Seroreactivity to hepatitis E virus in areas where the disease is not endemic

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

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

Higher Risk of HEV Transmission and Exposure among Blood Donors in Europe and Asia in Comparison to North America: A Meta-Analysis

Background and aims: The increasing number of diagnosed hepatitis E virus (HEV) infections in Europe has led to the implementation of the testing of blood products in various countries. Many nations have not yet implemented such screening. To assess the need for HEV screening in blood products worldwide, we conducted a systematic review and meta-analysis assessing HEV RNA positivity and anti-HEV seroprevalence in blood donors. Methods: Studies reporting anti-HEV IgG/IgM or HEV RNA positivity rates among blood donors worldwide were identified via predefined search terms in PubMed and Scopus. Estimates were calculated by pooling study data with multivariable linear mixed-effects metaregression analysis. Results: A total of 157 (14%) of 1144 studies were included in the final analysis. The estimated HEV PCR positivity rate ranged from 0.01 to 0.14% worldwide, with strikingly higher rates in Asia (0.14%) and Europe (0.10%) in comparison to North America (0.01%). In line with this, anti-HEV IgG seroprevalence in North America (13%) was lower than that in Europe (19%). Conclusions: Our data demonstrate large regional differences regarding the risk of HEV exposure and blood-borne HEV transmission. Considering the cost–benefit ratio, this supports blood product screening in high endemic areas, such as Europe and Asia, in contrast to low endemic regions, such as the U.S.

Immunobiology and Host Response to HEV

Hepatitis E virus (HEV) usually causes acute self-limiting hepatitis but sometimes leads to chronic infection in immunocompromised persons. HEV is not directly cytopathic. Immunologically mediated events after HEV infection are believed to play important roles in the pathogenesis and clearance of infection. The anti-HEV antibody responses have been largely clarified since the determination of major antigenic determinant of HEV, which is located in the C-terminal portion of ORF2. This major antigenic determinant also forms the conformational neutralization epitopes. Robust anti-HEV immunoglobulin M (IgM) and IgG responses usually develop 3-4 weeks after infection in experimentally infected nonhuman primates. In humans, potent specific IgM and IgG responses occur in the very early phase of the disease and are critical in eliminating the virus, in concert with the innate and adaptive T-cell immune responses. Testing anti-HEV IgM is valuable in the diagnosis of acute hepatitis E. The long-term persistence and protection of anti-HEV IgG provide the basis for estimating the prevalence of HEV infection and for the development of a hepatitis E vaccine. Although human HEV has four genotypes, all the viral strains are considered to belong to a single serotype. It is becoming increasingly clear that the innate and adaptive T-cell immune responses play critical roles in the clearance of the virus. Potent and multispecific CD4+ and CD8+ T cell responses to the ORF2 protein occur in patients with acute hepatitis E, and weaker HEV-specific CD4+ and CD8+ T cell responses appear to be associated with chronic hepatitis E in immunocompromised individuals.

Epidemiology and Risk Factors for Acute Viral Hepatitis in Bangladesh: An Overview

Viral infections by hepatotropic viruses can cause both acute and chronic infections in the liver, resulting in morbidity and mortality in humans. Hepatotropic viruses, including hepatitis A virus (HAV), hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis D virus (HDV), and hepatitis E virus (HEV), are the major pathogens that cause acute and chronic infections in humans. Although all of these viruses can cause acute hepatitis in humans, HAV and HEV are the predominant causative agents in Bangladesh, where the occurrence is sporadic throughout the year. In this review, we provide an overview of the epidemiology of hepatotropic viruses that are responsible for acute hepatitis in Bangladesh. Additionally, we focus on the transmission modes of these viruses and the control and prevention of infections.

Seroprevalence of hepatitis E virus infection in the Americas: Estimates from a systematic review and meta-analysis

Background

Hepatitis E virus (HEV) infection is responsible for inflammatory liver disease and can cause severe health problems. Because the seroprevalence of HEV varies within different population groups and between regions of the continent, we conducted a systematic review on the topic in order to provide evidence for targeted prevention strategies.

Methods

We performed a systematic review in PubMed, SCIELO, LILACS, EBSCO, and Cochrane Library and included reports up to 25 May 2021 (PROSPERO registration number: CRD42020173934). We assessed the risk of bias, publication bias, and heterogeneity between studies and conducted a random-effect meta-analysis for proportions using a (binomial-normal) generalized linear mixed model (GLMM) fitted by Maximum Likelihood (ML). We also reported other characteristics like genotype and risk factors.

Results

Of 1212 identified records, 142 fulfilled the inclusion criteria and were included in the qualitative analysis and 132 in the quantitative analysis. Our random-effects GLMM pooled overall estimate for past infection (IgG) was 7.7% (95% CI 6.4%–9.2%) with high heterogeneity (I2 = 97%). We found higher seroprevalence in certain population groups, for example in people with pig related exposure for IgG (ranges from 6.2%–28% and pooled estimate of 13.8%, 95% CI: 7.6%–23.6%), or with diagnosed or suspected acute viral hepatitis for IgM (ranges from 0.3%–23.9% and pooled estimate of 5.5%, 95% CI: 2.0%–14.1%). Increasing age, contact with pigs and meat products, and low socioeconomic conditions are the main risk factors for HEV infection. Genotype 1 and 3 were documented across the region.

Conclusion

HEV seroprevalence estimates demonstrated high variability within the Americas. There are population groups with higher seroprevalence and reported risk factors for HEV infection that need to be prioritized for further research. Due to human transmission and zoonotic infections in the region, preventive strategies should include water sanitation, occupational health, and food safety.

Risk of Hepatitis E among Persons Who Inject Drugs in Hong Kong: A Qualitative and Quantitative Serological Analysis

Hepatitis E virus (HEV) is an important cause of hepatitis, which can be transmitted via the bloodborne route. However, risk of hepatitis E among persons who inject drugs (PWIDs) is poorly understood. This study aimed to elucidate whether PWIDs are at risk for hepatitis E. We performed HEV IgM, IgG and nucleic acid detection on a cohort of 91 PWIDs and 91 age- and sex-matched organ donors. Blood HEV IgG was measured using the WHO HEV antibody standard. The effects of age, gender and addictive injection use on HEV serostatus and concentration were assessed. HEV IgG seroprevalence was 42/91 (46.2%) in the PWID group and 20/91 (22%) in the donor group (odds ratio = 3.04 (1.59–5.79), p = 0.0006). The median HEV IgG concentration was 5.8 U/mL (IQR: 2.5–7.9) in the PWID group and 2.1 U/mL (IQR: 1.2–5.3) in the donor group (p = 0.005). Increasing age and addictive injection use were significantly associated with HEV IgG serostatus, but only addictive injection use was associated with HEV IgG concentration (p = 0.024). We conclude that PWIDs are at increased risk for hepatitis E and are prone to repeated HEV exposure and reinfection as indicated by higher HEV IgG concentrations.

