Epidemic hepatitis E in Pakistan: patterns of serologic response and evidence that antibody to hepatitis E virus protects against disease

Genotypic analysis of hepatitis E virus (HEV) from sporadic symptomatic cases in Pakistan

Pakistan is the fifth most populous nation in the world and faces several challenges, including devastating floods, sub-optimal sanitary conditions, clustered accommodations, and unregulated cross-border movements. These drastic population shifts make it vulnerable to the efficient spread of the Hepatitis E virus (HEV). The current study analyzed the genotypic characteristics and variants of the Hepatitis E virus circulating in the population of Pakistan. A total of 75 ELISA-IgM positive samples were collected from three metropolitan cities: Lahore, Peshawar, and Karachi, and subjected to viral RNA extraction. The amplification of the HEV RNA-dependent RNA polymerase (RdRp) region was done using Nested PCR and degenerate primers. Out of the total, 40% of the samples were positive for HEV RNA. Sequencing and phylogenetic analysis identified the new HEV isolates as Subtype 1 g, a subtype within an existing HEV genotype 1. This shift warrants investigation into its impact on clinical manifestation and disease severity. Importantly, this study marks the first HEV subtype analysis in Pakistan, contributing valuable insights into subtype diversity and prevalence in the region.

Prophylactic Hepatitis E Vaccine

The hepatitis E has been increasingly recognized as an underestimated global disease burden in recent years. Subpopulations with more serious infection associated damage or death include pregnant women, patients with basic liver diseases, and elderly persons. Vaccine would be the most effective means for prevention of HEV infection. The lack of an efficient cell culture system for HEV makes the development of classic inactive or attenuated vaccine infeasible. Hence, the recombinant vaccine approaches are explored deeply. The neutralizing sites are located almost exclusively in the capsid protein, pORF2, of the virion. Based on pORF2, many vaccine candidates showed potential of protecting primate animals, two of them were tested in human and evidenced to be well-tolerated in adults and highly efficacious in preventing hepatitis E. The world's first hepatitis E vaccine, Hecolin^® (HEV 239 vaccine), was licensed in China and launched in 2012.

Laboratory Diagnosis of HEV Infection

Serological and nucleic acid tests for detecting hepatitis E virus (HEV) have been developed for both epidemiologic and diagnostic purposes. The laboratory diagnosis of HEV infection depends on the detection of HEV antigen or HEV RNA in the blood, stool, and other body fluids, and serum antibodies against HEV (immunoglobulin [Ig]A, IgM, and IgG). Anti-HEV IgM antibodies and low avidity IgG can be detected during the acute phase of the illness and can last approximately 12 months, representing primary infection, whereas anti-HEV IgG antibodies can last more than several years, representing remote exposure. Thus, the diagnosis of acute infection is based on the presence of anti-HEV IgM, low avidity IgG, HEV antigen, and HEV RNA, while epidemiological investigations are mainly based on anti-HEV IgG. Although significant progress has been made in developing and optimizing different formats of HEV assays, improving their sensitivity and specificity, there are many shortcomings and challenges in inter-assay concordance, validation, and standardization. This article reviews the current knowledge on the diagnosis of HEV infection, including the most common available laboratory diagnostic techniques.

Comparative prevalence of different types of viral hepatitis in the district Dera Ismail Khan, Khyber Pakhtunkhwa, Pakistan

Background

Viral hepatitis causes both liver inflammation and damage and is a serious health problem.

Methods

The indoor data of different types of hepatitis were collected from the official records of the administration of District Head Quarter Hospital Dera Ismail Khan for 2 years (2020–2021).

Results

A total of 1193 cases of viral hepatitis during the study period were found including viral hepatitis C accounted for 547 (45.9%) cases, followed by the co-infection of viral hepatitis A and E 367 (30.8%) cases, and viral hepatitis B 279 (23.4%) cases. March showed the highest prevalence of hepatitis (33.2%), followed by February (10.2%). The co-infection of hepatitis A and E showed a relatively higher prevalence in 6 months from May to November except September including a peak in June (76.5%) during the study period. While viral hepatitis B demonstrated a comparatively higher percentage prevalence in both February and September with a peak in February (68%), and viral hepatitis C is dominant in January, March, and December with a peak in March (83.8%).

Conclusion

All types of viral hepatitis showed variation in prevalence over months and monthly variation concerning peak prevalence exists among different types of hepatitis. Both viral hepatitis A and E demonstrated similar trend in relative prevalence in both 2020 and 2021. Nevertheless, viral hepatitis A and B showed monthly and seasonal variation in relatively prevalence in both years. The study help in adopting strategies for the prevention of viral hepatitis in the study area.

Viral hepatitis in pregnancy

Viral hepatitis is caused by a heterogenous group of viral agents representing a wide range of phylogenetic groups. Many viruses can involve the liver and cause liver injury but only a subset are delineated as 'hepatitis viruses' based upon their primary site of replication and tropism for hepatocytes which make up the bulk of the liver cell population. Since their discovery, beginning with the agent that caused serum hepatitis in the 1960s, the alphabetic designations have been utilized. To date, we have five hepatitis viruses, A through E, though it is postulated that others may exist. This chapter will focus on those viruses. Note that hepatitis D is included as a subset of hepatitis B, as it cannot exist without concurrent hepatitis B infection. Pregnancy has the potential to affect all aspects of these viral agents due to the unique immunologic and physiologic changes that occur during and after the gestational period. In this review, we will discuss the most common viral hepatitis and their effects during pregnancy.

Prevalence of hepatitis E virus in children with acute hepatitis: one Egyptian center study

Introduction

The objective of the present study was to evaluate the prevalence of hepatitis E virus in acute hepatitis in pediatric patients.

Methods

This was a cross-sectional study including 180 children with acute hepatitis. Blood samples were obtained and subjected to study the serological markers of hepatitis B surface antigen (HBsAg), hepatitis B core IgM (HBc IgM), hepatitis C IgG (HCV IgG) and hepatitis A IgM (HAV IgM), hepatitis E IgM and IgG, cytomegalovirus IgM (CMV IgM) and specific antibodies IgM for Epstein Barr virus by ELISA. Also ELISA attempted the laboratory diagnosis of autoantibodies by performing assay of antinuclear and anti-smooth muscle antibodies. Real time PCR was used for determination of HEV-RNA in samples positive for HEV serological markers.

