Fatal course of an autochthonous hepatitis E virus infection in a patient with leukemia in Germany

Case Report: Chronic hepatitis E in a hematopoietic stem cell transplant recipient: The first report of hepatitis E virus genotype 4 causing chronic infection in a non-solid organ recipient

Hepatitis E virus (HEV) is one of the most important public health issues around the world, and chronic HEV infection has been reported in immunosuppressed individuals. This study reported a male case, with very severe aplastic anemia (AA), who developed chronic hepatitis E after hematopoietic stem cell transplantation (HSCT). Abnormal alanine aminotransferase (ALT) appeared after HSCT and persisted for twenty-nine months. The case was seropositive for anti-HEV IgG and IgM after HSCT. Twenty-two months after HSCT, HEV RNA and antigen (Ag) testing were positive and persisted for five and seven months, respectively. Positive stains of HEV Ag were present in a liver biopsy sample. HEV Ag was present in bone marrow. The individual rapidly developed liver cirrhosis and was rescued by a regimen of oral ribavirin. These factors suggested there is a risk of HEV infection in HSCT recipients.

Clinical features of hepatitis E infections in patients with hematologic disorders

Hepatitis E virus is increasingly being reported to cause chronic infection in immunocompromised patients. However, less is known about patients with an underlying hematologic disease. In particular, the impact of hepatitis E infection on oncological therapy has been poorly described. In this retrospective single-center study, we analyzed 35 hematologic patients with hepatitis E, including 20 patients under active oncological treatment and 15 patients who were in the posttreatment follow-up or under active surveillance. The primary aim was to describe the clinical courses with particular focus on any hepatitis E-related therapy modifications of cancer-directed therapy. In the majority (60%) of patients who were under active oncological treatment, hepatitis E-related therapy modifications were made, and 25% of deaths were due to progression of the hematologic disease. In patients receiving concomitant oncological treatment, no hepatitis Erelated deaths occurred. In contrast, two patients in the follow-up group died from hepatitis E-associated acute-onchronic liver failure. Chronic hepatitis E was observed in 34% of all cases and 43% received ribavirin therapy; of those, 27% achieved a sustained virological response. CD20-directed therapy was the only independent risk factor for developing chronic hepatitis E. We conclude that CD20-directed treatment at any time point is a risk factor for developing chronic hepatitis E. Nevertheless, since mortality from the progression of hematologic disease was higher than hepatitis E-related mortality, we suggest careful case-by-case decisions on modifications of cancer treatment. Patients in the posttreatment follow-up phase may also suffer from severe courses and hepatitis E chronicity occurs as frequently as in patients undergoing active therapy.

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.

Swine hepatitis E virus: Cross-species infection, pork safety and chronic infection

Swine hepatitis E virus (swine HEV) belongs to the species Orthohepevirus A within the genus Orthohepevirus in the family Hepeviridae. Four different genotypes of swine HEV within the species Orthohepevirus A have been identified so far from domesticated and wild swine population: genotypes 3 (HEV-3) and 4 (HEV-4) swine HEVs are zoonotic and infect humans, whereas HEV-5 and HEV-6 are only identified from swine. As a zoonotic agent, swine HEV is an emerging public health concern in many industrialized countries. Pigs are natural reservoir for HEV, consumption of raw or undercooked pork is an important route of foodborne HEV transmission. Occupational risks such as direct contact with infected pigs also increase the risk of HEV transmission in humans. Cross-species infection of HEV-3 and HEV-4 have been documented under experimental and natural conditions. Both swine HEV-3 and swine HEV-4 infect non-human primates, the surrogates of man. Swine HEV, predominantly HEV-3, can establish chronic infection in immunocompromised patients especially in solid organ transplant recipients. The zoonotic HEV-3, and to lesser extent HEV-4, have also been shown to cause neurological diseases and kidney injury. In this review, we focus on the epidemiology of swine HEV, host and viral determinants influencing cross-species HEV infection, zoonotic infection and its associated pork safety concern, as well as swine HEV-associated chronic infection and neurological diseases.