Enterically Transmitted Non-A, Non-B Hepatitis and the Discovery of Hepatitis E Virus

The recognition of hepatitis E as a discreet disease entity in the late 1970s followed the development of serological tests for hepatitis A and the discovery that large waterborne outbreaks of hepatitis in India were not caused by hepatitis A virus (HAV). These "enterically transmitted non-A, non-B hepatitis" outbreaks had distinctive epidemiologic features, including the highest attack rates among young adults, little secondary household transmission of infection, and severe disease in pregnant women. The responsible agent, hepatitis E virus (HEV), was identified several years later in extracts of feces from a self-inoculated virologist. Multiple genetically related HEV genotypes are now known to exist, two of which are common in domestic swine herds and the cause of sporadic cases of acute hepatitis in economically well-developed countries. HEV genotypes possess impressive genetic and biologic diversity, and present many unanswered questions concerning their natural host range, potential for zoonotic transmission, and disease pathogenesis.

Hepatitis E virus seroprevalence and determinants in various study populations in the Netherlands

BACKGROUND

The epidemiology of hepatitis E virus (HEV) is not fully understood. In this study, we assessed putative risk factors for HEV seropositivity in various study populations in the Netherlands.

METHODS

Data and samples from five different study populations were analysed: (A) blood donors (n = 5,239), (B) adults reporting a vegetarian life style since the age of 12 years (n = 231), (C) residents of Amsterdam, the Netherlands, with different ethnic backgrounds (n = 1,198), (D) men who have sex with men (MSM) (HIV positive and HIV negative) (n = 197), and (E) persons who use drugs (PWUD) (HIV positive and HIV negative) (n = 200). Anti-HEV immunoglobulin M (IgM) and immunoglobulin G (IgG) testing was performed using ELISA test (Wantai).

RESULTS

HEV IgM seroprevalence was low across all study populations (<1% to 8%). The age and gender-adjusted HEV IgG seroprevalence was 24% among blood donors (reference group) and 9% among the vegetarian group (adjusted Relative Risk [aRR]:0.36, 95%CI:0.23-0.57). Among participants of different ethnic backgrounds, the adjusted HEV IgG seroprevalence was 16% among participants with a Dutch origin (aRR:0.64, 95%CI:0.40-1.02), 2% among South-Asian Surinamese (aRR:0.07, 95%CI:0.02-0.29), 3% among African Surinamese (aRR:0.11, 95%CI:0.04-0.34), 34% among Ghanaian (aRR:1.53, 95%CI:1.15-2.03), 19% among Moroccan (aRR:0.75, 95%CI:0.49-1.14), and 5% among Turkish (aRR:0.18, 95%CI:0.08-0.44) origin participants. First generation Moroccans had a higher risk for being IgG HEV seropositive compared to second generation Moroccan migrants. The statistical power to perform these analyses in the other ethnic groups was too low. In the MSM group the IgG HEV seroprevalence was 24% (aRR:0.99, 95%CI:0.76-1.29), and among PWUD it was 28% (aRR:1.19, 95%CI:0.90-1.58). The number of sexual partners in the preceding six months was not significantly associated with IgG HEV seropositivity in MSM. The association between HIV status and HEV seropositivity was significant in PWUD, yet absent in MSM. HIV viral load and CD4 cell count were not associated with HEV seropositivity in HIV positive MSM and PWUD.

CONCLUSIONS

Vegetarians were significantly less often HEV seropositive. Ethnic origin influenced the risk for being IgG HEV seropositive. MSM and PWUD were not at higher risk for being IgG HEV seropositive than blood donors.

Vaccine Development against Zoonotic Hepatitis E Virus: Open Questions and Remaining Challenges

Hepatitis E virus (HEV) is a fecal-orally transmitted foodborne viral pathogen that causes acute hepatitis in humans and is responsible for hepatitis E outbreaks worldwide. Since the discovery of HEV as a zoonotic agent, this virus has been isolated from a variety of hosts with an ever-expanding host range. Recently, a subunit HEV vaccine developed for the prevention of human disease was approved in China, but is not yet available to the rest of the world. Meanwhile, notable progress and knowledge has been made and revealed in recent years to better understand HEV biology and infection, including discoveries of quasi-enveloped HEV virions and of a new function of the HEV-ORF3 product. However, the impact of these new findings on the development of a protective vaccine against zoonotic HEV infection requires further discussion. In this review, hallmark characteristics of HEV zoonosis, the history of HEV vaccine development, and recent discoveries in HEV virology are described. Moreover, special attention is focused on quasi-enveloped HEV virions and the potential role of the HEV-ORF3 product as antibody-neutralization target on the surface of quasi-enveloped HEV virions to provide new insights for the future development of improved vaccines against zoonotic HEV infection.

Hepatitis E prevalence in a sexual high-risk population compared to the general population

Transmission routes of the hepatitis E virus (HEV) are under debate. Here, we studied possible sexual transmission by comparing HEV prevalence in a Dutch sexual high-risk population (n = 1,482) with that in a general population (n = 1,487) while assessing sociodemographic and sexual risk factors. Overall prevalence of anti-HEV IgG of 18.9% (n = 562) was, adjusting for confounders, similar between the two populations (p = 0.44). Prevalence was higher with each year's increase in age (adjusted OR: 1.03, 95%CI: 1.02-1.04, p<0.01), among men (adjusted OR: 1.24, 95%CI: 1.02-1.50, p = 0.03) and among individuals diagnosed with sexually transmitted infections (adjusted OR: 1.60, 95%CI: 1.02-2.49, p = 0.04). Our results only hint at the possibility of a sexual transmission route for HEV given higher rates in those with chlamydia and/or gonorrheal infections. Sexual transmission is not a dominant transmission route, as its prevalence was not higher for the sexual high-risk population than for the general population.

Zoonotic Hepatitis E Virus: An Ignored Risk for Public Health

Hepatitis E virus (HEV) is a quasi-enveloped, single-stranded positive-sense RNA virus. HEV belongs to the family Hepeviridae, a family comprised of highly diverse viruses originating from various species. Since confirmation of HEV's zoonosis, HEV-induced hepatitis has been a public health concern both for developing and developed countries. Meanwhile, the demonstration of a broad host range for zoonotic HEV suggests the existence of a variety of transmission routes that could lead to human infection. Moreover, anti-HEV antibody serosurveillance worldwide demonstrates a higher than expected HEV prevalence rate that conflicts with the rarity and sporadic nature of reported acute hepatitis E cases. In recent years, chronic HEV infection, HEV-related acute hepatic failure, and extrahepatic manifestations caused by HEV infection have been frequently reported. These observations suggest a significant underestimation of the number and complexity of transmission routes previously predicted to cause HEV-related disease, with special emphasis on zoonotic HEV as a public health concern. Significant research has revealed details regarding the virology and infectivity of zoonotic HEV in both humans and animals. In this review, the discovery of HEV zoonosis, recent progress in our understanding of the zoonotic HEV host range, and classification of diverse HEV or HEV-like isolates from various hosts are reviewed in a historic context. Ultimately, this review focuses on current understanding of viral pathogenesis and cross-species transmission of zoonotic HEV. Moreover, host factors and viral determinants influencing HEV host tropism are discussed to provide new insights into HEV transmission and prevalence mechanisms.

