Hepatitis E virus in blood components: a prevalence and transmission study in southeast England

Hepatitis A Virus and Hepatitis E Virus Seroprevalence Among Blood Donors in Tehran, Iran

BACKGROUND

Hepatitis A virus (HAV) and Hepatitis E virus (HEV) are both transmitted by the fecal-oral route and are known as the leading causes of acute viral hepatitis in the world, especially in developing countries. There is a lack of updated data on HAV and HEV seroprevalence in Iran.

OBJECTIVES

The aim of this study was to determine the seroprevalence of HAV and HEV among a group of blood donors in Tehran, Iran.

MATERIALS AND METHODS

A cross-sectional study was performed from July 2014 to December 2014, on a total of 559 blood donors referred to the Tehran blood transfusion center. The serum samples were tested for antibodies to HAV and HEV, using the enzyme-linked immunosorbent assay.

RESULTS

In the present study, 536 (95.9%) cases were male and 23 (4.1%) female with mean age of 38 years. Out of 559 blood donors, 107 (19.1%) were first-time donors, 163 (29.2%) lapsed donors and 289 (51.7%) regular donors. Anti-HAV was found in 395 (70.7%) and anti-HEV in 45 (8.1%) of the blood donors. The HAV and HEV seroprevalence increased by age. There was no significant difference between genders in terms of anti-HAV and anti-HEV status. The HAV and HEV seroprevalence was significantly related to the level of education, where the donors with higher level of education had lower rate of HAV and HEV seroprevalence. The HAV and HEV seroprevalence was significantly higher in regular and lapsed donors than in first-time donors.

CONCLUSIONS

The present study showed that both HAV and HEV infections are still endemic in Iran.

[Specific infections in organ transplantation]

This article is concerned with the important topic of infections associated with organ transplantation and includes a discussion on four subtopics. The first section describes the current options in the prevention and therapy of viral hepatitis in association with liver transplantation. Infections with hepatitis B, C, D (delta) and E are discussed with special emphasis on the interferon-free treatment of hepatitis C with the new antiviral drugs.The second section deals with Pseudomonas aeruginosa (PA) infections following lung transplantation (LuTx), which is one of the most frequently detected pathogens in the airway after LuTx. Patients with cystic fibrosis are particularly affected. This is important because studies have shown a clear correlation between chronic PA infections after LuTx and development of chronic transplant failure. Even if the data are still sparse, recommendations on prevention and therapeutic strategies are given. The theme of the third section is the high importance of viral infections after kidney transplantation. In addition to acquired infections, the transplanted organ as well as the recipient can be the source of the infection. The better the transplanted organ is tolerated under moderate immunosuppression, the less common and severe virus infections are. The focus of this section is on three common pathogens: cytomegalovirus, polyomavirus BK and hepatitis viruses.The final section deals with Aspergillus infections following transplantation of various organs. In this context Aspergillus spp. are one of the most commonly occurring fungal diseases. The epidemiology, risk factors, diagnostics, prophylaxis and therapy of invasive aspergillosis are presented.

A Public Health initiative on hepatitis E virus epidemiology, safety and control in Portugal--study protocol

BACKGROUND

The discovery of autochthonous hepatitis E in industrialized countries has changed the understanding of hepatitis E virus (HEV) infection in these regions, now known to be mainly due to zoonotic transmission of genotype 3. The foodborne route of transmission via consumption of contaminated meat from HEV infected pigs is well documented as well as the direct occupational exposure to animal reservoirs. Accumulating evidence also points to an emerging potential threat to blood safety after the identification of viremic blood donors and the documentation of HEV-contaminated blood or blood products. Moreover, the origin of several iatrogenic cases remains unclear and porcine-derived pharmaceutic products have been suspected as a cause. Severe morbidity following HEV infection in patients receiving immunosuppressive therapy and in those with severe immunodeficiency from other causes has been recently recognized as a serious consequence of this infection in industrialized countries. In Portugal no large-scale HEV seroprevalence study has been undertaken, no professional risk groups have been identified, and the risk of blood donation from HEV silent infected donors is unknown. The present paper describes seroepidemiological and molecular approaches to answer these questions.

METHODS/DESIGN

To address these issues a study protocol was designed that will approach: i) the seroprevalence of HEV among the Portuguese general population; ii) HEV infection among butchers and slaughterhouse workers (occupational risk); iii) the silent HEV infection in Portuguese blood donors (HEV transfusion-associated risk); iv) the potential HEV contamination of porcine-derived pharmaceutical products. Commercial enzyme immunoassays and real-time/conventional RT-PCR assays will be used.