Updates in Hepatitis E virus (HEV) field; lessons learned from human liver chimeric mice

Hepatitis E virus (HEV) is the most common cause of viral hepatitis globally, and it is an emerging pathogen in developed countries. In vivo studies of HEV have long been hindered due to the lack of an efficient small animal model. Recently, human liver chimeric mice were described as an elegant model to study chronic HEV infection. HEV infection was established in mice with humanized liver that were challenged with stool preparations containing HEV genotype (gt)1 and/or gt3. An increase in viral load and the level of HEV Ag in mouse samples were markers of active infection. Plasma-derived HEV preparations were less infectious. The kinetics of HEV ORF2 Ag during HEV infection and its impact on HEV diagnosis were described in this model. In addition, the nature of HEV particles and HEV ORF2 Ag were characterized. Moreover, humanized mice were used to study the impact of HEV infection on the hepatic innate transcriptome and evaluation of anti-HEV therapies. This review highlights recent advances in the HEV field gathered from well-established experimental mouse models, with an emphasis on this model as a tool for elucidating the course of HEV infection, the study of the HEV life cycle, the interaction of the virus with the host, and the evaluation of new anti-HEV therapies.

The burden of hepatitis E among patients with haematological malignancies: A retrospective European cohort study

BACKGROUND & AIMS

The burden of hepatitis E virus (HEV) infection among patients with haematological malignancy has only been scarcely reported. Therefore, we aimed to describe this burden in patients with haematological malignancies, including those receiving allogeneic haematopoietic stem cell transplantation.

METHODS

We conducted a retrospective, multicentre cohort study across 11 European centres and collected clinical characteristics of 50 patients with haematological malignancy and RNA-positive, clinically overt hepatitis E between April 2014 and March 2017. The primary endpoint was HEV-associated mortality; the secondary endpoint was HEV-associated liver-related morbidity.

RESULTS

The most frequent underlying haematological malignancies were aggressive non-Hodgkin lymphoma (NHL) (34%), indolent NHL (iNHL) (24%), and acute leukaemia (36%). Twenty-one (42%) patients had received allogeneic haematopoietic stem cell transplantation (alloHSCT). Death with ongoing hepatitis E occurred in 8 (16%) patients, including 1 patient with iNHL and 1 patient >100 days after alloHSCT in complete remission, and was associated with male sex (p = 0.040), cirrhosis (p = 0.006) and alloHSCT (p = 0.056). Blood-borne transmission of hepatitis E was demonstrated in 5 (10%) patients, and associated with liver-related mortality in 2 patients. Hepatitis E progressed to chronic hepatitis in 17 (34%) patients overall, and in 10 (47.6%) and 6 (50%) alloHSCT and iNHL patients, respectively. Hepatitis E was associated with acute or acute-on-chronic liver failure in 4 (8%) patients with 75% mortality. Ribavirin was administered to 24 (48%) patients, with an HEV clearance rate of 79.2%. Ribavirin treatment was associated with lower mortality (p = 0.037) and by trend with lower rates of chronicity (p = 0.407) when initiated <24 and <12 weeks after diagnosis of hepatitis E, respectively. Immunosuppressive treatment reductions were associated with mortality in 2 patients (28.6%).

CONCLUSION

Hepatitis E is associated with mortality and liver-related morbidity in patients with haematological malignancy. Blood-borne transmission contributes to the burden. Ribavirin should be initiated early, whereas reduction of immunosuppressive treatment requires caution.

LAY SUMMARY

Little is known about the burden of hepatitis E among patients with haematological malignancy. We conducted a retrospective European cohort study among 50 patients with haematological malignancy, including haematopoietic stem cell transplant recipients, with clinically significant HEV infection and found that hepatitis E is associated with hepatic and extrahepatic mortality, including among patients with indolent disease or among stem cell transplant recipients in complete remission. Hepatitis E virus infection evolved to chronic hepatitis in 5 (45.5%) patients exposed to a rituximab-containing regimen and 10 (47.6%) stem cell transplant recipients. Reducing immunosuppressive therapy because of hepatitis E was associated with mortality, while early ribavirin treatment was safe and effective.