Risk Factors Associated with Blood Exposure for Sporadic Hepatitis E in Dhaka, Bangladesh

Fecal contamination of drinking water is associated with large hepatitis E virus (HEV) outbreaks of genotypes 1 and 2 in endemic areas. Sporadic transmission of HEV genotypes 3 and 4 in high-income countries has been associated with exposure to blood and animal contact. The objective of the study was to identify the risk factors for hepatitis E and the genotype(s) causing sporadic hepatitis E in Dhaka, Bangladesh. We selected, from a diagnostic center in Dhaka between November 2008 and November 2009, cases presenting with jaundice and anti-HEV IgM antibodies and age-matched controls were defined as those with no history of jaundice and normal blood test results. Serum samples were tested for HEV RNA using real-time reverse transcriptase polymerase chain reaction followed by a sequencing and phylogenetic analysis. A total of 109 cases and 109 controls were enrolled. The cases were more likely to be male (adjusted matched odds ratios [mOR] 2.2, 95% CI: 1.2-3.9; P = 0.01), or have reported contact with another person's blood or blood product, or contact with blood-contaminated sharp instruments (adjusted mOR 2.1, 95% CI: 1.1-4.1; P = 0.03) than controls. There were no significant differences between the cases and the controls in terms of reported high-risk sexual intercourse, consumption of undercooked meat, or contact or drinking fecally-contaminated water. The sera from three cases carried HEV RNA, all belonging to genotype 1. Findings from this study suggest that contact with human blood and sharing sharp instruments may transmit sporadic hepatitis E in Dhaka, Bangladesh. Efforts to prevent the transmission of blood-borne pathogens may also prevent sporadic HEV transmission in this endemic setting.

Immunobiology and Host Response to HEV

Hepatitis E virus (HEV) causes acute self-limiting hepatitis in most cases and chronic infection in rare circumstances. It is believed to be noncytopathic, so immunologically mediated events should play important roles in its pathogenesis and infection outcomes. The anti-HEV antibody response was clarified when the major antigenic determinants on the ORF2 polypeptide were determined, which are located in its C-terminal portion. This subregion also forms the conformational neutralization epitopes. Robust anti-HEV immunoglobulin M (IgM) and IgG responses usually develop 3-4 weeks after infection in experimentally infected nonhuman primates. In humans, potent specific IgM and IgG responses occur in the very early phase of the disease and are critical in eliminating the virus, in concert with the innate and adaptive T-cell immune responses. They are also very valuable in the diagnosis of acute hepatitis E, when patients are tested for both anti-HEV IgM and IgG. The long-term persistence and protection of anti-HEV IgG provide the basis for estimating the prevalence of HEV infection and for the development of a hepatitis E vaccine. Although HEV has four genotypes, all the viral strains are considered to belong to a single serotype. It is becoming increasingly clear that the innate and adaptive T-cell immune responses play critical roles in the clearance of the virus. Potent and multispecific CD4⁺ and CD8⁺ T-cell responses to the ORF2 protein occur in patients with acute hepatitis E, and weaker HEV-specific CD4⁺ and CD8⁺ T-cell responses appear to be associated with chronic hepatitis E in immunocompromised individuals.

Hepatitis E: the current state of play

The hepatitis E virus (HEV) is a major cause of acute hepatitis globally. Genotypes 1 and 2 (G1 and G2) are obligate human pathogens transmitted faeco-orally, leading to epidemics in developing countries. In contrast, genotypes 3 and 4 (G3 and G4) have a wider host range, including humans, but are primarily porcine viruses and are transmitted from animals to humans as a food-borne zoonosis when meat from an infected animal is consumed. HEV is increasingly recognised as a problem in developed countries, including countries in Europe. G3 HEV is now the most common cause of acute viral hepatitis in the UK and cases continue to rise. The majority of these infections are acquired within the UK and thought to be from insufficiently cooked meat, predominantly processed pork meat. Previously thought to only cause self-limiting disease, HEV infection can persist in immunosuppressed patients, which may lead to chronic hepatitis and the rapid development of cirrhosis. Of particular interest to the transfusion community has been the possibility of transfusion-transmitted HEV, which has been reported from countries classically considered HEV-endemic but also non-endemic countries in Europe and Japan. This has prompted some countries to introduce screening for HEV in blood donations.

Seroepidemiology of HEV and HAV in two populations with different socio-economic levels and hygienic/sanitary conditions

The epidemiological scenarios of hepatitis E virus (HEV) and hepatitis A virus (HAV) infections have changed in the last few decades, but precise epidemiological data on the prevalence of anti-HEV and anti-HAV, alone or in combination, in the general population are scanty. We investigated HEV and HAV seroprevalence comparing two population samples living in Northern (Abbiategrasso, Milan) and Southern Italy (Cittanova, Reggio Calabria), the latter being characterized by a poorer socio-economic level and hygienic/sanitary conditions. Based on census records, we randomly enrolled and tested 3,365 subjects (Abbiategrasso, n = 2,489; Cittanova, n = 876) aged 18-75 years for anti-HAV and anti-HEV. Anti-HAV (71.3 % vs 52.5 %) and anti-HEV (17.8 % vs 9.0 %) prevalence rates were higher in Southern Italy (both p < 0.001). Most anti-HEV-positive subjects also had anti-HAV. Subjects testing positive for anti-HAV, alone or with anti-HEV, were older (p < 0.001 in both populations) and showed a trend toward declining prevalence in the youngest birth cohorts. The prevalence of subjects with a positive result for anti-HEV alone did not change in birth cohorts in the two towns. Detection of anti-HEV was independently associated with anti-HAV, town, birth cohort, and education level in multivariate analysis. Low socio-economic level and hygienic/sanitary conditions are associated with high HAV and HEV seroprevalence rates in Italy. Recent improvements, especially in the South, have led to a declining prevalence of anti-HAV, alone or with anti-HEV. Seroprevalence of HEV alone is uniformly low and does not change in birth cohorts born between 1938 and 1993.

Binding Preference of Anti-HEV Antibodies in Sera Collected in Algeria for Antigens Derived From HEV Genotype 1‏

BACKGROUND

Two hepatitis E virus (HEV) outbreaks occurred in Algeria (1979 - 1980 and 1987 - 1988). However, to date, no study on the prevalence of anti-HEV antibodies has been conducted in Algeria, and the genotype of the circulating strains remains unclear.