DISCUSSION

This study is the first evaluation of the seroepidemiological status to HEV infection of the Portuguese population, the first to potentially identify professional risk groups, and to evaluate the safety of blood and blood products and porcine-derived pharmaceutics in Portugal. It will generate valuable data applicable for preventive and control measures against HEV infection (e.g., introduction of systematic screening of blood donors, control of blood products or porcine derived pharmaceutical products), thus helping to manage the burden of this viral disease.

Proposed reference sequences for hepatitis E virus subtypes

The nomenclature of hepatitis E virus (HEV) subtypes is inconsistent and makes comparison of different studies problematic. We have provided a table of proposed complete genome reference sequences for each subtype. The criteria for subtype assignment vary between different genotypes and methodologies, and so a conservative pragmatic approach has been favoured. Updates to this table will be posted on the International Committee on Taxonomy of Viruses website (http://talk.ictvonline.org/r.ashx?C). The use of common reference sequences will facilitate communication between researchers and help clarify the epidemiology of this important human pathogen. This subtyping procedure might be adopted for other taxa of the genus Orthohepevirus.

Chronic Hepatitis E Infection in a Persistently Immunosuppressed Patient Unable to Be Eliminated after Ribavirin Therapy

Recent case reports have shown that hepatitis E virus (HEV) infection can cause chronic hepatitis in immunosuppressed or immunocompromised patients. A 37-year-old woman suffered from prolonged elevation of aminotransferases after chemotherapy for Burkitt's lymphoma and was diagnosed with chronic hepatitis E due to a transfusion during chemotherapy. After an 8-month administration of ribavirin, complete HEV clearance was not achieved, likely due to prolonged hypogammaglobulinemia. This case indicates that HEV infection should be ruled out during liver dysfunction in immunosuppressed or immunocompromised patients and suggests that an alternative therapeutic strategy for such patients will be needed.

Current concepts in the prevention of pathogen transmission via blood/plasma-derived products for bleeding disorders

The pathogen safety of blood/plasma-derived products has historically been a subject of significant concern to the medical community. Measures such as donor selection and blood screening have contributed to increase the safety of these products, but pathogen transmission does still occur. Reasons for this include lack of sensitivity/specificity of current screening methods, lack of reliable screening tests for some pathogens (e.g. prions) and the fact that many potentially harmful infectious agents are not routinely screened for. Methods for the purification/inactivation of blood/plasma-derived products have been developed in order to further reduce the residual risk, but low concentrations of pathogens do not necessarily imply a low level of risk for the patient and so the overall challenge of minimising risk remains. This review aims to discuss the variable level of pathogenic risk and describes the current screening methods used to prevent/detect the presence of pathogens in blood/plasma-derived products.

Hepatitis E, the neglected one

Hepatitis E virus (HEV) infection is a worldwide disease. It is the first cause of acute viral hepatitis in the world with an estimated 20 million cases every year and 56 000 deaths. In developing countries, hepatitis E is a waterborne infection. In these countries, HEV genotypes 1 and 2 cause large outbreaks and affect young subjects with a significant mortality rate in pregnant women and patients with cirrhosis. In the developed countries, HEV genotypes 3 and 4 are responsible for autochthonous, sporadic hepatitis and transmission is zoonotic. HEV can cause neurological disorders and in immunocompromised patients, chronic infections. The progression of acute hepatitis E is most often mild and resolves spontaneously. Diagnostic tools include anti-HEV IgM antibodies in serum and/or viral RNA in the blood or stools by PCR. Ribavirin is used to treat chronic infection. A vaccine has been developed in China.

Hepatitis E virus and neurological injury

Hepatitis E is hyperendemic in many developing countries in Asia and Africa, and is caused by hepatitis E virus (HEV) genotypes 1 and 2, which are spread via the faecal-oral route by contaminated water. Recent data show that HEV infection is also endemic in developed countries. In such geographical settings, hepatitis E is caused by HEV genotypes 3 and 4, and is mainly a porcine zoonosis. In a minority of cases, HEV causes acute and chronic hepatitis, but infection is commonly asymptomatic or unrecognized. HEV infection is associated with a number of extrahepatic manifestations, including a range of neurological injuries. To date, 91 cases of HEV-associated neurological injury--most commonly, Guillain-Barré syndrome, neuralgic amyotrophy, and encephalitis/myelitis--have been reported. Here, we review the reported cases, discuss possible pathogenic mechanisms, and present our perspectives on future directions and research questions.

