Host risk factors and autochthonous hepatitis E infection

New foe treated with old guns - supportive role of steroids in the treatment of acute severe hepatitis E

Background

Autochthonous hepatitis E has been observed with growing incidence in industrialized countries. Hepatitis E virus infection causes an acute hepatitis with spontaneous resolution in the majority of cases. However, in individual cases, hepatitis E may lead to life-threatening acute liver failure. In this report, we describe a case of acute liver injury caused by an autochthonous hepatitis E that resolved under steroid treatment. To our knowledge, this is the first case report describing supportive steroid monotherapy for acute liver injury due to hepatitis E.

Case presentation

A 63-year-old Caucasian male presented with acute liver injury of unknown origin. After excluding the most prevalent causes of acute liver injury, liver histology revealed signs of immune-mediated toxic or drug-induced liver injury. Therefore, immunosuppressive treatment with prednisolone was started. After initialization of steroid treatment, polymerase chain reaction analyses of peripheral blood and liver tissue revealed an acute hepatitis E virus infection (genotype 3). Under sustained steroid treatment, acute liver injury improved and hepatitis E infection resolved.

Conclusion

Steroid treatment might be an option to prevent progress of life-threatening liver failure and liver transplantation in patients with hepatitis E-induced acute liver injury and high-grade inflammation.

Hepatitis E in patients with hepatic disorders and HIV-infected patients in Croatia: is one diagnostic method enough for hepatitis E diagnosis?

We assessed hepatitis E virus (HEV) seroprevalence in patients with hepatic disorders as well as in human immunodeficiency virus (HIV)-infected patients and emphasised the issue of possible non-specific anti-HEV seroresponse and need for combining diagnostic methods for hepatitis E diagnosis. Over a two-year period, from March 2011 to February 2013, we determined anti-HEV immunoglobulin M (IgM) and IgG by enzyme immunoassays (EIA; Mikrogen, Germany) in 504 hepatitis patients negative for acute viral hepatitis A-C. Furthermore, 88 samples from randomly selected consecutive HIV-infected patients were also analysed. All EIA reactive samples were additionally tested by line immunoblot assays (LIA; Mikrogen, Germany). HEV nested reverse transcription polymerase chain reaction (RT-PCR) was carried out in 14 anti-HEV IgM LIA-positive patients. Anti-HEV IgM or IgG were detected in 16.9 % of patients by EIA and confirmed by LIA in 10.7 % [95 % confidence interval (CI) 8.3-13.7 %] of hepatitis patients. HEV RNA was detected in five patients. The agreement between EIA and LIA assessed by Cohen's kappa was 0.47 (95 % CI 0.55-0.75) for IgM and 0.83 (95 % CI 0.78-0.93) for IgG. Anti-HEV IgM and IgG seroprevalence in HIV-infected patients was 1.1 %, respectively. Our findings show a rather high HEV seroprevalence in patients with elevated liver enzymes in comparison to HIV-infected patients. Discordant findings by different methods stress the need to combine complementary methods and use a two-tier approach with prudent interpretation of reactive serological results for hepatitis E diagnosis.

Hepatitis E virus in patients with acute severe liver injury

AIM: To examine the incidence of hepatitis E (HepE) in individuals with acute liver injury severe enough to warrant treatment at a transplant unit.

METHODS: Hepatitis E virus (HEV) is an emerging pathogen in developed countries causing severe illness, particularly in immunocompromised patients or those with underlying chronic liver disease. HepE infection is often under diagnosed, as clinicians can be reluctant to test patients who have not travelled to regions traditionally considered hyperendemic for HepE. There are few data regarding the significance of HEV in patients with very severe acute liver injury in developed countries. Eighty patients with acute severe liver injury attending the Scottish Liver Transplant unit were tested for HEV and anti-HEV IgG and IgM. Severe acute liver injury was defined as a sudden deterioration in liver function confirmed by abnormal liver function tests and coagulopathy or presence of hepatic encephalopathy. Eighty percent of these patients were diagnosed with paracetomol overdose. No patients had a history of chronic or decompensated chronic liver disease at time of sampling. IgG positive samples were quantified against the World Health Organization anti-HEV IgG standard. Samples were screened for HEV viral RNA by quantitative reverse transcription polymerase chain reaction.