Hepatitis E Virus Infection in Blood Donors and Risk to Patients in the United States and Canada

Hepatitis E virus (HEV) is the most common cause of acute hepatitis worldwide including large water-borne outbreaks, zoonotic infections and transfusion transmissions. Several countries have initiated or are considering blood donor screening in response to high HEV-RNA donation prevalence leading to transfusion-transmission risk. Because HEV transmission is more common through food sources, the efficacy of blood donor screening alone may be limited. HEV-nucleic acids in 101 489 blood donations in the United States and Canada were studied. A risk-based decision-making framework was used to evaluate the quantitative risks and cost-benefit of HEV-blood donation screening in Canada comparing three scenarios: no screening, screening blood for all transfused patients or screening blood for only those at greatest risk. HEV-RNA prevalence in the United States was one per 16 908 (95% confidence interval [CI], 1:5786-1:81987), whereas Canadian HEV-RNA prevalence was one per 4615 (95% CI, 1:2579-1:9244). Although 4-fold greater, Canadian HEV-RNA prevalence was not significantly higher than in the United States. Viral loads ranged from 20 to 3080 international units per mL; all successfully typed infections were genotype 3. No HEV-RNA false-positive donations were identified for 100 percent specificity. Without donation screening, heart and lung transplant recipients had the greatest HEV-infection risk (1:366962) versus kidney transplant recipients with the lowest (1:2.8 million) at costs of $225 546 to $561 810 per quality-adjusted life-year (QALY) gained for partial or universal screening, respectively. Higher cost per QALY would be expected in the United States. Thus, HEV prevalence in North America is lower than in countries performing blood donation screening, and if implemented, is projected to be costly under any scenario.

Acute liver failure caused by hepatitis E virus genotype 3 and 4: A systematic review and pooled analysis

BACKGROUND & AIMS

Acute liver failure caused by hepatitis E virus genotype 3 and 4 has been rarely described. Because of the presence of a short golden therapeutic window in patients with viral acute liver failure from other causes, it is possible that early recognition and treatment might reduce the morbidity and mortality. We performed a systematic review and pooled analysis of acute liver failure caused by hepatitis E virus genotype 3 and 4.

METHODS

Two reviewers appraised studies after searching multiple databases on June 12th, 2017. Appropriate tests were used to compare hepatitis E virus genotype 3 vs 4, suspected vs confirmed genotypes, hepatitis E virus-RNA positive vs negative, and to discern important mortality risk factors.

RESULTS

We identified 65 patients, with median age 58 years (range: 3-79), and a male to female ratio of 1.2:1. The median bilirubin, ALT, AST and alkaline phosphatase (expressed by multiplication of the upper limit of normal) levels were 14.8, 45.3, 34.8 and 1.63 respectively. Antihepatitis E virus IgG, antihepatitis E virus IgM and hepatitis E virus-RNA were positive in 84%, 91% and 86% of patients respectively. The median interval from symptoms onset to acute liver failure was 23 days, and 16 patients underwent liver transplantation. Final outcome was reported in 58 patients and mortality was 46%. Age was a predictor of poor prognosis in multivariate analysis. No important differences were found between patients infected with genotype 3 vs 4, patients with confirmed vs suspected genotypes, or patients with positive vs negative RNA.

CONCLUSION

Acute liver failure caused by hepatitis E virus genotype 3 and 4 is rare, similar between genotypes, occurs commonly in middle-aged/elderly patients and has a very high mortality. Age is predictive of poor prognosis in multivariate analysis.

Impact of hepatitis E virus testing on the safety of blood components in Germany - results of a simulation study

Hepatitis E virus (HEV) infections may be acquired through transfusion of blood components. As transfusion-transmitted infections mostly affect vulnerable individuals, measures to ensure the supply of safe blood components are under discussion. On the basis of the epidemiological situation in Germany, different testing strategy scenarios were investigated through simulation studies. Testing for HEV RNA by nucleic acid amplification technique (NAT) assays with a pool size of 96, and a 95% LoD of 20 IU/ml will result in an 80% reduction in expected HEV transmissions as well as of consequent chronic infections with subsequent severe complications.