Hepatitis E virus is the leading cause of acute viral hepatitis in Lothian, Scotland

Acute viral hepatitis affects all ages worldwide. Hepatitis E virus (HEV) is increasingly recognized as a major cause of acute hepatitis in Europe. Because knowledge of its characteristics is limited, we conducted a retrospective study to outline demographic and clinical features of acute HEV in comparison to hepatitis A, B and C in Lothian over 28 months (January 2012 to April 2014). A total of 3204 blood samples from patients with suspected acute hepatitis were screened for hepatitis A, B and C virus; 913 of these samples were also screened for HEV. Demographic and clinical information on patients with positive samples was gathered from electronic patient records. Confirmed HEV samples were genotyped. Of 82 patients with confirmed viral hepatitis, 48 (59%) had acute HEV. These patients were older than those infected by hepatitis A, B or C viruses, were more often male and typically presented with jaundice, nausea, vomiting and/or malaise. Most HEV cases (70%) had eaten pork or game meat in the few months before infection, and 14 HEV patients (29%) had a recent history of foreign travel. The majority of samples were HEV genotype 3 (27/30, 90%); three were genotype 1. Acute HEV infection is currently the predominant cause of acute viral hepatitis in Lothian and presents clinically in older men. Most of these infections are autochthonous, and further studies confirming the sources of infection (i.e. food or blood transfusion) are required.

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.

Hepatitis E virus infection: Epidemiology and treatment implications

Hepatitis E virus (HEV) infection is now established as an emerging enteric viral hepatitis. Standard treatments in acute and chronic hepatitis E remain to be established. This study undertakes a review of the epidemiology, treatment implication and vaccine prevention from published literature. HEV infection is a worldwide public health problem and can cause acute and chronic hepatitis E. HEV genotypes 1 and 2 are primarily found in developing countries due to waterborne transmission, while the zoonotic potential of genotypes 3 and 4 affects mostly industrialized countries. An awareness of HEV transmission through blood donation, especially in the immunocompromised and solid organ transplant patients, merits an effective anti-viral therapy. There are currently no clear indications for the treatment of acute hepatitis E. Despite concerns for side effects, ribavirin monotherapy or in combination with pegylated interferon alpha for at least 3 mo appeared to show significant efficacy in the treatment of chronic hepatitis E. However, there are no available treatment options for specific patient population groups, such as women who are pregnant. Vaccination and screening of HEV in blood donors are currently a global priority in managing infection. New strategies for the treatment and control of hepatitis E are required for both acute and chronic infections, such as prophylactic use of medications, controlling large outbreaks, and finding acceptable antiviral therapy for pregnant women and other patient groups for whom the current options of treatment are not viable.

Incidence and duration of hepatitis E virus infection in Dutch blood donors

BACKGROUND

The incidence of hepatitis E virus (HEV) infection in the Netherlands is high. Blood donors are not routinely screened for HEV infection, but since January 2013, donations used for the production of solvent/detergent (S/D)-treated plasma have been screened for HEV RNA.

STUDY DESIGN AND METHODS

Donations were screened for HEV RNA in pools of 96 and 192 donations. In addition, all donations made between 60 days before and after each HEV RNA-positive donation were tested individually for HEV RNA and anti-HEV immunoglobulin G.

RESULTS

The screening of 59,474 donations between January 2013 and December 2014 resulted in identification of 45 HEV RNA-positive donations (0.076%) from 41 donors. HEV RNA loads ranged from 80 to 2.3 × 10(6) IU/mL. The number of positive donations increased significantly over time (p = 0.03). Thirty-three of 90 donations made up to 60 days before or after HEV RNA-positive donations were positive when tested individually, while they had not been detected in the pool screening. The mean duration of HEV viremia in the healthy blood donor is estimated to be 68 days.

CONCLUSION

The incidence of HEV infection in the Netherlands is high and increased during the study period. In 2013 and 2014, HEV RNA was detected in 1 per 762 donations intended for production of S/D plasma.

Extended Microbiological Characterization of Göttingen Minipigs in the Context of Xenotransplantation: Detection and Vertical Transmission of Hepatitis E Virus

Xenotransplantation has been proposed as a solution to the shortage of suitable human donors. Pigs are currently favoured as donor animals for xenotransplantation of cells, including islet cells, or organs. To reduce the xenotransplantation-associated risk of infection of the recipient the pig donor should be carefully characterised. Göttingen minipigs from Ellegaard are often used for biomedical research and are regularly tested by their vendor for the presence of numerous bacteria, fungi, viruses and parasites. However, screening for some pathogens transmittable to humans had not been performed.The presence of microorganisms was examined in Göttingen Minipigs by PCR methods. Since zoonotic transmission of porcine hepatitis E virus HEV to humans has been demonstrated, extended search for HEV was considered as a priority. RNA from sera, islet and other cells from 40 minipigs were examined for HEV using different real-time reverse transcription (RT)-PCRs, among them two newly established. In addition, sera were examined by Western blot analysis using two recombinant capsid proteins of HEV as antigens. HEV RNA was not detected in pigs older than one year including gilts, but it was detected in the sera of three of ten animals younger than 1 year. Furthermore, HEV was also detected in the sera of three sows six days after delivery and their offspring, indicating vertical transmission of the virus. PCR amplicons were cloned, sequenced and the viruses were found to belong to the HEV genotype (gt) 3/4. Anti-HEV immunoglobulins G were detected in one sow and maternal antibodies in her six day old piglet. Since Göttingen minipigs were negative for many xenotransplantation-relevant microorganisms, they can now be classified as safe. HEV may be eliminated from the Ellegaard herd by selection of negative animals and/or by treatment of the animals.

