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

Hepatitis E Virus in the Role of an Emerging Food-Borne Pathogen

Viral hepatitis E represents an important global health problem caused by the hepatitis E virus (HEV). Cases of HEV infection are increasingly associated with food-borne transmissions after the consumption of raw or undercooked food products from infected animals in high-income regions. Although most cases of infection are asymptomatic, severe courses of infection have been reported in specific groups of people, predominantly among pregnant women and immunocompromised patients. The viral nucleic acid of HEV is increasingly being reported in food-producing animals and different products of an animal origin. Even though the incubation period for HEV infection is long, several direct epidemiological links between human cases and the consumption of HEV-contaminated meat and meat products have been described. In this article, we review the current knowledge on human HEV infections, HEV in different food-producing animals and products of an animal origin, as well as the accumulation and resistance to HEV in farm and slaughterhouse environments. We also provide preventive measures to help eliminate HEV from animals, the human population, and the environment.

The Epidemiology of Hepatitis E in Israel and Potential Risk Factors: A Cross-Sectional Population-Based Serological Survey of Hepatitis E Virus in Northern Israel

Hepatitis E Virus (HEV) has gained public health attention as one of the causative agents of viral hepatitis. Our study aimed to provide data about HEV seropositivity in the Israeli general population, including its seroprevalence geographical distribution, and to identify variables as possible risk factors for HEV exposure. A seroprevalence cross-sectional study was conducted: HEV serological status was determined in 716 blood samples collected from the routine check-up blood samples. Demographic information was available for all samples. The overall prevalence of HEV IgG in an apparently healthy population in the north of Israel was 10.5%, with no evidence of positive HEV IgM. There was a significant association between HEV seropositivity and elderly age and low socioeconomic status (SES). The age-adjusted seroprevalence was significantly lower among Jews compared to Arabs with a rate ratio of 2.02. We identified clusters (hot spots) of HEV infection in three regions under study. Our results confirmed a high prevalence of anti-HEV in the country where clinical hepatitis E is not endemic. For the first time, this study showed that a hot spot analysis was able to provide new knowledge about actual exposure zones. As HEV infection is not a notifiable disease, it is probably underdiagnosed. Thus, better awareness among physicians is warranted.

Rapid visual detection of hepatitis E virus combining reverse transcription recombinase-aided amplification with lateral flow dipstick and real-time fluorescence

Hepatitis E virus (HEV) is a globally prevalent zoonotic pathogen that is primarily spread through the fecal-oral route, such as by consuming undercooked or contaminated pork. HEV infection leads to an estimated 3.3 million symptomatic cases of viral hepatitis and 70,000 deaths in human populations each year. Therefore, a rapid and accurate method for detecting HEV in serum or stool samples is essential. In this study, we aimed to develop and evaluate two methods for the rapid and convenient detection of HEV RNA: reverse transcription recombinase-aided amplification with lateral flow dipstick (RT-RAA-LFD) and quantitative real-time reverse transcription recombinase-aided amplification (qRT-RAA). We optimized the reaction conditions and assessed their sensitivity and specificity. The RT-RAA-LFD assay completed its reaction at 39°C within 15 minutes, achieving a 95% limit of detection (LOD) of 247 copies/μL. The qRT-RAA assay, completed at 42°C within 20 minutes, had a 95% LOD of 25 copies/μL. Both assays demonstrated no cross-reactivity with other porcine pathogens and exhibited strong specificity. In testing 245 porcine bile and fecal samples, the RT-RAA-LFD assay showed a kappa value of 0.943 (P < 0.001) with a 97.14% (238/245) coincidence rate compared with quantitative reverse transcription PCR. Similarly, the qRT-RAA assay achieved a kappa value of 0.976 (P < 0.001) with a 98.78% (242/245) coincidence rate. In conclusion, these two RT-RAA assays show promising potential as effective diagnostic tools for broad and efficient screening of swine HEV in veterinary clinics.

IMPORTANCE

Hepatitis E virus (HEV) is a globally widespread zoonotic pathogen that poses a significant public health risk. Swine serve as the primary natural host for zoonotic HEV. This study introduces a rapid and precise method for detecting swine HEV RNA, showcasing its potential as an effective diagnostic tool for comprehensive and efficient screening of swine HEV in veterinary clinics.

Endemic maintenance of human-related hepatitis E virus strains in synurbic wild boars, Barcelona Metropolitan Area, Spain

Hepatitis E virus (HEV), shared by humans, domestic animals, and wildlife, is an emerging global public health threat. Because wild boars are a major reservoir of HEV, the new zoonotic interfaces resulting from wild boar population increase and synurbization significantly contribute to increasing the risk of zoonotic transmission of HEV. This study characterizes HEV strains of synurbic wild boars and assesses their relationship with sympatric human and domestic swine HEV strains. We analyzed the faeces of 312 synurbic wild boars collected from 2016 to 2021 in the Barcelona Metropolitan Area (BMA), where there is a high density of wild boars, and found 7 HEV-positive samples among those collected between 2019 and 2020. The molecular analysis of these isolates, along with 6 additional wild boar HEV isolates from a previous study, allowed us to establish a close phylogenetic relationship between these HEV strains and human HEV isolates from sympatric blood donors and domestic pigs from Catalonia. HEV-positive wild boar samples belonged to piglet, juvenile and yearling individuals, but not adults, indicating the endemic maintenance of HEV in the wild boar population of the BMA by naïve young individuals. All wild boar HEV isolates in this study classified within HEV genotype 3. The results show, for the first time, a close molecular similarity between the HEV strains endemically maintained by the synurbic wild boars in the BMA and citizens from the same area and period. The data could also indicate that HEV infection presents a seasonal and interannual variability in wild boars of BMA. Further investigation is required to unveil the HEV transmission routes between synurbic wild boars and sympatric citizens. These findings can serve in other synurbic wildlife-human interfaces throughout the world.