Molecular and serological infection marker screening in blood donors indicates high endemicity of hepatitis E virus in Poland

BACKGROUND

Until now, markers of hepatitis E virus (HEV) infection have not been studied in blood donors throughout Poland, and no acute case of HEV infection has been closely documented or confirmed by HEV RNA detection. The prevalence of HEV infection markers, including HEV RNA in Polish blood donors and virus genotypes was investigated.

STUDY DESIGN AND METHODS

In total, 12,664 individual donations from 22 Polish blood transfusion centers were tested for HEV RNA by transcription-mediated amplification. In addition, 3079 first-time donors sampled throughout Poland also were screened for antibodies to HEV. HEV RNA and immunoglobulin M-positive donations were confirmed using real-time reverse transcription-polymerase chain reaction and Western blotting, respectively.

RESULTS

Ten donors were identified as RNA initial reactive (one of 1266 donors), and six (one of 2109) were identified as repeat reactive and confirmed by real-time reverse transcription-polymerase chain reaction or seroconversion. Sequence analysis identified HEV Genotype 3c in one donor and Genotype 3i in two others. On average, 43.5% of donors were immunoglobulin G-positive. Immunoglobulin G seroprevalence ranged from 22.7% to 60.8% in group ages 18 to 27 years and 48 to 57 years, respectively and differed between administrative regions from 28.9% in Podlasie to 61.3% in Wielkopolska. Thirty-nine of the donors were immunoglobulin M-positive, and seven donors were IgM positive only (0.2%). Of 37 immunoglobulin M-reactive samples tested by Western blot, 24 (64.9%) were confirmed.

CONCLUSIONS

The current results indicate a high level of HEV endemicity throughout Poland compared with other countries. There is an urgent need to consider the protection of recipients of blood components against transfusion-transmitted HEV infection.

[Risk of transmission of blood-derived pathogens by transfusion in Poland]

Blood transfusion in Poland is the safest in history. High virological level of safety has been achieved mainly by improving not only the qualification of donors and methods used for donor screening, but also applying leukoreduction, pathogen reduction technology and grace period for serum.In this article, we discuss the improvement of the epidemic situation among blood donors for hepatitis B virus (HBV) and hepatitis C virus (HCV) and the increasing trend for HIV. Preliminary results of residual risk calculation for these pathogens are presented.Hepatitis E virus (HEV) and Babesia microti were considered as new factors potentially relevant for the safety of blood transfusion in our country. Due to evidence of West Nile virus (WNV) circulation in the ecosystem in Poland, it is also necessary to monitor the infections with this pathogen.In this article, it was emphasized that the reporting of all possible complications associated with transfusion and meticulous implementation of the look-back procedure play a key role for monitoring the risk of transmission of infectious agents by blood. It is especially important in view of the increasing epidemiological problems associated with emerging infectious agents.

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.

Is hepatitis E virus an emerging problem in industrialized countries?

Hepatitis E virus (HEV) is yearly responsible for approximately 20 million infections worldwide. Although most infections occur in developing countries, HEV appears to be an emerging problem in several industrialized countries, where it is mostly associated with either traveling to an HEV endemic area or contact with pigs, which represent a major reservoir of HEV. The major risk groups for HEV infection and its ensuing complications are elderly men, pregnant women, young children, immunocompromised patients, patients with preexisting liver disease, and workers that come into close contact with HEV-infected animals. Whereas HEV mainly causes acute self-limiting infections, chronic infections may occur among immunocompromised patients (e.g., transplant recipients and human immunodeficiency virus [HIV]-infected patients). Accordingly, HEV-HIV coinfection leads to accelerated liver cirrhosis and increased mortality rates compared to HEV infection alone, which is, except during pregnancy, usually associated with only low mortality. In the Western world, the most common genotype (gt) causing HEV infection is gt 3. Ribavirin (RBV) and interferon have been used successfully for treatment of HEV, but this treatment is contraindicated in certain patient groups. Therefore, novel antiviral compounds are highly needed, especially given that viral isolates with RBV resistance have been recently identified. Moreover, eradication of HEV is hampered by long-term environmental persistence of the virus, which represents a continuous source of the virus. In 2011, the first prophylactic HEV vaccine, Hecolin, was approved in China, but it is not yet globally available. In this review, we will discuss the molecular virology of HEV, mode of transmission in industrialized countries, and potential implications for different specific patient populations.

