Molecular evidence of patient-to-patient transmission of hepatitis E virus in a hematology ward

Nosocomial transmission of hepatitis E virus and development of chronic infection: The wider impact of COVID-19

Background

Transmission of hepatitis E virus (HEV) within the healthcare setting is extremely rare. Additionally, the development of chronic HEV infection in association with severe acute respiratory syndrome coronavirus disease 2 (SARS-CoV-2) infection and/or its immunomodulatory therapy has not been reported previously.

Aims

To describe the investigation and management of a nosocomial HEV transmission incident during the coronavirus disease 2019 (COVID-19) pandemic.

Methods

Epidemiological and molecular investigation of two individuals hospitalised with COVID-19 who were both diagnosed with HEV infection.

Results

Findings from our investigation were consistent with transmission of HEV from one patient with a community-acquired HEV infection to another individual (identical HEV sequences were identified in the two patients), most likely due to a breach in infection control practices whilst both patients shared a bed space on the intensive care unit (ICU). Chronic HEV infection requiring treatment with ribavirin developed in one patient with prolonged lymphopaenia attributable to COVID-19 and/or the immunomodulators received for its treatment. Further investigation did not identify transmission of HEV to any other patients or to healthcare workers.

Conclusions

The extraordinary demands that the COVID-19 pandemic has placed on all aspects of healthcare, particularly within ICU settings, has greatly challenged the ability to consistently maintain optimal infection prevention and control practices. Under the significant pressures of the COVID-19 pandemic a highly unusual nosocomial HEV transmission incident occurred complicated further by progression to a chronic HEV infection in one patient.

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

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

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

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

Transmission and Epidemiology of Hepatitis E Virus Genotype 3 and 4 Infections

Following the introduction of robust serological and molecular tools, our understanding of the epidemiology of zoonotic hepatitis E virus (HEV) has improved considerably in recent years. Current thinking suggests that consumption of pork meat products is the key route of infection in humans, but it is certainly not the only one. Other routes of infection include environmental spread, contaminated water, and via the human blood supply. The epidemiology of HEV genotype (gt)3 and gt4 is complex, as there are several sources and routes of infection, and it is likely that these vary between and within countries and over time.

Hiding in Plain Sight? It's Time to Investigate Other Possible Transmission Routes for Hepatitis E Virus (HEV) in Developed Countries

Historically in developed countries, reported hepatitis E cases were typically travellers returning from countries where hepatitis E virus (HEV) is endemic, but now there are increasing numbers of non-travel-related ("autochthonous") cases being reported. Data for HEV in New Zealand remain limited and the transmission routes unproven. We critically reviewed the scientific evidence supporting HEV transmission routes in other developed countries to inform how people in New Zealand may be exposed to this virus. A substantial body of indirect evidence shows domesticated pigs are a source of zoonotic human HEV infection, but there is an information bias towards this established reservoir. The increasing range of animals in which HEV has been detected makes it important to consider other possible animal reservoirs of HEV genotypes that can or could infect humans. Foodborne transmission of HEV from swine and deer products has been proven, and a large body of indirect evidence (e.g. food surveys, epidemiological studies and phylogenetic analyses) support pig products as vehicles of HEV infection. Scarce data from other foods suggest we are neglecting other potential sources of foodborne HEV infection. Moreover, other transmission routes are scarcely investigated in developed countries; the role of infected food handlers, person-to-person transmission via the faecal-oral route, and waterborne transmission from recreational contact or drinking untreated or inadequately treated water. People have become symptomatic after receiving transfusions of HEV-contaminated blood, but it is unclear how important this is in the overall hepatitis E disease burden. There is need for broader research efforts to support establishing risk-based controls.

Hepatitis E in High-Income Countries: What Do We Know? And What Are the Knowledge Gaps?

Hepatitis E virus (HEV) is a positive-strand RNA virus transmitted by the fecal–oral route. HEV genotypes 1 and 2 infect only humans and cause mainly waterborne outbreaks. HEV genotypes 3 and 4 are widely represented in the animal kingdom, and are mainly transmitted as a zoonosis. For the past 20 years, HEV infection has been considered an imported disease in developed countries, but now there is evidence that HEV is an underrecognized pathogen in high-income countries, and that the incidence of confirmed cases has been steadily increasing over the last decade. In this review, we describe current knowledge about the molecular biology of HEV, its clinical features, its main routes of transmission, and possible therapeutic strategies in developed countries.