HEV in Blood Donors in Switzerland: The Route to Safe Blood Products

The hepatitis E virus (HEV) is an emerging infectious disease with zoonotic potential, causing acute hepatitis in humans. Infections in healthy individuals are often acute, self-limiting and asymptomatic, thus leading to the underdiagnosis of HEV infections. Asymptomatic HEV infections pose a problem for blood transfusion safety by increasing the risk for transfusion-transmitted HEV infections. Here, we describe the journey from determining the HEV seroprevalence among blood donors to the implementation of routine HEV RNA testing of all blood products in Switzerland in 2018 and summarise the HEV cases detected since. In total, 290 HEV-positive blood donations were detected by mini-pool nucleic acid testing (NAT) in Switzerland in the period of October 2018-December 2023, equal to an incidence of 20.7 per 100,000 donations. Thanks to the implemented scheme, no transfusion-transmitted infections occurred in this period. Furthermore, blood donation monitoring has proven to be an effective means of detecting HEV outbreaks in the general population. HEV cases in Swiss blood donors are caused by two major genotypes, the Swiss-endemic subtypes 3h3 and 3c. Interestingly, 11 HEV cases (5%) were of genotype 3ra, a variant found in wild and farmed rabbits. Our results indicate that mini-pool NAT is an efficient method to reduce the risk of transfusion-transmitted HEV infections.

Assessment of Hepatitis E virus transmission risks: a comprehensive review of cases among blood transfusion recipients and blood donors

Background

Hepatitis E Virus is a major cause of acute and fulminant hepatitis, particularly in developing countries. While the virus is commonly spread through the fecal-oral route, numerous cases of transfusion transmitted Hepatitis E Virus (TT-HEV) have been reported, raising concerns about its transmission via blood transfusions, especially in industrialized countries. The high prevalence of antibodies and viremia among asymptomatic blood donors further heightens the risk of transfusion-related transmission. However, there is still debate about the best strategy to minimize TT-HEV.

Objective

The review was conducted to Summarize the literature on TT-HEV infection cases and the prevalence of HEV among blood donors.

Methods

The databases PubMed, Scopus, Web of Science, Embase, and CINAHL were searched for relevant studies from 2000 to 2022.Serological and molecular screening data of HEV in blood donors were used to gather prevalence and incidence rates.TT-HEV cases were reviewed by examining evidence of HEV infection before and after transfusion.

Results

A total of 121 manuscripts reports the prevalence and incidence of HEV among blood donors and cases of TT-HEV. Twenty-six articles reported confirmed cases of TT-HEV and 101 articles reported on HEV prevalence or incidence among blood donors.

Conclusion

TT-HEV transmission through blood products is a real concern, especially for immunocompromised patients.The risk and severity of infection could vary between immunocompetent and immunosuppressed patients.To increase transfusion safety, the evaluation recommends HEV screening protocols, especially in endemic region.

Performance Comparison of Four Hepatitis E Antibodies Detection Methods

HEV antibody detection constitutes the main screening test for HEV infection. The aim of this study is to compare the sensitivity and specificity of four techniques: LIAISON® MUREX DiaSorin anti-HEV IgG and anti-HEV IgM assays, Hepatitis E VIRCLIA® IgM and IgG monotests, WANTAI HEV-IgM and IgG ELISA and VIDAS® anti-HEV IgM and IgG tests in five panels of samples configurated according to the immunoblot (RecomLine, Mikrogen, Neuss, Germany). Anti-HEV IgM sensitivity in the acute phase was 100% in all techniques, while sensitivity, including the immediate convalescence phase, was 96.74% for LIAISON®, 83.14% for VIRCLIA®, 84.78% for WANTAI and 88.04% for VIDAS®. Anti-HEV IgM specificity was 100% for both LIAISON® and VIRCLIA®. Anti-HEV IgM WANTAI agreed with VIRCLIA® with a good Kappa coefficient (κ = 0.71). Anti-HEV IgG post-infection sensitivity was 100% for LIAISON®, VIDAS® and VIRCLIA® and 99% for WANTAI. Anti-HEV IgG specificity reached 97.17% for LIAISON and 88.68% for VIRCLIA®. Our results demonstrated a better capacity of LIAISON® MUREX anti-HEV IgM than that of competitors for detecting acute infections as well as accurate anti-HEV IgG results and in how to resolve them.

Systematic Evaluation of Guidelines for the Diagnosis and Treatment of Hepatitis E Virus Infection

Background and Aims

The hepatitis E virus (HEV) is a zoonotic disease, and infection with HEV in humans primarily causes acute infections and can progress to chronic manifestation in immunocompromised individuals. Over the past decade, guidelines for diagnosing and treating HEV infection have been developed. This study aimed to systematically assess the quality of current guidelines for diagnosing and treating HEV infection, and we analyzed the differences in guideline quality and primary recommendations and explored possible reasons for these differences.

Methods

Guidelines published between 2013 and 2022 were searched, and studies were identified using selection criteria. The study assessed the quality of the included guidelines using the Appraisal of Guidelines for Research and Evaluation tool, extracted the primary recommendations in the guidelines, determined the highest level of evidence supporting the recommendations, and reclassified the evidence using the Oxford Centre for Evidence-Based Medicine grading system.

Results

Seven guidelines were included in the final analysis. The quality of the guidelines varied widely. The discrepancies may have been caused by the lack of external experts, the failure to consider influencing factors in guideline application, and the lack of consideration of the public's opinion. Analysis of the heterogeneity in primary recommendations revealed differences in algorithms for managing chronic HEV infection, the dosage of ribavirin, and a low level of evidence supporting the primary recommendations.

Conclusions

Guideline quality and primary recommendations vary considerably. Refinement by guideline developers and researchers would facilitate updating and applying guidelines for diagnosing and treating HEV infection.

Hepatitis E Virus in the United States and Canada: Is It Time to Consider Blood Donation Screening?