Epidemiology of Hepatitis E Virus in European Countries

Over the last decade the seroprevalence of immunoglobulin (IgG) anti hepatitis E virus (HEV) has been increasing in European countries and shows significant variability among different geographical areas. In this review, we describe the serological data concerning the general population and risk groups in different European countries. Anti-HEV antibody prevalence ranged from 1.3% (blood donors in Italy) to 52% (blood donors in France). Various studies performed on risk groups in Denmark, Moldova and Sweden revealed that swine farmers have a high seroprevalence of HEV IgG (range 13%-51.1%), confirming that pigs represent an important risk factor in HEV infection in humans. Subtypes 3e,f are the main genotypes detected in the European population. Sporadic cases of autochthonous genotype 4 have been described in Spain, France, and Italy. Although most HEV infections are subclinical, in immune-suppressed and transplant patients they could provoke chronic infection. Fulminant hepatitis has rarely been observed and it was related to genotype 3. Interferon and ribavirin treatment was seen to represent the most promising therapy.

Hepatitis E virus in the countries of the Middle East and North Africa region: an awareness of an infectious threat to blood safety

PURPOSE

Hepatitis E virus (HEV) is mainly transmitted through contaminated water supplies which make the virus endemic in developing countries including countries of the Middle East and North Africa (MENA) region. Recent reports suggest potential risk of HEV transmission via blood transfusion.

METHODS

Related articles on HEV were collected by searching through the 25 countries of the MENA region using Pubmed and Medline within the past 14 years: January 2000-August 2014.

RESULTS

One hundred articles were extracted, of which 25 were not eligible. The articles discussed the seroprevalence of HEV and HEV markers in 12 countries. Eight articles provided data on HEV in blood donors. The seroprevalence of HEV in the general MENA population ranged from 2.0 to 37.5% and was higher in males than in females. Prevalence increased with age, but exposure seems to be in early life.

CONCLUSIONS

In the MENA region, the role of HEV as an infectious threat to blood safety is under-investigated. More data are needed to quantify the risk of transmission and to assess clinical outcomes. This requires, at least, surveillance screening of donors and recipients for HEV markers using sensitive and specific serological tests. At the present time, serious consideration should be given to selective screening for certain groups of patients (e.g., immunocompromised, pregnant women and others) who commonly require blood transfusion and are at high risk of hepatic failure or chronicity from HEV infection.

The emergence of hepatitis E virus in Europe

ABSTRACT 

Hepatitis E virus (HEV) infections appear to be an emerging problem in Europe. Infections are mainly caused by viruses of genotype 3. Pigs and wild boar are the main reservoirs of HEV in Europe and most autochthonous infections are probably caused by the consumption of uncooked or undercooked infected meat. Nevertheless, transfusion-associated transmission has been described in different European countries but the efficiency of this route of transmission need to be further investigated. Most acute infections are asymptomatic or the induced symptoms are rather nonspecific. Although people that are otherwise completely healthy can spontaneously clear an HEV infection, people with underlying liver disease and/or suffering from immune deficiencies may require treatment to avoid chronicity and exacerbation of liver disease. In this review, we give an epidemiological overview of HEV in Europe and the potential complications.

