Hepatitis E

HEV infection in stem cell transplant recipients-retrospective study of EBMT Infectious Diseases Working Party

HEV infection is an emerging cause of acute and chronic hepatitis in stem cell transplant (SCT) recipients. We performed a retrospective observational study among EBMT centers with the aim of describing characteristics, management and outcome of HEV after SCT. There were 34 cases of HEV infection from 12 centers in 6 countries, diagnosed in median 4.5 months after SCT; 20 of acute and 14 of chronic infection. Non-hepatic findings possibly associated with HEV infection were present in 9 (26%). Patients with chronic infection had more characteristics associated with severely immunocompromised status. Ribavirin was provided to 16 patients (47%; 40% with acute and 57% with chronic infection), in median for 75 days. Three (19%) patients discontinued it due to side effects. HEV-RNA clearance occurred in 29 patients (85%; 85% in acute and 86% in chronic infection). HEV was considered a cause of death in 3 (9%), with 2 cases with late diagnosis. Reduction of immunosuppression in those receiving it, and ribavirin treatment in those with chronic infection were associated with shorter time to HEV-RNA clearance. Policy on HEV testing varied between the centers. In conclusion, acute and chronic HEV hepatitis should be promptly diagnosed and managed in SCT recipients.

The Hepatitis E Virus Open Reading Frame 2 Protein: Beyond Viral Capsid

Hepatitis E virus (HEV) is a zoonotic pathogen causing hepatitis in both human and animal hosts, which is responsible for acute hepatitis E outbreaks worldwide. The 7.2 kb genome of the HEV encodes three well-defined open reading frames (ORFs), where the ORF2 translation product acts as the major virion component to form the viral capsid. In recent years, besides forming the capsid, more functions have been revealed for the HEV-ORF2 protein, and it appears that HEV-ORF2 plays multiple functions in both viral replication and pathogenesis. In this review, we systematically summarize the recent research advances regarding the function of the HEV-ORF2 protein such as application in the development of a vaccine, regulation of the innate immune response and cellular signaling, involvement in host tropism and participation in HEV pathogenesis as a novel secretory factor. Progress in understanding more of the function of HEV-ORF2 protein beyond the capsid protein would contribute to improved control and treatment of HEV infection.

Hepatitis E: Genotypes, strategies to prevent and manage, and the existing knowledge gaps

Hepatitis E virus (HEV) is considered an emergent source of viral hepatitis worldwide, with an increasing burden of jaundice, liver failure, extrahepatic illnesses, and deaths in developed countries. With the scarcity of data from efficient animal models, there are still open-ended questions about designing new models to study pathogenesis, types, virology, and evolution of these viruses. With an emphasis on available data and updates, there is still enough information to understand the HEV life cycle, pathogen interaction with the host, and the valuation of the role of vaccine and new anti-HEV therapies. However, the World Health Organization (WHO) and the European Association for the Study of the Liver (EASL) preferred to stress prevention and control measures of HEV infections in animals, zoonotic transmission, and foodborne transmission. It is being reviewed that with current knowledge on HEV and existing prevention tools, there is an excellent room for in-depth information about the virus strains, their replication, pathogenicity, and virulence. The current knowledge set also has gaps regarding standardized and validated diagnostic tools, efficacy and safety of the vaccine, and extrahepatic manifestations specifically in pregnant females, immunocompromised patients, and others. This review highlights the areas for more research exploration, focusing on enlisted research questions based on HEV infection to endorse the need for significant improvement in the current set of knowledge for this public health problem.

Hepatitis E Virus Infection-Immune Responses to an Underestimated Global Threat

Infection with the hepatitis E virus (HEV) is one of the main ubiquitous causes for developing an acute hepatitis. Moreover, chronification plays a predominant role in immunocompromised patients such as transplant recipients with more frequent severe courses. Unfortunately, besides reduction of immunosuppression and off-label use of ribavirin or pegylated interferon alfa, there is currently no specific anti-viral treatment to prevent disease progression. So far, research on involved immune mechanisms induced by HEV is limited. It is very difficult to collect clinical samples especially from the early phase of infection since this is often asymptomatic. Nevertheless, it is certain that the outcome of HEV-infected patients correlates with the strength of the proceeding immune response. Several lymphoid cells have been identified in contributing either to disease progression or achieving sustained virologic response. In particular, a sufficient immune control by both CD4⁺ and CD8⁺ T cells is necessary to prevent chronic viral replication. Especially the mechanisms underlying fulminant courses are poorly understood. However, liver biopsies indicate the involvement of cytotoxic T cells in liver damage. In this review, we aimed to highlight different parts of the lymphoid immune response against HEV and point out questions that remain unanswered regarding this underestimated global threat.

Hepatitis E virus as a trigger for Guillain-Barré syndrome

Background

Hepatitis E virus (HEV) is the most common cause of acute viral hepatitis worldwide. An association with neuralgic amyotrophy and Guillain-Barré syndrome (GBS) was previously described. Concerning GBS, studies from other countries found an acute HEV infection in 5–11% of cases. However, HEV prevalence shows considerable regional variations. Therefore, we retrospectively analyzed the frequency of HEV infections in association with GBS in a monocentric cohort in Southwestern Germany.

Methods

Overall, 163 patients with GBS treated in our clinic between 2008 and 2018 of whom serum and/or cerebrospinal fluid (CSF) samples were available, were identified. Serum samples were analyzed for anti-HEV immunoglobulin (Ig)M and IgG antibodies by ELISA. Additionally, both serum and cerebrospinal fluid (CSF) samples were tested for HEV RNA by PCR if IgM was positive or patients presented within the first 7 days from GBS symptom onset. A group of 167 healthy volunteers and 96 healthy blood donors served as controls.

Results

An acute HEV infection was found in two GBS patients (1.2%) with anti-HEV IgM and IgG antibodies. HEV PCR in serum and CSF was negative in these two patients as well as in all other tested cases. Seroprevalences indicated that acute infection did not differ significantly from controls (0.8%). Anti-HEV IgG seroprevalence indicating previous infection was unexpectedly high (41%) and revealed an age-dependent increase to more than 50% in patients older than 60 years.

Conclusion

In this study, serological evidence of an acute HEV infection in patients with GBS was rare and not different from controls. Comparing our data with previous studies, incidence rates show considerable regional variations.

Hepatitis E virus-associated haemophagocytic lymphohistiocytosis

We report the first documented case of hepatitis E virus-associated haemophagocytic lymphohistiocytosis. This case emphasizes the fact that infectious agents other than those classically described should be taken into consideration as a potential trigger of virus-associated haemophagocytic syndrome. Prompt recognition is crucial to start early treatment of the underlying infection and possibly improve the outcome of this frequently fatal syndrome.