Results

From a total of 180 children with acute jaundice 69.4% were males and 39.6% were females with mean age ± standard deviation 5.8±3.5 years. Positive HEV markers were found in 47 patients (26.1%). A comparison between demographic, clinical and laboratory findings in children with positive HEV markers and children negative for HEV markers, revealed significant association with contact of animals (p=0.001), rural residence (p=0.001), presence of positive autoantibodies (p=0.001) and positive HAV IgM (p=0.001). The markers of hepatitis E virus showed significantly higher prevalence in children below age of 6 years (p=0.04).

Conclusions

HEV infection is more common in preschool age. There is a significant association between contact with animals, rural residence and other hepatitis affection like autoimmune hepatitis and other viral hepatitis viruses such as hepatitis A.

Seroprevalence of hepatitis E virus among different age groups in Tehran, Iran

Hepatitis E virus (HEV) is considered to be a public health problem on a global scale, especially in developing countries. This study aims to investigate the seroprevalence of HEV in the Tehrani population. This descriptive-analytical study was carried out between the years 2017 and 2018 in Tehran, Iran. A total of 493 individuals whose blood samples and demographic data were collected via questionnaires through random cluster sampling were selected. To determine the presence of specific IgG antibody against HEV, commercial kits were used through ELISA. Chi-squared tests, logistic regression and t test were also required to conduct the statistical analysis. Of the 493 participants, with a mean age of 40.98 ± 17.10 years, included in this study, 180 were men and 313 were women. Of these, 48 (9.7%) had IgG antibodies against HEV. No significant difference was observed between the sexes (or different age groups) and positive antibody. It has been reported that the prevalence rate of this infection is high in Tehran, which is indicative of the endemic nature of this infection in society. The results of this study are similar to those obtained from the east of Golestan province, Iran but different from those obtained from Isfahan province, Iran. As a high percentage of people are susceptible to the infection in society, it is likely to have the prevalence of an epidemic.

Clinical Manifestations, Pathogenesis and Treatment of Hepatitis E Virus Infections

Hepatitis E virus (HEV) is the most common cause of acute viral hepatitis throughout the world. Most infections are acute but they can become chronic in immunocompromised patients, such as solid organ transplant patients, patients with hematologic malignancy undergoing chemotherapy and those with a human immunodeficiency virus (HIV) infection. Extra-hepatic manifestations, especially neurological and renal diseases, have also been described. To date, four main genotypes of HEV (HEV1-4) were described. HEV1 and HEV2 only infect humans, while HEV3 and HEV4 can infect both humans and animals, like pigs, wild boar, deer and rabbits. The real epidemiology of HEV has been underestimated because most infections are asymptomatic. This review focuses on the recent advances in our understanding of the pathophysiology of acute HEV infections, including severe hepatitis in patients with pre-existing liver disease and pregnant women. It also examines the mechanisms leading to chronic infection in immunocompromised patients and extra-hepatic manifestations. Acute infections are usually self-limiting and do not require antiviral treatment. Conversely, a chronic HEV infection can be cleared by decreasing the dose of immunosuppressive drugs or by treating with ribavirin for 3 months. Nevertheless, new drugs are needed for those cases in which ribavirin treatment fails.

Adaptive Immune Responses in Hepatitis A Virus and Hepatitis E Virus Infections

Both hepatitis A virus (HAV) and hepatitis E virus (HEV) cause self-limited infections in humans that are preventable by vaccination. Progress in characterizing adaptive immune responses against these enteric hepatitis viruses, and how they contribute to resolution of infection or liver injury, has therefore remained largely frozen for the past two decades. How HAV and HEV infections are so effectively controlled by B- and T-cell immunity, and why they do not have the same propensity to persist as HBV and HCV infections, cannot yet be adequately explained. The objective of this review is to summarize our understanding of the relationship between patterns of virus replication, adaptive immune responses, and acute liver injury in HAV and HEV infections. Gaps in knowledge, and recent studies that challenge long-held concepts of how antibodies and T cells contribute to control and pathogenesis of HAV and HEV infections, are highlighted.

Donor-Derived Genotype 4 Hepatitis E Virus Infection, Hong Kong, China, 2018

Hepatitis E virus (HEV) genotype 4 (HEV-4) is an emerging cause of acute hepatitis in China. Less is known about the clinical characteristics and natural history of HEV-4 than HEV genotype 3 infections in immunocompromised patients. We report transmission of HEV-4 from a deceased organ donor to 5 transplant recipients. The donor had been viremic but HEV IgM and IgG seronegative, and liver function test results were within reference ranges. After a mean of 52 days after transplantation, hepatitis developed in all 5 recipients; in the liver graft recipient, disease was severe and with progressive portal hypertension. Despite reduced immunosuppression, all HEV-4 infections progressed to persistent hepatitis. Four patients received ribavirin and showed evidence of response after 2 months. This study highlights the role of organ donation in HEV transmission, provides additional data on the natural history of HEV-4 infection, and points out differences between genotype 3 and 4 infections in immunocompromised patients.

Immunization against Hepatitis E

Soon after the 1991 molecular cloning of hepatitis E virus (HEV), recombinant viral capsid antigens were expressed and tested in nonhuman primates for protection against liver disease and infection. Two genotype 1 subunit vaccine candidates entered clinical development: a 56 kDA vaccine expressed in insect cells and HEV 239 vaccine expressed in Escherichia coli Both were highly protective against hepatitis E and acceptably safe. The HEV 239 vaccine was approved in China in 2011, but it is not yet prequalified by the World Health Organization, a necessary step for introduction into those low- and middle-income countries where the disease burden is highest. Nevertheless, the stage is set for the final act in the hepatitis E vaccine story-policymaking, advocacy, and pilot introduction of vaccine in at-risk populations, in which it is expected to be cost-effective.