RESULTS: Four cases of hepatitis E were identified. Three of the four cases were only diagnosed on retrospective testing and were initially erroneously ascribed to drug-induced liver injury and decompensated chronic liver disease, with the cause of the decompensation uncertain. One case was caused by HEV genotype 1 in a traveller returning from Asia, the other three were autochthonous and diagnosed on retrospective testing. In two of these cases (where RNA was detected) HEV was found to be genotype 3, the most prevalent genotype in developed countries. Three patients survived, two of whom had been misdiagnosed as having drug induced liver injury. The fourth patient died from sepsis and liver failure precipitated as a result of hepatitis E infection and previously undiagnosed cirrhosis. Histopathology data to date is limited to mainly that seen for endemic HepE. All patients, with the exception of patient 1, demonstrated characteristics of HepE infection, as seen in previously described locally acquired cases.

CONCLUSION: In patients with acute severe liver injury, HEV testing should be part of the initial diagnostic investigation algorithm irrespective of suspected initial diagnosis, age or travel history.

Hepatitis E virus infection

Hepatitis E virus (HEV) infection is a worldwide disease. An improved understanding of the natural history of HEV infection has been achieved within the last decade. Several reservoirs and transmission modes have been identified. Hepatitis E is an underdiagnosed disease, in part due to the use of serological assays with low sensitivity. However, diagnostic tools, including nucleic acid-based tests, have been improved. The epidemiology and clinical features of hepatitis E differ between developing and developed countries. HEV infection is usually an acute self-limiting disease, but in developed countries it causes chronic infection with rapidly progressive cirrhosis in organ transplant recipients, patients with hematological malignancy requiring chemotherapy, and individuals with HIV. HEV also causes extrahepatic manifestations, including a number of neurological syndromes and renal injury. Acute infection usually requires no treatment, but chronic infection should be treated by reducing immunosuppression in transplant patients and/or the use of antiviral therapy. In this comprehensive review, we summarize the current knowledge about the virus itself, as well as the epidemiology, diagnostics, natural history, and management of HEV infection in developing and developed countries.

Epidemiology and associated risk factors of hepatitis e virus infection in plateau state, Nigeria

A cross-sectional study in Nigeria was undertaken to determine the epidemiology, seroprevalence, and associated risk factors, of hepatitis E virus (HEV). A total of 462 subjects were used for the study, categorized into four groups: apparently healthy persons, pregnant women, HIV positive subjects, and animal handlers. Information was obtained from subjects using interviewer-administered questionnaire. Blood samples were collected and analyzed for HEV antibodies (IgG and IgM) using enzyme-linked immunosorbent assay (ELISA) technique. Results obtained were analyzed using Statistical Package for Social Sciences (SPSS) version 17.0 statistical software. The overall seroprevalence of IgG and IgM was 42.7 and 0.9%, respectively. Animal handlers had the highest seroprevalence (66.7%). The associated risk factors for IgM seroprevalence were rural dwelling (P = 0.039, odds ratio (OR) 3.3, 95% confidence interval (CI) 0.7–15.4), blood transfusion (P < 0.001, OR 9.6, 95% CI 2.6–35.6), attending to animals (P = 0.032, OR 4.9, 95% CI 0.9–26.6), and waste disposal (P < 0.001). Factors associated with IgG were age (P = 0.044), location (P < 0.001), marital status (P < 0.001), formal education (P < 0.001), farming as occupation (P < 0.001), rural dwelling (P = 0.001), waste disposal (P < 0.001), alcohol consumption (P = 0.001, OR 2.4, 95% CI 1.4–4.0), open defecation (P < 0.001, OR 2.9, 95% CI 1.4–5.7), attending to animals (P < 0.001, OR 2.3, 95% CI 1.6–3.4), consuming unwashed fruits/vegetables (P < 0.001, OR 4.2, 95% CI 0.3–54.1), and stream/river as a source of drinking water (P < 0.001, OR 3.6, 95% CI 1.6–7.8). Preventive public health measures should be reinforced among all communities, particularly domestic animal handlers and pregnant women. Potable water should be provided for all communities. Data suggest that HEV remains an under-recognized and significant public health problem, warranting further attention and research.