Viral hepatitis update: Progress and perspectives

Viral hepatitis, secondary to infection with hepatitis A, B, C, D, and E viruses, are a major public health problem and an important cause of morbidity and mortality. Despite the huge medical advances achieved in recent years, there are still points of conflict concerning the pathogenesis, immune response, development of new and more effective vaccines, therapies, and treatment. This review focuses on the most important research topics that deal with issues that are currently being solved, those that remain to be solved, and future research directions. For hepatitis A virus we will address epidemiology, molecular surveillance, new susceptible populations as well as environmental and food detections. In the case of hepatitis B virus, we will discuss host factors related to disease, diagnosis, therapy, and vaccine improvement. On hepatitis C virus, we will focus on pathogenesis, immune response, direct action antivirals treatment in the context of solid organ transplantation, issues related to hepatocellular carcinoma development, direct action antivirals resistance due to selection of resistance-associated variants, and vaccination. Regarding hepatitis D virus, we describe diagnostic methodology, pathogenesis, and therapy. Finally, for hepatitis E virus, we will address epidemiology (including new emerging species), diagnosis, clinical aspects, treatment, the development of a vaccine, and environmental surveillance.

Hepatitis E virus prevalence among blood donors in Dali, China

BACKGROUND

Hepatitis E virus (HEV) is a nonenveloped RNA virus causing hepatitis E worldwide. The increase in transfusion-transmitted cases of HEV infections from asymptomatic blood donors causing serious illnesses among immunosuppressed recipients has been reported in the past few years. China is one of the most prevalent regions of HEV; as a result, it is important to evaluate the risk of transfusion-transmitted HEV.

METHODS

A total of 1864 serum samples (including demographic characteristics) from blood donors were randomly collected from February to March 2018 in Dali city. Anti-HEV IgG, IgM and IgA antibodies and HEV antigen were examined by enzyme-linked immunosorbent assay (ELISA). HEV RNA was detected by real-time PCR. Multivariable logistic regression modelling was used to examine the risk factors associated with HEV prevalence.

RESULTS

Overall, the positive rates of anti-HEV IgG, IgM, and IgA antibodies were 13.36% (249/1864), 1.13% (21/1864), and 1.82% (34/1864), respectively. However, none of the 1864 serum samples were HEV antigen positive or HEV RNA positive. Females (16.69%) had a significantly higher HEV seroprevalence than males (13.04%) (odds ratio [OR] 1.34 [95% CI, 1.02-1.75]). Bai (18.85%) donors had a significantly higher HEV seroprevalence than Han (12.21%) blood donors (odds ratio [OR], 1.65 [95% CI, 1.24-2.19] for Bai).

CONCLUSIONS

HEV showed a seroprevalence among blood donors in Yunnan Province, some of which were even recent infections, indicating a threat to the safety of blood transfusions. Whether to formulate a strategy for HEV screening in blood centres needs further research.

Hepatitis E virus persists in the ejaculate of chronically infected men

BACKGROUND & AIMS

Hepatitis E virus (HEV) infections are prevalent worldwide. Various viruses have been detected in the ejaculate and can outlast the duration of viremia, indicating replication beyond the blood-testis barrier. HEV replication in diverse organs, however, is still widely misunderstood. We aimed to determine the occurrence, features and morphology of HEV in the ejaculate.

METHODS

The presence of HEV in testis was assessed in 12 experimentally HEV-genotype 3-infected pigs. We further tested ejaculate, urine, stool and blood from 3 chronically HEV genotype 3-infected patients and 6 immunocompetent patients with acute HEV infection by HEV-PCR. Morphology and genomic characterization of HEV particles from various human compartments were determined by HEV-PCR, density gradient measurement, immune-electron microscopy and genomic sequencing.

RESULTS

In 2 of the 3 chronically HEV-infected patients, we observed HEV-RNA (genotype 3c) in seminal plasma and semen with viral loads >2 logs higher than in the serum. Genomic sequencing showed significant differences between viral strains in the ejaculate compared to stool. Under ribavirin-treatment, HEV shedding in the ejaculate continued for >9 months following the end of viremia. Density gradient measurement and immune-electron microscopy characterized (enveloped) HEV particles in the ejaculate as intact.

CONCLUSIONS

The male reproductive system was shown to be a niche of HEV persistence in chronic HEV infection. Surprisingly, sequence analysis revealed distinct genetic HEV variants in the stool and serum, originating from the liver, compared to variants in the ejaculate originating from the male reproductive system. Enveloped HEV particles in the ejaculate did not morphologically differ from serum-derived HEV particles.

LAY SUMMARY

Enveloped hepatitis E virus particles could be identified by PCR and electron microscopy in the ejaculate of immunosuppressed chronically infected patients, but not in immunocompetent experimentally infected pigs or in patients with acute self-limiting hepatitis E.

The prevalence of HEV among non-A-C hepatitis in Qatar and efficiency of serological markers for the diagnosis of hepatitis E

BACKGROUND

The rapid growth of Qatar in the last two decades has attracted a large influx of immigrant workers who mostly come from HEV-hyperendemic countries. Thus, we aim to investigate the prevalence of HEV among acute non-A-C hepatitis patients in Qatar; and to evaluate the performance of four dominant commercial serological assays for HEV diagnosis.

METHODS

259 patients with non-A-C hepatitis were tested using the Wantai HEV-IgM, HEV-IgG, HEV-Ag ELISA kits, and the MP Biomedical HEV-Total Ab ELISA kit. ALT levels were tested and HEV RNA (viral loads) was performed using Taqman AmpliCube HEV RT-PCR kit (Mikrogen, Neuried, Germany). The performance of each kit was assessed according to the RT-PCR results.

RESULTS

HEV-RNA was detected in 23.1% of the samples. Most of these HEV-RNA-positive cases belonged to non-Qatari residents from the Indian subcontinent; India, Pakistan, etc. HEV-Ag, HEV-IgM, HEV-IgG, HEV-Total Ab were detected in 5.56%, 8.65%, 32.1%, and 34.2% of all tested samples, respectively. Elevated ALT levels were highly correlated with the HEV-Ag, HEV-IgM, HEV-RNA but not with the HEV-IgG and HEV-Total Ab. Although HEV-Ag was very specific (100%), yet its sensitivity was poor (36.7%). HEV-IgM demonstrated the best second marker for diagnosis of acute HEV after RT-PCR as jugged by the overall performance parameters: specificity (96.2%), sensitivity (71.4%), PPV (83.3%), NPP (92.7%), agreement with RT-PCR (91.0%), and Kappa-value (0.71).

