Seroprevalence and incidence of hepatitis E virus infection in German blood donors

Elevated liver enzymes in a German tertiary-care hospital: Distribution, diagnostic steps and diagnosis groups

BACKGROUND

The determination of liver blood tests is frequently performed in hospitalized patients, and abnormal values require further diagnostics. Yet, analyses considering the management of elevated liver enzymes are missing. Therefore, this study aimed to analyze the distribution of abnormal liver function tests and the subsequent diagnostic steps across different medical specialties.

METHODS

From our Hannover liver-injury database, we identified 63,300 cases of patients who were hospitalized between January 2008 and July 2021 with AST or ALT > 3 ULN or AP or TBI > 2 ULN at any time point during hospitalization. Of these, 29,547 cases fulfilled the inclusion criteria and were subjected to further analysis. Cases were analyzed according to the three groups: internal medicine, surgery and others. Analyses were performed regarding baseline characteristics, liver-related diagnostics and factors influencing hospital mortality.

RESULTS

Elevated liver blood tests were mainly observed in internal medicine (n=17,762, 60.1%), followed by the surgery department 34.2% (n=10,105). Notably, 40.2% (n=11,896) developed liver enzyme elevation above the cut-offs during the hospital stay. Testing for hepatitis B and C was more often performed in the surgery department compared to in internal medicine. In total, 5.6% of the cases (n=1,640) had a liver biopsy. Hyperbilirubinemia (total bilirubine ≥ 2ULN) and AST/ALT ratios >2 were associated with in-hospital mortality.

CONCLUSION

Clinicians are often faced with elevated liver enzymes. However, diagnostic steps differ between different specialties. Physicians should be aware of the increased in-hospital mortality in cases with hyperbilirubinemia or elevated AST/ALT ratios.

Seroprevalence and incidence of hepatitis E virus infection in the general population of Iwate prefecture, Japan: A retrospective cohort study

AIM

Hepatitis E virus (HEV) causes subclinical or acute self-limiting hepatitis. We surveyed the current seroprevalence and incidence of HEV infection among the general population in Iwate Prefecture, Japan, where the endemic infection is presumed to be low.

METHODS

Between 2014 and 2016, we recruited individuals from Iwate Prefecture, Japan, who visited a general medical work-up program. Serum anti-HEV antibody and HEV RNA were measured twice, with an interval of 2 years. Anti-HEV antibody was measured with enzyme-linked immunosorbent assay and HEV RNA with reverse transcription-polymerase chain reaction.

RESULTS

Study participants comprised 1284 Japanese (650 men and 634 women) with age ranging 20-89 years. A total of 90 participants were found to be positive for anti-HEV immunoglobulin G on the first visit, with a prevalence of 7.0% (95% confidence interval [CI] 5.6%-8.4%). Seroprevalence was higher in men than in women (10.1% vs. 3.7%, p < 0.001), and in those aged in their 50s-80s than in those aged in their 20s-40s (p = 0.006). Positive seroconversion indicating new HEV infection was found in seven of 1194 seronegative participants (0.59%; 95% CI 0.15%-1.0%), indicating the incidence of HEV infection to be 272 per 100 000 person-years (95% CI 109-561).

CONCLUSIONS

Our observations suggest that the incidence of HEV infection is high and that it is a leading cause of hepatitis virus infection in Iwate Prefecture, Japan.

Evaluation of Prevalence of Hepatitis E Clinical Markers among Donors in Estonia

Hepatitis E virus (HEV) is now considered the most common cause of acute hepatitis worldwide. There are no published data about the prevalence of antibodies to HEV and RNA in donor sera in Estonia, and this precludes planning measures for preventing HEV proliferation through blood transfusion services. Here, were report data from an analysis of 1002 sera on the prevalence of anti-HEV IgG and IgM and the viral RNA. The antibodies were found in 48 donor sera (4.8%); of these, 40 (4%) harbored anti-HEV IgG, 15 (1.5%) contained anti-HEV IgM, and 7 donors had anti-HEV antibodies of both classes simultaneously. HEV RNA was not detected in any blood serum. Statistical associations of infection risk factors (gender, age, travel in the last six months, contact with pigs and/or wild boars in the last six months, consumption of thermally unprocessed/raw pork or boar meat, raw/unfiltered tap water or water from natural sources, unpasteurized farm dairy products, and unwashed berries and/or vegetables) were assessed. None of the listed factors were found to be associated with a higher or lower risk of anti-HEV antibody presence. At the same time, an increasing share of anti-HEV IgG carriers with age was found. The absence of HEV RNA in the analyzed donor plasma samples proves that HEV acute infection prevalence in Estonia does not exceed the average level of European countries. There is no urgent necessity to enter a requirement for a total screening of blood plasma for HEV RNA prevalence in Estonia.

Prevalence, incidence, and outcomes of hepatitis E virus coinfection in patients with chronic hepatitis C

This study aimed to elucidate the anti-hepatitis E virus (HEV) immunoglobulin G (IgG) prevalence and incidence of seroconversion and seroreversion as well as its risk factors and to analyze the clinical outcomes of HEV and hepatitis C virus (HCV) coinfected patients compared to those of HCV-monoinfected patients. We prospectively enrolled 502 viremic HCV patients with paired plasma samples (at intervals of ≥ 12 months) from 5 tertiary hospitals. Anti-HEV IgG positivity was tested using the Wantai ELISA kit in all paired samples. Mean age was 58.2 ± 11.5 years old, 48.2% were male, 29.9% of patients had liver cirrhosis, and 9.4% of patients were diagnosed with hepatocellular carcinoma (HCC). The overall prevalence of anti-HEV IgG positivity at enrollment was 33.3%, with a higher prevalence in males and increasing prevalence according to the subject's age. During the 916.4 person-year, the HEV incidence rate was 0.98/100 person-years (9/335, 2.7%). Hepatic decompensation or liver-related mortality was not observed. There were six seroreversion cases among 172 anti-HEV-positive patients (1.22/100 person-years). In conclusion, approximately one-third of the adult Korean chronic HCV patients were anti-HEV IgG positive. The HEV incidence rate was 1 in 100 persons per year, without adverse hepatic outcomes or mortality.

Emerging Pathogen Threats in Transfusion Medicine: Improving Safety and Confidence with Pathogen Reduction Technologies

Emerging infectious disease threats are becoming more frequent due to various social, political, and geographical pressures, including increased human-animal contact, global trade, transportation, and changing climate conditions. Since blood products for transfusion are derived from donated blood from the general population, emerging agents spread by blood contact or the transfusion of blood products are also a potential risk. Blood transfusions are essential in treating patients with anemia, blood loss, and other medical conditions. However, these lifesaving procedures can contribute to infectious disease transmission, particularly to vulnerable populations. New methods have been implemented on a global basis for the prevention of transfusion transmissions via plasma, platelets, and whole blood products. Implementing proactive pathogen reduction methods may reduce the likelihood of disease transmission via blood transfusions, even for newly emerging agents whose transmissibility and susceptibility are still being evaluated as they emerge. In this review, we consider the Mirasol PRT system for blood safety, which is based on a photochemical method involving riboflavin and UV light. We provide examples of how emerging threats, such as Ebola, SARS-CoV-2, hepatitis E, mpox and other agents, have been evaluated in real time regarding effectiveness of this method in reducing the likelihood of disease transmission via transfusions.