Development of new hepatitis E vaccines

Hepatitis E virus (HEV) infection is an emerging zoonotic disease posing a severe threat to public health in the world, especially to pregnant women. Currently, no specific treatments are available for HEV infection. Therefore, it is crucial to develop vaccine to prevent this infection. Although several potential candidate vaccines against HEV have been studied for their immunogenicity and efficacy, only Hecolin® which is developed by Xiamen Innovax Biotech Co., Ltd. and approved by China Food and Drug Administration (CFDA) in 2012, is the licensed HEV vaccine in the world so far. Extensive studies on safety, immunogenicity and efficacy in phase III clinical trials have shown that Hecolin® is a promising vaccine for HEV prevention and control. In this article, the advances on HEV vaccine development and research are briefly reviewed.

A Ten Year Immunopersistence Study of Hepatitis E Antibodies in Rural Bangladesh

Hepatitis E virus (HEV) is a major cause of acute, viral hepatitis in Southeast Asia. Several studies have suggested that antibody persistence after HEV infection may be transient, possibly increasing the risk of re-infection and contributing to the frequency of outbreaks in HEV endemic regions. The specific conditions under which antibodies to HEV are lost, or "sero-reversion" occurs, are poorly understood. Here, one hundred participants from population-based studies in rural Bangladesh were revisited in 2015, ten years after a documented HEV infection to examine long-term antibody persistence. Twenty percent (95% confidence interval: 12.0, 28.0) no longer had detectable antibodies at follow-up, suggesting that antibodies generally persist for at least a decade after infection in rural Bangladesh. Those who were seronegative at follow-up were generally younger at infection than those who remained positive (14.4 years versus 33.6 years, P > 0.0001). This age-dependent antibody loss could partially explain cross-sectional sero-prevalence data from South East Asia where children have reportedly low antibody prevalence. The results of this study provide new insight into the immunological persistence of HEV infection in a micronutrient deficient rural population of South Asia, highlighting the importance of age at infection in the ability to produce long-lasting antibodies against HEV.

Immunity against hepatitis E virus infection: Implications for therapy and vaccine development

Hepatitis E virus (HEV) is the leading cause of acute viral hepatitis worldwide and an emerging cause of chronic infection in immunocompromised patients. As with viral infections in general, immune responses are critical to determine the outcome of HEV infection. Accumulating studies in cell culture, animal models and patients have improved our understanding of HEV immunopathogenesis and informed the development of new antiviral therapies and effective vaccines. In this review, we discuss the recent progress on innate and adaptive immunity in HEV infection, and the implications for the devolopment of effective vaccines and immune-based therapies.

Prophylactic Hepatitis E Vaccine

Hepatitis E has been increasingly recognized as an underestimated global disease burden in recent years. Subpopulations with more serious infection-associated damage or death include pregnant women, patients with basic liver diseases, and elderly persons. Vaccine would be the most effective means for prevention of HEV infection. The lack of an efficient cell culture system for HEV makes the development of classic inactive or attenuated vaccine infeasible. Hence, the recombinant vaccine approaches are explored deeply. The neutralizing sites are located almost exclusively in the capsid protein, pORF2, of the virion. Based on pORF2, many vaccine candidates showed potential of protecting primate animals; two of them were tested in human and evidenced to be well tolerated in adults and highly efficacious in preventing hepatitis E. The world's first hepatitis E vaccine, Hecolin^® (HEV 239 vaccine), was licensed in China and launched in 2012.

Laboratory Diagnosis of HEV Infection

Serological and nucleic acid tests for detecting hepatitis E virus (HEV) have been developed for both epidemiologic and diagnostic purposes. The laboratory diagnosis of HEV infection depends on the detection of HEV antigen, HEV RNA, and serum antibodies against HEV (immunoglobulin [Ig]A, IgM, and IgG). Anti-HEV IgM antibodies can be detected during the acute phase of the illness and can last approximately 4 or 5 months, representing recent exposure, whereas anti-HEV IgG antibodies can last more than 10 years, representing remote exposure. Thus, the diagnosis of acute infection is based on the presence of anti-HEV IgM, HEV antigen, and HEV RNA, while epidemiological investigations are mainly based on anti-HEV IgG. Although significant progress has been made in developing and optimizing different formats of HEV assays, improving their sensitivity and specificity, there are many shortcomings and challenges in inter-assay concordance, validation, and standardization. This article reviews the current knowledge on the diagnosis of HEV infection, including the most common available laboratory diagnostic techniques.

The global burden of hepatitis E outbreaks: a systematic review

Hepatitis E virus (HEV) is responsible for repeated water-borne outbreaks since the past century, representing an emerging issue in public health. However, the global burden of HEV outbreak has not been comprehensively described. We performed a systematic review of confirmed HEV outbreaks based on published literatures. HEV outbreaks have mainly been reported from Asian and African countries, and only a few from European and American countries. India represents a country with the highest number of reported HEV outbreaks. HEV genotypes 1 and 2 were responsible for most of the large outbreaks in developing countries. During the outbreaks in developing countries, a significantly higher case fatality rate was observed in pregnant women. In fact, outbreaks have occurred both in open and closed populations. The control measures mainly depend upon improvement of sanitation and hygiene. This study highlights that HEV outbreak is not new, yet it is a continuous global health problem.

