly amongst solid organ transplant recipients. Chronic HEV infection remains an underdiagnosed disease and chronic infection can lead to rapidly progressive liver fibrosis and cirrhosis. This review examines current understanding of the HEV. We illustrate typical clinical presentations, management strategies [(based upon guidelines from both the British Transplant Society (BTS) and European Association for the study of liver (EASL)] and outcomes of HEV infection in different cohorts of patients by highlighting select transplant and non-transplant patient cases, from one of the largest tertiary Hepatology centres in Europe.

Hepatitis E virus (HEV) in Scotland: evidence of recent increase in viral circulation in humans

BackgroundPrevious studies showed low levels of circulating hepatitis E virus (HEV) in Scotland. We aimed to reassess current Scottish HEV epidemiology. Methods: Blood donor samples from five Scottish blood centres, the minipools for routine HEV screening and liver transplant recipients were tested for HEV antibodies and RNA to determine seroprevalence and viraemia. Blood donor data were compared with results from previous studies covering 2004-08. Notified laboratory-confirmed hepatitis E cases (2009-16) were extracted from national surveillance data. Viraemic samples from blood donors (2016) and chronic hepatitis E transplant patients (2014-16) were sequenced. Results: Anti-HEV IgG seroprevalence varied geographically and was highest in Edinburgh where it increased from 4.5% in 2004-08) to 9.3% in 2014-15 (p = 0.001). It was most marked in donors < 35 years. HEV RNA was found in 1:2,481 donors, compared with 1:14,520 in 2011. Notified laboratory-confirmed cases increased by a factor of 15 between 2011 and 2016, from 13 to 206. In 2011-13, 1 of 329 transplant recipients tested positive for acute HEV, compared with six cases of chronic infection during 2014-16. Of 10 sequenced viraemic donors eight and all six patients were infected with genotype 3 clade 1 virus, common in European pigs. Conclusions: The seroprevalence, number of viraemic donors and numbers of notified laboratory-confirmed cases of HEV in Scotland have all recently increased. The causes of this change are unknown, but need further investigation. Clinicians in Scotland, particularly those caring for immunocompromised patients, should have a low threshold for testing for HEV.

Demonstration of real-time and accelerated stability of hepatitis E vaccine with a combination of different physicochemical and immunochemical methods

Hepatitis E, which is caused by infection with hepatitis E virus (HEV), is a global health problem in both developed and developing countries. An efficacious hepatitis E vaccine was licensed (by China) in 2011 with a trade name of Hecolin®. The antigen contained in this vaccine is a truncated version of the sole capsid protein encoded by open reading frame 2, which is designated p239. In this study, the real-time and real-condition stability and accelerated stability of five lots of hepatitis E vaccine products at the end of the designated shelf life, were assessed by a well-established quality analysis platform. The protein integrity of p239 that was recovered from the vaccine lots was demonstrated using CE-SDS, LC-MS and MALDI-TOF MS. The particle characteristics of the recovered vaccine antigen were assessed by TEM and HPSEC. The immunogenicity of hepatitis E vaccines was assessed by a mouse potency assay, which is part of product release and stability testing. Several methods were employed to assess the antigenicity of vaccines with or without adjuvant dissolution. Specifically, the well-established methods of sandwich ELISA and surface plasma resonance (SPR)-based BIAcore were used with unique murine monoclonal antibodies. Most interesting, two 'dissolution-free' immunoassays were also used for in situ antigenicity assessment of the vaccines. In addition to the confirmation of vaccine stability at the end of expiry dating, i.e., after storage in recommended conditions (2-8 °C) for 36 months, the mouse potency assay and sandwich ELISA were used to assess the accelerated stability of prefilled syringes to demonstrate the feasibility of out-of-cold-chain storage. In summary, molecular and functional characterization confirmed the shelf life stability of the vaccine at the end of expiry dating and the feasibility of transporting the hepatitis E vaccine for a given period of time out of cold chains.

The burden of hepatitis E among patients with haematological malignancies: A retrospective European cohort study

BACKGROUND & AIMS

The burden of hepatitis E virus (HEV) infection among patients with haematological malignancy has only been scarcely reported. Therefore, we aimed to describe this burden in patients with haematological malignancies, including those receiving allogeneic haematopoietic stem cell transplantation.