Hepatitis E virus (HEV) is the most common cause of acute viral hepatitis in the world and can lead to severe complications in immunocompromised individuals. HEV is primarily transmitted through eating pork, which has led to an increased in anti-HEV IgG seropositivity in the general population of Europe in particular. However, it can also be transmitted intravenously, such as through transfusions. The growing evidence of HEV contamination of blood products and documented cases of transmission have given rise to practice changes and blood product screening of HEV in many European countries. This review covers the abundant European literature and focuses on the most recent data pertaining to the prevalence of HEV RNA positivity and IgG seropositivity in the North American general population and in blood products from Canada and the United States. Currently, Health Canada and the Food and Drug Administration do not require testing of HEV in blood products. For this reason, awareness among blood product prescribers about the possibility of HEV transmission through blood products is crucial. However, we also demonstrate that the province of Quebec has a prevalence of anti-HEV and HEV RNA positivity similar to some European countries. In light of this, we believe that HEV RNA blood donation screening be reevaluated with the availability of more cost-effective assays.

The question of screening organ donors for hepatitis e virus: a case report of transmission by kidney transplantation in France and a review of the literature

BACKGROUND

Hepatitis E is a potentially serious infection in organ recipients, with an estimated two-thirds of cases becoming chronic, and with a subsequent risk of cirrhosis and death. In Europe, transmission occurs most often through the consumption of raw or undercooked pork, more rarely through blood transfusion, but also after solid organ transplantation. Here we describe a case of Hepatitis E virus (HEV) infection transmitted following kidney transplantation and review the literature describing cases of HEV infection transmitted by solid organ transplantation.

CASE PRESENTATION

Three weeks after kidney transplantation, the patient presented with an isolated minimal increase in GGT and hepatic cytolysis 6 months later, leading to the diagnosis of genotype 3c hepatitis E, with a plasma viral load of 6.5 log10IU/mL. In retrospect, HEV RNA was detected in the patient's serum from the onset of hepatitis, and in the donor's serum on the day of donation, with 100% identity between the viral sequences, confirming donor-derived HEV infection. Hepatitis E had a chronic course, was treated by ribavirin, and relapsed 10 months after the end of treatment.

DISCUSSION

Seven cases of transmission of HEV by solid organ transplantation have been described since 2012 without systematic screening for donors, all diagnosed at the chronic infection stage; two patients died. HEV organ donor transmission may be underestimated and there is insufficient focus on immunocompromised patients in whom mild liver function test impairment is potentially related to hepatitis E. However, since HEV infection is potentially severe in these patients, and as evidence accumulates, we believe that systematic screening of organ donors should be implemented for deceased and living donors regardless of liver function abnormalities, as is already the case in the UK and Spain. In January 2024, the French regulatory agency of transplantation has implemented mandatory screening of organ donors for HEV RNA.

Prevalence of Acute Hepatitis E Virus Infections in Swiss Blood Donors 2018-2020

INTRODUCTION

Hepatitis E virus (HEV) genotype 3 is the major cause of acute viral hepatitis in several European countries. It is acquired mainly by ingesting contaminated pork, but has also been reported to be transmitted through blood transfusion. Although most HEV infections, including those via blood products, are usually self-limiting, they may become chronic in immunocompromised persons. It is thus essential to identify HEV-infected blood donations to prevent transmission to vulnerable recipients.

AIMS

Prior to the decision whether to introduce HEV RNA screening for all Swiss blood donations, a 2-year nationwide prevalence study was conducted.

METHODS

All blood donations were screened in pools of 12-24 samples at five regional blood donation services, and HEV RNA-positive pools were subsequently resolved to the individual donation index donation (X). The viral load, HEV IgG and IgM serology, and HEV genotype were determined. Follow-up investigations were conducted on future control donations (X + 1) and previous archived donations of the donor (X - 1) where available.

RESULTS

Between October 2018 and September 2020, 541,349 blood donations were screened and 125 confirmed positive donations were identified (prevalence 1:4331 donations). At the time of blood donation, the HEV RNA-positive individuals were symptom-free. The median viral load was 554 IU/mL (range: 2.01-2,500,000 IU/mL). Men (88; 70%) were more frequently infected than women (37; 30%), as compared with the sex distribution in the Swiss donor population (57% male/43% female, p < 0.01). Of the 106 genotyped cases (85%), all belonged to genotype 3. Two HEV sub-genotypes predominated; 3h3 (formerly 3s) and 3c. The remaining sub-genotypes are all known to circulate in Europe. Five 3ra genotypes were identified, this being a variant associated with rabbits. In total, 85 (68%) X donations were negative for HEV IgM and IgG. The remaining 40 (32%) were positive for HEV IgG and/or IgM, and consistent with an active infection. We found no markers of previous HEV in 87 of the 89 available and analyzed archive samples (X - 1). Two donors were HEV IgG-positive in the X - 1 donation suggesting insufficient immunity to prevent HEV reinfection. Time of collection of the 90 (72%) analyzed X + 1 donations varied between 2.9 and 101.9 weeks (median of 35 weeks) after X donation. As expected, none of those tested were positive for HEV RNA. Most donors (89; 99%) were positive for anti-HEV lgG/lgM (i.e., seroconversion). HEV lgM-positivity (23; 26%) indicates an often-long persistence of lgM antibodies post-HEV infection.

CONCLUSION

The data collected during the first year of the study provided the basis for the decision to establish mandatory HEV RNA universal screening of all Swiss blood donations in minipools, a vital step in providing safer blood for all recipients, especially those who are immunosuppressed.

Hepatitis E Virus in Domestic Ruminants and Virus Excretion in Milk-A Potential Source of Zoonotic HEV Infection

The hepatitis E virus is a serious health concern worldwide, with 20 million cases each year. Growing numbers of autochthonous HEV infections in industrialized nations are brought on via the zoonotic transmission of HEV genotypes 3 and 4. Pigs and wild boars are the main animal reservoirs of HEV and play the primary role in HEV transmission. Consumption of raw or undercooked pork meat and close contact with infected animals are the most common causes of hepatitis E infection in industrialized countries. However, during the past few years, mounting data describing HEV distribution has led experts to believe that additional animals, particularly domestic ruminant species (cow, goat, sheep, deer, buffalo, and yak), may also play a role in the spreading of HEV. Up to now, there have not been enough studies focused on HEV infections associated with animal milk and the impact that they could have on the epidemiology of HEV. This critical analysis discusses the role of domestic ruminants in zoonotic HEV transmissions. More specifically, we focus on concerns related to milk safety, the role of mixed farming in cross-species HEV infections, and what potential consequences these may have on public health.