Higher Risk of HEV Transmission and Exposure among Blood Donors in Europe and Asia in Comparison to North America: A Meta-Analysis

Background and aims: The increasing number of diagnosed hepatitis E virus (HEV) infections in Europe has led to the implementation of the testing of blood products in various countries. Many nations have not yet implemented such screening. To assess the need for HEV screening in blood products worldwide, we conducted a systematic review and meta-analysis assessing HEV RNA positivity and anti-HEV seroprevalence in blood donors. Methods: Studies reporting anti-HEV IgG/IgM or HEV RNA positivity rates among blood donors worldwide were identified via predefined search terms in PubMed and Scopus. Estimates were calculated by pooling study data with multivariable linear mixed-effects metaregression analysis. Results: A total of 157 (14%) of 1144 studies were included in the final analysis. The estimated HEV PCR positivity rate ranged from 0.01 to 0.14% worldwide, with strikingly higher rates in Asia (0.14%) and Europe (0.10%) in comparison to North America (0.01%). In line with this, anti-HEV IgG seroprevalence in North America (13%) was lower than that in Europe (19%). Conclusions: Our data demonstrate large regional differences regarding the risk of HEV exposure and blood-borne HEV transmission. Considering the cost–benefit ratio, this supports blood product screening in high endemic areas, such as Europe and Asia, in contrast to low endemic regions, such as the U.S.

Hepatitis E Virus (HEV) Synopsis: General Aspects and Focus on Bangladesh

HEV is the most common cause of acute hepatitis globally. This review summarizes the latest knowledge on the epidemiology, clinical characteristics, testing, and treatment of HEV infection. We also focused on Bangladesh to highlight the distinct challenges and the possible remedies. In low-income settings, the virus is mainly transmitted between people by fecal contamination of drinking water causing large outbreaks, and sporadic cases. The disease is usually mild and self-limiting acute hepatitis. Still, pregnant women and their offspring in low-income countries are at particular risk for severe disease, with up to 20% maternal mortality. Despite the high burden of the disease, HEV remains a relatively neglected virus, with detection hampered by costly tests and a lack of suitable treatments. Molecular PCR diagnostics, together with ELISA antibody tests, remain the preferred methods for diagnosis of HEV; however, rapid bedside diagnostics are available and could offer a practical alternative, especially in low-income countries. One vaccine (HEV 239) is only available in China and Pakistan, as efficacy against the other genotypes remains uncertain. The effectiveness trial conducted in Bangladesh might lead the way in gathering more efficacy data and could, together with improved surveillance and raised awareness, dramatically reduce the global burden of HEV.

Increased Seroprevalence of Campylobacter jejuni, but not HEV, in healthcare workers in gastroenterological endoscopy

BACKGROUND

The exposure of healthcare workers (HCW) to fecal-orally transmitted pathogens like hepatitis E Virus (HEV), Campylobacter jejuni or Helicobacter pylori is still not known. The potential risk for employees or patients to acquire these infections through asymptomatic infected healthcare personnel has not yet been studied. Physicians and nurses in gastroenterology working in endoscopic workspaces were recruited. Employees from cardiology, presumed to possess a lower exposure, served as controls. The cytomegalovirus (CMV) seroprevalence was analyzed as a control pathogen without fecal-oral route of transmission. This study provides an objective view onto the potential exposure risk for HCW and patients in endoscopic workspaces. We hypothesize that HCW in gastroenterological endoscopy show a higher seroprevalence for fecal-oral pathogens like HEV, C. jejuni and H. pylori compared to HCW in cardiology.

OBJECTIVE

Primary objective was the assessment of antibody titers against HEV, C. jejuni and H. pylori in serum of HCW from gastroenterological endoscopy as well as cardiology. As a secondary objective we analyzed the seroprevalence against CMV.

METHODS

65 HCW were from gastroenterological endoscopy (n=42) and cardiology (n=23) in three medical centers in the German federal states of Brandenburg, Hamburg and Schleswig-Holstein and were prospectively studied. Antibody titers were determined via ELISA in serum.

RESULTS

HCW in gastroenterological endoscopy showed a significantly higher C. jejuni seroprevalence for IgG (19.1 %) compared to HCW from the field of cardiology (8.7 %; p=0.04). IgA titers against C. jejuni were negligible. HEV seroprevalence for IgG did not differ significantly between HCW in gastroenterological endoscopy (7.1 %) and cardiology (8.7 %), respectively. IgA and IgM titers against HEV were also negligible. All other antibody titers against CMV and H. pylori showed no significant difference.

CONCLUSIONS

Only the C. jejuni seroprevalence was significantly increased in HCW from the field of gastroenterological endoscopy. HEV seroprevalence showed no differences. The results for CMV and H. pylori were without pathological findings. However, there is no elevated risk for HEV exposure in medical staff working at an endoscopy unit, but for C. jejuni the protective measures might need to be improved.

Therapeutic Advances in Viral Hepatitis A-E

Viral hepatitis remains a significant global health problem. All forms of viral hepatitis A through E (A-E) can lead to acute symptomatic infection, while hepatitis B and C can lead to chronic infection associated with significant morbidity and mortality related to progression to cirrhosis, end-stage-liver disease, and liver cancer. Viral hepatitis occurs worldwide, though certain regions are disproportionately affected. We now, remarkably, have highly effective curative regimens for hepatitis C, and safe and tolerable medications to suppress hepatitis B activity, and to prevent liver damage and slow disease progression. We have effective vaccines for hepatitis A and B which provide long-lasting immunity, while improved sanitation and awareness can curb outbreaks of hepatitis A and E. However, more effective and available preventive and curative strategies are needed to achieve global eradication of viral hepatitis. This review provides an overview of the epidemiology, transmission, diagnosis, and clinical features of each viral hepatitis with a primary focus on current and future therapeutic and curative options.

[Safety of blood and blood products: test methods for the detection of hepatitis B, C, and E virus]

Infections with hepatitis B, C, and E virus (HBV, HCV, and HEV) can be transmitted via blood and cause severe acute or chronic liver infections. To ensure the safety of blood donations and protect recipients from virus transmissions, blood donations in Germany are tested for viral genomes using nucleic acid amplification techniques (NATs) as well as for viral antigens and antibodies by serological testing. This article describes the relevant regulations on the safety of blood and blood products in Germany and the various screening methods. The safety of blood products is assessed.Currently used NAT methods for detection of hepatitis viruses are based either on polymerase chain reaction (PCR) or isothermal methods such as transcription-mediated amplification (TMA), which enable a highly sensitive detection of viral infections and thereby contribute to the reduction of the diagnostic window. Antigen tests for the detection of viral surface protein of hepatitis B virus in blood donations were introduced in the 1970s in order to prevent potential transmissions. Since the introduction of mandatory testing for HCV-specific antibodies in 1992, HCV NAT testing in 1999, anti-HBc antibody testing in 2006, and the non-mandatory HBV NAT, which is voluntarily performed by most of the blood establishments, blood safety has increased tremendously. Only a few isolated cases of transfusion-transmitted infections in the early window period have been reported since. The success of the recent introduction of mandatory HEV NAT testing in 2020 will have to be assessed in the upcoming years. Besides blood donor screening, the system for blood safety in Germany is supplemented by additional measures for donor selection and pathogen inactivation.