CONCLUSION

Our study demonstrated a high prevalence of HEV virus in Qatar, mostly among immigrants from the Indian subcontinent. The HEV-IgM represents the best marker for detecting the acute HEV infection, where RT-PCR cannot be performed.

Enlightenment on oscillatory properties of 23 class B notifiable infectious diseases in the mainland of China from 2004 to 2020

A variety of infectious diseases occur in mainland China every year. Cyclic oscillation is a widespread attribute of most viral human infections. Understanding the outbreak cycle of infectious diseases can be conducive for public health management and disease surveillance. In this study, we collected time-series data for 23 class B notifiable infectious diseases from 2004 to 2020 using public datasets from the National Health Commission of China. Oscillatory properties were explored using power spectrum analysis. We found that the 23 class B diseases from the dataset have obvious oscillatory patterns (seasonal or sporadic), which could be divided into three categories according to their oscillatory power in different frequencies each year. These diseases were found to have different preferred outbreak months and infection selectivity. Diseases that break out in autumn and winter are more selective. Furthermore, we calculated the oscillation power and the average number of infected cases of all 23 diseases in the first eight years (2004 to 2012) and the next eight years (2012 to 2020) since the update of the surveillance system. A strong positive correlation was found between the change of oscillation power and the change in the number of infected cases, which was consistent with the simulation results using a conceptual hybrid model. The establishment of reliable and effective analytical methods contributes to a better understanding of infectious diseases’ oscillation cycle characteristics. Our research has certain guiding significance for the effective prevention and control of class B infectious diseases.

Mechanism of Cross-Species Transmission, Adaptive Evolution and Pathogenesis of Hepatitis E Virus

Hepatitis E virus (HEV) is the leading cause of acute hepatitis worldwide. While the transmission in developing countries is dominated by fecal-oral route via drinking contaminated water, the zoonotic transmission is the major route of HEV infection in industrialized countries. The discovery of new HEV strains in a growing number of animal species poses a risk to zoonotic infection. However, the exact mechanism and the determinant factors of zoonotic infection are not completely understood. This review will discuss the current knowledge on the mechanism of cross-species transmission of HEV infection, including viral determinants, such as the open reading frames (ORFs), codon usage and adaptive evolution, as well as host determinants, such as host cellular factors and the host immune status, which possibly play pivotal roles during this event. The pathogenesis of hepatitis E infection will be briefly discussed, including the special forms of this disease, including extrahepatic manifestations, chronic infection, and fulminant hepatitis in pregnant women.

ACG Clinical Guideline: Diagnosis and Management of Idiosyncratic Drug-Induced Liver Injury

Idiosyncratic drug-induced liver injury (DILI) is common in gastroenterology and hepatology practices, and it can have multiple presentations, ranging from asymptomatic elevations in liver biochemistries to hepatocellular or cholestatic jaundice, liver failure, or chronic hepatitis. Antimicrobials, herbal and dietary supplements, and anticancer therapeutics (e.g., tyrosine kinase inhibitors or immune-checkpoint inhibitors) are the most common classes of agents to cause DILI in the Western world. DILI is a diagnosis of exclusion, and thus, careful assessment for other etiologies of liver disease should be undertaken before establishing a diagnosis of DILI. Model for end-stage liver disease score and comorbidity burden are important determinants of mortality in patients presenting with suspected DILI. DILI carries a mortality rate up to 10% when hepatocellular jaundice is present. Patients with DILI who develop progressive jaundice with or without coagulopathy should be referred to a tertiary care center for specialized care, including consideration for potential liver transplantation. The role of systemic corticosteroids is controversial, but they may be administered when a liver injury event cannot be distinguished between autoimmune hepatitis or DILI or when a DILI event presents with prominent autoimmune hepatitis features.

In Vitro Assembly of Virus-Like Particles and Their Applications

Virus-like particles (VLPs) are increasingly used for vaccine development and drug delivery. Assembly of VLPs from purified monomers in a chemically defined reaction is advantageous compared to in vivo assembly, because it avoids encapsidation of host-derived components and enables loading with added cargoes. This review provides an overview of ex cella VLP production methods focusing on capsid protein production, factors that impact the in vitro assembly, and approaches to characterize in vitro VLPs. The uses of in vitro produced VLPs as vaccines and for therapeutic delivery are also reported.

Hepatitis E-Associated Hospitalizations in the United States: 2010-2015 and 2015-2017

Hepatitis E is considered rare in the United States (US) despite its widespread occurrence in Asian and African countries. The objective of this study was to describe the characteristics of hepatitis E-related pregnancies and acute-on-chronic liver failure and analyse trends for hepatitis E diagnosis among hospitalized patients in the US. We examined data from the 2010-2017 National Inpatient Sample from Healthcare Cost and Utilization Project to determine mortality, morbidity, pregnancy diagnoses, chronic liver disease diagnoses, and other conditions during hospitalization. Data were extracted for hospitalizations with hepatitis E as defined by ICD-9 codes 070.43 and 070.53 and ICD-10 code B17.2. Of 208,462,242 hospitalizations from 2010-2015, we identified 960 hepatitis E hospitalizations. The hospitalization rate of hepatitis E was 3.7 per 10 million in 2010 and 6.4 per 10 million in 2015 (β = 0.60, p = 0.011). From 2015 to 2017, the hospitalization appeared to increase with slope (β) of 0.50. Among those hospitalizations, 34 (4%) died and 85 (9%) had acute-on-chronic liver failure. Ninety-five (10%) had a diagnosis of pregnancy, there were no reports of maternal or foetus/neonate deaths, but there was a high proportion of adverse events for both during hospitalization. Having a chronic liver disease was associated with hepatic coma diagnosis (OR = 10.94, p = 0.002). Although the hospitalization rate of hepatitis E in the US is low, it appears to be increasing over time. Further studies are necessary in order to conclude a causal association of hepatitis E with adverse events and mortalities in pregnancy and chronic liver disease in the US.

Phylogeography and evolutionary history of hepatitis E virus genotype 3 in Argentina

BACKGROUND

Few studies about the evolutionary history of the hepatitis E virus (HEV) have been conducted. The aim of our work was to investigate and make inferences about the origin and routes of dispersion of HEV-3 in Argentina.

METHODS

Phylogenetic, coalescent and phylogeographic analyses were performed using a 322-bp ORF2 genomic fragment of all HEV-3 sequences with known date and place of isolation published at GenBank until May 2018 (n=926), including 16 Argentinian sequences (isolated from pigs, water and humans).