Monitoring of Anti-Hepatitis E Virus Antibody Seroconversion in Asymptomatically Infected Blood Donors: Systematic Comparison of Nine Commercial Anti-HEV IgM and IgG Assays

Diagnosis of hepatitis E virus (HEV) is usually determined serologically by detection of the presence of immunoglobulin (Ig)M antibodies or rising anti-HEV IgG titers. However, serological assays have demonstrated a significant variation in their sensitivities and specificities. In this study, we present the systematic comparison of different immunological anti-HEV assays using complete seroconversion panels of 10 virologically confirmed HEV genotype 3 infected individuals. Assay sensitivities were further evaluated by testing serially diluted World Health Organization (WHO) reference reagent for hepatitis E virus antibody and one patient sample infected with HEV genotype 3. Anti-HEV IgM and IgG antibody presence was determined using the immunological assays Wantai HEV IgM/IgG enzyme-linked immunosorbent assay (ELISA) (Sanbio, Uden, The Netherlands), recomWell HEV IgM/IgG (Mikrogen, Neuried, Germany), HEV IgM ELISA 3.0, HEV ELISA, HEV ELISA 4.0, Assure HEV IgM Rapid Test (all MP Biomedicals Europe, Illkirch Cedex, France) and Anti-HEV ELISA (IgM/IgG, Euroimmun, Lübeck, Germany). The assays showed differences regarding their analytical and diagnostic sensitivities, with anti-HEV IgM assays (n = 5) being more divergent compared to anti-HEV IgG (n = 4) assays in this study. Considerable variations were observed particularly for the detection period of IgM antibodies. This is the first study systematically characterizing serologic assays on the basis of seroconversion panels, providing sample conformity for a conclusive comparison. Future studies should include the assay comparison covering the four different genotypes.

Hepatitis E Pathogenesis

Although most hepatitis E virus (HEV) infections are asymptomatic, some can be severe, causing fulminant hepatitis and extra-hepatic manifestations, including neurological and kidney injuries. Chronic HEV infections may also occur in immunocompromised patients. This review describes how our understanding of the pathogenesis of HEV infection has progressed in recent years.

Viral Hepatitis in Pakistan: Past, Present, and Future

Viral hepatitis is a major cause of morbidity and mortality worldwide and a rising cause for concern in Asian countries. Weather it is blood borne or water/food borne hepatotropic virus, increasing burden is alarming for Asian countries. In this review we have evaluated the existing data to estimate the burden of viral hepatitis in populations of all age groups nationwide, along with an assessment of the risk factors and preventive and management strategies currently employed in Pakistan. The aim of our work is to consolidate and supplement the present knowledge regarding viral hepatitis in light of past and present trends and to provide future direction to the existing health policies.

How to cite this article

Butt AS, Sharif F. Viral Hepatitis in Pakistan: Past, Present, and Future. Euroasian J Hepato-Gastroenterol 2016;6(1):70-81.

Hepatitis E Virus Does Not Contribute to Hepatic Decompensation Among Patients With Advanced Chronic Hepatitis C

BACKGROUND & AIMS

Hepatitis E (HEV) can cause acute-on-chronic liver failure in persons with pre-existing liver disease. We investigated whether HEV infection contributes to hepatic decompensation in patients with previously stable, advanced chronic hepatitis C.

METHODS

We performed a case-control study using stored serum samples from subjects enrolled in the randomized phase of the Hepatitis C Antiviral Long-Term Treatment Against Cirrhosis Trial (n = 1050; mean age, 51 y; 70% male; 40% with cirrhosis at baseline). Cases were subjects who developed hepatic decompensation within a 24-week period. Controls (3 per case) were subjects without hepatic decompensation matched for fibrosis stage and followed up for a similar period. A serum sample obtained within 6 months after the decompensation event in cases and the same follow-up period in controls were tested for anti-HEV IgG. Subjects with a positive result had a baseline sample similarly tested for anti-HEV IgG. We measured levels of anti-HEV IgM and HEV RNA in blood samples from incident cases.

RESULTS

Of the 1050 subjects analyzed, 314 (30%) experienced a clinical event. Of the 314 subjects who experienced decompensation as defined, 89 (28%) were tested for anti-HEV, along with 267 controls (without decompensation). Similar proportions of cases and controls tested positive for anti-HEV (22.5% and 20.6%, respectively; P = .70). Ten incident HEV infections were identified-4 in cases (4.5%) and 6 in controls (2.2%) (P = .28). HEV RNA was not detected in blood samples from the 10 incident infections. Only 2 of the 4 incident infections among cases were related temporally to the decompensation event.

CONCLUSIONS

HEV does not appear to be a significant cause of hepatic decompensation among persons with previously stable, advanced chronic hepatitis C in the United States.

Incidence of Hepatitis E Antibodies in Swedish Lung Transplant Recipients

BACKGROUND

Hepatitis E virus (HEV) is an important cause of acute and chronic hepatitis in solid organ transplant recipients, especially liver transplant recipients. However, less is known of the incidence and prevalence of HEV in lung transplant recipients.

METHODS

In a prospective study, 62 patients were observed during the first year after lung transplantation. Sera were analyzed for anti-HEV immunoglobulin G (IgG) and IgM at 12 months after transplantation. Samples positive for anti-HEV were also analyzed for HEV RNA by polymerase chain reaction. Pretransplantation samples were analyzed for patients with detectable anti-HEV 1 year after transplantation.

RESULTS

Eight patients (13%) had anti-HEV IgG at the 12-month follow-up sample. HEV RNA could not be detected in any of these samples. One of these patients seroconverted during the follow-up without developing acute or chronic hepatitis.

CONCLUSIONS

Our results show that the prevalence of HEV antibodies among Swedish lung transplant recipients is similar when compared to the general population. It also suggests that the risk for HEV antibody seroconversion during first year is limited.

An outbreak of hepatitis E in an urban area of Bangladesh

We investigated an outbreak of jaundice in urban Bangladesh in 2010 to examine the cause and risk factors and assess the diagnostic utility of commercial assays. We classified municipal residents reporting jaundice during the preceding 4 weeks as probable hepatitis E cases and their neighbours without jaundice in the previous 6 months as probable controls. We tested the sera collected from probable cases and probable controls for IgM anti-hepatitis E virus (HEV), and the IgM-negative sera for IgG anti-HEV using a commercial assay locally. We retested the IgM-positive sera for both IgM and IgG anti-HEV using another assay at the Centre for Disease Control and Prevention (CDC), USA. Probable cases positive for IgM anti-HEV were confirmed cases; probable controls negative for both IgM and IgG anti-HEV were confirmed controls. We explored the local water supply and sanitation infrastructure and tested for bacterial concentration of water samples. Probable cases were more likely than probable controls to drink tap water (adjusted odds ratio: 3.4; 95% CI: 1.2-9.2). Fifty-eight percentage (36/62) of the case sera were IgM anti-HEV positive; and 75% of the IgM-positive samples were confirmed positive on retesting with another assay at CDC. Compared to confirmed controls, cases confirmed using either or both assays also identified drinking tap water as the risk factor. Two tap water samples had detectable thermotolerant coliforms. Research exploring decentralized water treatment technologies for sustainable safe water might prevent HEV transmission in resource-poor cities. Detection of serological markers in a majority of probable cases implied that available diagnostic assays could adequately identify HEV infection during outbreaks.