Hepatitis E virus - key points for the clinical haematologist

In recent years there has been a paradigm shift in our understanding of the epidemiology and clinical features of hepatitis E virus (HEV) infection. Once classically described as an acute hepatitis associated with waterborne outbreaks in areas of poor sanitation, HEV is now recognised to be endemic in Europe and is probably zoonotic in origin. Evidence for transfusion-transmitted HEV has prompted the introduction of blood donor screening in a number of countries, but the risk to the haematology patient from food sources remains. The aim of this review therefore, is to equip the clinical haematologist with the knowledge required to diagnose HEV infection and to aid decision-making in patient management. The article also provides information on addressing patient concerns about their risk of acquiring hepatitis E and how this risk can be mitigated.

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.

Acute Hepatitis E: Two Sides of the Same Coin

The relevance of acute hepatitis E virus (HEV) infections has been underestimated for a long time. In the past, HEV infection had been interpreted falsely as a disease limited to the tropics until the relevance of autochthonous HEV infections in the Western world became overt. Due to increased awareness, the incidence of diagnosed autochthonous HEV infections (predominantly genotype 3) in industrialized countries has risen within the last decade. The main source of infections in industrialized countries seems to be infected swine meat, while infections with the tropical HEV genotypes 1 and 2 usually are mainly transmitted fecal-orally by contaminated drinking water. In the vast majority of healthy individuals, acute HEV infection is either clinically silent or takes a benign self-limited course. In patients who develop a symptomatic HEV infection, a short prodromal phase with unspecific symptoms is followed by liver specific symptoms like jaundice, itching, uncoloured stool and darkened urine. Importantly, tropical HEV infections may lead to acute liver failure, especially in pregnant women, while autochthonous HEV infections may lead to acute-on-chronic liver failure in patients with underlying liver diseases. Immunosuppressed individuals, such as transplant recipients or human immunodeficiency virus (HIV)-infected patients, are at risk for developing chronic hepatitis E, which may lead to liver fibrosis and cirrhosis in the long term. Importantly, specific treatment options for hepatitis E are not approved by the regulation authorities, but off-label ribavirin treatment seems to be effective in the treatment of chronic HEV-infection and may reduce the disease severity in patients suffering from acute liver failure.

Ribavirin for Chronic Hepatitis Prevention among Patients with Hematologic Malignancies

Findings among a cohort of 26 patients who had hematologic malignancies and hepatitis E virus (HEV) infection support that HEV can induce chronic hepatitis. However, a 3-month course of ribavirin can induce a rapid viral clearance, reducing the risk for chronic hepatitis and enabling continuation of cytotoxic treatments for underlying malignancies.

Treatment of autochthonous acute hepatitis E with short-term ribavirin: a multicenter retrospective study

BACKGROUND & AIMS

Hepatitis E virus (HEV) genotypes 3 and 4 cause sporadic cases of infection in developed countries. Being elderly and having an underlying liver disease are the main risk factors for death in this population. Chronic infection has been described in immunocompromised patients. Ribavirin is now the antiviral treatment of choice in solid-organ-transplant recipients with chronic HEV infection. We hypothesized that early short-term treatment of acute HEV infection may be useful for patients with risk factors or undergoing chemotherapy.

METHODS

Between July 2010 and January 2014, 21 patients diagnosed with acute HEV infection were treated with ribavirin, at 600-800 mg/day for up to 3 months. All serum samples were positive for HEV RNA.

RESULTS

Nine patients were treated for severe hepatitis. Six patients were aged >70 years. Four patients were receiving an immunosuppressive therapy for an autoimmune disease and two patients were undergoing chemotherapy for a malignancy. Two patients received a fixed-dose regimen. For all other patients, ribavirin was stopped when HEV became undetectable in the serum. The median duration of ribavirin treatment was 26 days. Two patients developed severe anaemia. Two patients with encephalopathy died. One patient relapsed transiently. All patients were cleared of HEV and regained normalized liver-enzyme levels. Immunosuppressive treatment and chemotherapy could be resumed.