RESULTS

Phylogenetic analysis revealed two clades within HEV-3: abchij and efg. All Argentinian samples were grouped intermingled within clade 3abchij. The coalescent analysis showed that the most recent common ancestor for the clade 3abchij would have existed around the year 1967 (95% highest posterior density (HPD): 1963-1970). The estimated substitution rate was 1.01×10-2 (95%HPD: 9.3×10-3-1.09×10-2) substitutions/site/y, comparable with the rate previously described. The phylogeographic approach revealed a correspondence between phylogeny and place of origin for Argentinian samples, suggesting many HEV introductions in the country, probably from Europe and Japan.

CONCLUSIONS

This is the first evolutionary inference of HEV-3 that includes Argentinian strains, showing the circulation of many HEV-3 subtypes, obtained from different sources and places, with recent diversification processes.

ACCESSION NUMBERS

[KX812460], [KX812461], [KX812462], [KX812465], [KX812466], [KX812467], [KX812468], [KX812469].

Hepatitis E seroprevalence and viremia rate in immunocompromised patients: a systematic review and meta-analysis

BACKGROUND AND AIMS

Hepatitis E is an infectious disease of the liver caused by the hepatitis E virus (HEV). Immunocompromised patients present a particular risk group, as chronification of hepatitis E leading to life-threatening cirrhosis occurs when these patients are infected. Therefore, this study aims to estimate and compare the anti-HEV seroprevalence and the rate of HEV RNA positivity in transplant recipients and patients with human immunodeficiency virus (HIV).

METHODS

This systematic review and meta-analysis involved a literature search (PubMed, Scopus; 1,138 studies) including 120 studies from 1996 to 2019, reporting anti-HEV seroprevalence and/or HEV-RNA positivity. Statistical analysis was performed using a linear mixed-effects meta regression model.

RESULTS

Anti-HEV seroprevalence in 14 626 transplant recipients ranged from 6% (95% CI: 1.9-17.2) to 29.6% (95% CI: 21.6-39.) in different commercially available assays and did not differ significantly compared to 20 825 HIV positive patients (range: 3.5% (95% CI: 0.9-12.8) - 19.4% (95% CI: 13.5-26.9). In contrast, HEV-RNA positivity rate was significantly higher in transplant recipients than in HIV positive patients (1.2% (95% CI: 0.9-1.6) vs 0.39% (95% CI: 0.2-0.7); P-value = 0.0011).

CONCLUSION

Anti-HEV seroprevalence did not differ significantly between transplant recipients and HIV positive patients. Interestingly, rates of HEV-RNA positivity, indicating ongoing infection, were significantly higher in transplant recipients. These findings demonstrate that transplant patients have an elevated risk of chronic infection in comparison to HIV patients at comparable risk of HEV-exposure.

Identification and a full genome analysis of novel camel hepatitis E virus strains obtained from Bactrian camels in Mongolia

Hepatitis E virus (HEV) infects humans and a wide variety of other mammalian hosts. Recently, HEV strains belonging to genotype 8 (G8) within the Orthohepevirus A species of the Hepeviridae family, were identified in Bactrian camels (Camelus bactrianus) in China. The Bactrian camel (also known as the Mongolian camel) is native to the steppes of Central Asia. However, the HEV strains of Mongolian camels have not been examined. Among 200 serum samples from domestic Bactrian camels raised on 6 farms, in 6 soums in 3 provinces; 71 (35.5 %) were positive for anti-HEV IgG, with prevalence differing by farm (soum) (4.2-75.0 %); and 2 camels (1.0 %) that had been raised in Bogd, Bayankhongor Province, which had the highest seroprevalence among the six studied areas, were positive for HEV RNA. The two HEV strains (BcHEV-MNG140 and BcHEV-MNG146) obtained from the viremic camels in the present study shared 97.7 % nucleotide identity. They were closest to the reported G8 Chinese camel HEV strains but differed from them by 13.9-14.3 % over the entire genome, with a nucleotide difference of 24.0-26.5 % from the reported G1-G7 HEV strains. A phylogenetic tree indicated that the BcHEV-MNG140 and BcHEV-MNG146 strains were located upstream of a clade consisting of the Chinese camel HEV strains and formed a cluster with them, with a bootstrap value of 100 %, suggesting that they may represent a novel subtype within G8. These results indicate a high prevalence of HEV infection in Mongolian camels and suggest that the variability of camel HEV genomes is markedly high.

Beyond Metabolism: Role of the Immune System in Hepatic Toxicity

The liver is primarily thought of as a metabolic organ; however, the liver is also an important mediator of immunological functions. Key perspectives on this emerging topic were presented in a symposium at the 2018 annual meeting of the American College of Toxicology entitled "Beyond metabolism: Role of the immune system in hepatic toxicity." Viral hepatitis is an important disease of the liver for which insufficient preventive vaccines exist. Host immune responses inadequately clear these viruses and often potentiate immunological inflammation that damages the liver. In addition, the liver is a key innate immune organ against bacterial infection. Hepatocytes and immune cells cooperatively control systemic and local bacterial infections. Conversely, bacterial infection can activate multiple types of immune cells and pathways to cause hepatocyte damage and liver injury. Finally, the immune system and specifically cytokines and drugs can interact in idiosyncratic drug-induced liver injury. This rare disease can result in a disease spectrum that ranges from mild to acute liver failure. The immune system plays a role in this disease spectrum.

Are VIDAS® anti-HEV IgM and IgG assays fit for reliable diagnosis of hepatitis E virus infections? Comparison & case story telling

Objectives: Hepatitis E virus (HEV) genotype 3 is an emerging pathogen in developed countries. We evaluated the performance of two new serological assays for the detection of HEV, VIDAS® anti-HEV IgM and IgG. Methods: VIDAS® assays were performed on 77 clinical samples: 68 samples from patients suspected for HEV infection and 9 samples which previously tested positive for HEV IgM, IgG or HEV PCR. All samples were also tested using Wantai HEV assays. Cross-reactivity was assessed. To get a better view on the natural course of HEV infections, three clinical cases are described. Results: The concordance rate between VIDAS® and Wantai assays was good for HEV IgM (0.75,CI 0.52-0.98) and very good for HEV IgG (0.85,CI 0.72-0.98). Four samples tested borderline/positive with Wantai IgM but negative with VIDAS® IgM. All of these samples were HEV RNA negative, HEV IgG was positive in 2/4 samples. Five samples produced conflicting HEV IgG results. These tested positive with VIDAS® but negative with Wantai IgG. All five samples were HEV IgM and RNA negative. We detected no cross-reactivity. The clinical cases illustrate that HEV serology can still be negative in the very beginning of an acute infection. Conclusions: There is a good agreement between VIDAS® and Wantai anti-HEV IgM and IgG assays. Discrepant HEV IgM results probably reflect false positive Wantai IgM results (RNA-/IgG- samples) and longer-lasting positive Wantai IgM (RNA-/IgG+ samples). Discrepant HEV IgG results, could either represent resolved HEV infections (false negative Wantai IgG results) or false positive VIDAS® HEV IgG results.