OBJECTIVES

This study was conducted to investigate the presence of anti- HEV antibodies among outpatients and blood donors in three different hospitals in Northern Algeria and to determine the genotype of the circulating strains through the characterization of the immunoreactivity of anti-HEV antibodies.

METHODS

A total of 590 blood samples (379 from blood donors and 211 from outpatients) were collected in three health facilities in Northern Algeria and assessed for anti-HEV antibodies using an in-house double-antigen sandwich immunoassay. HEV open reading frame 2 recombinant proteins p166 (aa 452 - 617) generated from the four HEV genotypes were used as antigens. The genotype of the strains circulating in Algeria was predicted by an indirect ELISA by assessing the anti-HEV antibodies in serially diluted positive sera using the different p166 proteins.

RESULTS

Anti-HEV antibodies were detected in 20.17% of the samples. A significant correlation was found between the age of the subjects and the presence of anti-HEV antibodies (P < 0.001). Among blood donors, 83 (21.9%) were diagnosed positive for anti-HEV antibodies with two cases weakly positive for anti-HEV IgM antibodies. Moreover, 9.9% of the subjects aged less than 25 years old (born after the last HEV outbreak) were positive for anti-HEV antibodies. The indirect ELISA revealed that the anti-HEV antibodies within the positive sera reacted more strongly against the p166 antigens generated from genotype 1.

CONCLUSIONS

The present findings reveal a relatively high presence of anti-HEV IgGs and clearly indicate that HEV infection is still present in Northern Algeria. Further, the prediction of HEV genotype using different antigens generated from the different HEV genotypes shows that the causative strains are more likely to be of genotype 1.

Acute and Chronic Hepatitis E Virus Infection in Human Immunodeficiency Virus-Infected U.S. Women

Exposure to hepatitis E virus (HEV) is common in the United States, but there are few data on prevalence of HEV/human immunodeficiency virus (HIV) coinfection in U.S.

POPULATIONS

We tested 2,919 plasma samples collected from HIV-infected (HIV(+)) women and men enrolled in U.S. cohort studies for HEV viremia using a high-throughput nucleic acid testing (NAT) platform. NAT(+) samples were confirmed by real-time polymerase chain reaction. Samples were selected for testing primarily on the basis of biomarkers of liver disease and immune suppression. Prevalence of HEV viremia was 3 of 2,606 and 0 of 313 in tested plasma samples collected from HIV(+) women and men, respectively. All HEV isolates were genotype 3a. Based on follow-up testing of stored samples, 1 woman had chronic HEV infection for >4 years whereas 2 women had acute HEV detectable at only a single study visit.

CONCLUSIONS

To our knowledge, this is the first reported case of chronic HEV infection in an HIV(+) U.S. individual. We also confirm that chronic HEV infection can persist despite a CD4(+) count >200 cells/mm(3). Overall, though, these data suggest that HEV infection is rare in the HIV(+) U.S. population.

Emerging and Rare Viral Infections in Transplantation

Immunocompromised patients such as those undergoing solid organ or hematopoietic stem cell transplantation are at substantial risk for infection with numerous pathogens. Infections with cytomegalovirus (CMV), herpes simplex virus (HSV), Epstein–Barr virus (EBV), and human herpesvirus-6 (HHV-6) are well-described complications of transplantation. As viruses previously believed to be quiescent through widespread vaccination (e.g., measles and mumps) reemerge and molecular diagnostic techniques are refined, rare and emerging viral infections are increasingly diagnosed in transplant recipients. This chapter will review the clinical manifestations, diagnosis, and potential antiviral therapies for these viruses in the transplant population.

Local outbreak of hepatitis E: a rare cause of viral hepatitis in Australia

Hepatitis E is a not uncommon cause of viral hepatitis globally but is relatively rare in Australia. Here, we report a case of acute hepatitis E that was acquired in Sydney and was part of a cluster believed to be infected locally. This is to our knowledge the first known outbreak of locally acquired hepatitis E in Australia. We discuss pathogenesis, clinical features and means by which further spread of infection can be limited.

Prevalence and clinical consequences of Hepatitis E in patients who underwent liver transplantation for chronic Hepatitis C in the United States

Background

Infection with hepatitis E virus (HEV) in immunocompromised patients can lead to severe liver disease. Treatment options for HEV include peginterferon or ribavirin, routinely also used for the treatment of hepatitis C virus (HCV) infection.

We determined the prevalence and clinical consequences of HEV in United States (US) based patients who underwent liver transplantation (LT) for chronic HCV.

Methods

Seroprevalence of HEV in 145 US LT recipients with a history of chronic HCV was determined pre-LT, 1, 3 and 5 years post-LT. All last available samples and all samples in IgM positive patients and post-LT IgG seroconverters were tested for HEV RNA.

Results

Overall anti-HEV seroprevalence was 42 %. Five patients were HEV IgM positive pre-LT, one patient had IgM seroconversion post-LT and eight patients had IgG seroconversion post-LT. None of the tested samples were positive for HEV RNA. Eight out of nine of the post-LT seroconverters had been treated for HCV recurrence before or at the moment of seroconversion.

Conclusions

LT recipients in the US are at risk of acquiring HEV. Post-LT HCV treatment with interferons and/or ribavirin may have protected patients against chronic HEV. With the arrival of new direct antiviral agents for the treatment of HCV and the elimination of peginterferon and ribavirin from HCV treatment regimens, the prevalence of chronic HEV in this population may rise again.

Anti-Hepatitis E Antibody in Hemodialysis Patients in Isfahan, Iran: Prevalence and Risk Factors

BACKGROUND

Many studies have been performed regarding the prevalence of hepatitis E in the general population, but there is controversial evidence for an increased risk of the infection in patients on maintenance hemodialysis (HD).

OBJECTIVES

The primary end point of the present study was to determine if the prevalence of anti-hepatitis E virus IgG (anti-HEV IgG) is higher in patients on maintenance HD than in the normal population in Isfahan.

PATIENTS AND METHODS

In a case-control study performed in Isfahan in June 2012, we compared the seroprevalence of HEV among 274 patients on maintenance HD and 275 otherwise healthy individuals. The patients were recruited from 3 HD centers in Isfahan. Anti-HEV IgG was detected using a Dia Pro Diagnostic HEV enzyme immunoassay (ELISA) kit. Demographic and clinical data (sex, age, blood transfusion history, HD duration, age at HD initiation, and evidence of hepatitis B and hepatitis C infections) were obtained from the medical records of the HD patients.

RESULTS

Anti-HEV IgG was detected in 27 (9.9%) controls and 78 (28.3%) patients, with the difference being statistically significant (P < 0.05). Furthermore, there was a significant association between positive anti-HEV antibody, HD duration, and blood transfusion history in the HD patients.