Hepatitis E virus and the safety of plasma products: investigations into the reduction capacity of manufacturing processes

BACKGROUND

Hepatitis E virus (HEV) has been transmitted by transfusion of labile blood products and the occasional detection of HEV RNA in plasma pools indicates that HEV viremic donations might enter the manufacturing process of plasma products. To verify the safety margins of plasma products with respect to HEV, virus reduction steps commonly used in their manufacturing processes were investigated for their effectiveness to reduce HEV.

STUDY DESIGN AND METHODS

Detection methods for HEV removal (by reverse transcription quantitative polymerase chain reaction) and inactivation (using an infectivity assay) were established. Immunoaffinity chromatography and 20-nm virus filtration for Factor (F)VIII, cold ethanol fractionation, and low-pH treatment for immunoglobulin, heat treatment for human albumin, and 35-nm nanofiltration for FVIII inhibitor-bypassing activity (FEIBA) were investigated for their capacity to reduce HEV or the physicochemically similar viruses feline calicivirus (FCV) and hepatitis A virus (HAV).

RESULTS

For FVIII, HEV reduction of 3.9 and more than 3.9 log was demonstrated for immunoaffinity chromatography and 20-nm nanofiltration, respectively, and the cold ethanol fractionation for immunoglobulin removed more than 3.5 log of HEV, to below the limit of detection (LOD). Heat treatment of human albumin inactivated more than 3.1 log of HEV to below the LOD and 35-nm nanofiltration removed 4.0 log of HEV from the FEIBA intermediate. The results indicated HAV rather than FCV as the more relevant model virus for HEV.

CONCLUSION

Substantial HEV reduction during processes commonly used in the manufacturing of plasma products was demonstrated, similar to that previously demonstrated for HAV.

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

Background

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

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

Methods

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

Results

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

Conclusions

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

Survival and Elimination of Hepatitis E Virus: A Review

Recently, foodborne transmission of hepatitis E virus (HEV) has become a concern due to the identification of undercooked pork products as a risk factor for infection. The limited number of studies which have been performed indicate that HEV could remain infectious at temperatures used in some cooking regimes, although inactivation by heating at 71 °C for 20 min has been demonstrated. There are significant gaps in our knowledge regarding the survival of HEV in foods and the environment (including food contact surfaces), and also regarding the effect of elimination procedures used in food supply chain settings. The lack of a reliable infectivity assay has hampered extensive study. It is recommended that studies be undertaken to develop an efficient propagation system (based on in vitro cell culture), to facilitate the acquisition of extensive information on the survival of HEV in food and the environment, and its response to disinfection and elimination procedures.

Risks associated with red blood cell transfusions: potential benefits from application of pathogen inactivation

BACKGROUND

Red blood cell (RBC) transfusion risks could be reduced if a robust technology for pathogen inactivation of RBC (PI-RBCs) were to be approved.

MATERIALS AND METHODS

Estimates of per-unit and per-patient aggregate infectious risks for conventional RBCs were calculated; the latter used patient diagnosis as a determinant of estimated lifetime exposure to RBC units. Existing in vitro data for the two technologies under development for producing PI-RBCs and the status of current clinical trials are reviewed.

RESULTS

Minimum and maximum per-unit risk were calculated as 0.0003% (1 in 323,000) and 0.12% (1 in 831), respectively. The minimum estimate is for known lower-risk pathogens while the maximal estimate also includes an emerging infectious agent (EIA) and endemic area Babesia risk. Minimum and maximum per-patient lifetime risks by diagnosis grouping were estimated as 1.5 and 3.3%, respectively, for stem cell transplantation (which includes additional risk for cytomegalovirus transmission); 1.2 and 3.7%, respectively, for myelodysplastic syndrome; and 0.2 and 44%, respectively, for hemoglobinopathy.

DISCUSSION

There is potential for PI technologies to reduce infectious RBC risk and to provide additional benefits (e.g., prevention of transfusion-associated graft-versus-host disease and possible reduction of alloimmunization) due to white blood cell inactivation. PI-RBCs should be viewed in the context of having a fully PI-treated blood supply, enabling a blood safety paradigm shift from reactive to proactive. Providing insurance against new EIAs. Further, when approved, the use of PI for all components may catalyze operational changes in blood donor screening, laboratory testing, and component manufacturing.