Transfusion-transmitted hepatitis E: What we know so far?

Hepatitis E virus (HEV) is a major cause of viral hepatitis globally. There is growing concern about transfusion-transmitted HEV (TT-HEV) as an emerging global health problem. HEV can potentially result in chronic infection in immunocompromised patients, leading to a higher risk of liver cirrhosis and even death. Between 0.0013% and 0.281% of asymptomatic blood donors around the world have HEV viremia, and 0.27% to 60.5% have anti-HEV immunoglobulin G. HEV is infectious even at very low blood concentrations of the virus. Immunosuppressed patients who develop persistent hepatitis E infection should have their immunosuppressant regimen reduced; ribavirin may be considered as treatment. Pegylated interferon can be considered in those who are refractory or intolerant to ribavirin. Sofosbuvir, a nucleotide analog, showed modest antiviral activity in some clinical studies but sustained viral response was not achieved. Therefore, rescue treatment remains an unmet need. The need for HEV screening of all blood donations remains controversial. Universal screening has been adopted in some countries after consideration of risk and resource availability. Various pathogen reduction methods have also been proposed to reduce the risk of TT-HEV. Future studies are needed to define the incidence of transmission through transfusion, their clinical features, outcomes and prognosis.

Hepatitis E Virus: An emerging enigmatic and underestimated pathogen

Hepatitis E virus (HEV) is an RNA virus causing hepatitis E disease. The virus is of one serotype but has diverse genotypes infecting both humans and animals. Based on evidence from seroprevalence studies, about 2 billion people are estimated to have been infected with HEV globally. HEV, therefore, poses a significant public health and economic challenge worldwide. HEV was discovered in the 1980s and was traced back to the 1955 - 1956 outbreak of hepatitis that occurred in India. Subsequently, several HEV epidemics involving thousands of individuals have occurred nearly annually in different countries in Asia and Africa. Initially, the virus was thought to be only enterically transmitted, and endemic in developing countries. Due to the environmental hygiene and sanitation challenges in those parts of the world. However, recent studies have suggested otherwise with the report of autochthonous cases in industrialised countries with no history of travel to the so-called endemic countries. Thus, suggesting that HEV has a global distribution with endemicity in both developing and industrialised nations. Studies have also revealed that HEV has multiple risk factors, and modes of transmission as well as zoonotic potentials. Additionally, recent findings have shown that HEV leads to severe disease, particularly among pregnant women. In contrast to the previous narration of a strictly mild and self-limiting infection. Studies have likewise demonstrated chronic HEV infection among immunocompromised persons. Consequent to these recent discoveries, this pathogen is considered a re - emerging virus, particularly in the developed nations. However, despite the growing public health challenges of this pathogen, the burden is still underestimated. The underestimation is often attributed to poor awareness among clinicians and a lack of routine checks for the disease in the hospitals. Thus, leading to misdiagnosis and underdiagnosis. Hence, this review provides a concise overview of epidemiology, diagnosis, and prevention of hepatitis E.

Hepatitis E virus prevalence among blood donors in Dali, China

BACKGROUND

Hepatitis E virus (HEV) is a nonenveloped RNA virus causing hepatitis E worldwide. The increase in transfusion-transmitted cases of HEV infections from asymptomatic blood donors causing serious illnesses among immunosuppressed recipients has been reported in the past few years. China is one of the most prevalent regions of HEV; as a result, it is important to evaluate the risk of transfusion-transmitted HEV.

METHODS

A total of 1864 serum samples (including demographic characteristics) from blood donors were randomly collected from February to March 2018 in Dali city. Anti-HEV IgG, IgM and IgA antibodies and HEV antigen were examined by enzyme-linked immunosorbent assay (ELISA). HEV RNA was detected by real-time PCR. Multivariable logistic regression modelling was used to examine the risk factors associated with HEV prevalence.

RESULTS

Overall, the positive rates of anti-HEV IgG, IgM, and IgA antibodies were 13.36% (249/1864), 1.13% (21/1864), and 1.82% (34/1864), respectively. However, none of the 1864 serum samples were HEV antigen positive or HEV RNA positive. Females (16.69%) had a significantly higher HEV seroprevalence than males (13.04%) (odds ratio [OR] 1.34 [95% CI, 1.02-1.75]). Bai (18.85%) donors had a significantly higher HEV seroprevalence than Han (12.21%) blood donors (odds ratio [OR], 1.65 [95% CI, 1.24-2.19] for Bai).

CONCLUSIONS

HEV showed a seroprevalence among blood donors in Yunnan Province, some of which were even recent infections, indicating a threat to the safety of blood transfusions. Whether to formulate a strategy for HEV screening in blood centres needs further research.

Seroprevalence of Hepatitis E Virus Infection among Blood Donors in Bulgaria

Hepatitis E virus (HEV) infection is widespread among domestic pigs, industrial swine, and wild boars in Bulgaria. The aim of the current research was to present the HEV seroprevalence among blood donors in Bulgaria. In the present study, 555 blood donors (479 males and 76 females) were enrolled from five districts in the country (Shumen, Pleven, Stara Zagora, Plovdiv, and Sofia districts). All blood samples were tested for anti-HEV IgG using the recomWell HEV IgG ELISA test (Mikrogen GmbH, Neuried, Germany). Each participating donor completed a short, structured, and specific questionnaire to document data on the current study. Anti-HEV IgG positive results were detected in 144 (25.9%) blood donors, including 129 (26.9%) males and 15 (19.7%) females. The established HEV seropositivity was 28.8% (23/80) in Shumen district, 23.2% (22/95) in Pleven district, 27.1% (38/140) in Stara Zagora district, 27.5% (44/160) in Plovdiv district, and 21.3% (17/80) in Sofia district. A high HEV seroprevalence was found for persons who declared that they were general hunters (48.7%; 19/39; p = 0.001) and hunters of wild boars (51.6%; 16/31; p = 0.001). We present the first seroprevalence rates of HEV infection in blood donors from Bulgaria. The results of our research showed high HEV seropositivity among blood donors.

Hepatitis E virus: Efficacy of pasteurization of plasma-derived VWF/FVIII concentrate determined by pig bioassay

BACKGROUND

Hepatitis E virus (HEV) is the leading cause of acute hepatitis throughout the world. Increasing blood component transfusion-associated HEV infections highlight the need for reliable virus inactivation procedures for plasma derivatives from pooled plasma donations.