METHODS

We conducted a retrospective, multicentre cohort study across 11 European centres and collected clinical characteristics of 50 patients with haematological malignancy and RNA-positive, clinically overt hepatitis E between April 2014 and March 2017. The primary endpoint was HEV-associated mortality; the secondary endpoint was HEV-associated liver-related morbidity.

RESULTS

The most frequent underlying haematological malignancies were aggressive non-Hodgkin lymphoma (NHL) (34%), indolent NHL (iNHL) (24%), and acute leukaemia (36%). Twenty-one (42%) patients had received allogeneic haematopoietic stem cell transplantation (alloHSCT). Death with ongoing hepatitis E occurred in 8 (16%) patients, including 1 patient with iNHL and 1 patient >100 days after alloHSCT in complete remission, and was associated with male sex (p = 0.040), cirrhosis (p = 0.006) and alloHSCT (p = 0.056). Blood-borne transmission of hepatitis E was demonstrated in 5 (10%) patients, and associated with liver-related mortality in 2 patients. Hepatitis E progressed to chronic hepatitis in 17 (34%) patients overall, and in 10 (47.6%) and 6 (50%) alloHSCT and iNHL patients, respectively. Hepatitis E was associated with acute or acute-on-chronic liver failure in 4 (8%) patients with 75% mortality. Ribavirin was administered to 24 (48%) patients, with an HEV clearance rate of 79.2%. Ribavirin treatment was associated with lower mortality (p = 0.037) and by trend with lower rates of chronicity (p = 0.407) when initiated <24 and <12 weeks after diagnosis of hepatitis E, respectively. Immunosuppressive treatment reductions were associated with mortality in 2 patients (28.6%).

CONCLUSION

Hepatitis E is associated with mortality and liver-related morbidity in patients with haematological malignancy. Blood-borne transmission contributes to the burden. Ribavirin should be initiated early, whereas reduction of immunosuppressive treatment requires caution.

LAY SUMMARY

Little is known about the burden of hepatitis E among patients with haematological malignancy. We conducted a retrospective European cohort study among 50 patients with haematological malignancy, including haematopoietic stem cell transplant recipients, with clinically significant HEV infection and found that hepatitis E is associated with hepatic and extrahepatic mortality, including among patients with indolent disease or among stem cell transplant recipients in complete remission. Hepatitis E virus infection evolved to chronic hepatitis in 5 (45.5%) patients exposed to a rituximab-containing regimen and 10 (47.6%) stem cell transplant recipients. Reducing immunosuppressive therapy because of hepatitis E was associated with mortality, while early ribavirin treatment was safe and effective.

Cell culture isolation of Hepatitis E Virus Genotype 3 Strain obtained from human feces

Hepatitis E virus (HEV) is considered one of the leading causes of acute viral hepatitis worldwide, and about 20 million infections and approximately 57 000 deaths occurred every year. However, little is known about the replicative virus cycle due to the absence of a consensus cell culture model. A549 cell line is considered susceptible to HEV genotype 3, however, both viral strain and cell culture conditions could affect the viral isolation in vitro. The objective of this work was to isolate in vitro an HEV-3 strain obtained from human feces. To this, a genotype 3 HEV strain previously identified by genetic characterization was inoculated in A549 monolayers, and incubated for two hours at 37 °C. Five days post-infection, cells were passaged (subcultured) for the first time, and serial passages were done on average every four days during 41 days. HEV replication was evaluated through RT-qPCR in each passage, and reinfection of the cell line with the viral progeny derived from A549 infected monolayers was assessed through immunofluorescence and RT-qPCR. Viral RNA was detected in each passage from infected monolayers, and the highest amount was found after 26 days (2 x 106 copies/μL). In reinfection assay, capsid antigen was detected perinuclearly and forming foci, and 1x104 copies/μL of viral RNA was detected after 96 hours post infection. This shows that HEV recovered from the cell lysate monolayers was infectious. This viral isolate offers a critical tool to study the unknown aspect of HEV infection.