Ectopic Expression of Genotype 1 Hepatitis E Virus ORF4 Increases Genotype 3 HEV Viral Replication in Cell Culture

Hepatitis E virus (HEV) can account for up to a 30% mortality rate in pregnant women, with highest incidences reported for genotype 1 (gt1) HEV. Reasons contributing to adverse maternal-fetal outcome during pregnancy in HEV-infected pregnant women remain elusive in part due to the lack of a robust tissue culture model for some strains. Open reading frame (ORF4) was discovered overlapping ORF1 in gt1 HEV whose protein expression is regulated via an IRES-like RNA element. To experimentally determine whether gt3 HEV contains an ORF4-like gt1, gt1 and gt3 sequence comparisons were performed between the gt1 and the homologous gt3 sequence. To assess whether ORF4 protein could enhance gt3 replication, Huh7 cell lines constitutively expressing ORF4 were created and used to assess the replication of the Kernow-C1 gt3 and sar55 gt1 HEV. Virus stocks from transfected Huh7 cells with or without ORF4 were harvested and infectivity assessed via infection of HepG2/C3A cells. We also studied the replication of gt1 HEV in the ORF4-expressing tunicamycin-treated cell line. To directly show that HEV transcripts have productively replicated in the target cells, we assessed events at the single-cell level using indirect immunofluorescence and flow cytometry. Despite not naturally encoding ORF4, replication of gt3 HEV was enhanced by the presence of gt1 ORF4 protein. These results suggest that the function of ORF4 protein from gt1 HEV is transferrable, enhancing the replication of gt3 HEV. ORF4 may be utilized to enhance replication of difficult to propagate HEV genotypes in cell culture. IMPORTANCE: HEV is a leading cause of acute viral hepatitis (AVH) around the world. The virus is a threat to pregnant women, particularly during the second and third trimester of pregnancy. The factors enhancing virulence to pregnant populations are understudied. Additionally, field strains of HEV remain difficult to culture in vitro. ORF4 was recently discovered in gt1 HEV and is purported to play a role in pregnancy related pathology and enhanced replication. We present evidence that ORF4 protein provided in trans enhances the viral replication of gt3 HEV even though it does not encode ORF4 naturally in its genome. These data will aid in the development of cell lines capable of supporting replication of non-cell culture adapted HEV field strains, allowing viral titers sufficient for studying these strains in vitro. Furthermore, development of gt1/gt3 ORF4 chimeric virus may shed light on the role that ORF4 plays during pregnancy.

A review of food poisoning caused by local food in Japan

Increasingly popular worldwide, Japanese cuisine includes several raw preparations such as sashimi and sushi; however, limited information on food poisoning from Japanese local food is available in English literature. Without appropriate knowledge, physicians may underdiagnose traveler's diarrhea among people returning from Japan. To provide accurate information to primary care physicians worldwide, we conducted a narrative review on food poisoning research published in Japanese and English over the past four years, considering the frequency and clinical importance of various presentations.

Current Paradigm of Hepatitis E Virus Among Pediatric and Adult Patients

Hepatitis E virus (HEV) infection is a polymorphic condition, present throughout the world and involving children and adults. Multiple studies over the last decade have contributed to a better understanding of the natural evolution of this infection in various population groups, several reservoirs and transmission routes being identified. To date, acute or chronic HEV-induced hepatitis has in some cases remained underdiagnosed due to the lower accuracy of serological tests and due to the evolutionary possibility with extrahepatic manifestations. Implementation of diagnostic tests based on nucleic acid analysis has increased the detection rate of this disease. The epidemiological and clinical features of HEV hepatitis differ depending on the geographical areas studied. HEV infection is usually a self-limiting condition in immunocompetent patients, but in certain categories of vulnerable patients it can induce a sudden evolution toward acute liver failure (pregnant women) or chronicity (immunosuppressed patients, post-transplant, hematological, or malignant diseases). In acute HEV infections in most cases supportive treatment is sufficient. In patients who develop chronic hepatitis with HEV, dose reduction of immunosuppressive medication should be the first therapeutic step, especially in patients with transplant. In case of unfavorable response, the initiation of antiviral therapy is recommended. In this review, the authors summarized the essential published data related to the epidemiological, clinical, paraclinical, and therapeutic aspects of HEV infection in adult and pediatric patients.

Electrochemical DNA detection of hepatitis E virus genotype 3 using PbS quantum dot labelling

The aim of this study was to develop a highly specific electrochemical DNA sensor using functionalized lead sulphide (PbS) quantum dots for hepatitis E virus genotype 3 (HEV3) DNA target detection. Functionalized-PbS quantum dots (QDs) were used as an electrochemical label for the detection of HEV3-DNA target by the technique of square wave anodic stripping voltammetry (SWASV). The functionalized-PbS quantum dots were characterized by UV-vis, FTIR, XRD, TEM and zeta potential techniques. As-prepared, functionalized-PbS quantum dots have an average size of 4.15 ± 1.35 nm. The detection platform exhibited LOD and LOQ values of 1.23 fM and 2.11 fM, respectively. HEV3-DNA target spiked serum is also reported.Graphical abstract.

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.

Seroprevalence of hepatitis E virus among blood donors on Corsica, France, 2017

Background

Hepatitis E virus (HEV) is an emerging zoonotic pathogen and an important cause of acute viral hepatitis in European countries. Corsica Island has been previously identified as a hyperendemic area for HEV.

Aim

Our aim was to characterise the prevalence and titres of IgG antibodies to HEV among blood donors on Corsica and establish a model of the annual force of infection.

Methods

Between September 2017 and January 2018, 2,705 blood donations were tested for anti-HEV IgG using the Wantai HEV IgG enzyme immunoassay.

Results

The overall seroprevalence was 56.1%. In multivariate analysis, seroprevalence was higher in men than in women (60.0% vs 52.2%; p < 0.01), increased with age and was significantly higher among donors born on Corsica (60.6% vs 53.2%; p < 0.01). No significant difference was observed between the five districts of the island. IgG anti-HEV titres were mostly low (70% of positive donors had titres < 3 IU/mL). In Corsican natives, increasing seroprevalence by age could be explained by models capturing a loss of immunity (annual probability of infection: 4.5%; duration of immunity: 55 years) or by age-specific probabilities of infection (3.8% for children, 1.3% for adults).