STUDY DESIGN AND METHODS

An animal infection study was conducted to evaluate the efficiency of HEV inactivation by pasteurization during the manufacturing process of the von Willebrand Factor/Factor VIII (VWF/FVIII) concentrate Haemate P/Humate-P (CSL Behring, Marburg, Germany). For this purpose, groups of pigs were inoculated with stabilized VWF/FVIII intermediate spiked with HEV-positive liver homogenate and exposed to increasing incubation times of 0, 3, 6, and 10 h at 60°C. Animals were evaluated for virus replication over 27 days and in a subsequent trial over 92 days.

RESULTS

Virus replication was detected in animals up to the 6-h pasteurization group. In contrast, pasteurization for 10 h did not reveal virus detection when the observation period was 27 days. In an additional experiment using the 10-h pasteurized material, two individuals started virus excretion and seroconverted when the observation period was extended to 92 days. Based on the total infection rate (2 of 12) of the animals inoculated with the sample pasteurized for 10 h, a virus reduction factor of at least 4.7 log₁₀ is calculated.

CONCLUSION

This study demonstrates that pasteurization at 60°C for 10 h of an HEV-positive plasma derivative leads to the effective reduction of infectivity, resulting in a VWF/FVIII product with an appropriate margin of safety for HEV.

Current Paradigm of Hepatitis E Virus Among Pediatric and Adult Patients

Hepatitis E virus (HEV) infection is a polymorphic condition, present throughout the world and involving children and adults. Multiple studies over the last decade have contributed to a better understanding of the natural evolution of this infection in various population groups, several reservoirs and transmission routes being identified. To date, acute or chronic HEV-induced hepatitis has in some cases remained underdiagnosed due to the lower accuracy of serological tests and due to the evolutionary possibility with extrahepatic manifestations. Implementation of diagnostic tests based on nucleic acid analysis has increased the detection rate of this disease. The epidemiological and clinical features of HEV hepatitis differ depending on the geographical areas studied. HEV infection is usually a self-limiting condition in immunocompetent patients, but in certain categories of vulnerable patients it can induce a sudden evolution toward acute liver failure (pregnant women) or chronicity (immunosuppressed patients, post-transplant, hematological, or malignant diseases). In acute HEV infections in most cases supportive treatment is sufficient. In patients who develop chronic hepatitis with HEV, dose reduction of immunosuppressive medication should be the first therapeutic step, especially in patients with transplant. In case of unfavorable response, the initiation of antiviral therapy is recommended. In this review, the authors summarized the essential published data related to the epidemiological, clinical, paraclinical, and therapeutic aspects of HEV infection in adult and pediatric patients.

Hepatitis E seroprevalence in a German cohort of patients with inflammatory bowel diseases

BACKGROUND AND AIMS

The incidence of hepatitis E virus (HEV)-infections in industrialized nations has been increasing over the past years. Patients suffering from inflammatory bowel diseases (IBD) may be more prone to transmission. Data on HEV seroprevalence in IBD patients is scarce and has not been reported in German IBD patients. The German Health Examination Survey for Adults 2008-2011, which included 4.422 samples, found a HEV seroprevalence of 16.8%, increasing with age. The aim of the present study was to determine the seroprevalence of anti-HEV IgG in a German cohort of IBD patients, and to explore which parameters have an impact on HEV seroprevalence.

MATERIAL AND METHODS

This is an uncontrolled, cross-sectional, retrospective monocentric study. Among the patients visiting the IBD outpatient clinic between 25 January, 2019 and 24 September, 2019, 328 patients with Crohn's disease (CD) and 150 patients with ulcerative colitis (UC) were included in the study. IgG antibodies against HEV were determined by enzyme-linked immunosorbent assay. Positive antibody titers were verified using immunoblot analysis. Medical records were reviewed for demographic and clinical parameters to identify potential risk factors for HEV infection.

RESULTS

The prevalence of anti-HEV IgG antibodies was 17.4% in CD patients and 24.7% in UC patients. No patient with positive HEV PCR was detected. Greater age of CD und UC patients and longer duration of anti-interleukin 12/23 treatment in CD patients were associated with higher anti-HEV IgG antibody rates.

CONCLUSIONS

In summary, we conclude that patients with UC have a higher anti-HEV IgG antibody prevalence than the general population in Germany, and that immunosuppressive therapy may carry no higher risk for HEV infection.

Hepatitis E virus and blood transfusion safety

While the majority of worldwide hepatitis E viral (HEV) infections that occur in people are from contaminated water or food sources, there has also been a steadily rising number of reported cases of transfusion-transmitted HEV (TT-HEV) in blood donation recipients. For most, HEV infection is acute, self-limiting and asymptomatic. However, patients that are immunocompromised, especially transplant patients, are at much higher risk for developing chronic infections, which can progress to cirrhosis and liver failure, along with overall increased mortality. Because of the rising trend of HEV serological prevalence among the global population, and the fact that TT-HEV infection can cause serious clinical consequences among those patients most at need for blood donation, the need for screening for TT-HEV has been gaining in prominence as an important public health concern for both developing and developed countries. In the review, we summarise evidence for and notable cases of TT-HEV infections, the various aspects of HEV screening protocols and recent trends in the implementation of TT-HEV broad-based blood screening programmes.

HEV seroprevalence in blood donors in Turkey by two commercial total anti-HEV Ab ELISA kits

Previous hepatitis E virus (HEV) seroprevalence studies in Turkey have shown high variabilities, leading to conflicting results. We aimed to re-evaluate HEV seroprevalence among blood donors in Turkey using the Wantai (Beijing, China) and the Dia.Pro (Milan, Italy) total anti-HEV antibody (Ab) enzyme-linked immunosorbent assay (ELISA) kits and compare their performances and to investigate the presence of HEV RNA in blood donors. Serum total anti-HEV antibodies were determined in a total of 2011 volunteer blood donor samples collected from different regions of Turkey (807 from Ankara, 243 from Kayseri, 284 from İzmir, 200 from Malatya, 200 from Kahramanmaraş, and 277 from Van). HEV RNA was evaluated by a real-time polymerase chain reaction in a total of 272 anti-HEV seropositive samples. The country-wide HEV seroprevalence was calculated as 11.5% (Dia.Pro) and 12.2% (Wantai) with seropositivity rates of 12.0%-12.5% in Ankara, 7.4%-8.2% in Kayseri, 14.5%-15.5% in Malatya, 8.1%-8.8% in İzmir, 15.0%-16.0% in Kahramanmaraş, and 12.6%-13.4% in Van by Dia.Pro and Wantai kits, respectively. The lowest detectable Ab concentrations were 0.16 and 0.14 units/mL WHO, for the Dia.Pro and the Wantai assays, respectively, showing no significant difference between assays. HEV RNA was not detected in any of the anti-HEV seropositive samples. Compared with previous studies, HEV was shown to have a higher overall seroprevalence in Turkey. Despite its limitation, the current study represents the most comprehensive HEV seroprevalence study in Turkey performed with two different commercial ELISA assays with high sensitivities so far. Further investigation is required to determine HEV genotypes in Turkey.