Variability and pathogenicity of hepatitis E virus genotype 3 variants

Infection with hepatitis E virus (HEV) can be clinically inapparent or produce symptoms and signs of hepatitis of varying severity and occasional fatality. This variability in clinical outcomes may reflect differences in host susceptibility or the presence of virally encoded determinants of pathogenicity. Analysis of complete genome sequences supports the division of HEV genotype 3 (HEV-3) variants into three major clades: 3ra comprising HEV isolates from rabbits, and 3efg and 3abchij comprising the corresponding named subtypes derived from humans and pigs. Using this framework, we investigated associations between viral genetic variability of HEV-3 in symptomatic and asymptomatic infections by comparing HEV-3 subgenomic sequences previously obtained from blood donors with those from patients presenting with hepatitis in the UK (54 blood donors, 148 hepatitis patients), the Netherlands (38 blood donors, 119 hepatitis patients), France (24 blood donors, 55 hepatitis patients) and Germany (14 blood donors, 36 hepatitis patients). In none of these countries was evidence found for a significant association between virus variants and patient group (P>0.05 Fisher's exact test). Furthermore, within a group of 123 patients in Scotland with clinically apparent HEV infections, we found no evidence for an association between variants of HEV-3 and disease severity or alanine aminotransferase level. The lack of detectable virally encoded determinants of disease outcomes in HEV-3 infection implies a more important role for host factors in its clinical phenotype.

Current Knowledge on Hepatitis E

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

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.

Detection of Hepatitis E Virus Antibodies in Dogs in the United Kingdom

Hepatitis E virus (HEV) genotypes 3 and 4 are zoonotic pathogens, with pigs predominantly implicated in disease transmission. The rapid rise in human cases in developed countries over the past decade indicates a change in epidemiology of HEV, and it has been suggested that additional animal species may be involved in transmission of infection. Multiple studies have identified contact with dogs as a risk factor for HEV infection in industrialised nations, and a low seroprevalence to HEV has previously been reported in dogs in low-income countries. In this study we aimed to evaluate the possibility that dogs are susceptible to HEV, and determine the frequency with which this occurs. Serum samples from UK dogs with and without hepatitis were screened for HEV-specific antibodies, and canine liver and stool samples were analysed by qPCR for the presence of HEV RNA. We describe evidence to show HEV infection occurs at low levels in dogs in the UK, but the strain of origin is undetermined. The low seroprevalence level of HEV in dogs implies the risk of zoonotic disease transmission is likely to be limited, but further investigations will be required to determine if HEV-infected dogs can transmit HEV to man.

Epidemiology of domestically acquired hepatitis E virus infection in Japan: assessment of the nationally reported surveillance data, 2007-2013

In recent years, there has been an increase in the number of reported hepatitis E virus (HEV) infections from developed countries. To describe recent trends in notification and potential risk groups and risk factors in Japan, HEV infection cases and demographic, food consumption, clinical and laboratory data reported during 2007-2013 were analysed. In total, 530 HEV infections were reported during 2007-2013. Amongst 462 domestic cases, the mean age was 56.5 years (sd 13.9) and 80.1 % were male. Forty-three cases (9.3 %) were asymptomatic, amongst which 11 were detected from blood donations. Whilst ∼50 cases were reported annually during 2007-2011, the number of reported cases increased to 121 in 2012 and 126 in 2013. The increase was characterized by a rise in the number of domestic, symptomatic cases (P = 0.05) and cases confirmed by anti-HEV IgA detection (P < 0.01). HEV genotypes G3 and G4 were consistently dominant. The major suspected source of infection was food-borne, and the major suspected foods were pig, wild boar and deer meat. The observed increase during 2012-2013 was most likely due to the coverage of the anti-HEV IgA assay by the National Health Insurance system in Japan in October 2011 and its acceptance for surveillance purposes. However, the increase was not associated with detection of asymptomatic cases. Moreover, males aged 50-69 years remained as the high-risk group, and pork and other meats continued to be the most suspected items. Our findings indicated that HEV infection is an emerging and important public health concern in Japan.

Seroprevalence of Hepatitis E virus infection in the Irish pig population

Background

Hepatitis E is an acute viral disease of humans, occurring in explosive outbreaks in the developing world and as sporadic cases in returning travellers. Increasing recognition of indigenous transmission in Western countries suggests a zoonotic source of infection, most likely pigs. To determine if hepatitis E virus is present in Irish pigs, sera from 330 animals were examined for antibodies using a commercially available ELISA.

Findings

Antibodies were detected in 89 pigs (27%) in 13 herds (81%).

Conclusions

Hepatitis E virus is present in most Irish pig herds and in many animals within these herds.