CONCLUSIONS

Treatment of acute HEV infection using ribavirin seems safe and effective. Short-term treatment tailored to viraemia may be the best regimen for this indication.

Acute Hepatitis E Virus infection with coincident reactivation of Epstein-Barr virus infection in an immunosuppressed patient with rheumatoid arthritis: a case report

Background

Hepatitis E virus (HEV) is the most recently discovered of the hepatotropic viruses, and is considered an emerging pathogen in developed countries with the possibility of fulminant hepatitis in immunocompromised patients. Especially in the latter elevated transaminases should be taken as a clue to consider HEV infection, as it can be treated by discontinuation of immunosuppression and/or ribavirin therapy. To our best knowledge, this is a unique case of autochthonous HEV infection with coincident reactivation of Epstein-Barr virus (EBV) infection in an immunosuppressed patient with rheumatoid arthritis (RA).

Case presentation

A 68-year-old Swiss woman with RA developed hepatitis initially diagnosed as methotrexate-induced liver injury, but later diagnosed as autochthonous HEV infection accompanied by reactivation of her latent EBV infection. She showed confounding serological results pointing to three hepatotropic viruses (HEV, Hepatitis B virus (HBV) and EBV) that could be resolved by detection of HEV and EBV viraemia. The patient recovered by temporary discontinuation of immunosuppressive therapy.

Conclusions

In immunosuppressed patients with RA and signs of liver injury, HEV infection should be considered, as infection can be treated by discontinuation of immunosuppression.

Although anti-HEV-IgM antibody assays can be used as first line virological tools, nucleic acid amplification tests (NAAT) for detection of HEV RNA are recommended – as in our case - if confounding serological results from other hepatotropic viruses are obtained. After discontinuation of immunosuppressive therapy, our patient recovered from both HEV infection and reactivation of latent EBV infection without sequelae.

Xenotransplantation and Hepatitis E virus

Xenotransplantation using pig cells, tissues and organs may be associated with the transmission of porcine microorganisms to the human recipient. Some of these microorganisms may induce a zoonosis, that is an infectious disease induced by microorganisms transmitted from another species. With exception of the porcine endogenous retroviruses (PERVs), which are integrated in the genome of all pigs, the transmission of all other microorganisms can be prevented by specified or designated pathogen-free (spf or dpf, respectively) production of the animals. However, it is becoming clear in the last years that the hepatitis E virus (HEV) is one of the viruses which are difficult to eliminate. It is important to note that there are differences between HEV of genotypes (gt) 1 and gt2 on one hand and HEV of gt3 and gt4 on the other. HEV gt1 and gt2 are human viruses, and they induce hepatitis and in the worst case fatal infections in pregnant women. In contrast, HEV gt3 and gt4 are viruses of pigs, and they may infect humans, induce commonly only mild diseases, if any, and are harmless for pregnant women. The goal of this review was to evaluate the risk posed by HEV gt3 and gt4 for xenotransplantation and to indicate ways of their elimination from pigs in order to prevent transmission to the human recipient.

The impact of hepatitis E in the liver transplant setting

Hepatitis E virus (HEV) infection has been identified as a cause of graft hepatitis in liver transplant recipients. The true frequency and clinical importance of HEV infections after liver transplantations is a matter of debate. It is proposed that consumption of HEV-contaminated undercooked meat is a main source for HEV infections in developed countries--which might also account for some hepatitis E cases after organ transplantation. However, HEV is also transmitted by transfusion of blood products, likely representing a previously underestimated risk particularly for patients in the transplant setting. HEV infection can take chronic courses in immunocompromised individuals, associated in some cases with rapid progression to cirrhosis within 1-2 years of infection. Diagnosis in transplanted patients is based on HEV RNA testing as antibody assays are not sensitive enough. Selection of immunosuppressive drugs is important as different compounds may influence viral replication and the course of liver disease. Ribavirin has antiviral activity against HEV and should be administered for at least three months in chronically infected individuals; however, treatment failure may occur. HEV infections have also been linked to a variety of extrahepatic manifestations both during and after resolution of infection. In this review we summarize the emerging data on hepatitis E with a particular focus on the importance of HEV infections for liver transplant recipients.