Conclusion

We confirmed the high HEV seroprevalence on Corsica and identified three aspects that should be further explored: (i) the epidemiology in those younger than 18 years, (ii) common sources of contamination, in particular drinking water, that may explain the wide exposure of the population, and (iii) the actual protection afforded by the low IgG titres observed and the potential susceptibility to secondary HEV infection.

Role of Hepatitis E Virus Infection in North American Patients With Severe Acute Liver Injury

INTRODUCTION

The aim of this study was to determine the role of hepatitis E virus (HEV) infection in a large cohort of prospectively enrolled patients with severe acute liver injury (ALI).

METHODS

Serum samples from 594 consecutive adults enrolled between 2008 and 2018 in the US Acute Liver Failure Study Group ALI registry were tested for anti-HEV IgM and anti-HEV IgG levels. Those with detectable anti-HEV IgM underwent further testing for HEV RNA using real-time polymerase chain reaction.

RESULTS

The median age of patients was 38 years; 41% were men and 72% Caucasian. Etiologies of ALI included acetaminophen hepatotoxicity (50%), autoimmune hepatitis (8.9%), hepatitis B virus (8.9%), and idiosyncratic drug-induced liver injury (7.9%). Overall, 62 patients (10.4%) were negative for anti-HEV IgM but positive for IgG, whereas only 3 men (0.5%) were positive for both anti-HEV IgM and IgG. These 3 cases were initially diagnosed as having indeterminate, HEV, and hepatitis B virus-related ALI. One of these patients had detectable HEV RNA genotype 3, and another anti-HEV IgM+ patient had detectable HEV antigens by immunohistochemistry on liver biopsy. On multivariate modeling, older (odds ratio: 1.99) and non-Caucasian subjects (odds ratio: 2.92) were significantly more likely to have detectable anti-HEV IgG (P < 0.0001).

DISCUSSION

Acute HEV infection is an infrequent cause of ALI in hospitalized North American adults. The anti-HEV IgG+ patients were significantly older and more likely to be non-Caucasian. These data are consistent with other population-based studies that indicate exposure to HEV in the general US population is declining over time and might reflect a cohort effect.

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.

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.

Significance of Anti-Nuclear Antibodies and Cryoglobulins in Patients with Acute and Chronic HEV Infection

BACKGROUND

Hepatitis E virus (HEV) has been associated with immunological phenomena. Their clinical significance, however, still needs to be clarified, that is, whether cryoglobulins or autoantibodies impact overt disease in HEV-infected individuals. To better understand, we analyzed these different immune phenomena in three cohorts, each representing different types of HEV infection.

METHODS

The cohorts included: (i) immunocompetent patients with acute hepatitis E, (ii) immunosuppressed patients with chronic hepatitis E, and (iii) individuals with asymptomatic HEV infection. Together, they consisted of 57 individuals and were studied retrospectively for the presence of anti-nuclear antibodies (ANAs), cryoglobulins, and serum total IgG. They were then compared with a control cohort of 17 untreated patients with chronic hepatitis B virus (HBV) infection or hepatitis C virus (HCV) infection.

RESULTS

Thirteen (23%) were immunocompetent patients with acute hepatitis E (median alanine aminotransferase (ALT) = 872 U/L), 15 (26%) were immunosuppressed patients with chronic hepatitis E (median ALT = 137 U/L), and 29 (51%) were blood donors with asymptomatic HEV infection (median ALT = 35 U/L). Overall, 24% tested positive for elevated ANA titers of >1:160, and 11% presented with a specific ANA pattern. ANA detection was not associated with the type of HEV infection, IgG levels, sex, or age. All individuals tested negative for anti-mitochondrial antibodies, anti-neutrophil cytoplasmic antibodies, liver-kidney microsomal antibodies, anti-myeloperoxidase-, and anti-proteinase-3 antibodies. Five patients (9%) tested positive for cryoglobulins. Notably, cryoglobulinemia was present in overt hepatitis E (Groups (i) and (ii); one acute and four chronic HEV infections), but was not present in any of the asymptomatic blood donors (p = 0.02). The frequency of cryoglobulins and elevated ANAs did not differ significantly between HEV and HBV/HCV patients.

CONCLUSION

In line with findings on HBV and HCV infections, we frequently observed detection of ANAs (24%) and cryoglobulins (9%) in association with HEV infections. The presence of cryoglobulins was limited to patients with overt hepatitis E. We add to the findings on the immune phenomena of hepatitis E.

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.

Cryptogenic liver cirrhosis and hepatitis E virus (HEV): Are they related?

INTRODUCTION AND OBJECTIVES

Hepatitis E virus (HEV) is one of the most common causes of acute hepatitis. In recent years, its role in the development of chronic hepatitis and cirrhosis especially in immunosuppressed patients and its wide range of extrahepatic involvement have increased the amount of research on HEV. In this study we aimed to investigate the presence of HEV infection in individuals with cryptogenic cirrhosis.

MATERIALS AND METHODS

HEV antibodies were analysed using the Anti HEV enzyme-linked immunosorbent assay (ELISA) kit (anti-HEV ELISA; Diapro Prodiagnostic Bioprobes, Milan, Italy). HEV RNA was isolated with using QIAMP Viral RNA mini kit (QIAGEN, Hilden, Germany). The HEV RNA titre was detected with the Rotor Gene 3000 real time polymerase chain reaction (PCR) system using GenoSen's HEV (Rotor Gene) Quantitative Real Time PCR Kit (Genome Diagnostics Private Limited, the Netherlands).

RESULTS

Our study included 21 healthy volunteers (12 males) and 35 cryptogenic cirrhosis patients (19 males). The ages of the patients and the controls were similar (46±12.1 vs. 37.5±9.7years). The mean Child-Pugh score was 8±2.5. The anti HEV immunoglobulin G(IgG) positivity rate was 9.5% and 25.7% in the control and patient groups respectively (p>0.05). HEV RNA positivity was not detected in the control group, but 3 cases (8.6%) in the patient group were positive (p>0.05). The HEV RNA, aspartate aminotransferase (AST) and alanine aminotransferase(ALT) levels for these 3 cases were 326.461copies/mL, 91IU/L and 67IU/L; 480copies/mL, 68IU/L and 36IU/L and 72copies/mL, 42IU/L and 24IU/L respectively. There were positive correlations between HEV RNA levels and AST and ALT levels (p<0.05).

CONCLUSIONS

Anti HEVIgG and HEV RNA positivity rates are high in cryptogenic cirrhosis although it is not statistically significant and there is a positive correlation between HEV RNA and aminotransferases.

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.