Swine is a possible source of hepatitis E virus infection by comparative study of hepatitis A and E seroprevalence in Thailand

Hepatitis A virus (HAV) and hepatitis E virus (HEV) infection in developing countries are associated with contaminated food or water. Although Thailand is non-endemic for HEV, sporadic infections may occur from zoonotic transmission. Individuals between 7 months to 69 years (mean age = 32.8) from predominantly Islamic Narathiwat (n = 305) and swine farm-dense Lop Buri (n = 416) provinces were screened for anti-HEV and anti-HAV antibodies by commercial enzyme-linked immunosorbent assay and automated chemiluminescent microparticle immunoassay, respectively. Seroprevalence and relative antibody titers were analyzed according to age groups. HAV IgG antibody positive rates in Lop Buri and Narathiwat residents were 39.9% and 58%, respectively (p < 0.001). Greater than 90% of individuals >50 years old in both provinces possessed anti-HAV IgG. In contrast, seroprevalence for anti-HEV IgG was much higher in Lop Buri (37.3%) than in Narathiwat (8.9%) (p < 0.001). Highest anti-HEV IgG prevalence was found among 21-30 year-olds (50%) in Lop Buri and 41-50 year-olds (14.1%) in Narathiwat. In summary, fewer individuals possessed anti-HEV IgG in Narathiwat where most residents abstained from pork and fewer swine farms are present. Therefore, an increased anti-HEV IgG seroprevalence was associated with the density of swine farm and possibly pork consumption. Adults were more likely than children to have antibodies to both HEV and HAV.

Estimation of the infectious viral load required for transfusion-transmitted human T-lymphotropic virus type 1 infection (TT-HTLV-1) and of the effectiveness of leukocyte reduction in preventing TT-HTLV-1

BACKGROUND AND OBJECTIVES

The risk of transfusion-transmitted human T-lymphotropic virus type 1 infection (TT-HTLV-1) after prestorage leucocyte reduction (LR) remains unknown, as the proviral load in the blood component that would cause TT-HTLV-1 is undetermined. On the basis of the distribution of HTLV-1 proviral load among HTLV-1-sero-positive blood donors, we attempted to estimate the proviral load for transfusion-related infectivity. We also discuss the effectiveness of LR in preventing TT-HTLV-1.

MATERIALS AND METHODS

The HTLV-1 proviral load in 300 HTLV-1-sero-positive blood donors was determined by real-time polymerase chain reaction analysis. The proviral load required for transfusion-related infectivity was estimated using historical TT-HTLV-1 frequency data from a retrospective study on patients who had received blood from HTLV-1-sero-positive blood donors and the distribution pattern of HTLV-1 proviral load among blood donors.

RESULTS

HTLV-1 proviral loads ranged between < 0.01 and 25.0 copies per 100 leucocytes. Historical data showed TT-HTLV-1 frequency to be 80%. Assuming that 80% of the 300 sero-positive samples are infectious, it is estimated that the transfer of ≥ 9 × 10(4) cells containing the HTLV-1 provirus is required to establish TT-HTLV-1.

CONCLUSION

The residual number of HTLV-1-infected cells after LR is substantially lower than the viral load necessary for TT-HTLV-1. LR therefore appears to be effective in minimizing the incidence of TT-HTLV-1.

Declining prevalence of hepatitis E antibodies among Danish blood donors

BACKGROUND

The increasing incidence of reported hepatitis E cases in Europe has focused attention on hepatitis E virus (HEV) and the risk of transfusion-transmitted hepatitis E. The aim of this study was to investigate the prevalence of antibodies to HEV (anti-HEV) among Danish blood donors in 2013 and to compare it to previous studies in Denmark. In addition we wanted to compare the relative reactivity of two different assays.

STUDY DESIGN AND METHODS

Samples from 504 blood donors were collected and analyzed for anti-HEV with an in-house assay developed at the National Institutes of Health (NIH). In addition the samples were analyzed with the Wantai anti-HEV assay. Demographic information and possible HEV exposure was collected by self-administered questionnaire.

RESULTS

Using the NIH assay the prevalence of anti-HEV among Danish blood donors was 10.7% and with the Wantai assay the prevalence of anti-HEV was 19.8% (p < 0.001). In both cases the presence of anti-HEV was significantly correlated with increasing age. In addition, anti-HEV as measured by the Wantai test was significantly associated with contact with children (p = 0.01), but in multivariate analysis only age was associated with anti-HEV in both assays. By the NIH assay, the prevalence had declined from 20.6% in 2003 to 10.7% in 2013.

CONCLUSIONS

Anti-HEV prevalence had decreased by half among Danish blood donors over 10 years, but was still highly prevalent. The difference in reactivity of the two assays demonstrates the importance of using the same assay when comparing the anti-HEV prevalence in populations over time.