Prevalence and the impact of hepatitis E infection in pediatric liver transplanted recipients with hepatitis in Thailand

BACKGROUND

The hepatitis E virus (HEV) infection typically causes acute and self-limiting hepatitis. However, chronic infection can occur in immunocompromised hosts. This study determined the prevalence and impact of HEV infection in liver transplanted (LT) children who had transaminitis.

METHODS

The demographic data, anti-HEV IgM/IgG, serum/stool HEV RNA, and management for LT children with acute or persistent transaminitis from 2003 to 2020 were retrospectively reviewed. HEV serology was tested by ELISA, and HEV RNA was detected by semi-nested PCR.

RESULTS

Seventy-two children with LT with persistent transaminitis with a median age of 4.41 (1.32, 9.14) years (55.6% female) and one with acute hepatitis were investigated for HEV infection. Anti-HEV IgM, anti-HEV IgG, serum, or stool HEV RNA was investigated in 95.8% (N = 69), 93.1% (N = 67), 43.1% (N = 31), and 37.5% (N = 27) of patients, respectively. The prevalence of HEV infection was 37.5% (N = 27). There was no significant difference in characteristics between the HEV-infected and HEV-non-infected patients. Moreover, 22.2% (N = 16) and 15.3% (N = 11) of patients had past HEV infection and HEV-related acute or chronic infection, respectively. Most of the patients had primary treatment as the presumed graft rejection without improvement. In two patients, detectable HEV RNA in serum turned undetectable in approximately 2 weeks and 2 months, and liver enzyme levels normalized after reducing immunosuppressive therapy.

CONCLUSIONS

The prevalence of HEV infection among pediatric LT recipients with hepatitis was high. Chronic HEV infection was evidenced in two patients. Investigations of HEV infection in pediatric LT recipients with persistent transaminitis should guide proper management.

Universal nucleic acid donor screening revealed epidemiological features of hepatitis E and prevented transfusion-transmitted infection in Japan

BACKGROUND

More than 45 cases of transfusion-transmitted hepatitis E virus infection (TT-HEV) have been reported in Japan. Therefore, in 2020, universal individual donation nucleic acid amplification testing (ID-NAT) was implemented for HEV.

STUDY DESIGN AND METHODS

We characterized HEV NAT-positive blood donors. The number of new HEV infections and the asymptomatic infection rate were estimated using the HEV NAT-positive rate. HEV RNA quantitation, phylogenetic analysis, and antibody tests were performed, and the residual risk of TT-HEV was assessed based on the lookback study results.

RESULTS

A total of 5,075,100 blood donations were screened with ID-NAT during the first year of implementation, among which 2804 (0.055%; males: 0.060%, females: 0.043%) were NAT-positive with regional differences. Approximately 270,000 new HEV infection cases were estimated to occur annually in Japan, with an asymptomatic infection rate of 99.9%. The median HEV RNA concentration, excluding cases below the limit of quantification, was 205 IU/mL. Among the 1113 cases where the genotype could be determined, HEV-3 and HEV-4 accounted for 98.8% (1100) and 1.2% (13), respectively. The maximum duration of HEV viremia, including the pre- and post-ID-NAT window periods, was estimated to be 88.2 days. Within the 3 years since ID-NAT implementation, no confirmed cases of breakthrough TT-HEV were observed.

DISCUSSION

Multiple indigenous HEV strains are prevalent in Japan, infecting a significant number of individuals. However, since the implementation of ID-NAT, TT-HEV has been prevented due to the test's high sensitivity.

Hepatitis E Virus in Individuals Undergoing Heparin Therapy: An Observational Serological and Molecular Study

INTRODUCTION

Heparin is derived from swine and has been suggested as a possible source of HEV. To study the potential risk of HEV infection associated with heparin treatment, two groups of individuals were compared. Sera from heparinized (N=93) and non-heparinized individuals (N=111) were tested for markers of acute HEV infection and anti-HEV IgG seroprevalence.

METHODS

An acute HEV case was defined by the presence of anti-HEV IgM and/or HEV RNA. From the 93 heparinized individuals, one was positive for IgM and IgG anti-HEV and two were positive for HEV RNA (for both ORF3 and ORF2), and there were a total of two (2.2%) cases of current or recent HEV infection. From the 111 non-heparinized individuals, three were positive for IgM anti-HEV, one was positive for both IgM and IgG anti-HEV, and none was positive for HEV RNA, and there were a total of three (2.7%) cases of current or recent HEV infection. The difference between HEV cases in the heparinized individuals and the non-heparinized individuals was not statistically significant (2.2% vs. 2.7%; p = 0.799).

RESULTS

Concerning IgG anti-HEV, it was detected in 32 individuals from the heparinized group and in 18 from the non-heparinized control group. A statistically significant difference was observed in the presence of anti-HEV IgG in heparinized individuals and controls (p = 0.003).

CONCLUSION

This study has not found any association between heparin treatment and acute HEV infection, but has shown the use of therapeutic heparin as a risk factor for IgG anti-HEV seropositivity.

Clinical performance of a new multiplex assay for the detection of HIV-1, HIV-2, HCV, HBV, and HEV in blood donations in Catalonia (Spain)

BACKGROUND

Commercial multiplex nucleic acid tests (NATs) for HIV-1/HIV-2/HCV/HBV are widely used in developed countries to screen blood donations. HEV NAT screening has been implemented in some blood banks but is tested with a different assay.