Epidemiology of HEV in the Mediterranean basin: 10-year prevalence in Italy

OBJECTIVES

The present study is aimed at describing the seroprevalence and exploring potential risk factor(s) for hepatitis E virus (HEV) in participants who voluntarily underwent anti-HIV antibody testing.

STUDY DESIGN

Seroprevalence study.

SETTING

The HIV prevention unit at the National Institute for Infectious Diseases Lazzaro Spallanzani, serving as a referral centre for HIV infection in Lazio, an Italian Region with about 5.6 million inhabitants.

PARTICIPANTS

Participants are a random sample of all subjects who receive counselling and undergo serological tests for anti-HIV antibody (Ab) between 2002 and 2011.

RISK FACTORS AND OUTCOME

A set of 16 epidemiological variables (risk factors) were assessed for association with positivity to anti-HEV IgG (outcome).

RESULTS

Between 2002 and 2011, 27,351 serum specimens and related epidemiological information were collected; of these 1116 were randomly selected and analysed. The overall anti-HEV IgG prevalence was 5.38% (60 out of 1116) with evidence of potential heterogeneity between years of sampling (p=0.055). Multivariate analysis provided evidence that anti-HEV IgG prevalence increases by 4% per year of participants' age (95% CI 1% to 7%, p=0.002). In addition, men who have sex with men and participants who were born outside Italy have an OR for past HEV infection that is about two times higher than in those who were not (p=0.040 and p=0.027, respectively). Analysis of temporal trend showed that variation of anti-HEV IgG can be well explained by a cubic logistic regression model, which describes the variation of prevalence over time as a fluctuation within a 3-year period (p=0.032).

CONCLUSIONS

This study provides new evidence that besides the orofecal and zoonotic routes, intimate contacts between males may be a significant mode of HEV transmission.

A Comprehensive Study of Neutralizing Antigenic Sites on the Hepatitis E Virus (HEV) Capsid by Constructing, Clustering, and Characterizing a Tool Box

The hepatitis E virus (HEV) ORF2 encodes a single structural capsid protein. The E2s domain (amino acids 459-606) of the capsid protein has been identified as the major immune target. All identified neutralizing epitopes are located on this domain; however, a comprehensive characterization of antigenic sites on the domain is lacking due to its high degree of conformation dependence. Here, we used the statistical software SPSS to analyze cELISA (competitive ELISA) data to classify monoclonal antibodies (mAbs), which recognized conformational epitopes on E2s domain. Using this novel analysis method, we identified various conformational mAbs that recognized the E2s domain. These mAbs were distributed into 6 independent groups, suggesting the presence of at least 6 epitopes. Twelve representative mAbs covering the six groups were selected as a tool box to further map functional antigenic sites on the E2s domain. By combining functional and location information of the 12 representative mAbs, this study provided a complete picture of potential neutralizing epitope regions and immune-dominant determinants on E2s domain. One epitope region is located on top of the E2s domain close to the monomer interface; the other is located on the monomer side of the E2s dimer around the groove zone. Besides, two non-neutralizing epitopes were also identified on E2s domain that did not stimulate neutralizing antibodies. Our results help further the understanding of protective mechanisms induced by the HEV vaccine. Furthermore, the tool box with 12 representative mAbs will be useful for studying the HEV infection process.

Detailed investigation of ongoing subclinical hepatitis E virus infections; occurring in outbreak settings of North India

BACKGROUND & AIMS

Every year globally WHO reports 20 million Hepatitis E virus (HEV) infections. The disease occurs as sporadic cases or focused outbreaks and has potentials to cause massive epidemics. The reservoir of HEV during inter-epidemic period is not well characterized. The sporadic cases usually lack history of contact with clinically overt HEV patients. In the present context we evaluated the occurrence of subclinical HEV as a possible reservoir in endemic region.

METHODS

Blood samples were collected from 67 apparently healthy individuals and 10 acute viral hepatitis (AVH) patients during two HEV outbreaks in North India. The serum samples were tested for anti-HEV IgM, IgG, HEV-IgG avidity index, HEV viral load and conventional-PCR followed by sequencing and phylogenetic analysis.

RESULTS

A total of 14 (20.89%) apparently healthy individuals showed the presence of anti-HEV IgM and IgG. Of 14 based on HEV-IgG avidity index, 9 (64.28%) had secondary-exposure, 4 (28.57%) had primary exposure, while one patient had intermediate avidity. Subclinical subjects with primary exposure had significantly higher anti-HEV IgM index as compared to secondary-exposure (P = 0.0028). Viral load in clinically jaundiced patients was significantly higher as compared to subclinical subjects (P < 0.0001). Phylogenetic analysis showed HEV sequences retrieved from subclinical individuals clustered along with AVH patients, suggesting matched source. The significantly low viral load in subclinical subjects hints towards the dose dependency for progression of clinical manifestation.

CONCLUSION

We document subclinical HEV with low level viremia occurs during outbreak settings and goes un-noticed, which helps maintaining the virus in nature possibly leading to its endemicity.

Host immune status and response to hepatitis E virus infection

Hepatitis E virus (HEV), identified over 30 years ago, remains a serious threat to life, health, and productivity in developing countries where access to clean water is limited. Recognition that HEV also circulates as a zoonotic and food-borne pathogen in developed countries is more recent. Even without treatment, most cases of HEV-related acute viral hepatitis (with or without jaundice) resolve within 1 to 2 months. However, HEV sometimes leads to acute liver failure, chronic infection, or extrahepatic symptoms. The mechanisms of pathogenesis appear to be substantially immune mediated. This review covers the epidemiology of HEV infection worldwide, the humoral and cellular immune responses to HEV, and the persistence and protection of antibodies produced in response to both natural infection and vaccines. We focus on the contributions of altered immune states (associated with pregnancy, human immunodeficiency virus [HIV], and immunosuppressive agents used in cancer and transplant medicine) to the elevated risks of chronic infection (in immunosuppressed/immunocompromised patients) and acute liver failure and mortality (among pregnant women). We conclude by discussing outstanding questions about the immune response to HEV and interactions with hormones and comorbid conditions. These questions take on heightened importance now that a vaccine is available.