Hepatitis e virus: current concepts and future perspectives

For many years, hepatitis E was considered a disease found only in certain developing countries. In these geographical settings, hepatitis E virus (HEV) causes a self-limiting hepatitis in young adults, except in pregnant females, in whom the mortality is 25 %. Our understanding of HEV has changed radically in the past decade. It is now evident that HEV is a threat to global health. This review article considers the current concepts and future perspectives of HEV and its effects on human health, with particular reference to developed countries.

Hepatitis E

PURPOSE OF REVIEW

Hepatitis E has been regarded as a disease of the developing world, where it causes large waterborne outbreaks and sporadic cases of hepatitis. Recent research has shown this received wisdom to be mistaken.

RECENT FINDINGS

Recent studies have shown that authochtonous (locally acquired) hepatitis E does occur in developed countries, is caused by hepatitis E virus (HEV) genotypes 3 and 4, and is zoonotic with pigs as the primary host. Most infections are clinically inapparent. However, acute symptomatic hepatitis E has a predilection for middle-aged and elderly men, with an excess mortality in patients with underlying chronic liver disease. Chronic infection occurs in the immunosuppressed with rapidly progressive cirrhosis if untreated, the treatment of choice being ribavirin monotherapy for 3 months. Hepatitis E has a range of extra-hepatic manifestations, including a spectrum of neurological syndromes. HEV can be transmitted by blood transfusion and has recently been found in donated blood in a number of countries.

SUMMARY

The diagnosis should be considered in any patient with a raised alanine aminotranferase, irrespective of age or travel history. The safety of blood products needs to be fully assessed, as a matter of priority, as blood donors are not currently screened for HEV.

Hepatitis E: an emerging disease

Currently, the infection with the hepatitis E virus represents the most frequent cause for acute hepatitis and jaundice in the world. According to WHO estimations, around two billion people, representing one third of the world's population, live in endemic areas for HEV and, therefore, are at risk of infection. In developed countries, the circulation of the virus in both human and animal (swine, boar, deer) sewage has been confirmed; however, the incidence rate is low compared to that of developing countries where outbreaks of acute hepatitis transmitted via the fecal-oral route are originated, more frequently in the flooding season or after natural disasters, combined with deficient sanitary conditions. There are currently 4 known genotypes of HEV. Genotypes 1 and 2 are isolated in all human epidemic outbreaks in developing countries, while genotypes 3 and 4 are isolated not only in humans but also in animals, in both developing and industrialized countries. These data support genotypes 3 and 4 having zoonotic nature. The diagnosis of this disease is based in the detection of anti-HEV IgG and IgM in blood serum using enzyme-linked immunosorbent methods. However, the method that best confirms the diagnosis is the RT-PCR, which detects HEV RNA in blood serum and also provides the genotype. The clinical course is generally that of an acute hepatitis which in some cases may require hospitalization and that, in transplant patients or HIV infected individuals can become a chronic hepatitis. Furthermore, the virus constitutes an important risk for pregnant women. The hepatitis E can present a wide range of symptoms, from a subclinical case to chronic liver disease with extrahepatic manifestations. For this reason, the diagnostic is challenging if no differential diagnosis is included. There is no specific antiviral drug for hepatitis E, but satisfactory results have been observed in some patients treated with pegylated interferon alfa2a and/or ribavirin. This revision is an update of all the molecular, epidemiological, clinic and preventive knowledge on this emergent disease up to date.

Features of hepatitis E virus infection in humans and animals in Japan

In Japan, hepatitis E had long been considered to be a rare liver disease which can be accidentally imported from endemic countries in Asia and Africa, where the sanitation conditions are suboptimal. However, since the identification of the first autochthonous hepatitis E case and hepatitis E viremic domestic pigs in Japan in 2001, our understanding of hepatitis E virus (HEV) infection in this country has been changing markedly. This has largely been due to the development of serological and gene-based diagnostic assays, the accumulation of molecular epidemiological findings on HEV infection in humans and animals (as potential reservoirs for HEV in humans) and the recognition of the importance of zoonotic food-borne and other routes of transmission of HEV, including blood-borne transmission. Although it is now evident that autochthonous hepatitis E in Japan is far more common than was previously thought, clinical and subclinical HEV infections indigenous to Japan remain underdiagnosed and their prevalence is still underestimated due to the presence of unknown transmission routes and a low awareness of the infection status by many physicians in Japan. This review focuses on the features of HEV infection in humans and animals, as definitive or potential reservoirs for HEV, in Japan, and updates the current knowledge on the routes of transmission, including zoonotic routes, which are important for the maintenance and spread of HEV in Japan.