STUDY DESIGN AND METHODS

This study describes the clinical sensitivity and specificity of the Procleix® UltrioPlex E (UPxE) assay on the automated Procleix Panther® system for the simultaneous detection of HIV-1/HIV-2/HCV/HBV/HEV. To evaluate routine performance, 10,138 donations were tested in parallel with UPxE (in ID-NAT) and current assays (Procleix Ultrio Elite [UE] assay in ID-NAT and Procleix HEV assay in pool of 16). To assess clinical sensitivity, archived donations positive for HCV, HIV-1, HBV, HEV, or occult HBV infection (OBI) were tested (n = 104-186).

RESULTS

Five donations were initially reactive (IR) with UPxE; none of them were reactive with current assays. Two of the three samples IR for HIV-1/HIV-2/HCV/HBV were confirmed positive for HBV (HBV NAT and/or anti-HBV core positive) and classified as OBI. The two samples IR for HEV were confirmed positive (Procleix HEV assay in ID-NAT and in-house RT-PCR HEV assay). One sample IR for HIV-1/HIV-2/HCV/HBV with UPxE and another with UE were not confirmed. UPxE showed a specificity of 99.99% for HIV-1/HIV-2/HCV/HBV and 100% for HEV. Comparable sensitivities were observed for HIV-1, HCV, HBV, OBI, and HEV samples tested in the UPxE, UE, and Procleix HEV assays.

DISCUSSION

UPxE may provide an efficient solution for the simultaneous detection of HIV-1, HIV-2, HCV, HBV, and HEV in blood donations in a single test.

Hepatitis E Virus in Livestock-Update on Its Epidemiology and Risk of Infection to Humans

Hepatitis E virus (HEV) is a public health problem worldwide and an important food pathogen known for its zoonotic potential. Increasing numbers of infection cases with human HEV are caused by the zoonotic transmission of genotypes 3 and 4, mainly by consuming contaminated, undercooked or raw porcine meat. Pigs are the main reservoir of HEV. However, it should be noted that other animal species, such as cattle, sheep, goats, and rabbits, may also be a source of infection for humans. Due to the detection of HEV RNA in the milk and tissues of cattle, the consumption of infected uncooked milk and meat or offal from these species also poses a potential risk of zoonotic HEV infections. Poultry infected by avian HEV may also develop symptomatic disease, although avian HEV is not considered a zoonotic pathogen. HEV infection has a worldwide distribution with different prevalence rates depending on the affected animal species, sampling region, or breeding system.

Establishment and Characterization of the First Chinese National Standard for Nucleic Acid Amplification Technology Assays for Hepatitis E Virus Nucleic Acid Detection

The detection of hepatitis E virus (HEV) RNA is the gold standard for HEV infection diagnosis. In order to address the quality control requirements for HEV RNA detection kits within China, we aimed to establish the first Chinese national standard for HEV RNA detection through a collaborative study. The candidate standard was quantified using digital PCR (dPCR). A total of five laboratories were invited to determine the estimated mean value of this national standard relative to the World Health Organization International Standard (WHO IS). Additionally, four commercial kits were used to assess the applicability of the candidate standard. The stability was determined by freeze-thaw cycles and storage at 37 °C, 25 °C and 4 °C. The estimated mean value of this national standard relative to the WHO IS was 5.67 log10 IU/mL. Two out of the four commercial kits can detect as low as the estimated limit of detection (LOD). The degradation rates of samples in the stability study ranged from 4% to 19%. In conclusion, we have established the first Chinese national standard for HEV nucleic acid detection against WHO IS, which can be employed to evaluate the quality of HEV RNA detection kits.

Epidemiology of HEV Infection in Blood Donors in Southern Switzerland

From 2014 to 2016, the number of hepatitis E virus (HEV) infections in southern Switzerland increased dramatically and suggested food as a potential infection reservoir. We evaluated the effects of food control measures introduced to limit HEV infections, assessing anti-HEV IgG and IgM rates in blood donors before and after the implementation of food control measures in 2017. From 2012 to 2013, we screened 1283, and from 2017 to 2019, we screened 1447 donors for IgG and IgM antibodies. No statistically significant differences were detected for IgG (32.8% from 2012 to 2013 vs. 31.1% from 2017 to 2019, p = 0.337) or IgM rates (2.0% from 2012 to 2013 vs. 2.8% from 2017 to 2019, p = 0.21). Rural provenience and age > 66 are predictors for positive IgG serology. A total of 5.9% of 303 donors included in both groups lost IgG positivity. We also determined nucleic acid testing (NAT) rates after the introduction of this test in 2018, comparing 49,345 donation results from southern Switzerland with those of 625,559 Swiss donor controls, and only 9 NAT-positive donors were found from 2018 to 2023. The high HEV seroprevalence in southern Switzerland may depend on different food supply chains in rural and urban areas. Local preventive measures probably have a limited impact on blood HEV risk; thus, continuous NAT testing is recommended.

Impact of Hepatitis E Virus Screening in the UK Deceased Organ Donor Population

Universal Hepatitis E Virus (HEV) screening of deceased organ donors was implemented by the UK national organ procurement organisation in October 2017. Donor testing for HEV infection is done post-transplant; detection of HEV ribonucleic acid (RNA) in donor plasma is therefore not a contra-indication for organ donation, with the result being used to inform recipient management. Immediate post-transplant detection of donor HEV viraemia triggers notification to transplant centres. Follow up of liver and kidney recipients has shown that transmission through solid organs is very efficient, particularly through liver grafts, as expected; no other organ types were transplanted in this cohort. Although donors with higher plasma viral load (VL > 103 IU/mL) were invariably associated with recipient infection, transmission was also documented at lower VL levels. Knowledge of donor HEV status has led to identification of transmission of infection via solid organ grafts followed by close patient monitoring and informed clinical management decisions. The purpose of this strategy is to allow early detection of infection and recurrence and treatment to circumvent the risk of accelerated liver damage from chronic HEV infection due to undiagnosed, inadvertent donor-derived transmission of infection.