Transmission, diagnosis, and management of hepatitis E: an update

Hepatitis E virus (HEV) infection is an important public health concern in many developing countries, causing waterborne outbreaks as well as sporadic autochthonous hepatitis. HEV is mainly transmitted by the fecal–oral route in endemic areas through drinking of contaminated water. However, zoonotic transmission from animal reservoirs to humans has also been suggested. Three additional routes of HEV transmission have been proposed to occur: blood borne, human to human, and vertical transmission from mother to child. Acute HEV infection is usually diagnosed by detecting specific anti-HEV antibodies. However, the performance of the available assays in different settings is not optimal. Analysis of HEV ribonucleic acid in biologic specimens such as stools, serum, and liver biopsy by using nucleic acid amplification techniques is also employed. Nonetheless, additional consensus regarding the best technologies suitable for serosurveys and diagnosis of acute HEV infection is also needed. This review article summarizes the current status of HEV infection end epidemiology with particular emphasis in transmission, diagnosis, and clinical management.

Course and treatment of chronic hepatitis E virus infection in lung transplant recipients

OBJECTIVE

Persistent hepatitis E virus (HEV) infections have been described in various transplant cohorts. However, the frequency and the course of HEV infection in lung transplant recipients (Lu-Tr) are not well defined.

METHODS

We retrospectively analyzed serum from 95 Lu-Tr for HEV RNA and anti-HEV immunoglobulin-G (IgG) (with the MP assay). Anti-HEV seroprevalence was compared to that of 537 healthy individuals. Prospective HEV screening was subsequently initiated in Lu-Tr.

RESULTS

Elevated liver enzymes were observed in 44/95 (46.3%) patients. Anti-HEV IgG was present in 5/95 patients (5.3%), revealing a slightly higher prevalence compared to controls (2%, 11/537; P = 0.07). Chronic HEV infection with detectable viral replication was confirmed by polymerase chain reaction in 3 (3.2%) patients, all of whom demonstrated clinical and biochemical features of active liver disease (maximum alanine aminotransferase [ALTmax ] 89, 215, and 270 IU/L, respectively). One patient had died from multi-organ failure in combination with liver cirrhosis before HEV diagnosis. Two additional patients with chronic hepatitis E were identified during prospective screening (ALTmax 359 and 318 IU/L). All patients still alive commenced ribavirin therapy for 5 months, with dose adjustment (400-600 mg/day) according to renal function and hemoglobin level. Sustained resolution of HEV infection occurred in 2 patients. One patient is still under treatment, and the fourth died from graft failure considered unrelated to ribavirin therapy.

CONCLUSION

Chronic hepatitis E should be considered in the differential diagnosis of elevated liver enzymes, which are commonly seen in Lu-Tr. We observed 1 case of end-stage liver cirrhosis and death in an HEV-infected subject, who was not treated with ribavirin. Given this potentially devastating consequence, ribavirin therapy of persistent HEV infection appears to be acceptably safe and effective in Lu-Tr. However, larger prospective studies are warranted.

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.

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.

The clinical course of hepatitis E virus infection in patients of a tertiary Dutch hospital over a 5-year period

BACKGROUND

Hepatitis E virus (HEV) has long been known as a major cause of acute hepatitis in developing countries with occasional travel-related cases in developed countries, most of them belonging to genotype 1. Currently, genotype 3 HEV is recognized as an emerging public health issue in developed countries and can cause a chronic hepatitis in immunocompromised patients.

OBJECTIVES

The aim of this study was to get an overview of the clinical course of HEV infection, from July 2007 to December 2012, and further characterize HEV in patients of the University Medical Center Groningen (UMCG) over a 5-year time period.

METHODS

Since the second half of 2007, patients in the UMCG with unexplained hepatitis were screened for HEV and clinical data were collected. HEV was characterized by sequencing of the ORF1 and ORF2 regions.

RESULTS

In total, 34 patients of the 1129 tested patients showed HEV viremia. The majority of the infected patients were immunocompromised; 18 were solid organ transplant (SOT) patients and 9 were patients immunocompromised for other reasons. Seven patients diagnosed with HEV were immunocompetent. Viral genotyping revealed genotype 3 isolates, mostly genotype 3c.