Antiviral strategies for hepatitis E virus

The hepatitis E virus is a common cause of acute hepatitis. Contrary to hepatitis B and C, hepatitis E is mostly a mild infection, although it has a high mortality in pregnant women and can evolve to chronicity in immunocompromised patients. Ribavirin and pegylated interferon-α are the only available therapies, but both have side effects that are not acceptable for prophylaxis or treatment of mild infections. In addition, these drugs cannot be used for all patient types (e.g. in case of pregnancy, specific organ transplants or co-morbidities) and in resource-poor settings. Hence there is an urgent need for better antiviral treatments that are efficacious and safe, also during pregnancy. In this review, a concise introduction to the virus and disease is provided, followed by a discussion of the available assay systems and potential molecular targets (viral proteins and host factors) for the development of inhibitors of HEV replication. Finally, directions for future research are presented.

Hepatitis E: An emerging infection in high income countries

Hepatitis E virus (HEV) genotype 3 is the most recently characterized hepatotropic virus and is increasingly being recognized as the cause of unexplained liver disease in many western countries. Although asymptomatic in most cases, HEV GT3 may be responsible for a wide range of illnesses, from mild to fulminant acute hepatitis, and also chronic hepatitis in immunocompromised patients. Extrahepatic manifestations have been occasionally described. Anti-HEV antibody detection by immunoassays is hampered by moderate test accuracy particularly in immunocompromised hosts while a WHO international standard for molecular detection of HEV RNA by RT-PCR has recently been introduced. This review describes the basic virology, epidemiology, clinical virology and treatment of HEV GT3 infections in high income countries.

Protective immunity against HEV

Rural community of Dongtai City in eastern China is endemic for hepatitis E virus (HEV), with the zoonotic genotype 4 virus predominating. The virus appears to be widely distributed in environment at generally low levels, such that infection is common, but >97% of which are asymptomatic and provoke a modest antibody response. Naturally acquired immunity affords 75% protection against infection, prevents disease caused by primary infection and alleviates severity of the disease caused by the residual infection that had evaded host immune surveillance. The protection, however, is extended to a minority, while leaving the majority of population essentially without the benefits of immune protection. Vaccination affords similar level of protection as does natural immunity, but expands the protective coverage to the entire population.

Autochthonous hepatitis E in Scotland

BACKGROUND

Hepatitis E virus is well recognized cause of acute hepatitis. Traditionally hepatitis E virus (HEV) infections were generally associated with travel to Asia and Africa. Autochthonous hepatitis E is recognized as a major cause acute hepatitis in England and Wales. However, autochthonous hepatitis E has never been documented in Scotland.

OBJECTIVES

We attempted to determine if autochthonous HEV occurred in Scotland.

STUDY DESIGN

Samples from 377 individuals in the South-East of Scotland presenting with acute hepatitis were tested over six years. Acute hepatitis E was confirmed by detecting viraemia or documenting seroconversion and ORF-2 region sequenced. Structured interviews were carried out to identify risk factors for infection.

RESULTS

Sixteen individuals (4.2%) had evidence of past HEV infection. Twelve (3.2%) had acute HEV infection, 10 of whom had viraemia (genotype 1=3; genotype 3=7). Of these seven with genotype 3 infection, three had not travelled outside Scotland within the incubation period, while four had travelled to Spain (n=3) or Turkey (n=1). All three individuals with genotype 1 infection had travelled to the Indian subcontinent.

CONCLUSIONS

A significant proportion of HEV genotype 3 infections was autochthonous (43%). HEV screening should hence be an integral part of acute hepatitis screening in Scotland, irrespective of the travel history.