Hepatitis E virus infections in patients with MS on oral disease-modifying treatment

Objective

To test whether patients with MS on disease-modifying treatments (DMTs) are at a higher risk of acute or chronic hepatitis E virus (HEV) infections or extrahepatic manifestations, we monitored approximately 1,100 persons with MS (pwMS) during 3 years for HEV infection.

Methods

This is an observational case series study. All pwMS were followed in our MS center between January 2016 and December 2018 with at least annual standardized clinical and laboratory assessments. Patients with unexplained liver enzyme elevations were routinely screened for HEV infection.

Results

Four cases of acute HEV under DMT (fingolimod [n = 3]; dimethyl fumarate [n = 1]) were identified. Two presented with fulminant icteric hepatitis and one with a HEV-associated neurologic manifestation (neuralgic amyotrophy). No chronic HEV courses were observed. DMT was continued after clearing of HEV or normalization of liver function tests in all cases.

Conclusion

HEV infection is an important differential diagnosis of drug-induced liver injury in pwMS under DMT. Our data do not suggest an increased incidence of acute HEV infections or chronification in pwMS. However, epidemiologic studies in immunomodulatory-treated patients are needed to further investigate HEV disease courses and extrahepatic manifestations.

Estimation of the hepatitis E assay-dependent seroprevalence among Croatian blood donors

BACKGROUND

Seroprevalence of hepatitis E virus (HEV) in blood donors presenting to the Croatian Institute of Transfusion Medicine was assessed with 4 available tests (3 ELISA tests and 1 immunoblot (IB) test).

MATERIALS AND METHODS

In October and November 2014, a total of 1,036 serum samples of blood donors were collected for the study. Samples were primarily tested for total HEV antibodies by Dia.Pro HEV Ab test (a). All reactive samples were tested by ELISA tests: Dia.Pro HEV IgG (b) and IgM (c), Mikrogen recomWell HEV IgG_old (d) and IgM_old (e), recomWell HEV IgG_new (f) and IgM_new (g), and IB Mikrogen recomLine HEV IgG (h) and IgM (i). HEV IgM reactive samples also positive by the IB were further tested for HEV RNA.

RESULTS

There were 21.5% of samples reactive for total HEV antibodies (a). Seroprevalence of HEV IgG according to the b, d, f and h tests was 20.2%, 9.6%, 18.1% and 17.8%, respectively. Seroprevalence of HEV IgM according to the c, e, g and i tests was 4.4%, 1.5%, 2.0% and 1.7%, respectively. Out of 46 HEV IgM (Dia.Pro HEV IgM) positive samples, 18 (39.1%) were also positive by IB. HEV RNA was not detected in any of those samples. There was a significant association between age and HEV seroprevalence (P<0.001).

CONCLUSION

Different HEV antibody detection assays showed a high HEV IgG seroprevalence in Croatian blood donors. Among HEV IgG and HEV IgM positive samples HEV RNA was not detected.

Why all blood donations should be tested for hepatitis E virus (HEV)

Background

Hepatitis E is a liver disease caused by a small RNA virus known as hepatitis E virus (HEV). Four major genotypes infect humans, of which genotype 1 and 2 (HEV-1, HEV-2) are endemic mainly in Asia and responsible for waterborne epidemics. HEV-3 and HEV-4 are widely distributed in pigs and can be transmitted to humans mainly by undercooked meat, and contact with pigs. HEV-3 is the main genotype in industrialised countries with moderate climate conditions and object of this debate.

Main text

Whereas an HEV-3 infection in healthy humans is mostly asymptomatic, HEV-3 can induce chronic infection in immunocompromised individuals and acute-on-chronic liver failure (ACLF) in patients with underlying liver diseases. The number of reported cases of HEV-infections in industrialised nations increased significantly in the last years. Since HEV-3 has been transmitted by blood transfusion to other humans, testing of blood donors has been introduced or introduction is being discussed in some industrialised countries. In this article we summarise the arguments in favour of testing all blood donations for HEV-3.

Conclusion

The number of HEV infection in the population and the possibility of HEV transmission by blood transfusion are increasing. Transmission by blood transfusion can be dangerous for the recipients considering their immunosuppressive status, underlying disease or other circumstances requiring blood transfusion. This argues in favour of testing all blood donations for HEV-3 to prevent transmission.

Systematic review and meta-analysis of the seroprevalence of hepatitis E virus in the general population across non-endemic countries

BACKGROUND

Hepatitis E virus (HEV) has commonly been associated with large waterborne outbreaks of human jaundice in endemic areas but it has been increasingly recognised as a cause of sporadic human cases of jaundice in non-endemic areas, in individuals with no history of travel. Zoonotic exposure is widely hypothesized to be an important potential transmission route in these sporadic human cases. Serosurveys conducted to determine the frequency of HEV human exposure report wide ranges in prevalence across studies and locations. Our study objective was to compute meta-analysis summary estimates of human seroprevalence of HEV IgG within countries considered HEV non-endemic, where possible, and to determine whether this varied significantly across these countries, as well as investigating the role of potential HEV seroprevalence predictors such as population age structure.

MATERIALS AND METHODS

A broad literature search was conducted in six electronic databases. Citations were appraised, and relevant data extracted using forms designed and pre-tested a priori. Meta-analysis and meta-regression were conducted in R, with HEV IgG seroprevalence in blood donors or the general population being the outcome of interest, and country, assay, population age and sex structure, and chronological time investigated as predictors of the outcome.

RESULTS

From 4163 unique citations initially captured, data were extracted from 135 studies investigating HEV serology in blood donors or the general population, of 31 countries among those categorised as 'very high human development' by the United Nations. Country of sampling and assay employed were consistently significant predictors of HEV IgG seroprevalence with chronological time being a non-significant predictor in the dataset of captured studies.

CONCLUSIONS

While country of sampling and assay employed were significant predictors of HEV seroprevalence, comparison of HEV seroprevalence across non-endemic countries is hampered by the lack of a gold standard assay and uncertainty regarding residual bias across studies, as well as regional differences within some countries.

Hepatitis E virus (HEV)-The Future

Hepatitis (HEV) is widely distributed in pigs and is transmitted with increasing numbers to humans by contact with pigs, contaminated food and blood transfusion. The virus is mostly apathogenic in pigs but may enhance the pathogenicity of other pig viruses. In humans, infection can lead to acute and chronic hepatitis and extrahepatic manifestations. In order to stop the emerging infection, effective counter-measures are required. First of all, transmission by blood products can be prevented by screening all blood donations. Meat and sausages should be appropriately cooked. Elimination of the virus from the entire pork production can be achieved by sensitive testing and elimination programs including early weaning, colostrum deprivation, Caesarean delivery, embryo transfer, treatment with antivirals, protection from de novo infection, and possibly vaccination. In addition, contaminated water, shellfish, vegetables, and fruits by HEV-contaminated manure should be avoided. A special situation is given in xenotransplantation using pig cells, tissues or organs in order to alleviate the lack of human transplants. The elimination of HEV from pigs, other animals and humans is consistent with the One Health concept, preventing subclinical infections in the animals as well as preventing transmission to humans and disease.