CONCLUSION

Non-travel related HEV hepatitis is an important diagnosis. In immunocompromised patients HEV infection often has major clinical impact, necessitating medical intervention including antiviral treatment. In immunocompetent patients, the detection could expand our understanding about the route of transmission and the relation with the zoonotic origin. Therefore, besides an increasing awareness for HEV among clinicians and medical microbiologists, diagnostics should be routinely incorporated into standard patients care.

Chronic hepatitis e virus infection and treatment

It is now well accepted that hepatitis E virus (HEV) infection can induce chronic hepatitis and cirrhosis in immunosuppressed patients. Chronic genotype-3 HEV infections were first reported in patients with a solid-organ transplant. Thereafter, cases of chronic HEV infection have been reported in patients with hematological disease and in those who are human immunodeficiency virus (HIV)-positive. HEV-associated extra-hepatic manifestations, including neurological symptoms, kidney injuries, and hematological disorders, have been also reported. In transplant patients, reducing the dosage of immunosuppressive drugs allows the virus to be cleared in some patients. In the remaining patients, as well as hematological patients and patients who are HIV-positive, anti-viral therapies, such as pegylated interferon and ribavirin, have been found to be efficient in eradicating HEV infection. This review summarizes our current knowledge of chronic HEV infection, its treatment, and the extra-hepatic manifestations induced by HEV.

Hepatitis E virus infection

PURPOSE OF REVIEW

The spectrum of hepatitis E virus (HEV) infection has changed over the past 2 years, especially in the developed world. Herein, we review the progress made in studying the epidemiology, hepatic, and extrahepatic manifestations, and the treatment of HEV infection, over the past 2 years.

RECENT FINDINGS

HEV infection is an underdiagnosed disease because of the use of low-sensitivity serological assays. In addition to the four known genotypes, other new genotypes have also been recently described. HEV infection is not only a self-limiting disease but it can also evolve to chronic hepatitis and cirrhosis in organ transplant patients, hematological patients receiving chemotherapy, and HIV patients. HEV can also cause extrahepatic manifestations, such as neurological symptoms, kidney injury, and hematological disorders. Pegylated interferon and ribavirin have been found to effectively treat HEV infection.

SUMMARY

HEV is a worldwide disease that can cause hepatic and extrahepatic manifestations.

Risk of zoonotic transmission of HEV from rabbits

Hepatitis E virus strains from rabbits indicate that these mammals may be a reservoir for HEVs that cause infection in humans. Further issues remain to be clarified, including whether the genotype of rabbit HEV differs from human and swine HEV genotype 3 and whether rabbit HEV can infect human and other animals. HEV was found in farmed rabbits in several geographic areas of China, in USA and more recently in France. The prevalence of antibodies against HEV was 36%, 57% and 55% in rabbits from Virginia (USA), Gansu Province and Beijing (China), respectively. HEV RNA was detected in 16.5% of serum samples from farmed rabbits in Virginia, 7.5% in Gansu Province and 7.0% in Beijing. HEV RNA was detected in 7% of bile samples from farmed rabbits and in 23% of liver samples from wild rabbits in France. The full-length genomic sequences analysis indicates that all the rabbit strains belong to the same clade. Nucleotide sequences were 72.2-78.2% identical to HEV genotypes 1-4. Comparison with HEV sequences of human strains circulating in France and reference sequences identified a human strain closely related to rabbit HEV. A 93-nucleotide insertion in the X domain of the ORF1 of the human strain and in all the rabbit HEV strains was found. Moreover, the ability of rabbit HEV to cause cross-species infection in a pig model has recently been demonstrated. Rabbit HEV can replicate efficiently in human cell lines. Collectively, these data support the possibility of zoonotic transmission of HEV from rabbits.