Hepatitis E virus: foodborne, waterborne and zoonotic transmission

Hepatitis E virus (HEV) is responsible for epidemics and endemics of acute hepatitis in humans, mainly through waterborne, foodborne, and zoonotic transmission routes. HEV is a single-stranded, positive-sense RNA virus classified in the family Hepeviridae and encompasses four known Genotypes (1–4), at least two new putative genotypes of mammalian HEV, and one floating genus of avian HEV. Genotypes 1 and 2 HEVs only affect humans, while Genotypes 3 and 4 are zoonotic and responsible for sporadic and autochthonous infections in both humans and several other animal species worldwide. HEV has an ever-expanding host range and has been identified in numerous animal species. Swine serve as a reservoir species for HEV transmission to humans; however, it is likely that other animal species may also act as reservoirs. HEV poses an important public health concern with cases of the disease definitively linked to handling of infected pigs, consumption of raw and undercooked animal meats, and animal manure contamination of drinking or irrigation water. Infectious HEV has been identified in numerous sources of concern including animal feces, sewage water, inadequately-treated water, contaminated shellfish and produce, as well as animal meats. Many aspects of HEV pathogenesis, replication, and immunological responses remain unknown, as HEV is an extremely understudied but important human pathogen. This article reviews the current understanding of HEV transmission routes with emphasis on food and environmental sources and the prevalence of HEV in animal species with zoonotic potential in humans.

Hepatitis E: current status

Acute hepatitis E is a very common disease in developing countries, to the point that, according to World Health Organization estimates, one third of the world's population has been exposed to HEV. It also causes outbreaks in refugee camps or after natural disasters such as floods or earthquakes. Sporadic cases of acute hepatitis have been observed in practically all European countries and other developed geographical areas, not only in travelers from endemic countries but also in people with no risk factors. But, lately, new aspects of this infection are appearing in industrialized countries such as the possibility of the disease becoming chronic in transplant patients, the immunocompromised in general, and even in patients with previous liver disease who are immunocompetent. In this comprehensive review, we summarize the current knowledge on HEV infection.

Cutthroat trout virus as a surrogate in vitro infection model for testing inhibitors of hepatitis E virus replication

Hepatitis E virus (HEV) is one of the most important causes of acute hepatitis worldwide. Although most infections are self-limiting, mortality is particularly high in pregnant women. Chronic infections can occur in transplant and other immune-compromised patients. Successful treatment of chronic hepatitis E has been reported with ribavirin and pegylated interferon-alpha, however severe side effects were observed. We employed the cutthroat trout virus (CTV), a non-pathogenic fish virus with remarkable similarities to HEV, as a potential surrogate for HEV and established an antiviral assay against this virus using the Chinook salmon embryo (CHSE-214) cell line. Ribavirin and the respective trout interferon were found to efficiently inhibit CTV replication. Other known broad-spectrum inhibitors of RNA virus replication such as the nucleoside analog 2'-C-methylcytidine resulted only in a moderate antiviral activity. In its natural fish host, CTV levels largely fluctuate during the reproductive cycle with the virus detected mainly during spawning. We wondered whether this aspect of CTV infection may serve as a surrogate model for the peculiar pathogenesis of HEV in pregnant women. To that end the effect of three sex steroids on in vitro CTV replication was evaluated. Whereas progesterone resulted in marked inhibition of virus replication, testosterone and 17β-estradiol stimulated viral growth. Our data thus indicate that CTV may serve as a surrogate model for HEV, both for antiviral experiments and studies on the replication biology of the Hepeviridae.

[Acute, chronic and fulminant hepatitisE: seven years of experience (2004-2011)]

OBJECTIVE

To study the clinical and epidemiological profiles of in 43cases of acute hepatitis, 5cases of fulminant hepatitis, and one of chronic hepatitis due to hepatitis E virus (HEV), detected over a 7-year period.

PATIENTS

Forty-nine individuals (33male and 10female) treated between 2004 and 2011 in the Hospital Ramón y Cajal (Comunidad de Madrid, Spain). The diagnosis was made by the detection of IgG and IgM anti-HEV and RNA HEV in serum samples. Acute hepatitisE was defined by the presence of IgM anti-HEV and/or RNA HEV in serum, and chronic hepatitisE if the ARN was detectable more than 6months. Fulminant hepatitisE was diagnosed if encephalopathy was observed in addition to IgM anti-HEV and/or RNA HEV in serum.