Hepatitis E: an underestimated emerging threat

Hepatitis E virus (HEV) is the most common cause of viral hepatitis in the world. It is estimated that millions of people are infected every year, resulting in tens of thousands of deaths. However, these estimates do not include industrialized regions and are based on studies which employ assays now known to have inferior sensitivity. As such, this is likely to represent a massive underestimate of the true global burden of disease. In the developing world, HEV causes large outbreaks and presents a significant public-health problem. Until recently HEV was thought to be uncommon in industrialized countries, and of little relevance to clinicians in these settings. We now know that this is incorrect, and that HEV is actually very common in developed regions. HEV has proved difficult to study in vitro, with reliable models only recently becoming available. Our understanding of the lifecycle of HEV is therefore incomplete. Routes of transmission vary by genotype and location: endemic regions experience large waterborne epidemics, while sporadic cases in industrialized regions are zoonotic infections likely spread via the food chain. Both acute and chronic infection has been observed, and a wide range of extrahepatic manifestations have been reported. This includes neurological, haematological and renal conditions. As the complete clinical phenotype of HEV infection is yet to be characterized, a large proportion of cases go unrecognized or misdiagnosed. In many cases HEV infection does not feature in the differential diagnosis due to a lack of knowledge and awareness of the disease amongst clinicians. In combination, these factors have contributed to an underestimation of the threat posed by HEV. Improvements are required in terms of recognition and diagnosis of HEV infection if we are to understand the natural history of the disease, improve management and reduce the burden of disease around the world.

Hepatitis E virus: reasons for emergence in humans

Hepatitis E virus (HEV) infects both humans and other animal species. Recently, we have seen a steady increase in autochthonous cases of human HEV infection in certain areas especially in Europe, and large outbreaks in several African countries among the displaced population. This mini-review critically analyzes potential host, environmental, and viral factors that may be associated with the emergence of hepatitis E in humans. The existence of numerous HEV reservoir animals such as pig, deer and rabbit results in human exposure to infected animals via direct contact or through animal meat consumption. Contamination of drinking, irrigation and coastal water by animal and human wastes lead to emergence of endemic cases in industrialized countries and outbreaks in displaced communities especially in war-torn countries.

Hepatitis E virus infection in Thai blood donors

BACKGROUND

Hepatitis E virus (HEV) infection in several industrialized and developing countries is associated with the consumption of pork and other meat products, an exposure risk among the majority of blood donors. We aimed to evaluate the prevalence of HEV in plasma from healthy blood donors in Thailand.

STUDY DESIGN AND METHODS

We screened blood samples collected between October and December 2015, from 30,115 individual blood donors in 5020 pools of six, for HEV RNA using in-house real-time reverse-transcription polymerase chain reaction (RT-PCR). Thrice-reactive samples were subjected to a commercial real-time RT-PCR (cobas HEV test) and evaluated for anti-HEV immunoglobulin M and immunoglobulin G antibodies. Genotyping using nested RT-PCR, nucleotide sequencing, and phylogenetic analysis was performed.

RESULTS

Twenty-six donors were positive for HEV RNA by the in-house assay, nine of whom were also positive by cobas test. None of the latter were reactive for anti-HEV immunoglobulin M or immunoglobulin G antibodies. Six samples were successfully genotyped and found to be HEV genotype 3. Thus, the frequency of HEV infection among healthy Thai blood donors is 1 in 1158.

CONCLUSION

The presence of HEV RNA in the Thai blood supply was comparable to the rates reported in western European countries, but higher than in North America and Australia.

Hepatitis E virus treatment and ribavirin therapy: viral mechanisms of nonresponse

Hepatitis E virus (HEV) can cause chronic infections in immunosuppressed patients with adverse clinical outcomes. Intervention strategies are limited with ribavirin (RBV) being the only main therapeutic option as off-label drug. Recent reports on RBV monotherapy failures show a coherence with the presence of certain single nucleotide variants (SNVs) and in-frame insertions in the hypervariable region of open reading frame 1 in the HEV genome. Importantly, some of the alterations were present in the viral population as minor variant before RBV administration. Individualized infection medicine by early detection of emerging viral variants in patients could improve treatment outcome and prognosis.

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.

Quantification of stored red blood cell fluctuations by time-lapse holographic cell imaging

We propose methods to quantitatively calculate the fluctuation rate of red blood cells with nanometric axial and millisecond temporal sensitivity at the single-cell level by using time-lapse holographic cell imaging. For this quantitative analysis, cell membrane fluctuations (CMFs) were measured for RBCs stored at different storage times. Measurements were taken over the whole membrane for both the ring and dimple sections separately. The measurements show that healthy RBCs that maintain their discocyte shape become stiffer with storage time. The correlation analysis demonstrates a significant negative correlation between CMFs and the sphericity coefficient, which characterizes the morphological type of erythrocyte. In addition, we show the correlation results between CMFs and other morphological properties such as projected surface area, surface area, mean corpuscular volume, and mean corpuscular hemoglobin.

A nationwide retrospective study on prevalence of hepatitis E virus infection in Italian blood donors

BACKGROUND

In Europe, hepatitis E virus (HEV) infection is mainly a food-borne zoonosis, but it can also be transmitted by blood transfusion. It is usually a mild and self-limited infection. However, immunocompromised persons, who are also those more likely to undergo blood transfusions, may develop chronic hepatitis and often cirrhosis. Since this is a potential threat to blood safety, we aimed to investigate HEV prevalence in Italian blood donors.

MATERIALS AND METHODS

We used plasma donations collected during 2015-2016 by blood services (BS) scattered throughout the Italian regions and intended for the production of plasma-derived medicines. Plasma samples were tested for IgG and IgM anti-HEV and for HEV RNA using validated assays. Data concerning donor's age and sex, and the location of the BS were collected.

RESULTS

A total of 10,011 plasma samples were tested. Overall IgG and IgM prevalence rates were 8.7 and 0.4%, respectively. No sample was HEV RNA-positive. IgG prevalence was significantly higher in males and in donors aged 44 years and over. IgG prevalence differed greatly according to region. Overall regional rates over 15% were found in Abruzzo and in Sardinia, and rates of 10-15% were found in Lazio, Umbria and the Marche. Considering IgG prevalence according to the province where the BS was located, rates over 30% were found in Sardinia and Abruzzo. Age, sex and donor's region of residence were independently associated with IgG positivity. BS location produced significant heterogeneity on prevalence rates within the regions.