Hepatitis E virus genotype 3 diversity: phylogenetic analysis and presence of subtype 3b in wild boar in Europe

An increasing number of indigenous cases of hepatitis E caused by genotype 3 viruses (HEV-3) have been diagnosed all around the word, particularly in industrialized countries. Hepatitis E is a zoonotic disease and accumulating evidence indicates that domestic pigs and wild boars are the main reservoirs of HEV-3. A detailed analysis of HEV-3 subtypes could help to determine the interplay of human activity, the role of animals as reservoirs and cross species transmission. Although complete genome sequences are most appropriate for HEV subtype determination, in most cases only partial genomic sequences are available. We therefore carried out a subtype classification analysis, which uses regions from all three open reading frames of the genome. Using this approach, more than 1000 published HEV-3 isolates were subtyped. Newly recovered HEV partial sequences from hunted German wild boars were also included in this study. These sequences were assigned to genotype 3 and clustered within subtype 3a, 3i and, unexpectedly, one of them within the subtype 3b, a first non-human report of this subtype in Europe.

Hepatitis E virus: chronic infection, extra-hepatic manifestations, and treatment

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. It is an underdiagnosed disease because of the use of low-sensitivity serological assays; however, diagnostics tools, including nucleic-acid tests, have improved. HEV infection is usually an acute self-limiting disease, but causes chronic infection with rapidly progressive cirrhosis in adult and pediatric organ-transplant-patients. HEV infection evolves to chronic hepatitis in nearly 60% of HEV-infection solid-organ-transplant patients. HEV can also cause extra-hepatic manifestations, such as neurological symptoms and kidney injury. Reducing immunosuppression in transplant patients can lead to HEV clearance in one-third of patients with chronic hepatitis. The use of anti-viral therapies, such as pegylated-interferon and ribavirin, has been found to efficaciously treat HEV infection.

Fatal outcome of autochthonous hepatitis E in a patient with B cell lymphoma in Southeastern France

We describe a case of fatal fulminant hepatitis E concomitant to malignant B cell lymphoma in a 73-year-old French woman. Infection was with an autochthonous hepatitis E virus of genotype 3f. Frequent consumption of uncooked pig liver sausage (figatellu) was the only risk factor found.

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.

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.

Autochthonous hepatitis e virus infections: a new transfusion-associated risk?

Hepatitis E virus (HEV) has been recognized since 2004 as a transfusion-transmissible infectious agent, and recent epidemiological data suggest that it may pose a safety threat to the blood supply. It has recently become obvious that hepatitis E is endemic in industrialized countries, and that more infections are autochthonous than travel-associated. Epidemiological and phylogenetic analysis suggests that HEV infection has to be considered as a zoonosis and that viral transmission from animals (pigs, wild animals) occurs through food or direct contact. The seroprevalence and incidence of HEV in the general population and blood donors in European countries indicate an underestimated risk for transfusion transmissions. Recently reported cases of transfusion transmission of HEV infection, and detection of viremic, asymptomatic blood donors in nucleic acid amplification technique screening programs give an indication of the importance of this virus. Diagnostic assays for detection of anti-HEV antibodies, HEV antigens and RNA are discussed. Recent studies support the idea that active immunization can prevent hepatitis E, highlighting the need for vaccination programs. Here we review current knowledge of HEV and its epidemiology, blood transmission and prevention of this disease with emphasis on blood supply.

Hepatitis E: when to treat and how to treat

HEV generally causes a self-limited acute infection and treatment remains supportive. However, severe hepatitis or fulminant hepatic failure may occur, more so during pregnancy. It is an important cause of acute-on-chronic liver failure in endemic areas. Chronic HEV infection and progressive disease has been reported in recipients of solid organ transplants, haematological malignancies, HIV patients and those on haemodialysis. Clearance of HEV may occur after reducing immunosuppressive therapy, especially those targeting T-cells, in about one third of cases. Antiviral therapy should be considered for patients for whom immunosuppressive therapy cannot be reduced and for those who do not achieve viral clearance after reducing immunosuppression. For the patients with severe infection, fulminant hepatic failure and acute-on-chronic infection, ribavirin monotherapy should be considered to expedite the viral clearance and recovery. Although ribavirin therapy is contraindicated in pregnancy owing to teratogenicity, the risks of untreated HEV to the mother and fetus are high and treatment may be offered. A twelve-week course of pegylated interferon, ribavirin or a combination of the two agents leads to viral clearance in about two-thirds of patients with chronic hepatitis E. Three- to twelve-month treatment with pegylated interferon clears virus in liver transplant recipients and patients on haemodialysis. In kidney and heart transplant patients where interferon may lead to organ rejection, ribavirin may be given.