Hepatitis E: A disease of reemerging importance

Hepatitis E virus (HEV) is the most common cause of acute viral hepatitis worldwide. Originally considered to be restricted to humans, it is now clear that HEV and HEV-like viruses have several animal reservoirs with complex ecology and genetic diversity, as exemplified by the recent discovery of HEV in dromedaries, a previously underestimated reservoir of zoonotic viruses prior to the emergence of Middle East Respiratory Syndrome coronavirus. Zoonotic foodborne transmission from pigs and feral animals such as wild boar is of increasing importance in the rapidly industrializing countries of the Asia Pacific region. Such zoonotic hepatitis E infection has particular relevance to the increasing population living with immunosuppression, due to the risk of chronic hepatitis E in these patients. Fortunately, major strides have been made recently in the management of chronic hepatitis E patients. Furthermore, an effective vaccine is also available that promises better control of hepatitis E burden in the near future. This review highlights these major recent developments in the epidemiology, treatment, and prevention of hepatitis E.

Seroprevalence and Incidence of hepatitis E in blood donors in Upper Austria

BACKGROUND

In recent years various studies showed, that hepatitis E virus (HEV) is a growing public health problem in many developed countries. Therefore, HEV infections might bear a transmission risk by blood transfusions. The clinical relevance still requires further investigations. The aim of this study was to provide an overview of acute HEV infections in Upper Austrian blood donors as well as a risk estimation of this transfusion-related infection.

METHODS AND FINDINGS

A total of 58,915 blood donors were tested for HEV RNA using a commercial HEV RT-PCR Kit. 7 of these donors (0.01%) were PCR-positive with normal laboratory parameters in absence of clinical signs of hepatitis. Viral load determined by quantitative real-time PCR showed a HEV nucleic acid concentration of 2,217 293,635 IU/ml. At follow-up testing (2-11 weeks after donation) all blood donors had negative HEV RNA results. Additionally, genotyping was performed by amplification and sequencing of the ORF1 or ORF2 region of the HEV genome. All HEV RNA positive donor samples revealed a genotype 3 isolate. For the antibody screening, anti-HEV IgM and IgG were detected by ELISA. Follow up serological testing revealed that no donor was seropositive for HEV IgM or IgG antibodies at time of donation. Moreover, we verified the prevalence of anti-HEV IgG in 1,203 of the HEV RNA negative tested blood donors. Overall 13.55% showed positive results for anti-HEV IgG.

CONCLUSIONS

In the presented study, we investigated HEV infections in blood donations of Upper Austria over 1 year. We concluded that 1 out of 8,416 blood donations is HEV RNA positive. Seroprevalence of anti HEV IgG results in an age-related increase of 13.55%. Therefore, based on this data, we recommend HEV-PCR screening to prevent transmission of hepatitis E virus by transfusion.

Systematic serological testing for hepatitis E virus in kidney transplant recipients

Hepatitis E virus (HEV) genotype 3 is endemic in Europe and hyperendemic in southern France. Recent reports of a high prevalence of HEV RNA in blood donations and in culinary specialties from this geographical area confirmed the endemicity of HEV and sources of viral transmission in this geographical area. HEV causes acute and chronic hepatitis in solid organ transplant recipients. Since March 2012, we have implemented systematic HEV serological testing in our cohort of kidney transplant recipients (KTRs) in Marseille in southeastern France. The aim of our study was to assess HEV exposure in this cohort between March 2012 and May 2014. During these 27 months, we found that 39% of the patients who underwent kidney transplantation had an anti-HEV IgG response using a sensitive microplate enzyme immunoassay. This seroprevalence was approximately 43% at both 1 and 8 years after, using the same assay. In addition, systematic HEV serological testing detected 6 cases of HEV infection among 578 KTRs (1%) during the 27 months of the study, with 5 at an acute stage and 1 at a chronic stage. In conclusion, continuous HEV monitoring in this population is useful for better understanding the epidemiology of HEV in France, because these patients are a well-monitored population. Moreover, HEV monitoring in KTRs is clinically relevant because HEV represents a clinical threat in these patients. Nevertheless, HEV serological testing may be more fruitful for identifying HEV infections when performed in cases of biological liver abnormalities than when performed systematically.

Hepatitis E virus: do locally acquired infections in Australia necessitate laboratory testing in acute hepatitis patients with no overseas travel history?

Hepatitis E virus (HEV) is emerging as a global public health threat. Water-borne HEV outbreaks are common in developing countries and are associated with genotypes 1 and 2. In industrialised countries, sporadic cases of zoonotic transmission associated with genotypes 3 and 4 are increasingly being reported. Transfusion- and transplantation-transmitted HEV have been documented, although ingestion of contaminated food is thought to be the major transmission route. Severe disease is possible and chronic hepatitis infection occurs in solid-organ-transplant recipients and in patients with immunosuppressive disorders. In Australia, HEV cases are mainly travellers returning from disease endemic countries. Indeed, there are few reported cases of locally acquired HEV. Pigs in Australia have been shown to be infected with HEV, which indicates the possibility of zoonotic transmission. The extent of locally acquired infection is not known, however it may be greater than expected and may necessitate laboratory testing in patients reporting no overseas travel.