Hepatitis E virus infection in buffaloes in South China

ABSTRACT Hepatitis E virus (HEV) infection is an important global public health issue. HEV infections are recognized as a zoonotic disease. Swine are believed to be the main reservoir of HEV. Recently, yaks, cows, and yellow cattle have been reported as new reservoirs of HEV. However, whether other species of cattle and buffaloes are sensitive to HEV infection is unknown. To investigate the prevalence of HEV infection in buffaloes, enzyme-linked immunosorbent assay (ELISA) and reverse transcription-nested polymerase chain reaction (RT-nPCR) were performed. Only one buffalo was positive to anti-HEV IgM antibody (1/106, 0.94%), and none were positive for anti-HEV IgG antibody. To our surprise, five serum (5/106, 4.72%) and three milk samples (3/40, 7.50%) from buffaloes were positive to HEV RNA. All strains of HEV isolated from buffaloes belong to genotype 4. Results indicate that buffaloes may be a new reservoir of HEV.

Experimental infection of hepatitis E virus induces pancreatic necroptosis in miniature pigs

Infection by hepatitis E virus (HEV) via the oral route causes acute hepatitis. Extra-hepatic manifestations of HEV infection may stem from various causes; however, its distribution in organs such as the liver, as well as the mechanisms underlying HEV-induced cell injury, remain unclear. The objective of this study was to determine the chronological distribution of HEV in various tissues of HEV-challenged miniature pigs and to investigate the mechanisms underlying HEV-induced cell death in the pancreas and liver. Virological and serological analyses were performed on blood and faecal samples. Histopathology of the liver and extra-hepatic tissues was analysed. Cell death pathways and immune cell characterisation in inflammatory lesions were analysed using immunohistochemistry. The liver and pancreas displayed inflammation and cellular injury, and a large amount of HEV was observed in the lesions. The liver was infiltrated by T and natural killer cells. HEV was identified in all organs except the heart, and was associated with immune cells. Although the liver and the pancreas strongly expressed TNF-α and TRAIL, TUNEL assay results were negative. RIP3 and pMLKL were expressed in the pancreas. RIP3, but not pMLKL, was expressed in the liver. Pancreatitis induced in HEV-infected miniature pigs is associated with necroptosis.

Design and development of a chimeric vaccine candidate against zoonotic hepatitis E and foot-and-mouth disease

Background

Zoonotic hepatitis E virus (HEV) infection emerged as a serious threat in the industrialized countries. The aim of this study is exploring a new approach for the control of zoonotic HEV in its main host (swine) through the design and development of an economically interesting chimeric vaccine against HEV and against a devastating swine infection: the foot-and-mouth disease virus (FMDV) infection.

Results

First, we adopted a computational approach for rational and effective screening of the different HEV-FMDV chimeric proteins. Next, we further expressed and purified the selected chimeric immunogens in Escherichia coli (E. coli) using molecular cloning techniques. Finally, we assessed the antigenicity and immunogenicity profiles of the chimeric vaccine candidates. Following this methodology, we designed and successfully produced an HEV-FMDV chimeric vaccine candidate (Seq 8-P222) that was highly over-expressed in E. coli as a soluble protein and could self-assemble into virus-like particles. Moreover, the vaccine candidate was thermo-stable and exhibited optimal antigenicity and immunogenicity properties.

Conclusion

This study provides new insights into the vaccine development technology by using bioinformatics for the selection of the best candidates from larger sets prior to experimentation. It also presents the first HEV-FMDV chimeric protein produced in E. coli as a promising chimeric vaccine candidate that could participate in reducing the transmission of zoonotic HEV to humans while preventing the highly contagious foot-and-mouth disease in swine.

Unexpected long-lasting anti-HEV IgM positivity: Is HEV antigen a better serological marker for hepatitis E infection diagnosis?

Hepatitis E virus (HEV) is the leading cause of acute hepatitis worldwide. The minimum criterion for diagnosis of acute infection is detection of anti-HEV antibodies, although there are scant data on IgM duration. Our aim was to assess the persistence of HEV markers after acute self-limited hepatitis E. HEV serological tests (IgM by Mikrogen and Wantai and HEV-Ag) and HEV RNA were carried out in two cohorts: (a) patients with prior acute hepatitis E (ALT >10 x ULN plus positive IgM ± HEV RNA) currently self-limited and (b) 50 blood donors with positive HEV RNA. Among 25 cases of prior acute hepatitis E, after a median follow-up of 34 months, all presented undetectable HEV RNA. However, anti-HEV IgM remained detectable in 14 (56%) by Mikrogen, 6 (24%) by Wantai and none for HEV-Ag. Anti-HEV IgM tested positive in 80%-100% within the second year and 17%-42% over 3 years later, by Wantai and Mikrogen, respectively. Among HEV RNA-positive donors, 12 (25%) tested positive for either IgM by Mikrogen or Wantai, 9 (18%) for both and 18 (36%) for HEV-Ag. HEV-Ag positivity was more likely as HEV RNA was higher (14% if <2.2 log IU/mL; 64% if RNA ≥ 3.7). Overall, HEV-Ag performed best, with a positive predictive value of 100% and diagnostic accuracy of 57%. Anti-HEV IgM exhibited unexpectedly long persistence after a self-limited acute hepatitis E. HEV-Ag had the best performance and could be especially useful in settings where HEV RNA is not available.

Protist enteroparasites in wild boar (Sus scrofa ferus) and black Iberian pig (Sus scrofa domesticus) in southern Spain: a protective effect on hepatitis E acquisition?

BACKGROUND

Several studies have independently evaluated the occurrence of hepatitis E virus (HEV) and enteroparasites in swine, but no surveys have been conducted to jointly assess the prevalence and genetic diversity of enteroparasites in pigs and wild boars, their sympatric transmission between hosts, and their potential interaction with HEV.

METHODS

We prospectively collected serum and faecal samples from black Iberian domestic pigs and wild boars from southern Spain between 2015‒2016. We evaluated for HEV in serum and faeces, and for the presence of enteroparasites (Giardia duodenalis, Cryptosporidium spp., Blastocystis sp., Neobalantidium coli and Strongyloides spp.) in the same faecal samples. The prevalence of each intestinal parasite species was calculated.

RESULTS

A total of 328 animals (56.7% black Iberian pigs and 43.3% wild boars) were included in the study. The overall global prevalence of HEV in serum was 16.8%. The overall global prevalence of each enteroparasite species was 19.5% for G. duodenalis, 8.2% for Cryptosporidium spp., 41.8% for Blastocystis sp., 31.4% for N. coli, and 8.8% for Strongyloides spp. HEV-infected animals showed a significantly lower prevalence of G. duodenalis (3.2 vs 20%; P = 0.002) and Blastocystis sp. (38.7 vs 80%; P < 0.001) than those uninfected by HEV. Animals carrying G. duodenalis and Blastocystis sp. infections showed a significantly lower rate of HEV infection than those not harbouring these enteroparasites (P < 0.001).