Isolation of Subtype 3c, 3e and 3f-Like Hepatitis E Virus Strains Stably Replicating to High Viral Loads in an Optimized Cell Culture System

The hepatitis E virus (HEV) is transmitted via the faecal-oral route in developing countries (genotypes 1 and 2) or through contaminated food and blood products worldwide (genotypes 3 and 4). In Europe, HEV subtypes 3c, 3e and 3f are predominant. HEV is the leading cause of acute hepatitis globally and immunocompromised patients are particularly at risk. Because of a lack of cell culture systems efficiently propagating wild-type viruses, research on HEV is mostly based on cell culture-adapted isolates carrying uncommon insertions in the hypervariable region (HVR). While optimizing the cell culture system using the cell culture-adapted HEV strain 47832c, we isolated three wild-type strains derived from clinical specimens representing the predominant spectrum of HEV in Europe. The novel isolates 14-16753 (3c), 14-22707 (3e) and 15-22016 (3f-like) replicate to high viral loads of 10⁸, 10⁹ and 10^6.5 HEV RNA copies/mL at 14 days post-inoculation, respectively. In addition, they could be kept as persistently infected cell cultures with constant high viral loads (~10⁹ copies/mL) for more than a year. In contrast to the latest isolates 47832c, LBPR-0379 and Kernow-C1, the new isolates do not carry genome insertions in the HVR. Optimization of HEV cell culture identified amphotericin B, distinct salts and fetal calf serum (FCS) as important medium supplements. Overconfluent cell layers increased infectivity and virus production. PLC/PRF/5, HuH-7-Lunet BLR, A549 and HepG2/C3A supported replication with different efficiencies. The novel strains and optimized cell culture system may be useful for studies on the HEV life cycle, inactivation, specific drug and vaccine development.

Patterns of mutation within an emerging endemic lineage of HEV-3a

The hepatitis E virus can cause chronic infections in immuno-suppressed patients, and cases have been on the rise globally. Viral mutations during such infections are difficult to characterize. We deep-sequenced viral populations from 15 immunocompromised patients with chronic HEV to identify the viral lineage and describe viral mutational hotspots within and across patients. A total of 21 viral RNA samples were collected between 2012 and 2017 from a single hospital in Singapore. Sequences covering a total of 3894 bp of the HEV genome were obtained. Phylogenetic analyses identified all sequences as belonging to the HEV-3a sub-clade and clearly indicate a unique local lineage. Deep sequencing reveals variable viral population complexity during infections. Comparisons of viral samples from the same patients spaced 2-19 months apart revealed rapid nucleotide replacements in the dominant viral sequence in both ribavirin treated and treatment-naive patients. Mutational hotspots were identified within ORF3 and the PCP/HVR domain of ORF1.

Phylogenetic analysis of two genotype 3 Hepatitis E viruses from wild boar, Italy

The complete and near-complete genome sequences (7206 nt and 7229 nt) of two wild boar HEV strains detected in Southern Italy were obtained by the next generation sequencing. Phylogenetic analysis and p distance comparisons of one of the strains with HEV-3 reference subtype strains confirmed the detection of a subtype 3i (p distance = 0.110) strain in wild boar, never detected in Italy either in wild boar or pigs. The sequence of the second strain was not classifiable in any of the subtypes defined to date, showing a p distance > 0.138 and a low nucleotide identity with all HEV reference strains. The virus may represent a novel subtype, with a low relationship to other strains of genotype 3 detected in wild boar, pigs, or humans in Europe. This result suggests the circulation in Italy of an emerging or uncommon HEV strain. Sequencing followed by phylogenetic analyses of the complete HEV coding regions are important tools for understanding the evolutionary and epidemiological dynamics underlying the wide genetic diversity of HEV strains.