DISCUSSION

The detected IgG rate of 8.7% in this study represents one of the lowest seroprevalence rates reported among blood donors in Europe. Particularly high prevalence rates in some regions and provinces may be explained by local eating habits and/or intensive environmental HEV contamination. Before considering the introduction of HEV RNA screening for blood donations in Italy, further important issues should be addressed and prospective incidence and reliable cost-benefit studies are needed.

Laboratory challenges in the diagnosis of hepatitis E virus

Hepatitis E virus (HEV) is an RNA virus that is an important cause of both acute and chronic hepatitis worldwide. To date, there are eight HEV genotypes that can infect mammals. HEV-1 and HEV-2 infect exclusively humans, while HEV-3 and HEV-4 infect humans and various animals, mainly pigs and deer. Additionally, two new genotypes (HEV-5 and HEV-6) infect mainly wild boar. Recently, newly discovered genotypes HEV-7 and HEV-8 were found to infect camels and possibly humans. Nevertheless, the epidemiological distribution of HEV-7 is not well established. HEV-8 is another newly discovered genotype that was identified in 2016 in Chinese Bactrian camels. Although faecal-oral transmission is the most common route of HEV transmission, HEV can be vertically transmitted from infected mothers to their fetuses. HEV may also spread by zoonotic transmission from infected animals to humans and through person-to-person contact. Nowadays, since the number of reported cases linked to blood donations is increasing annually, HEV is recognized as a transfusion-transmitted virus. Laboratory diagnostic techniques vary in their specificity and sensitivity for HEV detection. Direct techniques allow for detection of the viral proteins, antigens and viral nucleic acid, while HEV-specific IgG and IgM antibodies can help establish a diagnosis in acute and chronic infections. In this review, we will discuss recent technologies in the laboratory diagnosis of HEV, including serological and molecular methods to assess the specificity and sensitivity of currently available HEV commercial assays.

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.

Seroprevalence and incidence of hepatitis E virus among blood donors: A review

Hepatitis E virus (HEV) is an RNA virus with 4 main genotypes. HEV-1 and HEV-2 infect solely humans, while HEV-3 and HEV-4 infect humans and various animals such as pigs, deer, and rabbits. HEV-5 and HEV-6 infect mainly wild boar. Recently, new genotypes, known as HEV-7 and HEV-8, were found to infect camels and humans. HEV is globally distributed into different epidemiological patterns based on socioeconomic factors and ecology. Although HEV is mainly transmitted through the fecal-oral route, it was also recognized as a transfusion-transmitted virus. Transmission through blood donation was documented worldwide with rising annual observations, accounting for more than 2.5% of all transmissions. HEV infection is usually asymptomatic or subclinical in immunocompetent individuals, so it remains questionable whether there is an urgent need to screen for HEV prior to blood transfusion. Moreover, recent studies conducted in the Middle East and North Africa (MENA) region indicate that HEV is highly endemic. Here, we provide a review on HEV epidemiology, transmission, and laboratory diagnosis, giving special emphasis to the newly discovered genotypes, HEV-7 and HEV-8. Furthermore, we underscore the findings of recent HEV seroprevalence and viremia studies among blood donors worldwide. We also shed light on similar studies performed among blood donors in the MENA region.

Low hepatitis E virus RNA prevalence in a large-scale survey of United States source plasma donors

BACKGROUND

Hepatitis E virus (HEV) is a small, nonenveloped, single-stranded, RNA virus of emerging concern in industrialized countries. HEV transmission through transfusion of blood components has been reported, but not via plasma-derived medicinal products (PDMPs) manufactured with virus inactivation and/or removal steps. This study aimed to determine the prevalence of HEV among US source plasma donors.

STUDY DESIGN AND METHODS

Samples were collected from US source plasma donors at centers across the United States and were initially screened for HEV RNA in 96-sample minipools using the Roche cobas HEV test on the cobas 8800 system. Assuming a sensitivity of 18.6 IU/mL, the minipool screening strategy allowed for reliable detection of individual donations with HEV RNA titers of more than 2 × 10³ IU/mL. Reactive minipools were resolved to individual donations, which were further analyzed to quantify viral RNA concentration, determine HEV genotype, and immunoglobulin (Ig)G and IgM HEV antibody status.

RESULTS

A total of 128,020 samples were collected from 96 CSL Plasma centers in the United States, representing 27 states. The prevalence of HEV RNA-positive samples was 0.002% with three unique HEV-positive donors identified, all HEV Subgenotype 3a. Virus titers of HEV-positive samples were relatively low (10³ -10⁴ IU HEV RNA/mL). One positive donation was HEV IgG seropositive.

CONCLUSION

Routine screening of US source plasma donations for HEV would not substantially improve the safety of most PDMPs. The low prevalence and potential viral load of HEV, together with effective virus reduction steps in manufacturing processes, results in a low residual risk and acceptable safety margins for PDMPs derived from US plasma donors.

Hepatitis E in Canadian blood donors

BACKGROUND

Hepatitis E virus (HEV) is a virus of emerging importance to transfusion medicine as studies on blood donors and other populations demonstrate that the prevalence of endemic cases is higher than previously recognized and the risk to vulnerable transfusion recipients is not insignificant.

STUDY DESIGN AND METHODS

We carried out an HEV prevalence study on 13,993 Canadian blood donors with polymerase chain reaction (PCR) testing on all donors and antibody testing on a subset of 4102 donors. HEV antibody-positive and age- and sex-matched antibody-negative donors were invited to participate in a scripted telephone interview about risk factors.

RESULTS

There were no PCR-positive samples found (95% confidence interval [CI], 0%-0.026%). The seroprevalence of HEV in our tested population was 5.9% (95% CI, 5.16%-6.59%). HEV antibody positivity was associated with male sex and increasing age. In case-control analysis history of living outside Canada (odds ratio [OR], 2.9; 95% CI, 1.56-5.32) and contact with farm animals (OR, 1.5; 95% CI, 1.01-2.28) were associated with HEV seropositivity.

CONCLUSION

This is the largest data set to date on HEV infection in Canada. Results suggest low lifetime exposure to HEV and that infectious donations are rare.

Hepatitis E in blood donors: investigation of the natural course of asymptomatic infection, Germany, 2011

Asymptomatic hepatitis E virus (HEV) infections have been found in blood donors from various European countries, but the natural course is rarely specified. Here, we compared the progression of HEV viraemia, serostatus and liver-specific enzymes in 10 blood donors with clinically asymptomatic genotype 3 HEV infection, measuring HEV RNA concentrations, plasma concentrations of alanine/aspartate aminotransferase, glutamate dehydrogenase and bilirubin and anti-HEV IgA, IgM and IgG antibodies. RNA concentrations ranged from 77.2 to 2.19×10⁵ IU/mL, with viraemia lasting from less than 10 to 52 days. Donors showed a typical progression of a recent HEV infection but differed in the first detection of anti-HEV IgA, IgM and IgG and seropositivity of the antibody classes. The diagnostic window between HEV RNA detection and first occurrence of anti-HEV antibodies ranged from eight to 48 days, depending on the serological assay used. The progression of laboratory parameters of asymptomatic HEV infection was largely comparable to the progression of symptomatic HEV infection, but only four of 10 donors showed elevated liver-specific parameters. Our results help elucidate the risk of transfusion-associated HEV infection and provide a basis for development of screening strategies. The diagnostic window illustrates that infectious blood donors can be efficiently identified only by RNA screening.