CONCLUSIONS

Our study found a high prevalence of enteroparasites in black Iberian pigs and wild boars in southern Spain, suggesting a sympatric co-transmission of some of the species investigated. It is suggested that extracellular G. duodenalis and Blastocystis sp. might have a protective effect on HEV acquisition in swine.

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.

Prevalence of anti-hepatitis E virus IgG antibodies in sera from hemodialysis patients in Tripoli, Lebanon

Hepatitis E virus (HEV) is an important global public health concern. Several studies reported a higher HEV prevalence in patients undergoing regular hemodialysis (HD). In Lebanon, the epidemiology of HEV among HD patients has never been investigated previously. In this study, we examine the seroprevalence of HEV infection among 171 HD patients recruited from three hospital dialysis units in Tripoli, North Lebanon. Prevalence of anti-HEV IgG antibodies was evaluated in participant's sera using a commercial enzyme-linked immunosorbent assay (ELISA). The association of socio-demographic and clinical parameters with HEV infection in patients was also evaluated. Overall, 96 women and 75 men were enrolled in this study. Anti-HEV IgG antibodies were found positive in 37/171 HD patients showing a positivity rate of 21.63%. Among all examined variables, only the age of patients was significantly associated with seropositivity (P = 0.001). This first epidemiological study reveals a high seroprevalence of HEV infection among Lebanese HD patients. However, further evaluations that enroll larger samples and include control groups are required to identify exact causative factors of the important seropositivity rate in this population.

Hepatitis E virus outbreak associated with rainfall in the Central African Republic in 2008-2009

BACKGROUND

Infection by hepatitis E virus (HEV) can cause a high burden of morbidity and mortality in countries with poor access to clean water and sanitation. Our study aimed to investigate the situation of HEV infections in the Central African Republic (CAR).

METHODS

A retrospective analysis of the blood samples and notification forms collected through the national yellow fever (YF) surveillance program, but for which a diagnosis of YF was discarded, was carried out using an anti-HEV IgM ELISA and a HEV-specific RT-PCR.

RESULTS

Of 2883 YF-negative samples collected between January 2008 and December 2012, 745 (~ 26%) tested positive by at least either of the 2 tests used to confirm HEV cases. The results revealed that the CAR was hit by a large HEV outbreak in 2008 and 2009. The results also showed a clear seasonal pattern with correlation between HEV incidence and rainfall in Bangui. A phylogenetic analysis showed that the circulating strains belonged to genotypes 1e and 2b.

CONCLUSIONS

Overall, this study provides further evidences that HEV can be a significant cause of acute febrile jaundice, particularly among adults during rainy season or flood, in a country from Sub-Saharan Africa.

Time course alterations of virus sequences and immunoglobulin titers in a chronic hepatitis E patient

AIM

Hepatitis E virus (HEV) can cause chronic infection in immunocompromised hosts. However, the dynamics of HEV during persistent infection is not well understood. To elucidate time course alterations in virus sequences and anti-HEV antibodies during persistent infection, we analyzed the HEV sequences and titers of anti-HEV antibodies from a chronic hepatitis E patient.

METHODS

Serum samples were obtained from a chronic hepatitis E patient under corticosteroid therapy for neurological disease. The titers of anti-HEV antibodies (immunoglobulin A, immunoglobulin M, and immunoglobulin G) in serum samples were detected by enzyme immunoassay. The full or near-full nucleotide sequences of HEV isolated from consecutive serum samples were identified and compared. Phylogenetic analysis was also performed.

RESULTS

Alterations of anti-HEV antibodies from a chronic hepatitis E patient were different from those previously reported in acute hepatitis E patients. The virus sequence was unchanged in the period without treatment, but nucleotide mutations were observed after ribavirin treatment was started. In addition, the sequence of this strain had extremely high identity to that isolated from swine liver in Japan.

CONCLUSIONS

Virus mutations in HEV emerged after ribavirin treatment was started. Sequence analysis may useful for deciding the treatment strategy for chronic hepatitis E patients who did not eliminate the virus with 3 months of RBV treatment and inferring the origin of the infection. This report provides insights into the chronicity of hepatitis E, and the impact of persistent infection and ribavirin treatment on the emergence of virus mutations.

Poor Outcomes of Acute Hepatitis E in Patients With Cirrhotic Liver Diseases Regardless of Etiology

Background: Chronic liver diseases (CLDs) have been documented to exacerbate clinical outcomes of acute hepatitis E (AHE). This study aimed to uncover the role of etiology and status of CLD in the adverse outcomes of AHE. We found that superinfection with hepatitis E virus (HEV) in patients with cirrhotic CLD can cause a worsen outcome, leading to exacerbation of AHE, compared with HEV-infected patients without CLD or with noncirrhotic CLD. Additional analysis revealed that the etiology of CLD is not associated with outcomes of AHE patients. These finding suggests that the overall liver status plays a predominant role in determining the outcomes of AHE.

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 virus-associated Guillain-Barre syndrome: Revision of the literature

INTRODUCTION

The association between preceding infection of hepatitis E virus (HEV) and Guillain-Barre syndrome (GBS) has been found for more than a decade, while hepatitis E virus-associated Guillain-Barre syndrome (HEV-associated GBS) still remains poorly understood. Initially discovered in 2000, the association between GBS and HEV has been focused by neurologists increasingly. Five percent of patients with GBS had preceding acute HEV infection in the Netherlands and higher rate was found in Bangladesh (11%) where HEV is endemic.

METHOD

An extensive review of relevant literature was undertaken.

RESULTS

Hepatitis E virus infection may induce GBS via direct viral damage according to recent research findings. On the other hand, the presence of antiganglioside GM1 or GM2 antibodies in serum of some HEV-associated GBS patients indicates that HEV infection may trigger GBS by activating autoimmune response to destroy myelin or axon mistakenly. Management of HEV-associated GBS has no obvious difference from GBS. It mainly consists of supportive therapy and immunotherapy. Intravenous immunoglobulin (IVIG) or plasma exchange (PLEX) was used in most reported cases, which is the main strategy for clinical treatment of HEV-associated GBS. Whether antiviral therapy could be additional strategy other than the routine therapy to shorten the length of disease course is one of the most urgent problems and requires further study.

CONCLUSIONS

An overview of possible pathogenesis will gain a first insight into why HEV, traditionally recognized as only hepatotropic, can induce many neurological disorders represented by GBS. Moreover, understanding of the underlying mechanisms may contribute to development of a novel therapeutic strategy. This review also summarizes management and clinical characteristics of HEV-associated GBS, aiming to achieve early recognition and good recovery.