Chronic hepatitis e in heart transplant recipients

Chronic courses of hepatitis E virus (HEV) infections have been described in immunosuppressed patients. We aimed to study the role of HEV infections in heart transplant recipients (HTR). 274 HTR were prospectively screened for HEV infection using an anti-HEV-IgG ELISA and HEV-PCR. In addition, 137 patients undergoing cardiac surgery (non-HTR) and 537 healthy subjects were studied cross-sectionally. The anti-HEV-IgG seroprevalence was 11% in HTR, 7% in non-HTR and 2% in healthy controls (HTR vs. healthy controls p<0.0001; non-HTR vs. healthy controls p<0.01). Anti-HEV tested positive in 4.0% in control cohorts of other immunocompromised patients (n = 474). Four HTR (1.5%) were chronically infected with HEV as shown by HEV-PCR and all four patients had liver transaminases of >200 IU/L and histological or clinical evidence of advanced liver disease. In three patients ribavirin treatment was successful with a sustained biochemical and virological response while treatment failed in one cirrhotic patient after ribavirin dose reduction. Heart transplant recipients and patients undergoing cardiac surgery have an increased risk for HEV infections. Chronic hepatitis E may explain elevated liver enzymes in heart transplant recipients. Treatment of HEV infection with ribavirin is effective but the optimal dose and duration of ribavirin therapy remains to be determined.

[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.

Low risk of hepatitis E virus reactivation after haematopoietic stem cell transplantation

BACKGROUND

Hepatitis E virus (HEV) is an emerging cause of acute hepatitis in industrialized countries. HEV infection can evolve to chronic hepatitis in immunocompromised patients. Additionally, HEV reactivation after haematopoietic stem cell transplantation has been reported.

OBJECTIVE

To assess the prevalence of anti-HEV antibodies in patients who underwent haematopoietic stem cell transplantation in south-western France and the risk of HEV reactivation after transplantation.

STUDY DESIGN

We have investigated the prevalence of anti-HEV antibodies in 88 patients who underwent allogenic or autologous haematopoietic stem cell transplantation with two anti-HEV IgG assays and have evaluated the risk of HEV reactivation in pretransplant seropositive patients by testing for HEV RNA in blood samples collected after stem cell transplantation.

RESULTS

While only 11 patients (12.5%) tested positive for anti-HEV IgG with the Adaltis assay, 32 patients (36.4%) tested positive for anti-HEV IgG with the Wantai assay before transplantation. Three anti-HEV IgG positive patients were also anti-HEV IgM positive. Plasma HEV RNA was negative in all the patients before transplantation. We looked for HEV reactivation in pretransplant seropositive patients by testing 89 blood samples for HEV RNA 1, 3 and 6 months after transplantation. We detected no reactivation. Similarly, we detected no HEV RNA in pretransplant seronegative patients after transplantation.

CONCLUSION

Despite strong immunosuppression, the risk of HEV reactivation after stem cell transplantation appears to be very low.

Circulation of genotype 4 hepatitis E virus in Europe: first autochthonous hepatitis E infection in France

BACKGROUND

Human HEV infections reported in Europe without previous travel to endemic regions are linked to exposure to genotype 3 Hepatitis E virus (HEV).Genotype 3 is widely distributed through human cases and zoonotic reservoir. The geographical distribution of genotype 4 is limited to Asian countries.

OBJECTIVES

The first human case of autochthonous genotype 4 hepatitis E infection was reported in France.

STUDY DESIGN

The HEV infection was described in an immunosuppressed patient, presenting an acute myeloblastic leukemia. Investigation of the case was performed on detection of HEV markers in the patient and in the environment.

RESULTS

Hepatitis E infection was diagnosed on the basis of HEV RNA viremia, and detection of anti-HEV IgM. The prognostic of leukemia was favorable and HEV was cleared without relapsing. HEV isolate was classified into genotype 4.

CONCLUSIONS

The recent characterization of genotype 4 HEV through swine surveillance in Europe and the description of the first human case in France open interesting questions about the circulation of this genotype: health risks in human population, transmission patterns, and zoonotic reservoir.

Progress in research of chronic hepatitis E

Hepatitis E caused by hepatitis E virus (HEV) has long been considered as an acute self-limiting disease. But in recent years, cases which progress to chronic liver disease mainly in immunocompromised patients have been detected, such as organ transplant recipients and patients with human immunodeficiency virus infection. Studies indicate that chronic HEV hepatitis may result in cirrhosis and end-stage liver disease. Since clearance of the virus depends on the development of specific immunity, lowering the immunosuppressive medication is generally recommended. Ribavirin, interferon-alpha-2a and interferon-alpha-2b were found to be effective in patients with chronic HEV infection.