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.

Age-related and regional differences in the prevalence of hepatitis E virus-specific antibodies in pigs in Germany

An increasing number of acute autochthonous human hepatitis E virus (HEV)-infections was noticed in Germany and other developed countries, most likely the result of a zoonotic virus transmission from pig, wild boar and deer. Currently there is still a lack of profound data concerning the actual prevalence of HEV-specific antibodies in domestic pig herds in Germany, in particular for regions with high pig density, and its age-dependency. 2273 domestic pig sera were collected in 2011 mainly from Bavaria, North Rhine-Westphalia and Lower Saxony from areas having a high pig density. Initially, 420 randomly selected pig sera were tested in three commercially available and in two in-house HEV-antibody ELISAs. 43.6% (183/420) to 65.5% (275/420) of the sera were demonstrated to be reactive against human pathogenic HEV genotypes 1 and/or 3. The majority of sera reacted only weakly or not at all with the rat HEV antigen with very few sera showing a stronger reactivity to this antigen compared to the genotype 3 antigen. The results of all three HEV-IgG tests, i.e. the PrioCHECK(®) HEV Ab porcine ELISA kit, the ID Screen(®) Hepatitis E Indirect Multi-species ELISA kit and the genotype 3 in-house ELISA were in good accordance. Therefore, the remaining sera were tested using the PrioCHECK(®) HEV Ab porcine ELISA kit. Samples with a borderline result were finally determined by application of the conjugate-modified recomLine HEV IgG assay. A total of 1065 of the 2273 sera (46.9%) were found to be anti-HEV IgG-positive. While 38.4% (306/796) of fatteners (age between 3 and 9 months) exhibited HEV-specific antibodies, 51.4% (759/1477) of sows (age older than 9 months) exhibited anti-HEV antibodies (P<0.001). Fatteners kept in Southern Germany had a significantly higher HEV IgG prevalence compared to fatteners kept in the high pig density federal states North Rhine-Westphalia and Lower Saxony but also in German federal states with a low pig density. In conclusion, the present study clearly demonstrates that a high percentage of domestic pigs in Germany have had contact with HEV. Seroprevalence depends on the pig's age and herd origin with the most significant regional variations for fatteners. The presence of anti-HEV-free herds may indicate that it is feasible to establish and sustain HEV-free pig herds. HEV seroprevalence still depends on the assay used for testing. This demonstrates an urgent need for test validation.

Hepatitis E virus: an underestimated opportunistic pathogen in recipients of allogeneic hematopoietic stem cell transplantation

Hepatitis E virus (HEV) is increasingly acknowledged as a cause of hepatitis in healthy individuals as well as immunocompromised patients. Little is known of HEV infection in recipients of allogeneic hematopoietic stem cell transplantation (alloHSCT). Therefore, we set out to study the incidence and sequelae of HEV as a cause of hepatitis in a recent cohort of 328 alloHSCT recipients. HEV RNA was tested in episodes of liver enzyme abnormalities. In addition, HEV RNA and HEV serology were assessed pre- and post-alloHSCT. We found 8 cases (2.4%) of HEV infection, of which 5 had developed chronic HEV infection. Seroprevalence pre-alloHSCT was 13%. Four patients died with HEV viremia, with signs of ongoing hepatitis, having a median time of infection of 4.1 months. The 4 surviving patients cleared HEV after a median period of 6.3 months. One patient was diagnosed with HEV reactivation after a preceding infection prior to alloHSCT. Although the incidence of developing acute HEV post-alloHSCT is relatively low, the probability of developing chronic hepatitis in severely immunocompromised patients is high. Therefore, alloHSCT recipients should be screened pretransplantation by HEV serology and RNA. Furthermore, a differential diagnosis including hepatitis E is mandatory in all alloHSCT patients with severe liver enzyme abnormalities.