Transfusion-transmission of hepatitis E virus through red blood cell transfusion but not through platelet concentrates: A case report from Spain

BACKGROUND

Few cases of transfusion-transmitted hepatitis E virus (HEV) have been published in Spain. Here, we describe a well-characterized lookback investigation of a transfusion-transmitted HEV case at the Community Centre for Blood and Tissues of Asturias (Spain).

CASE REPORT

A female patient with chronic myeloid leukemia underwent an allogeneic bone marrow transplant in March 2019 and showed alterations in liver function shortly afterwards. This patient received blood components from 30 different donors in the 3 months before the transplant. Frozen plasma samples from these donations were investigated for the presence of HEV-RNA. One frequent donor was identified as asymptomatic HEV RNA-positive at the time of his whole blood donation. The investigation revealed that this donor's plasma unit, originally intended for the fractionation industry, had a viral RNA concentration of 1.9 × 104 copies/mL. HEV RNA was detected initially in the index patient who received the red cell concentrate from this donor 25 days after the transfusion. HEV RNA isolated from both donor and recipient were identified as subtype 3f. The recipient of platelet concentrate (PC), treated with a riboflavin-based pathogen reduction technology (PRT) was not infected, being negative for the presence of HEV IgM, IgG, and HEV RNA before and after the transfusion.

CONCLUSION

This case study shows that HEV was transmitted through red cell transfusion to a recipient, while the patient who received riboflavin/UV light treated PC did not develop signs of infection. A causal relationship between PRT treatment of the PC and the non-transmission of HEV remains to be established.

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.

Seroprevalence of hepatitis E viral infection among apparently healthy personnels and patients with certain neurological disorders in Alexandria University Hospitals

Introduction

Hepatitis E virus (HEV) is one of the leading causes of acute viral hepatitis. There are thought to be 20 million infections per year in poorer nations with inadequate sanitation. In Egypt, awareness about the possible hazards linked to HEV infection is limited due to low socioeconomic and educational levels. Only a small number of sequences have been characterized, making HEV study in Egypt constrained. Numerous factors may have contributed to this neglect. Various extra-hepatic symptoms of HEV infection include neurological problems are recognized. Many European nations have implemented regular HEV monitoring, or targeted screening of blood provided by patients at greater risk to stop the spread of HEV by transfusion.

Aim

Assess the prevalence of HEV infection in asymptomatic blood donors. Increasing awareness about HEV testing in patients with some unexplained neurological disorders.

Methods

Cross-sectional study involving 550 patients: 500 apparently healthy blood donors and 50 patients with some neurological disorders. All subjects were tested for serological markers (IgG and IgM) for HEV using ELISA technique in addition to HEV RNA PCR testing for seropositive patients.

Results

Five hundred asymptomatic blood donors (370 males and 130 females), ages ranging from 20 to 50 years (median 33), 22.6% of them tested positive for HEV (IgG and IgM) of which 2 subjects only had positive HEV RNA PCR testing. In the second group 50 patients (26 males and 24 females) with various unexplained neurological disorders. Liver functions were within normal or showed only a mild increase. Forty-four percent of the patients had positive serology for HEV, with 6 patients testing positive for HEV RNA on PCR.

Conclusion

No need for mass screening for HEV serology among blood donors. HEV infection needs to be considered in patients with unexplained neurological disorders even if the liver functions are not markedly elevated.

Hepatitis E Virus in Finland: Epidemiology and Risk in Blood Donors and in the General Population

Autochthonous hepatitis E (HEV) cases have been increasingly recognized and reported in Europe, caused predominantly by the zoonotic HEV genotype 3. The clinical picture is highly variable, from asymptomatic to acute severe or prolonged hepatitis in immunocompromised patients. The main route of transmission to humans in Europe is the ingestion of undercooked pork meat. Transfusion-transmitted HEV infections have also been reported. The aim of the study was to determine the HEV epidemiology and risk in the Finnish blood donor population. A total of 23,137 samples from Finnish blood donors were screened for HEV RNA from individual samples and 1012 samples for HEV antibodies. Additionally, laboratory-confirmed hepatitis E cases in 2016-2022 were extracted from national surveillance data. The HEV RNA prevalence data was used to estimate the risk of transfusion transmission of HEV in the Finnish blood transfusion setting. Four HEV RNA-positive were found, resulting in 1:5784 (0.02%) RNA prevalence. All HEV RNA-positive samples were IgM-negative, and genotyped samples represented genotype HEV 3c. HEV IgG seroprevalence was 7.4%. From the HEV RNA rate found in this study and data on blood component usage in Finland in 2020, the risk estimate for a severe transfusion-transmitted HEV infection is 1:1,377,000 components or one in every 6-7 years. In conclusion, the results indicate that the risk of transfusion-transmitted HEV (HEV TTI) in Finland is low. However, continuous follow-up of the HEV epidemiology in relation to the transfusion risk landscape in Finland is necessary, as well as promoting awareness in the medical community of the small risk for HEV TTI, especially for immunocompromised patients.

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.

Seven years (2015-2021) of blood donor screening for HEV-RNA in France: lessons and perspectives

BACKGROUND

The French health authorities are considering expanding the current selective hepatitis E virus (HEV)-RNA testing procedure to include all donations in order to further reduce transfusion-transmitted HEV infection. Data obtained from blood donors (BDs) tested for HEV-RNA between 2015 and 2021 were used to assess the most efficient nucleic acid testing (NAT) strategy.

MATERIALS AND METHODS

Viral loads (VLs) and the plasma volume of blood components, as well as an HEV-RNA dose of 3.85 log IU as the infectious threshold and an assay with a 95% limit of detection (LOD) at 17 IU/mL, were used to assess the proportion of: (i) HEV-RNA-positive BDs that would remain undetected; and (ii) blood components associated with these undetected BDs with an HEV-RNA dose >3.85 log IU, considering 4 NAT options (Individual testing [ID], MP-6, MP-12, and MP-24).