RESULTS

The median age was 46.67 and 49.6years in acute hepatitisE and fulminant hepatitisE, respectively. The risk factors recorded were travel to endemic areas in 13patients, 4were in contact with animals, 4suffered from hepatic steatosis due to alcohol consumption, 3consumed uncontrolled foods, and 2drank water from streams.

DISCUSSION

HEV is the cause of acute self-limited hepatitis, although 36.73% of the studied cases had to be hospitalised. However a small number of patients, 10.2%, had fulminant hepatitis requiring liver transplant. Chronic hepatitisE is very infrequent in immunocompetent individuals. The increase in incidence of hepatitisE is due to the introduction of better diagnostic tests in recent years.

Hepatitis E: source and route of infection, clinical manifestations and new developments

Hepatitis E was previously thought to be a disease of developing countries causing significant morbidity and mortality in young adults, particularly among pregnant women and patients with pre-existing chronic liver disease. Recent studies have shown that hepatitis E is also an issue in developed countries. In this setting, hepatitis E is a zoonotic infection and causes acute infection mainly in middle-aged and elderly men; and chronic infection in the immunosuppressed. The scope and burden of disease are still emerging. The diagnosis of hepatitis E should be considered in any patient with hepatitis, irrespective of their age or travel history.

New models of hepatitis E virus replication in human and porcine hepatocyte cell lines

Hepatitis E virus (HEV) causes acute, enterically transmitted hepatitis in human. It is associated with large epidemics in tropical and subtropical regions where it is endemic or with sporadic cases in non-endemic regions. Unlike other hepatitis viruses, HEV has several animal reservoirs. Phylogenetic studies on HEV human and animal sequences, and the identification of cases of direct transmission from animal to human strongly suggest that HEV is a zoonotic agent. The lack of efficient cell culture models limits studies on molecular and cellular aspects of HEV infection and species barrier crossing. The present study reports on the development of two new in vitro models of HEV replication using a human hepatoma-derived cell line, HepaRG, and a porcine embryonic stem cell-derived cell line, PICM-19. These two cell lines have morphological and functional properties similar to primary hepatocytes. These in vitro culture systems support HEV replication and release of encapsidated RNA. These new models represent a powerful tool for studying the viral replication cycle, species barrier crossing and virulence factors.

Prevalence of hepatitis E virus infection in pediatric solid organ transplant recipients--a single-center experience

HEV infection appears to be an emerging disease in industrialized countries. The aim of this study was to evaluate the prevalence of HEV infection in pediatric solid organ transplant recipients. One hundred and twenty-four pediatric recipients of liver (n = 41) or kidney (n = 83) transplants aged between one and 18 yr were screened for anti-HEV IgG antibodies. Patients were tested for fecal HEV RNA excretion if they showed anti-HEV seropositivity. As a control group, 108 immunocompetent pediatric patients without liver disease aged between three and 18 yr were screened for anti-HEV IgG. HEV seroprevalence was 2.4% in renal Tx (2/83), 4.9% in liver Tx patients (2/41), and 3.2% overall (4/124). Three of these four patients were HEV RNA-negative. In one renal transplant patient, HEV genotype 3 RNA excretion persisted and liver enzymes were elevated, indicating chronic hepatitis. In the control group, eight patients (7.4%) were HEV IgG-positive without biochemical evidence of hepatitis. The prevalence of HEV infection in pediatric renal or liver transplant recipients is not higher compared with immunocompetent children. Chronic HEV infection with long-term carriage of the virus may develop in pediatric transplant recipients. Autochthonous HEV infection needs to be considered in uncertain cases of hepatitis in immunosuppressed as well as immunocompetent children.

Hepatitis E

Hepatitis E virus (HEV) was discovered during the Soviet occupation of Afghanistan in the 1980s, after an outbreak of unexplained hepatitis at a military camp. A pooled faecal extract from affected soldiers was ingested by a member of the research team. He became sick, and the new virus (named HEV), was detected in his stool by electron microscopy. Subsequently, endemic HEV has been identified in many resource-poor countries. Globally, HEV is the most common cause of acute viral hepatitis. The virus was not initially thought to occur in developed countries, but recent reports have shown this notion to be mistaken. The aim of this Seminar is to describe recent discoveries regarding HEV, and how they have changed our understanding of its effect on human health worldwide.