Chronic genotype 1 hepatitis E infection from immunosuppression for ileo-colonic Crohn's disease

We report a case of a 33-year-old man with a background of longstanding ileo-colonic Crohn's disease and primary sclerosing cholangitis. Following a trip to India he developed diarrhoea which was treated as an exacerbation of Crohn's disease. Liver tests became chronically deranged after increasing immunosuppression, which comprised mercaptopurine, adalimumab and prednisolone. Chronic genotype 1 hepatitis E was diagnosed and successfully treated with reduction of immunosuppression followed by a 24-week course of ribavirin. We believe that this is the first reported case of chronic hepatitis E in genotype 1. Deranged liver tests should prompt testing for hepatitis E infection in the context of immunosuppression for inflammatory bowel disease.

Prevalence of hepatitis E in liver transplant recipients in Greece

Hepatitis E virus (HEV) is a well-known cause of acute hepatitis. Immunocompromised subjects, including liver transplant recipients, are considered to be at risk for HEV infection, which occasionally follows a chronic course. The diagnosis of HEV infection in these patients must be based on HEV RNA testing, as serology has variable performance. The aim of this study was to assess the prevalence of HEV infection in liver transplant recipients in Greece by means of HEV RNA testing. Liver transplant recipients followed in the sole transplant centre in Greece were prospectively included. HEV RNA was detected by real-time RT-PCR. Positive samples were further analysed using a nested reverse transcription RT-PCR kit, which amplifies a 137-nucleotide sequence within the ORF2/ORF3 overlapping region to detect the HEV genotype and perform phylogenetic analysis. The mean age of the included patients (n = 76) was 54 years. The most common indication for liver transplantation was viral hepatitis (57%). The majority of the patients (75%) received a calcineurin inhibitor as part of their immunosuppressive regimen and had normal liver enzymes. HEV RNA was found positive in only 1/76 (1.3%) patient. Phylogenetic analysis showed that the sequence clustered into the HEV genotype 3 clade. This patient experienced an acute hepatitis flare, which nonetheless did not become chronic. The prevalence of HEV infection in liver transplant recipients in Greece is similar (1.3%) to that reported previously in other countries. Transplant physicians should be aware of this condition and its associated consequences.

Prevalence of hepatitis E virus viremia and antibodies among healthy blood donors in India

BACKGROUND

Hepatitis E virus (HEV) is transmitted primarily through contaminated water and food. Recently, HEV viremia in blood donors and transfusion-related transmission of HEV have been reported, leading to calls to screen donated blood for this virus. However, these data are from regions where genotype 3 HEV is predominant. In India, where human infections are caused only by genotype 1 HEV, the frequency of subclinical HEV viremia is unknown.

METHODS

Minipools of sera prepared from three donor units each from our institution's  blood bank in Lucknow, India, were tested for HEV RNA using a sensitive amplification-based assay. A randomly selected subset was also tested for IgG anti-HEV antibodies using a commercial (Wantai) immunoassay.

RESULTS

Sera from 1799 donors (median [range] age 30 [18-63] years; 1746 [97.0%] men) were collected (June-July 2016, 900; November-December 2016, 899). Of these, 17 (0.95%), 16 (0.90%), and 3 (0.17%) tested positive for HBsAg, anti-HCV, and anti-HIV antibodies, respectively. None of the donors tested positive for HEV RNA. Of 633 randomly selected donors (age 30 [18-63] years, 613 [96.8%] male) tested for IgG anti-HEV, 383 (60.5%) tested positive. Seropositivity rate increased with age, being 70/136 (52%), 177/299 (59%), 100/154 (65%), 30/34 (88%), and 6/10 (60%) in the 18-24, 25-34, 35-44, 45-54, and 55 years or older age groups, respectively.

CONCLUSIONS

In healthy blood donors from northern India, HEV viremia is infrequent though anti-HEV antibody prevalence is high. This suggests that asymptomatic HEV viremia may be less frequent in areas with genotype 1 predominance than those with genotype 3 predominance.

First Report of the Presence of Hepatitis E Virus in Scottish-Harvested Shellfish Purchased at Retail Level

Shellfish samples (n = 310) purchased from local supermarkets were analysed for the presence of hepatitis E virus (HEV) by nested RT-PCR and real-time qRT-PCR. Overall, 2.9% of samples tested positive for the presence of HEV. Phylogenetic analysis of HEV sequences revealed all as being genotype 3 HEV. This is the first report of the detection of HEV in commercially sold shellfish in Scotland. These findings may encourage further research that will help address the gaps in the knowledge in respect to foodborne transmission of HEV in Scotland and the rest of the United Kingdom.