Seroprevalence of hepatitis e virus among primary school children

Objectives: To investigate the seroprevalence of anti-hepatitis E virus antibody among primary school children in the two different areas of Denizli, Turkey.

Methodology: Anti-HEV antibodies were investigated in 185 primary school children (91 from rural areas and 94 from urban areas of Denizli). The children were divided into two age groups as seven-year old group and fourteen-year old group. Samples were tested for anti-HEV Ab by an enzyme-linked immunoassay.

Results: A total of 23 primary school children were anti-HEV Ab positive, giving a prevalence of 12.4%. The seroprevalence rate was 13.1% in rural areas and 11.7% in urban areas. The difference in the seropositive rates was not statistically significant (p>0.05). Among 185 primary school children, Anti-HEV antibodies were positive 17 (18.1%) in seven-year old group, and 6 (6.6%) in fourteen-year old group. The difference in the seropositive rates was statistically significant (p<0.05).

Conclusions: There was no association between the anti-HEV Ab and gender, socioeconomic level, parental educational level, rural or urban areas. Anti-HEV Ab seroprevalence was higher in seven-year old children than fourteen-year old children.

Endemic hepatitis E in the Czech Republic

BACKGROUND

An increasing incidence of endemic hepatitis E (HE) has been reported in developed countries. Thus, an evaluation of the clinical characteristics of the disease and the utility of the current diagnostic methods is warranted.

METHODS

Fifty-one adult acute patients with HE hospitalized in a single center between the years 2009 and 2012 were evaluated. Serological and molecular techniques (detection of hepatitis E virus [HEV] RNA from stool and serum samples by quantitative reverse transcription polymerase chain reaction) with sequencing and phylogenetic analysis were used for diagnosis, and the clinical, laboratory, and epidemiological parameters of the patients were evaluated.

RESULTS

Forty-nine (96.1%) patients had acute endemic HE and 2 (3.9%) had an imported infection. In the cohort of patients with acute symptomatic HE (n = 47), men outnumbered women (40:7), the patients were in older middle age (mean, 60.57 years), and they had elevated median values of total bilirubin (6.67 mg/dL), alanine aminotransferase (2288.82 U/L), aspartate aminotransferase (1251.76 U/L), gamma-glutamyl transferase (360.53 U/L), and alkaline phosphatase (197.06 U/L). Serology was positive in 50 (98%) of the patients, and 1 case was diagnosed by polymerase chain reaction only. HEV RNA was detected in at least 1 specimen from 84.3% of the patients, and 28 of 29 tested isolates belonged to genotype 3. The eating of meat, innards, other home-prepared pork products, or the tasting of raw meat before cooking were the most frequently reported data (reported by 25 patients [49.0%]).

CONCLUSIONS

Large numbers of the endemic cases of HE were caused by HEV genotype 3, and the clinical characteristics of endemic HE were demonstrated.

Serological cross reactivity to CMV and EBV causes problems in the diagnosis of acute hepatitis E virus infection

Hepatitis E virus (HEV) infection is an important public health concern as a major cause of enterically-transmitted hepatitis worldwide. The detectable window of viraemia is narrow, and HEV IgM and IgG rise simultaneously in acute infection. Furthermore, previous investigators have shown HEV IgM false positive reactions occur against EBV, CMV and potentially hepatitis A. A retrospective analysis of HEV serology testing was performed at a London tertiary referral hospital over a 3-year period. A thousand four hundred and twenty three serum samples were tested for HEV serology, with 33 samples HEV IgM positive and 28 HEV IgM equivocal. One hundred and eleven samples were HEV IgG positive but IgM negative suggesting past infection. No patients with HEV IgM positivity had false positive reactions against hepatitis A. A high degree of EBV and CMV cross reactivity was noted, with 33.3% and 24.2% of HEV IgM positive samples also testing positive for EBV and CMV IgM, respectively. HEV RNA was detected in four HEV IgM positive samples, indicating true positivity, although three demonstrated cross reactivity against EBV. Only 13.3% of samples with positive HEV IgM were HEV PCR positive, highlighting a low positive predictive value of serology testing. Overall a high level of HEV, EBV and CMV IgM cross reactivity was demonstrated, indicating that serology is unreliable in the diagnosis of acute viral hepatitis. It is concluded that that the diagnosis of viral hepatitis should be based on clinical features, raised transaminases, serology, and confirmatory PCR testing.

Clinicolaboratory study of mother-to-neonate transmission of hepatitis E virus in Egypt

OBJECTIVES

To study the presence of hepatitis E viremia in neonates with congenital infections.

METHODS

We included 29 neonates with clinical signs and symptoms suggesting congenital infections, along with their mothers. The control group comprised 29 healthy neonates and their mothers. Laboratory evaluations were performed for each sample for liver function profiles and virological studies for hepatitis viruses B, C, and E.

RESULTS

The most common viral markers in mothers were for hepatitis C immunoglobulin G (IgG) (41%), followed by hepatitis B surface antigen (34%) and hepatitis E virus (HEV) IgG (31%). The most common presentations in neonates were respiratory distress syndrome, followed by preterm birth and signs of sepsis (both 41%) and hepatosplenomegaly (13%).

CONCLUSIONS

This study highlights the occurrence of HEV infection among other etiological conditions causing congenital infections. Vertical transmission from mothers was common in our patients. Although HEV ran a milder course, more studies are needed.

Infection by Brazilian and Dutch swine hepatitis E virus strains induces haematological changes in Macaca fascicularis

BACKGROUND

Hepatitis E virus (HEV) has been described as an emerging pathogen in Brazil and seems to be widely disseminated among swine herds. An autochthonous human case of acute hepatitis E was recently reported. To obtain a better understanding of the phenotypic profiles of both human and swine HEV strains, a experimental study was conducted using the animal model, Macaca fascicularis.