In silico and in vitro interrogation of a widely used HEV RT-qPCR assay for detection of the species Orthohepevirus A

Hepatitis E virus (HEV) infection is a public health concern worldwide, associated with waterborne outbreaks in developing countries and reported as an emerging zoonotic infection in high-income countries. A recent consensus proposal classified the isolates from human, swine, wild boar, deer, mongoose, rabbit and camel in seven genotypes within the species Orthohepevirus A. In this report a popular HEV RT-qPCR assay was assessed for the detection of the species Orthohepevirus A. In silico analysis of 189 complete genome sequences showed that the assay targets a highly conserved region in the Orthohepevirus A genome. Additionally, plasmid standards were constructed to test the effect of probe- and primer-binding site mutations in the assay performance. The assay proved robust enough to detect strains with mutations in the probe-binding site and in the 3' end primer-binding site regions. A degenerate version of the reverse primer improves the performance of the assay particularly in the detection of HEV-5 and 6. The addition and detection of MS2 RNA in each RT-qPCR reaction monitored for amplification inhibition and did not affect the performance of the assay in the detection of the HEV RNA international standard. Therefore, the RT-qPCR assay can be confidently used for the RNA detection of the seven genotypes within the species Orthohepevirus A.

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.

Seroprevalence of hepatitis E virus (HEV) and detection of HEV RNA with a transcription-mediated amplification assay in blood donors from Catalonia (Spain)

BACKGROUND

Hepatitis E virus (HEV) is an emerging threat to the safety of blood transfusion. The aim of this study was to determine HEV immunoglobulin (Ig)G and RNA prevalence in Catalan blood donors.

STUDY DESIGN AND METHODS

Nearly 10,000 samples were collected from anonymized, unpaid donors at the Banc de Sang i Teixits (Barcelona, Spain) from June to December 2013. For the serology study, a subset of 1082 donations was tested in parallel for HEV IgG using Wantai and Mikrogen enzyme-linked immunosorbent assay tests. Samples were tested individually (individual-donation nucleic acid test [ID-NAT]) for HEV RNA using the Procleix HEV assay (95% limit of detection 7.9 IU/mL). Procleix repeat-reactive donations were confirmed by an in-house real-time polymerase chain reaction (PCR) test.

RESULTS

The prevalences of IgG anti-HEV in Catalan blood donors were 19.96% (Wantai assay) and 10.72% (Mikrogen assay). Screening of 9998 samples with the Procleix HEV assay yielded three real-time PCR-confirmed and IgM and IgG anti-HEV-positive donations with viral loads of 250, 564, and 2755 IU/mL. The donation with highest viral load was genotype 3f. HEV RNA positivity rate was one per 3333 donations (0.03%; 95% confidence interval, 0.01%-0.09%).

CONCLUSION

The Procleix HEV ID-NAT screening system has provided evidence of HEV RNA presence in Catalan blood donors. Further data are needed to assess the impact of HEV infection in at-risk patients to design the best strategy to increase blood safety.

Hepatitis E in Germany--an under-reported infectious disease

BACKGROUND

At least 17% of the population in Germany has been infected with the hepatitis E virus (HEV); thus, HEV infections are more frequent than was previously assumed. However, fewer than 500 HEV infections were reported to the Robert Koch Institute in 2013.

METHOD

Review of pertinent literature retrieved by a selective search in PubMed.

RESULTS

Persons living in Germany generally acquire hepatitis E infection within the country by consuming infected and undercooked pork; in rare cases, hepatitis E infections are imported from the tropics. HEV can be transmitted via blood products, blood transfusions, and organ transplantation. More than 99% of HEV infections are asymptomatic and self-limiting, but there are also severe cases with acute liver failure. Immunosuppressed persons can develop chronic HEV infection, potentially leading, within a few years, to liver cirrhosis with life-threatening sequelae. Moreover, HEV infection may be associated with extrahepatic manifestations such as Guillain-Barré syndrome. In two retrospectively evaluated case series, ribavirin was found to be active against HEV and can be used to treat either acute or chronic HEV infection.

CONCLUSION

Hepatitis E must be considered in the differential diagnosis of elevated hepatic enzyme levels and of systemic and neurological conditions of uncertain origin. The infection is usually self-limiting but can take a severe course in immunosuppressed persons. In such cases, ribavirin can be used as an antiviral treatment.