A nationwide retrospective study on prevalence of hepatitis E virus infection in Italian blood donors

BACKGROUND

In Europe, hepatitis E virus (HEV) infection is mainly a food-borne zoonosis, but it can also be transmitted by blood transfusion. It is usually a mild and self-limited infection. However, immunocompromised persons, who are also those more likely to undergo blood transfusions, may develop chronic hepatitis and often cirrhosis. Since this is a potential threat to blood safety, we aimed to investigate HEV prevalence in Italian blood donors.

MATERIALS AND METHODS

We used plasma donations collected during 2015-2016 by blood services (BS) scattered throughout the Italian regions and intended for the production of plasma-derived medicines. Plasma samples were tested for IgG and IgM anti-HEV and for HEV RNA using validated assays. Data concerning donor's age and sex, and the location of the BS were collected.

RESULTS

A total of 10,011 plasma samples were tested. Overall IgG and IgM prevalence rates were 8.7 and 0.4%, respectively. No sample was HEV RNA-positive. IgG prevalence was significantly higher in males and in donors aged 44 years and over. IgG prevalence differed greatly according to region. Overall regional rates over 15% were found in Abruzzo and in Sardinia, and rates of 10-15% were found in Lazio, Umbria and the Marche. Considering IgG prevalence according to the province where the BS was located, rates over 30% were found in Sardinia and Abruzzo. Age, sex and donor's region of residence were independently associated with IgG positivity. BS location produced significant heterogeneity on prevalence rates within the regions.

DISCUSSION

The detected IgG rate of 8.7% in this study represents one of the lowest seroprevalence rates reported among blood donors in Europe. Particularly high prevalence rates in some regions and provinces may be explained by local eating habits and/or intensive environmental HEV contamination. Before considering the introduction of HEV RNA screening for blood donations in Italy, further important issues should be addressed and prospective incidence and reliable cost-benefit studies are needed.

Hepatitis E virus infection in Turkey: a systematic review

Hepatitis E virus (HEV), a non-enveloped single stranded RNA virus causes sporadic cases of hepatitis or outbreaks. The disease is generally self-limited although it may cause fulminant hepatitis in pregnant women, elderly, those with underlying chronic hepatitis, immunosuppressed, and transplant recipients. It is transmitted through fecal–oral route and zoonotic transmission. Hepatitis is a main health care problem in Turkey; HBV and HCV prevalences are 4 and 1% respectively. Hepatitis D represents another considerable hepatitis etiology with a prevalence of 5–27%. The information about HEV is not clear. In this systematic review, we aimed to analyze HEV studies reported from Turkey, to determine the current situation of the disease in the country, to delineate the limits of the studies and to determine the future study areas. The prevalence of HEV ranged from 0 to 12.4%. Children had lower prevalence than the adults. The prevalence was determined as 7–8% in pregnant women, 13% in chronic HBV patients, 54% in chronic HCV patients, 13.9–20.6% in patients with chronic renal failure, and ≈ 35% in agriculture workers. Among individuals immigrating form Turkey to Europe, HEV seroprevalence was found 10.3% in Italy and 33.4% in the Netherlands. HEV prevalence seems high in certain risk groups. Although previous studies suggest that Turkey is among the endemic countries of HEV, there are some pitfalls for the analysis of data: the studies are not powered enough to represent the whole population; they did not include immunosuppressed patients and solid organ recipients; and the prevalence of non-A non-B hepatitis was not determined.

Viral Hepatitis and Acute Liver Failure: Still a Problem

Although the overall prevalence is on the decline, viral hepatitis still plays a major role in the development of acute liver failure (ALF) worldwide. Hepatitis A, B, D, and E contribute to most fulminant viral courses. These viruses have not gained much attention in recent years yet remain relevant from a clinical perspective as the incidence in certain populations is on the increase. Other viral therapies and immunotherapies are currently being examined as treatments for hepatitis D and hepatitis E. Clinicians should still maintain a high index of suspicion for viral causes in approaching patients with ALF.