METHODS

Six cynomolgus monkeys (Macaca fascicularis) were inoculated intravenously with swine HEV genotype 3 that was isolated from naturally and experimentally infected pigs in Brazil and the Netherlands. Two other monkeys were inoculated with HEV genotype 3 that was recovered from Brazilian and Argentinean patients with locally acquired acute and fulminant hepatitis E. The haematological, biochemical, and virological parameters of all animals were monitored for 67 days.

RESULTS

Subclinical hepatitis was observed in all monkeys after inoculation with HEV genotype 3 that was recovered from the infected swine and human patients. HEV RNA was detected in the serum and/or faeces of 6 out of the 8 cynomolgus monkeys between 5 and 53 days after inoculation. The mild inflammation of liver tissues and elevations of discrete liver enzymes were observed. Seroconversions to anti-HEV IgM and/or IgG were detected in 7 animals. Reactivities to anti-HEV IgA were also detected in the salivary samples of 3 animals. Interestingly, all of the infected monkeys showed severe lymphopenia and a trend toward monocytosis, which coincided with elevations in alanine aminotransferase and antibody titres.

CONCLUSIONS

The ability of HEV to cross the species barrier was confirmed for both the swine (Brazilian and Dutch) and human (Argentinean) strains, thus reinforcing the zoonotic risk of hepatitis E in South America. Cynomolgus monkeys that were infected with HEV genotype 3 developed subclinical hepatitis that was associated with haematological changes. Haematological approaches should be considered in future studies of HEV infection.

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.

Antigenic determinants of hepatitis E virus and vaccine-induced immunogenicity and efficacy

There is emerging evidence for an under-recognized hepatitis E virus (HEV) as a human pathogen. Among different reasons for this neglect are the unsatisfactory performance and under-utilization of commercial HEV diagnostic kits; for instance, the number of anti-HEV IgM kits marketed in China is about one-fifth of that of hepatitis A kits. Over the last two decades, substantial progress has been achieved in furthering our knowledge on the HEV-specific immune responses, antigenic features of HEV virions, and development of serological assays and more recently prophylactic vaccines. This review will focus on presenting the evidence of the importance of HEV infection for certain cohorts such as pregnant women, the key antigenic determinants of the virus, and immunogenicity and clinical efficacy conferred by a newly developed prophylactic vaccine. Robust immunogenicity, greater than 195-fold and approximately 50-fold increase of anti-HEV IgG level in seronegative and seropositive vaccinees, respectively, as well as impressive clinical efficacy of this vaccine was demonstrated. The protection rate against the hepatitis E disease and the virus infection was shown to be 100% (95% CI 75-100) and 78% (95% CI 66-86), respectively.

Diagnosis of hepatitis E

Hepatitis E, caused by infection with hepatitis E virus (HEV), is a common cause of enterically-transmitted acute hepatitis in developing countries. Occasional cases of sporadic hepatitis E have been increasingly recognized in developed countries over the past decade. These cases differ from those in developing countries in being possibly caused by zoonotic transmission, often affecting people with a suppressed immune system and occasionally leading to persistent HEV infection. The commonly used tests for HEV infection include detection of IgM and IgG anti-HEV antibodies and detection of HEV RNA. IgM anti-HEV antibodies can be detected during the first few months after HEV infection, whereas IgG anti-HEV antibodies represent either recent or remote exposure. The presence of HEV RNA indicates current infection, whether acute or chronic. Although several diagnostic assays for anti-HEV antibodies are available, they have undergone fairly limited testing and often provide discordant results, particularly for IgG antibodies. Thus, although the available antibody assays might be useful for case diagnosis in areas with high disease endemicity, their use for case diagnosis in areas with low endemicity and for seroprevalence studies remains problematic. Improved validation of existing anti-HEV antibody assays or development of new assays with superior performance characteristics is urgently needed.

Protective role of humoral immune responses during an outbreak of hepatitis E in Egypt

Although the seroprevalence of hepatitis E virus (HEV) is approximately 80% in adult Egyptians living in rural areas, symptomatic HEV-caused acute viral hepatitis (AVH) is sporadic and relatively uncommon. To investigate the dichotomy between HEV infection and clinical AVH, HEV-specific immune responses in patients with symptomatic and asymptomatic HEV infection during a waterborne outbreak in Egypt were examined. Of 235 acute hepatitis patients in Assiut hospitals screened for HEV infection, 42 (17.9%) were acute hepatitis patients confirmed as HEV-caused AVH; 37 (88%) of the 42 patients were residents of rural areas, and 14 (33%) were from one village (Kom El-Mansoura). Another 200 contacts of AVH cases in this village were screened for HEV and 14 (7.0%), all of whom were family members of AVH cases, were asymptomatic HEV IgM-positive. HEV infections in this village peaked during the summer. Asymptomatic HEV seroconverters had significantly higher levels of epitope-specific neutralising (p=0.006) and high avidity (p=0.04) anti-HEV antibodies than the corresponding AVH cases. In conclusion, naturally acquired humoral immune responses appear to protect HEV-exposed subjects from AVH during an HEV outbreak in Egypt.

Evolution of the hepatitis E virus hypervariable region

The presence of a hypervariable (HVR) region within the genome of hepatitis E virus (HEV) remains unexplained. Previous studies have described the HVR as a proline-rich spacer between flanking functional domains of the ORF1 polyprotein. Others have proposed that the region has no function, that it reflects a hypermutable region of the virus genome, that it is derived from the insertion and evolution of host sequences or that it is subject to positive selection. This study attempts to differentiate between these explanations by documenting the evolutionary processes occurring within the HVR. We have measured the diversity of HVR sequences within acutely infected individuals or amongst sequences derived from epidemiologically linked samples and, surprisingly, find relative homogeneity amongst these datasets. We found no evidence of positive selection for amino acid substitution in the HVR. Through an analysis of published sequences, we conclude that the range of HVR diversity observed within virus genotypes can be explained by the accumulation of substitutions and, to a much lesser extent, through deletions or duplications of this region. All published HVR amino acid sequences display a relative overabundance of proline and serine residues that cannot be explained by a local bias towards cytosine in this part of the genome. Although all published HVRs contain one or more SH3-binding PxxP motifs, this motif does not occur more frequently than would be expected from the proportion of proline residues in these sequences. Taken together, these observations are consistent with the hypothesis that the HVR has a structural role that is dependent upon length and amino acid composition, rather than a specific sequence.