RESULTS

Of the 510,118 BDs collected during the study period, 510 (0.10%) were HEV-RNA-positive. Based on measurable VLs available in 388 cases, 1%, 15.2%, 21.8%, and 32.6% of BDs would theoretically pass undetected due to a VL below the LOD of ID, MP-6, MP-12, and MP-24 testing, respectively. All BDs associated with a potentially infectious blood component would be detected with ID-NAT while 13% of them would be undetected with MP-6, 19.6% with MP-12, and 30.4% with MP-24 depending on the plasma volume. No red blood cell (RBC) components with an HEV-RNA dose >3.85 log IU would enter the blood supply, regardless of the NAT strategy used.

DISCUSSION

A highly sensitive ID-NAT would ensure maximum safety. However, an MP-based strategy can be considered given that: (i) the risk of transmission is closely related to the plasma volume of blood components; (ii) RBC are the most commonly transfused components and have a low plasma content; and (iii) HEV-RNA doses transmitting infection exceed 4 log IU. To minimise the potential risk associated with apheresis platelet components and fresh frozen plasma, less than 12 donations should be pooled using an NAT assay with a LOD of approximately 20 IU/mL.

Seroprevalence of Hepatitis E virus in children and adolescents living in urban Bogotá: An explorative cross-sectional study

The majority of Hepatitis E Virus (HEV)-related studies are carried out in adults whereas information about HEV seroprevalence, clinical disease manifestation, molecular epidemiology, and transmission patterns in children is limited. To estimate HEV seroprevalence among scholar children living in an urban setting and to analyze risk factors for an infection, we invited children aged 5-18 years from Bogotá (Colombia) for a cross-sectional survey. We collected self-reported data on demographics, social, clinical, and exposure variables in a structured interview. Venous blood samples were analyzed with two commercially available ELISAs for HEV-specific IgG antibodies. Among the 263 participants, we found three HEV IgG-reactive samples (1.1%) using both assays. We additionally characterized the samples for HEV IgM using a commercially available IgM ELISA and for HEV RNA. Here, we found one IgM-reactive sample, which was also reactive for IgG. In contrast, none of the IgM- and IgG-reactive sera samples showed detectable RNA levels indicating HEV exposure had not been recently. All participants reported access to drinking water and sanitary systems in their households and frequent hand washing routines (76-88%). Eighty percent of children reported no direct contact with pigs, but occasional pork consumption was common (90%). In contrast to the majority of studies performed in Colombian adults, we found a low unadjusted HEV seroprevalence of 1.1% (95% CI: 0.3-3.6%) for both HEV IgG ELISAs in our study population. While the majority of participants reported pork consumption, we speculate in the absence of viral RNA for genotyping in the affected individuals, that existing access to drinking water and sanitary systems within our study group contribute to the low HEV seroprevalence.

Immunoadsorption as maintenance therapy for refractory neuromyelitis optica spectrum disorder

Background

Neuromyelitis optica spectrum disorder (NMOSD) is a rare relapsing autoimmune disease of the central nervous system, affecting mainly optic nerves and spinal cord. NMOSD pathophysiology is associated with anti-aquaporin-4 (AQP4) immunoglobulin G (IgG) autoantibodies. Rapid extracorporeal elimination of autoantibodies with apheresis techniques, such as immunoadsorption (IA), was proven to be an effective treatment of NMOSD attacks. Data on the long-term use of IA to prevent attacks or progression of NMOSD are lacking.

Objectives

The aim of this study was to evaluate efficacy and safety of maintenance IA for preventing recurrence of NMOSD attacks in patients refractory to other immunotherapies.

Design

Case study.

Methods

Retrospective analysis of two female patients with severe NMOSD refractory to conventional immunotherapies was performed. Both patients had responded to tryptophan IA (Tr-IA) as attack therapy and subsequently were treated with biweekly maintenance Tr-IA.

Results

Patient 1 (AQP4-IgG seropositive, age 42 years) had 1.38 attacks of optic neuritis per year within 10.1 years before commencing regular Tr-IA. With maintenance Tr-IA for 3.1 years, one mild attack occurred, which was responsive to steroid pulse therapy. Expanded Disability Status Scale (EDSS) was stable at 5.0. Visual function score of the last eye improved from 3 to 1. Patient 2 (AQP4-IgG seronegative, age 43 years) experienced 1.7 attacks per year, mainly acute myelitis and optic neuritis, during the period of 10.0 years before the start of Tr-IA. During regular Tr-IA treatment, no further NMOSD attack occurred. The patient was clinically stable without any additional immunosuppressive treatment for 5.3 years. EDSS improved from 6.0 to 5.0, and the ambulation score from 7 to 1. Tolerability of Tr-IA was good in both patients. No serious adverse events occurred during long-term clinical trajectories.

Conclusion

Tr-IA was well tolerated as maintenance treatment and resulted in clinical stabilization of two patients with highly active NMOSD, who were refractory to standard drug therapy.

Prevalence of HEV RNA in Croatian blood donors

OBJECTIVES

HEV infection is asymptomatic for immunocompetent blood donors (BD). Transfused HEV-infected blood products may cause potentially hazardous HEV infection in immunocompromised patients. Evaluation of the need for routine BD HEV RNA screening primarily demands the establishment of HEV infection prevalence in Croatian BD.

MATERIALS AND METHODS

We tested BD samples in ID-NAT with the Procleix UltrioPlex E screening test for simultaneous detection of HBV DNA, HCV RNA, HIV-1,2 RNA, and HEV RNA (Grifols, Spain). HEV infection was confirmed with HEV RNA quantitative test (Altona Diagnostics, Germany) and HEV IgM and HEV IgG antibody test (DIA.PRO Diagnostic Bioprobes, Italy). We analysed the HEV RNA sequence and performed a phylogenetic analysis. We recorded BD's anamnestic data and dietary habits. BDs gave follow-up samples after two months and did not donate blood for six months.