CONCLUSIONS

Considering the results, it seems necessary to conduct prospective studies in order to identify factors responsible for the high seroprevalence of HEV in Isfahan HD units.

Current Knowledge on Hepatitis E

Although only a single serotype of hepatitis E virus (HEV), the causative agent of hepatitis E, has been identified, there is great genetic variation among the different HEV isolates reported. There are at least four major recognized genotypes of HEV: genotypes 1 and 2 are mainly restricted to humans and linked to epidemic outbreaks in nonindustrialized countries, whereas genotypes 3 and 4 are zoonotic in both developing and industrialized countries. Besides human strains, genotype 3 and 4 strains of HEV have been genetically characterized from swine, sika deer, mongooses, sheep, and rabbits. Currently, there are approximately 11,000 human and animal sequences of HEV available at the International Nucleotide Sequence Database Collaboration. HEV is the major cause of waterborne outbreaks of hepatitis in areas of poor sanitation. Additionally, it is responsible for sporadic cases of viral hepatitis in not only endemic but industrialized countries as well. Transmission of HEV occurs predominantly by the fecal-oral route, although parenteral and perinatal routes have been reported. HEV infection develops in most individuals as a self-limiting, acute, icteric hepatitis; with mortality rates around 1%. However, some affected individuals will develop fulminant hepatic failure, a serious condition that is frequently fatal without a liver transplant. This complication is particularly common when the infection occurs in pregnant women, where mortality rates rise dramatically to up to 25%. Among the preventive measures available to avoid HEV infection, two separate subunit vaccines containing recombinant truncated capsid proteins of HEV have been shown to be highly effective in the prevention of disease. One of them, HEV 239, was approved in China, and its commercialization by Innovax began in November 2012 under the name Hecolin(®).

A novel linear neutralizing epitope of hepatitis E virus

Hepatitis E virus (HEV) is a serious public health problem that causes acute hepatitis in humans and is primarily transmitted through fecal and oral routes. The major anti-HEV antibody responses are against conformational epitopes located in a.a. 459-606 of HEV pORF2. All reported neutralization epitopes are present on the dimer domain constructed by this peptide. While looking for a neutralizing monoclonal antibody (MAb)-recognized linear epitope, we found a novel neutralizing linear epitope (L2) located in a.a. 423-437 of pORF2. Moreover, epitope L2 is proved non-immunodominant in the HEV-infection process. Using the hepatitis B virus core protein (HBc) as a carrier to display this novel linear epitope, we show herein that this epitope could induce a neutralizing antibody response against HEV in mice and could protect rhesus monkeys from HEV infection. Collectively, our results showed a novel non-immunodominant linear neutralizing epitope of hepatitis E virus, which provided additional insight of HEV vaccine.

Current epidemiology of hepatitis E virus infection in the United States: low seroprevalence in the National Health and Nutrition Evaluation Survey

Analysis of the National Health and Nutrition Evaluation Survey (NHANES) 1988-1994 dataset found a relatively high seroprevalence (21%) of hepatitis E virus (HEV) infection in the U.S. general population. Using data obtained within the NHANES 2009-2010 survey, where a high performance assay for HEV was used, we estimated the weighted seroprevalence of HEV infection among U.S. individuals 6 years and older. We also evaluated factors associated with HEV seropositivity. A total of 8,814 individuals were included in the analysis. The median age of study participants was 37 years (interquartile range [IQR] 17-58 years), with 51.2% being female. The weighted national seroprevalence of HEV was 6% (95% confidence interval [CI] 5.1%-6.9%). About 0.5% of those with HEV had evidence of recent exposure (immunoglobulin M-positive). In the univariate analyses, factors associated with HEV seropositivity were increasing age (P-trend<0.001), birth outside of the U.S., Hispanic race, and "meat" consumption (>10 times/month). No significant association was observed with low socioeconomic status, water source, or level of education. In the multivariate analysis, only older age remained predictive of HEV seropositivity.

CONCLUSION

The weighted national seroprevalence of HEV in the U.S. is much less than previously reported. Using data obtained with a high performance assay, the seroprevalence of HEV was estimated at 6.0% in the U.S. Based on these results, the seroprevalence of HEV is only one-third as high as previously reported.

Decline in hepatitis E virus antibody prevalence in the United States from 1988-1994 to 2009-2010

BACKGROUND

Previous population-based estimates in the United States have shown a relatively high prevalence of hepatitis E virus (HEV) antibody. We sought to determine whether changes in the prevalence of HEV antibody have occurred over time.

METHODS

We analyzed data from the 2009-2010 National Health and Nutrition Examination Survey (NHANES) and NHANES III (1988-1994). Using the same serologic assay, we compared the estimated anti-HEV immunoglobulin G (IgG) prevalence and risk factors for antibody positivity for the 2 periods.

RESULTS

The prevalence of HEV antibody among those aged ≥6 years declined from 10.2% (95% confidence interval [CI], 9.1%-11.4%) during 1988-1994 to 6.0% (5.2%-6.8%) during 2009-2010, and the prevalence for those of US birth ranged from 9.6% (8.4%-10.9%) to 5.2% (4.4%-6.2%). Among US-born persons, the estimated HEV antibody prevalence declined significantly for all subgroups of age, sex, region of residence, and number of persons per room in the household; significant declines also were observed for persons at or above poverty level and for persons of non-Hispanic white, non-Hispanic black, and Mexican American race/ethnicity. No clear associations with food consumption were found.

CONCLUSIONS

The anti-HEV prevalence is declining in the United States. Although the decline suggests a decrease in exposure to HEV over time, the risks associated with exposure remain unknown.

Hepatitis viruses and liver transplantation: evolving trends in antiviral management

Viral hepatitis is both a leading indication for liver transplant (LT) and an important cause of posttransplant graft loss and mortality. Treatment and prevention of hepatitis B virus in LT recipients, with the observed corresponding improvement in post-LT outcomes, is among the great success stories in transplantation. By comparison, treatment of hepatitis C virus with safe and effective regimens is only just becoming a reality. Chronic hepatitis E virus infection in LT recipients represents a newly described phenomenon that can also lead to graft loss; early diagnosis and treatment may be key in the management of these patients.

A study of viral hepatitis e infection in a tertiary care hospital in mysore, South India

Background.

 In this study, we aimed to explore the clinical and epidemiological profile of all patients with hepatitis E virus (HEV) who were admitted to a tertiary care hospital in Mysore, India and to further assess various factors that influence the prognosis of these patients.

Methods.

 Two hundred ninety patients with HEV infection were included in the study and interviewed. They were subjected to clinical examination and laboratory investigations, including complete hemogram, renal, and liver function tests. Viral markers for HBV, HAV, HCV, and HEV by hepatitis B surface antigen, anti-HAV, anti-HCV, and anti-HEV antibodies, respectively, were done using the enzyme-linked immunosorbent assay method. Final outcome was recorded in the form of discharge or death.