Hepatitis E: Epidemiology and prevention

Hepatitis E is caused by the hepatitis E virus (HEV), the major etiologic agent of enterically transmitted non-A hepatitis worldwide. HEV is responsible for major outbreaks of acute hepatitis in developing countries, especially in many parts of Africa and Asia. The HEV is a spherical, non-enveloped, single-stranded, positive sense RNA virus that is approximately 32 nm to 34 nm in diameter and is the only member in the family Hepeviridae and genus Hepevirus. There are four distinct genotypes of HEV (genotypes 1-4). While genotype 1 is predominantly associated with large epidemics in developing countries, genotype 3 has recently emerged as a significant pathogen in developed countries. The clinical manifestations and the laboratory abnormalities of hepatitis E are not distinguishable from that caused by other hepatitis viruses. However, high mortality among pregnant women particularly during the third trimester distinguishes HEV from other causes of acute viral hepatitis. Specific etiologic diagnosis among infected cases can be made by serological testing or detection of viral nucleic acid by reverse transcription polymerase chain reaction. Although there are vaccine candidates that had been shown to be safe and efficacious in clinical trials, none are approved currently for use. There is no specific therapy for acute hepatitis E as treatment remains supportive.

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.

Toward the development of a hepatitis E vaccine

Hepatitis E virus (HEV) causes large epidemics of enterically transmitted acute hepatitis and accounts for a majority of sporadic acute hepatitis in endemic countries. Due to a very high mortality rate among infected pregnant women and substantial morbidity, disability and costs associated with hepatitis E, concerted efforts are being made to develop an efficacious vaccine. Experimental vaccines, based on recombinant proteins derived from the capsid gene of HEV, have been shown efficacious in pre-clinical trials in macaques conferring cross-protection against various genotypes. Two vaccine candidates, the rHEV vaccine expressed in baculovirus and the HEV 239 vaccine, expressed in Escherichia coli, were successfully evaluated in Phase II/III trials. However, at this time no approved vaccine against hepatitis E is commercially available.

Seroprevalence of hepatitis E virus in the UK farming population

Hepatitis E is a zoonosis that can be acquired by the consumption of contaminated food or water, or via person-to-person spread. However, little is known about the transmission of hepatitis E virus (HEV) in the UK. We investigated the epidemiology of indigenous hepatitis E infection using the PHLS Farm Cohort, a sentinel group with a history of close contact with a range of domestic animals. Ten of the 413 subjects tested were positive for hepatitis E IgG antibodies (2.4%). Seroprevalence peaked in those aged 51 to 60 years (relative risk 3.3, 95% CI: 1.0-10.5). Male participants (relative risk 3.6, 95% CI: 0.6-21.2) and those from farms in the Hereford area of the United Kingdom (relative risk 2.7, 95% CI: 0.8-8.4), an area of mixed livestock farming, were more likely to have serological evidence of previous HEVs exposure, although these findings were not statistically significant. Exposure to pigs, or water from a private supply, was not identified as a significant risk factor. The results of this study suggest that UK farming populations are exposed to HEV, but the predominant route of transmission remains elusive.

Epidemiology and risk factors of incident hepatitis E virus infections in rural Bangladesh

Hepatitis E virus (HEV) is the most common cause of acute viral hepatitis in the world. Most of South Asia is HEV endemic, with frequent seasonal epidemics of hepatitis E and continuous sporadic cases. This author group's epidemiologic work and clinical reports suggest that Bangladesh is HEV endemic, but there have been few population-based studies of this country's HEV burden. The authors calculated HEV infection rates, over an 18-month interval between 2003 and 2005, by following a randomly selected cohort of 1,134 subjects between the ages of 1 and 88 years, representative of rural communities in southern Bangladesh. Baseline prevalence of antibody to hepatitis E virus (anti-HEV) was 22.5%. Seroincidence was 60.3 per 1,000 person-years during the first 12 months and 72.4 per 1,000 person-years from >12 to 18 months (during the monsoon season), peaking by age 50 years and with low rates during childhood. Few of the seroconverting subjects reported hepatitis-like illness. Overall incidence was calculated to be 64 per 1,000 person-years, with 1,172 person-years followed. No significant associations were found between anti-HEV incidence and demographic or socioeconomic factors for which data were available. This is the first study to document annual HEV infection rates among "healthy" and very young to elderly subjects in a rural Bangladeshi population.

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.

[Rare acute hepatitis in a female patient with hemochromatosis: a zoonosis?]

A 58-year-old female patient was transferred by her general practitioner with fatigue, nausea and icterus which had begun 2 weeks prior to admission. Laboratory results revealed acute hepatitis (ALAT [alanine aminotransferase] 3,871 U/l, ASAT [aspartate aminotransferase] 2,004 U/l, bilirubin 6.7 mg/dl, gamma-GT [gamma-glutamyl transferase] 503 U/l). The patient's medical history included genetic hemochromatosis (without cirrhosis). Hepatitis A to C, infection with herpesviruses or Leptospira interrogans were excluded by serologic and molecular biological tests. There was no diagnostic evidence for underlying autoimmune or additional metabolic liver disease. Due to a trip to Africa 5 months earlier, the patient was tested for hepatitis E, leading to positive anti-hepatitis E-IgM and negative anti-hepatitis E-IgG. PCR (polymerase chain reaction) detection of hepatitis E virus (HEV) was positive as well. In conclusion, acute HEV infection was diagnosed. After close reconsideration, the nonfitting incubation period precluded a travel-associated infection. Additionally, there was no evidence for current HEV infections within the patient's social environment, so that a zoonotic origin has to be discussed.