Genotype 3 diversity and quantification of hepatitis E virus RNA

Genotype 3 hepatitis E viruses (HEVs) are distributed across the world and are now considered to be an emerging public health concern in industrialized countries. At least 10 genotype 3 subtypes have been identified in humans and animals worldwide. It was recently reported that the sensitivities of HEV RNA assays differ greatly. We have assessed the influence of genotype 3 diversity on the performances of two HEV RNA assays: one targeting the ORF3 gene and the other targeting the ORF2 gene. We tested a panel of 5 HEV-positive reference samples of genotypes 3a, 3b, 3c, 3e, and 3f at 10-fold serial dilutions. The HEV RNA concentrations obtained with both reverse transcription (RT)-PCRs were correlated, but the RT-PCR based on ORF2 underestimated the HEV RNA concentrations. The mean [ORF3 - ORF2] difference was 1.41 log copies/ml. We also tested 34 clinical specimens of genotypes 3c (n = 15), 3e (n = 4), and 3f (n = 15), representing the most prevalent subtypes in Europe. The mean [ORF3 - ORF2] differences were 1.41 log copies/ml for genotype 3c, 0.96 log copies/ml for genotype 3e, and 0.70 log copies/ml for genotype 3f. The bias between the 2 RT-PCR assays was significantly greater for genotype 3c than for genotype 3f (P = 0.007). We therefore recommend the use of an RT-PCR protocol based on ORF3 to quantify HEV RNA of genotype 3 strains.

Chronic hepatitis e infection resulting in graft failure in a liver transplant tourist

Hepatitis E, usually an acute hepatitis in the immunocompetent, has a chronic form described in immunocompromised hosts. We report the clinical course and outcome of an adult liver transplant recipient whose posttransplant period was complicated by chronic hepatitis E, Epstein-Barr virus infection, and cellular rejection of the graft.

The molecular epidemiology of hepatitis E virus infection

Molecular characterization of various hepatitis E virus (HEV) strains circulating among humans and animals (particularly swine, deer and boars) in different countries has revealed substantial genetic heterogeneity. The distinctive four-genotype distribution worldwide of mammalian HEV and varying degrees of genetic relatedness among local strains suggest a long and complex evolution of HEV in different geographic regions. The population expansion likely experienced by mammalian HEV in the second half of the 20th century is consistent with an extensive genetic divergence of HEV strains and high prevalence of HEV infections in many parts of the world, including developed countries. The rate and mechanisms of human-to-human transmission and zoonotic transmission to humans vary geographically, thus contributing to the complexity of HEV molecular evolution.

Hepatitis E virus infection in developed countries

Hepatitis E was considered to be endemic infectious disease in developing countries in tropical or subtropical regions with poor sanitary conditions. Large, previously reported outbreaks were mainly due to contaminated water or heavy flooding. Prototype hepatitis E viruses of genotypes I and II were obtained from such endemic cases. In developed countries, in contrast, hepatitis E was rare and diagnosed only in travelers or imported cases. However, the development of accurate diagnostic tests, mainly PCR detection elucidated that autochthonous hepatitis E in developed countries is far more common than previously thought. Although the main route of transmission is food-borne, other routes including blood-borne have been suggested. Recent developments of gene-based diagnostic assays and molecular epidemiology have disclosed the significance of hepatitis E virus infection in developed countries.

Hepatitis E in high-income countries

PURPOSE OF REVIEW

To discuss recent advances in characterising viral Hepatitis E (HEV) in nonendemic regions, with a special focus on epidemiology in high-income countries, different clinical aspects of the disease, possible zoonotic origin of these cases and the improvement of Hepatitis E diagnosis.

RECENT FINDINGS

In high-income countries, most cases of Hepatitis E are acquired locally and not imported from endemic regions. Different genotypes are involved in indigenous cases than those in endemic regions. Particular population groups, such as transplant recipients, can be persistently infected by hepatitis E and develop chronic diseases. Viral hepatitis E is frequently observed in people in animal care occupations. Indeed, HEV has a large animal reservoir and this emerging disease in developed countries has probably a zoonotic origin.

SUMMARY

Recent studies on viral Hepatitis E have shown that the epidemiology of the disease differs between endemic and nonendemic regions. Several lines of evidence suggest that Hepatitis E is more frequent than was suspected and that it has a possible animal origin. Particular attention must be paid to the possible chronic evolution of various forms of the disease. Surveillance of human cases and animal reservoirs must be developed further.