Results.

 Males had higher (82.8%) incidence of HEV infection. Yellowish discoloration of urine was the most common symptom, and icterus was the most common sign at presentation. Hepatomegaly was most common finding on abdominal examination. Mean duration of hospital stay was higher among diabetics (10 days vs 7.11 ± 3.52 days). Overall, mortality observed was 3.45%. A higher mean age (P = .000) and duration of hospital stay (P = .000) were associated with higher mortality. Mortality was significantly higher among patients with alcohol abuse (25% vs 0%) (P = .004). Higher mean prothrombin time-international normalised ratio (PT-INR) (1.6 ± 0.13 vs 1.21 ± 0.32), total bilirubin (20.3 ± 5.08 vs 11.33 ± 7.26 mg/dL), and direct bilirubin (15.05 ± 3.64 vs 6.35 ± 3.71 mg/dL) were associated with higher mortality, whereas lower mean serum albumin (2.6 ± 0.11 vs 3.41 ± 0.40 gm/dL) was associated with higher mortality. Increase in renal parameters (ie, urea [97 ± 33.48 vs 32.43 ± 18.41 mg/dL] and creatinine [2.9 ± 1.38 vs 1.12 ± 0.64 mg/dL]) and electrolyte imbalances (ie, hyperkalemia [5.95 ± 1.21 vs 4.29 ± 0.51 mmol/L] and hyponatremia [123 ± 3.56 vs 136.04 ± 2.97 mmol/L]) were associated with higher mortality. There were 20-fold increases in mean serum glutamic-oxaloacetic transaminase (SGOT) and serum glutamic-pyruvic transaminase (SGPT) values (SGPT: SGOT = 1.148) and a 1-fold increase in mean alkaline phosphatase.

Conclusions.

 Higher mean age, duration of hospital stay, PT-INR, total bilirubin, direct bilirubin, blood urea, serum creatinine, potassium values, alcohol abuse, presence of ascites, and fulminant hepatitis were associated with higher mortality, whereas lower mean serum albumin and sodium values were associated with higher mortality. Diabetics had a higher mean duration of hospital stay.

Hepatitis E virus among persons who inject drugs, San Diego, California, USA, 2009-2010

Data about prevalence of hepatitis E virus infection in persons who inject drugs are limited. Among 18–40-year-old persons who inject drugs in California, USA, prevalence of antibodies against hepatitis E virus was 2.7%. This prevalence was associated with age but not with homelessness, incarceration, or high-risk sexual behavior.

Hepatitis E virus infections in humans and animals

Hepatitis E has traditionally been considered an endemic disease of developing countries. It generally spreads through contaminated water. However, seroprevalence studies have shown that hepatitis E virus (HEV) infections are not uncommon in industrialized countries. In addition, the number of autochthonous hepatitis E cases in these countries is increasing. Most HEV infections in developed countries can be traced to the ingestion of contaminated raw or undercooked pork meat or sausages. Several animal species, including pigs, are known reservoirs of HEV that transmit the virus to humans. HEVs are now recognized as an emerging zoonotic agent. In this review, we describe the general characteristics of HEVs isolated from humans and animals, the risk factors for human HEV infection, and the current status of human vaccine development.

Hepatitis E virus infection in Latin America: a review

Data reported during recent years reveal the complex picture of the epidemiology of hepatitis E virus (HEV) infection in Latin America. Whereas in countries like Argentina and Brazil is almost identical to the characteristic of most countries from North America and Europe, HEV in the Caribbean and Mexico involves the water-borne, non-zoonotic viral genotypes responsible for epidemics in Asia and Africa. Nevertheless, Latin America has been considered a highly endemic region for hepatitis E in the scientific literature, a generalization that ignores the above complexity. In addition, reports from isolated Amerindian communities, which display well known, important and very specific epidemiological features for hepatitis B and D virus infections are neither taken into account when considering the epidemiology of hepatitis E in the region. This review updates compilation of the available information for the HEV infection, both among humans and other mammals, in Latin America, discusses the strengths and the weaknesses of our current knowledge, and identifies future areas of research.

High occurrence of hepatitis E virus in samples from wastewater treatment plants in Switzerland and comparison with other enteric viruses

Hepatitis E virus (HEV) is responsible for many enterically transmitted viral hepatitides around the world. It is currently one of the waterborne diseases of global concern. In industrialized countries, HEV appears to be more common than previously thought, even if it is rarely virulent. In Switzerland, seroprevalence studies revealed that HEV is endemic, but no information was available on its environmental spread. The aim of this study was to investigate -using qPCR- the occurrence and concentration of HEV and three other viruses (norovirus genogroup II, human adenovirus-40 and porcine adenovirus) in influents and effluents of 31 wastewater treatment plants (WWTPs) in Switzerland. Low concentrations of HEV were detected in 40 out of 124 WWTP influent samples, showing that HEV is commonly present in this region. The frequency of HEV occurrence was higher in summer than in winter. No HEV was detected in WWTP effluent samples, which indicates a low risk of environmental contamination. HEV occurrence and concentrations were lower than those of norovirus and adenovirus. The autochthonous HEV genotype 3 was found in all positive samples, but a strain of the non-endemic and highly pathogenic HEV genotype I was isolated in one sample, highlighting the possibility of environmental circulation of this genotype. A porcine fecal marker (porcine adenovirus) was not detected in HEV positive samples, indicating that swine are not the direct source of HEV present in wastewater. Further investigations will be necessary to determine the reservoirs and the routes of dissemination of HEV.

A cross-sectional study of hepatitis E virus infection in healthy people directly exposed and unexposed to pigs in a rural community in northern Thailand

A cross-sectional study of the association between occupational pig exposure and hepatitis E virus (HEV) infection in adult pig farmers and the general population who were not directly exposed to pigs was conducted in Nan Province, Thailand, from November 2010 to April 2011. All participants were interviewed to provide information on their job history, eating habits and other potential confounders. The prevalence of anti-HEV immunoglobulin G antibodies (IgG) among 513 subjects was 23.0%. Hand washing with water and soap was associated with a lower seroprevalence of HEV infection, whereas living in an area with frequent flooding (OR 1.64, 95% CI: 1.00-2.68) and consuming internal pig organs more than twice per week (OR 3.23, 95%CI: 1.15-9.01) were both associated with a higher seroprevalence of anti-HEV IgG. There was no association between HEV seroprevalence and frequent, direct occupational pig contact.

Phylogenetic analysis of hepatitis e virus in northwest India

Genotyping and subtyping are important to understand epidemiology of the hepatitis E virus so as to improve control measures to prevent transmission of virus in the community. Hence, the aim of the current study was to identify the prevalent HEV genotypes in Rajasthan in acute sporadic hepatitis E cases with varying degree of liver failure. We studied hepatitis E virus (HEV) isolates from hospitalized patients in Rajasthan, western India. In a total of seventeen HEV sequences, six acute viral hepatitis, seven acute liver failure, and 4 acute- on-chronic cases were analyzed. Subtypes 1a and 1c of HEV are prevalent in Northwest India.