Hepatitis E virus seroprevalence among the general population in a livestock-dense area in the Netherlands: a cross-sectional population-based serological survey

Background

Recent serological studies indicate that hepatitis E virus (HEV) is endemic in industrialised countries. The increasing trend in the number of autochthonous cases of HEV genotype 3 in Western European countries, stresses the importance to get insight in the exact routes of exposure. Pigs are the main animal reservoir, and zoonotic food-borne transmission of HEV is proven. However, infected pigs can excrete large amounts of virus via their faeces enabling environmental transmission of HEV to humans. This might pose a risk for of neighbouring residents of livestock farming.

Methods

Within a large study on the health of people living in the vicinity of livestock farming we performed a cross-sectional population-based serological survey among 2,494 non-farming adults from the general population in a livestock-dense area in the south of the Netherlands. Participants completed risk factor questionnaires and blood samples of 2,422 subjects (median age 58 years, range 20–72) were tested for anti-HEV IgG using an enzyme immune assay (Wantai). The aim of this study was to determine the HEV seroprevalence and to assess whether seropositivity in adults was associated with living in the vicinity of pig farms.

Results

The average seroprevalence of HEV was 28.7% (95% CI: 26.9–30.5). Determinants associated with an increased risk for HEV seropositivity were male gender and low level of education. There was a clear trend of increasing prevalence with increasing age (Chi-square test for linear trend, X² = 83.1; p < 0.001). A high number of pigs within 1,000 m of the residential address was not a risk factor for seropositivity.

Conclusions

This study confirmed the high HEV seroprevalence (29%) in the general population of the Netherlands, but presence of antibodies was not associated with residential proximity to pig farms. The prevalence increased with age from 10% in adolescents to 33% among those aged 50 and above, supporting the assumption of a cumulative lifetime exposure to HEV in the Netherlands as well as a higher infection pressure in the past. Our findings cannot refute the assumption that transmission is primarily food-borne.

Prevalence of hepatitis E virus infection among blood donors in mainland China: a meta-analysis

BACKGROUND

The risk of hepatitis E virus (HEV) infection from blood transfusion has raised increasing concern in many countries. Several transfusion-transmitted cases have been described in the United Kingdom and Japan. The objective was to investigate the prevalence of HEV infection among Chinese blood donors and analyze the potential risk of HEV infection through blood transfusion in China.

STUDY DESIGN AND METHODS

Major English and Chinese research databases were used as background research for the study of locations, years, and the number of HEV infections among blood donors in China. The pooled, estimated rate of HEV infection was calculated. Subgroup analyses, for age, sex, and alanine aminotransferase (ALT) levels were performed using software for comprehensive meta-analysis.

RESULTS

The pooled rates of anti-HEV IgM- and anti-HEV IgG-positive donations were 1.09% (95% confidence interval [CI], 0.95%-1.26%) and 30% (95% CI, 25%-34%), respectively. The prevalence of anti-HEV IgM was significantly higher in donors with elevated ALT (4.34%) compared with the rate in donors with normal ALT (1.35%; χ²  = 39.66, p < 0.01). The anti-HEV IgM and IgG rates were higher in the Southwest region (1.58 and 41%, respectively) compared to the rates in other regions of China (chi-square test, p < 0.05). The anti-HEV IgG rate was also significantly higher in donors 30 years and older compared with donors between 18 and 29 years of age (39% vs. 22%, respectively; χ²  = 1457.10, p < 0.01). Genetic analysis of HEV from RNA-positive donors indicated that the majority of HEV infections were Genotype 1 (19/33 = 58%), while the remaining 14 isolates were Genotype 4 (14/33 = 42%; χ²  = 0.758, p > 0.05).

CONCLUSION

Qualified donations after routine blood donor screening still carry a potential risk for transmitting HEV. The major genotypes in Chinese donors in this study were Genotypes 1 and 4.

Retrospective Study Evaluating Seroprevalence of Hepatitis E Virus in Blood Donors and in Swine Veterinarians in Italy (2004)

Hepatitis E is an emerging viral disease in developed countries, with sporadic cases occasionally linked to the consumption of raw or undercooked pork, wild boar or deer meat. Cases due to transfusion or transplantation have also been reported. In developed countries, hepatitis E is considered a zoonosis and pig is the main reservoir. In the last few years, several studies conducted in Europe reported variable seroprevalence rates among the general population, ranging between 0.26% and 52.5%. A higher seroprevalence was described among workers who come in contact with pigs. The aim of this retrospective study was to evaluate the seroprevalence of anti-HEV IgG and IgM antibodies in blood donors (170) and in pig veterinarians (83). Archival sera were collected in Italy in 2004. The observed seroprevalence was 9.64% and 8.82% in veterinarians and blood donors, respectively. Overall, only three sera from blood donors were positive for IgM, but no HEV-RNA was detected.

High prevalence of anti-hepatitis E virus antibodies in outpatients with chronic liver disease in a university medical center in Germany

AIM/OBJECTIVES/BACKGROUND

Hepatitis E virus (HEV) is an emerging disease in developed countries. HEV seroprevalence ranges from 3.2 to 10% in Europe, but is higher in endemic areas such as southern France. In Germany, an increasing incidence of HEV infections has been reported recently. Risk factors for the acquisition of HEV are incompletely understood.

METHODS

We screened 295 consecutive patients with chronic liver disease attending the outpatient department at Charité University Hospital for HEV seroprevalence. Epidemiological characteristics were analyzed and patients were questioned for risk factors using a standardized questionnaire. A total of 78 patients without known liver disease were also tested for HEV IgG.

RESULTS

Out of 295 screened patients, 62 tested positive for HEV-IgG. Overall, 50% of the HEV-positive patients were women and 23.8% had underlying liver cirrhosis. HEV-positive patients were older than HEV-negative patients (mean age 56 vs. 48.6 years). Seroprevalence increased with age from 13% in patients 30-39 years of age to 36.4% in patients 70-79 years of age. Of the total, 46.7% of HEV-IgG-positive patients had contact with domestic animals and 38.3% had received blood transfusions. A total of 50% of the HEV-IgG-positive patients had regularly consumed uncooked meat and 45% had regularly consumed wild game or wild boar, which was significantly more frequent than in HEV-IgG-negative patients.

CONCLUSION

HEV-IgG seroprevalence was 21% in a cohort of patients with chronic liver disease and 24.4% in a cohort of patients without known liver disease. The higher seroprevalence found among elderly patients suggests a lifetime accumulation of risk of exposure to HEV. The results from this study imply that regular testing should be performed for HEV in developed countries in case of liver disease of unknown etiology.