[Hepatitis E virus: A new entity]

Hepatitis E virus (HEV) is a RNA enterically transmitted virus that causes large waterborne epidemics of acute hepatitis E in endemic regions (Asia and Africa). Sporadic hepatitis E is an emerging disease in developed countries such as France. The majority of acute hepatitis E in France is indigenous (non travel-associated) and is due to infection with HEV genotype 3. Diagnosis is made on the presence of specific serum antibodies and on viral RNA detection in serum or stools. Characteristic pathological signs of acute hepatitis E are severe intralobular necrosis, polymorph inflammation and acute cholangitis in portal tract with numerous neutrophils. Severe forms of hepatitis are associated with underlying chronic liver disease such alcoholic disease. In immunocompetent patients, HEV causes acute resolutive hepatitis and there is no chronic evolution. Conversely, chronic hepatitis E is frequent in immunocompromised patients with a risk of rapid evolution to cirrhosis. Histologic lesions of chronic hepatitis E are similar to those observed in patients chronically infected with hepatitis C virus with dense lymphocytic portal infiltrate, constant peacemeal necrosis and fibrosis.

Hepatitis E virus excretion can be prolonged in patients with hematological malignancies

BACKGROUND

Hepatitis E virus (HEV) is transmitted via the fecal-oral route and locally acquired sporadic hepatitis E can occur in Western countries. Chronic hepatitis E virus infections have been recently described in solid organ transplant recipients. There is little data on the evolution of hepatitis E in patients immunocompromised for other reasons.

OBJECTIVES

The aim of this study was to evaluate the clinical course of hepatitis E in patients immunocompromised because of hematological malignancies.

STUDY DESIGN

Starting on November 2003, all patients in the Toulouse University Hospital Hematology Department with unexplained elevated transaminases were tested for hepatitis E using viral RNA detection in serum or stools and serology.

RESULTS

Acute hepatitis E was diagnosed in six middle-aged hematology patients. All cases were autochthonous. HEV strains were genotype 3. All patients had a significant increase of transaminases (6-95 upper limit normal) and only two had HEV IgG. Five patients were asymptomatic and one had jaundice. Transmission of HEV occurred between two patients who had overlapping stays in the hematology ward. All five evaluable patients ultimately cleared their HEV but viremia was prolonged over 6 months in three patients and specific treatment had to be postponed in two patients.

CONCLUSION

Screening for HEV should be carried out routinely in hematology patients with elevated transaminases, and patient-to-patient transmission is a concern. Further studies are required to determine whether management of malignancy, particularly stem-cell transplantation should be adapted to HEV status.

Hepatitis E virus infection as a cause of graft hepatitis in liver transplant recipients

Hepatitis E virus (HEV) infection induces self-limiting liver disease in immunocompetent individuals. Cases of chronic hepatitis E have recently been identified in organ transplant recipients. We questioned if chronic hepatitis E plays a role in graft hepatitis after liver transplantation in a low endemic area. Two hundred twenty-six liver transplant recipients, 129 nontransplanted patients with chronic liver disease, and 108 healthy controls were tested for HEV antibodies. HEV RNA was investigated in all sera from transplanted patients. HEV antibodies were detected in 1 healthy control (1%), 4 patients with chronic liver disease (3%), and 10 liver transplant recipients (4%). Three liver transplant patients also tested positive for HEV RNA. Two of them developed persistent viremia with HEV genotype 3. The patients were anti-HEV immunoglobulin G-negative and HEV RNA-negative before transplantation and had an episode of acute hepatitis 5 or 7 months after transplantation, which led to advanced liver fibrosis after 22 months in 1 patient. Seroconversion to anti-HEV occurred not before 4 months after the first detection of HEV RNA. The possibility of reverse zoonotic transmission was experimentally confirmed by the infection of 5 pigs with a patient's serum. The pigs showed histological inflammation in the liver, and HEV RNA was detectable in different organs, including muscle. In conclusion, the prevalence of HEV infection in Central European liver transplant recipients is low; however, chronic hepatitis E may occur and needs to be considered in the differential diagnosis of graft hepatitis. The diagnosis of HEV infection should be based on HEV RNA determination in immunosuppressed patients. We suggest that immunocompromised individuals should avoid eating uncooked meat and contact with possibly HEV-infected animals.