Hepatitis E virus genotype 3 in wild rats, United States

The role of rodents in the epidemiology of zoonotic hepatitis E virus (HEV) infection has been a subject of considerable debate. Seroprevalence studies suggest widespread HEV infection in commensal Rattus spp. rats, but experimental transmission has been largely unsuccessful and recovery of zoonotic genotype 3 HEV RNA from wild Rattus spp. rats has never been confirmed. We surveyed R. rattus and R. norvegicus rats from across the United States and several international populations by using a hemi-nested reverse transcription PCR approach. We isolated HEV RNA in liver tissues from 35 of 446 rats examined. All but 1 of these isolates was relegated to the zoonotic HEV genotype 3, and the remaining sequence represented the recently discovered rat genotype from the United States and Germany. HEV-positive rats were detected in urban and remote localities. Genetic analyses suggest all HEV genotype 3 isolates obtained from wild Rattus spp. rats were closely related.

[Hepatitis E. Current perspectives]

Infection with hepatitis E virus (HEV) is highly prevalent in developing countries and the WHO estimates one third of the world population has had contact with the virus. Its diagnosis and epidemiology are well known in endemic countries but, recently, there have been sporadic cases in developed countries in patients with no history of travel. Currently in these countries, hepatitis E is considered a zoonosis yet there remain to be known other routes of transmission. Another interesting aspect is that HEV can cause chronic hepatitis in transplanted patients, other immunocompromised patients and even in immunocompetent people. There have also been reported cases of fulminant hepatitis and other extrahepatic manifestations. The diagnosis is based on serological studies and detection of viral RNA in blood and feces. The vaccine is a good option to prevent this infection that affects a large number of people in deprived geographical areas but unfortunately it is not available yet.

Hepatitis E virus infection in patients infected with the human immunodeficiency virus

Hepatitis E virus (HEV) is a newly-identified causative agent of acute and chronic hepatitis in severely immunocompromized patients. The present study sought to assess the prevalences of past, recent, on-going, and chronic HEV infections in patients infected with human immunodeficiency virus (HIV) in Marseille, South-eastern France, and to determine if they were correlated with the patients' immunological status or with cirrhosis. Anti-HEV IgG and IgM and HEV RNA testing were concurrently performed on the plasma from 184 patients infected with HIV, including 81 with a CD4+ T-lymphocyte count (CD4 count) <50 cells/mm(3) and 32 with a cirrhosis. Prevalence of anti-HEV IgG and IgM was 4.4% (8/184) and 1.6% (3/184), respectively. Past, recent, and on-going infections were observed in 3.3% (6/184), 1.6% (3/184), and 0.5% (1/184) of the patients, respectively. Anti-HEV antibodies prevalence did not differ significantly according to CD4 count, cirrhosis, sex, age, mode of HIV transmission, and infection with hepatitis B or C virus. Anti-HEV IgG seroreversion was observed in two patients. The patient whose plasma tested positive for HEV RNA had a CD4 count <50 cells/mm(3) ; HEV genotype was 3f. In this patient, longitudinal testing showed HEV RNA positivity during a 10-month period, indicating chronic HEV infection; in contrast, anti-HEV IgG never tested positive. Further studies are needed to evaluate the performance of commercial HEV serological assays in patients infected with HIV and to assess the actual incidence, prevalence, and outcome of HEV infection in this special group of patients. HEV RNA testing is necessary for such purposes.

Host risk factors and autochthonous hepatitis E infection

INTRODUCTION

In developed countries autochthonous hepatitis E infection is caused by hepatitis E virus (HEV) genotype 3 or 4 and mainly affects middle aged/elderly men. Host factors might explain why older men develop clinically overt disease.

METHODS

Retrospective review of 53 patients with symptomatic autochthonous hepatitis E infection to determine putative host risk factors. Patients were compared with 564 controls with adjustment for age and sex. Anti-HEV seroprevalence was determined in controls and 189 patients with chronic liver disease.

RESULTS

Mean age of the patients was 62.4 years, 73.6% were men. Compared with controls, patients with hepatitis E were more likely to drink at least 22 U alcohol/week (OR=9.4; 95% confidence interval=3.8-25.0; P<0.001). The seroprevalence of anti-HEV IgG in controls increased with age (P<0.001) but was similar in men and women. There was no association between alcohol consumption and anti-HEV IgG seroprevalence in the control group. There was no difference in the anti-HEV IgG seroprevalence between the controls and patients with chronic liver disease of all aetiologies, but seroprevalence was higher in controls (13.8%) than patients with alcoholic liver disease (4.8%, P=0.04).

CONCLUSION

Clinically apparent hepatitis E infection is more common in individuals who consume at least 22 U alcohol/week. Patients with established chronic alcoholic liver disease have a low seroprevalence compared with controls. The reason for this observation is uncertain, but patients with alcoholic liver disease have clinically severe disease with a high mortality when exposed to HEV. The low seroprevalence in this group may represent a 'culled' population.

Serological diagnostics of hepatitis E virus infection

Development of accurate diagnostic assays for the detection of serological markers of hepatitis E virus (HEV) infection remains challenging. In the course of nearly 20 years after the discovery of HEV, significant progress has been made in characterizing the antigenic structure of HEV proteins, engineering highly immunoreactive diagnostic antigens, and devising efficient serological assays. However, many outstanding issues related to sensitivity and specificity of these assays in clinical and epidemiological settings remain to be resolved. Complexity of antigenic composition, viral genetic heterogeneity and varying epidemiological patterns of hepatitis E in different parts of the world present challenges to the refinement of HEV serological diagnostic assays. Development of antigens specially designed for the identification of serological markers specific to acute infection and of IgG anti-HEV specific to the convalescent phase of infection would greatly facilitate accurate identification of active, recent and past HEV infections.

Hepatitis E virus infection in sheltered homeless persons, France

To determine the prevalence of hepatitis E virus (HEV) infection among sheltered homeless persons in Marseille, France, we retrospectively tested 490 such persons. A total of 11.6% had immunoglobulin (Ig) G and 2.5% had IgM against HEV; 1 person had HEV genotype 3f. Injection drug use was associated with IgG against HEV.

Discovery of hepatitis E: the epidemic non-A, non-B hepatitis 30 years down the memory lane

Hepatitis E was first recognised during an epidemic of hepatitis, which occurred in Kashmir Valley in 1978. The epidemic involved an estimated 52,000 cases of icteric hepatitis with 1700 deaths. The disease had unique clinical and epidemiological features. The epidemic was water-borne with highly compressed epidemic curve. Following the epidemic, secondary waves of hepatitis did not occur. Clinical profile was characterized by cholestasis in around 20% of patients. The disease predominantly occurred in young adults. There was increased incidence and severity of the disease in pregnant women. A subset of patients had distinctive liver histology with bile plugs in the canaliculi and formation of pseudo-ductules by hepatocytes around the bile plugs. All surviving patients had self limiting disease. Sera lacked serological markers of acute hepatitis A and hepatitis B. Based on these data, the possibility of another human hepatitis virus distinct from post-transfusion non-A, non-B hepatitis was postulated. Balayan et al. (1983) successfully transmitted the disease into himself by oral administration of pooled stool extracts of 9 patients from a non-A, non-B hepatitis outbreak which had occurred in a Soviet military camp located in Afghanistan. Reyes et al. (1990) cloned and sequenced hepatitis E virus genome. Over the years, hepatitis E was identified as a major health problem in developing countries with unsafe water supplies and poor sanitary disposal. Data from sero-surveys forced re-evaluation of the epidemiology of hepatitis E and gave an indirect indication to vocationally acquired HEV infections in industrialized countries. Soon, autochthonous hepatitis E was recognised as a clinical problem in such countries. Several animal species especially domestic swine, wild boar and wild deer were found to be reservoirs of hepatitis E virus genotype 3 & 4 in these countries. Human infections occur through intake of uncooked or undercooked meat of the infected animals and pig livers or sausages made from these livers and sold in supermarkets. Chronic hepatitis E resulting in rapidly progressive liver cirrhosis and end stage liver disease was described in organ transplant patients and those with other immunodeficiency states from many European countries. Two recombinant hepatitis E virus vaccines have successfully undergone phase 3 trials.

Clinical characteristics of hepatitis E in a "Non-Endemic" population

Hepatitis E virus (HEV) is a ribonucleic acid (RNA) virus with predominant fecal oral spread. Traditionally in Western Europe it is associated with travel to endemic countries, but an increasing number of locally acquired cases have been reported throughout England. Patients presenting with acute non-travel associated HEV infection in south Wales over a 25-month period were monitored, in an attempt to understand the clinical picture and epidemiology in our patient population. Twenty-four patients were identified with non-travel associated HEV infection and studied prospectively. Patient demographics, symptoms, and serial laboratory results were recorded. There was a male/female ratio of 3:1, with a median patient age of 65.5 years old. Patients developed a significant icteric hepatitis (median peak bilirubin: 139 µmol/L, median peak AST: 1,973 IU/L and ALT: 2,021 IU/L), with liver function remaining abnormal for ∼7 weeks. All patients in whom HEV RNA was isolated were infected with genotype 3. Forty-six percent of patients presented during winter months. The data show a group mortality rate of 4.2%, similar to that reported in endemic countries. HEV results in a severe and occasionally fatal hepatitis. Testing for hepatitis E is now recommended in any patient presenting with acute hepatitis of unknown etiology.

Profile of acute infectious markers in sporadic hepatitis E

Laboratory diagnosis of acute infection of hepatitis E virus (HEV) is commonly based on the detection of HEV RNA, IgM and/or rising IgG levels. However, the profile of these markers when the patients present have not been well determined. To clarify the extent of misdiagnosed sporadic hepatitis E in the initial laboratory detection, serial sera of 271 sporadic acute hepatitis cases were collected, detected and the dynamics of each acute marker during the illness course were analyzed. 91 confirmed cases of hepatitis E were identified based on the presentation of HEV RNA, IgM or at least 4 fold rising of IgG levels. 21 (23.1%) hepatitis E cases were false negative for the viral RNA and 40 (44.0%) for rising IgG, because occurrence of these markers were confined to acute phase of infection and viremia had already subsided and antibody level peaked when these patients presented. IgM was detected in 82 (90.1%) cases. It is the most prevalent of the three markers, because the antibody persisted until early convalescence. Nine cases negative for IgM were positive for rising IgG and one was also positive for the viral RNA; all of these nine cases showed high avid IgG in their acute phase sera, which indicated re-infection. In summary, it is not practicable to determine the true occurrence of sporadic hepatitis E. Nevertheless, it could be closely approximated by approach using a combination of all three acute markers.

Pathogenesis of hepatitis E virus and hepatitis C virus in chimpanzees: similarities and differences

The chimpanzee is the only animal model for investigating the pathogenesis of viral hepatitis types A through E in humans. Studies of the host response, including microarray analyses, have relied on the close relationship between these two primate species: chimpanzee samples are commonly tested with human-based reagents. In this study, the host responses to two dissimilar viruses, hepatitis E virus (HEV) and hepatitis C virus (HCV), were compared in multiple experimentally infected chimpanzees. Affymetrix U133+2.0 human microarray chips were used to assess the entire transcriptome in serial liver biopsies obtained over the course of the infections. Respecting the limitations of microarray probes designed for human target transcripts to effectively assay chimpanzee transcripts, we conducted probe-level analysis of the microarray data in conjunction with a custom mapping of the probe sequences to the most recent human and chimpanzee genome sequences. Time points for statistical comparison were chosen based on independently measured viremia levels. Regardless of the viral infection, the alignment of differentially expressed genes to the human genome sequence resulted in a larger number of genes being identified when compared with alignment to the chimpanzee genome sequence. This probably reflects the lesser refinement of gene annotation for chimpanzees. In general, the two viruses demonstrated very distinct temporal changes in host response genes, although both RNA viruses induced genes that were involved in many of the same biological systems, including interferon-induced genes. The host response to HCV infection was more robust in the magnitude and number of differentially expressed genes compared to HEV infection.

Bovine serum albumin antibodies as a disease marker for hepatitis E virus infection

This report evaluates the significance of antibody/bovine serum albumin (BSA) interactions as a risk factor for the diagnosis of acute hepatitis E. Serum samples from 40 patients with acute hepatitis E and from 40 age/sex matched healthy adult subjects were tested for IgA, IgG, and IgM by ELISA and by turbidimetric assay. BSA was used as a target to characterize changes in levels of interacting immunoglobulins. Initial results obtained before removal of antibodies that interacted with BSA suggested that HEV patients had increased levels of IgM in their sera. It was found that normal individuals had mean IgA, IgG, and IgM levels of 2.55 mg/mL, 9.80 mg/mL, and 1.73 mg/mL, respectively while HEV patients had mean levels of 2.66 mg/mL, 10.04 mg/mL, and 2.01 mg/mL (P < .26, P < .32, and P < .0004). However, the mean level of IgM in HEV-infected sera after purification from antibodies that interacted with BSA was determined to be 1.72 mg/mL indicating that there was no significant difference in IgM level in HEV patients compared to normal individuals (P < .6). The presence of antibodies that interact with BSA might serve as a diagnostic tool for detection of high-risk patients.