RESULTS

Between December 2021 and March 2022, we tested 8,631 donations and found four HEV RNA-positive donations, which equals to one in 2,158 donations (0.046 %, 95 % confidence interval, 0.018 %-0.119 %). Confirmatory HEV RNA testing gave results from negative to 4.73E + 3 IU/ml HEV RNA. Three donations were in the serological window period. We have genotyped HEV RNA of two infected BD as genotype HEV-3c. Blood donors didn't report any health problems and their diet included pork. Testing on follow-up samples presented seroconversion and no HEV RNA could be detected.

CONCLUSION

The incidence of HEV RNA infection in BD in Croatia corresponds with other European data. The decision on implementation of HEV NAT screening in Croatia needs an expert team evaluation of the possible risk of TT-HEV infection.

Dual Infection of Hepatitis A Virus and Hepatitis E Virus- What Is Known?

Viral hepatitis is an infection of human hepatocytes resulting in liver damage. Dual infection of two hepatotropic viruses affects disease outcomes. The hepatitis A virus (HAV) and hepatitis E virus (HEV) are two enterically transmitted viruses; they are single-stranded RNA viruses and have common modes of transmission. They are transmitted mainly by the fecal-oral route and ingestion of contaminated food, though the HAV has no animal reservoirs. The HAV and HEV cause acute self-limiting disease; however, the HEV, but not HAV, can progress to chronic and extrahepatic infections. The HAV/HEV dual infection was reported among acute hepatitis patients present in developing countries. The impact of the HAV/HEV on the prognosis for acute hepatitis is not completely understood. Studies showed that the HAV/HEV dual infection increased abnormalities in the liver leading to fulminant hepatic failure (FHF) with a higher mortality rate compared to infection with a single virus. On the other hand, other reports showed that the clinical symptoms of the HAV/HEV dual infection were comparable to symptoms associated with the HAV or HEV monoinfection. This review highlights the modes of transmission, the prevalence of the HAV/HEV dual infection in various countries and among several study subjects, the possible outcomes of this dual infection, potential model systems for studying this dual infection, and methods of prevention of this dual infection and its associated complications.

Prophylactic Hepatitis E Vaccine

The hepatitis E has been increasingly recognized as an underestimated global disease burden in recent years. Subpopulations with more serious infection associated damage or death include pregnant women, patients with basic liver diseases, and elderly persons. Vaccine would be the most effective means for prevention of HEV infection. The lack of an efficient cell culture system for HEV makes the development of classic inactive or attenuated vaccine infeasible. Hence, the recombinant vaccine approaches are explored deeply. The neutralizing sites are located almost exclusively in the capsid protein, pORF2, of the virion. Based on pORF2, many vaccine candidates showed potential of protecting primate animals, two of them were tested in human and evidenced to be well-tolerated in adults and highly efficacious in preventing hepatitis E. The world's first hepatitis E vaccine, Hecolin^® (HEV 239 vaccine), was licensed in China and launched in 2012.

Transmission of Hepatitis E Virus

Transmission of hepatitis E virus (HEV) occurs predominantly by the fecal-oral route. Large epidemics of hepatitis E in the developing countries of Asia and Africa are waterborne and spread through contaminated drinking water. The reservoir of HEV in developed countries is believed to be in animals with zoonotic transmission to humans, possibly through direct contact or the consumption of undercooked contaminated meat. And HEV transmission through blood transfusion, organ transplantation, and vertical transmission has been reported.

Morphogenesis of Hepatitis E Virus

Hepatitis E virus, a leading cause of acute hepatitis worldwide, has been recognized as non-enveloped virus since its discovery in the 1980s. However, the recent identification of lipid membrane-associated form termed as "quasi-enveloped" HEV has changed this long-held notion. Both naked HEV and quasi-enveloped HEV play important roles in the pathogenesis of hepatitis E. However, the biogenesis and the mechanisms underlying the composition, biogenesis regulation, and functions of the novel quasi-enveloped virions remain enigmatic. In this chapter, we highlight the most recent discoveries on the dual life cycle of these two different types of virions, and further discuss the implication of the quasi-envelopment in our understanding of the molecular biology of HEV.

Laboratory Diagnosis of HEV Infection

Serological and nucleic acid tests for detecting hepatitis E virus (HEV) have been developed for both epidemiologic and diagnostic purposes. The laboratory diagnosis of HEV infection depends on the detection of HEV antigen or HEV RNA in the blood, stool, and other body fluids, and serum antibodies against HEV (immunoglobulin [Ig]A, IgM, and IgG). Anti-HEV IgM antibodies and low avidity IgG can be detected during the acute phase of the illness and can last approximately 12 months, representing primary infection, whereas anti-HEV IgG antibodies can last more than several years, representing remote exposure. Thus, the diagnosis of acute infection is based on the presence of anti-HEV IgM, low avidity IgG, HEV antigen, and HEV RNA, while epidemiological investigations are mainly based on anti-HEV IgG. Although significant progress has been made in developing and optimizing different formats of HEV assays, improving their sensitivity and specificity, there are many shortcomings and challenges in inter-assay concordance, validation, and standardization. This article reviews the current knowledge on the diagnosis of HEV infection, including the most common available laboratory diagnostic techniques.

Immunobiology and Host Response to HEV

Hepatitis E virus (HEV) usually causes acute self-limiting hepatitis but sometimes leads to chronic infection in immunocompromised persons. HEV is not directly cytopathic. Immunologically mediated events after HEV infection are believed to play important roles in the pathogenesis and clearance of infection. The anti-HEV antibody responses have been largely clarified since the determination of major antigenic determinant of HEV, which is located in the C-terminal portion of ORF2. This major antigenic determinant also forms the conformational neutralization epitopes. Robust anti-HEV immunoglobulin M (IgM) and IgG responses usually develop 3-4 weeks after infection in experimentally infected nonhuman primates. In humans, potent specific IgM and IgG responses occur in the very early phase of the disease and are critical in eliminating the virus, in concert with the innate and adaptive T-cell immune responses. Testing anti-HEV IgM is valuable in the diagnosis of acute hepatitis E. The long-term persistence and protection of anti-HEV IgG provide the basis for estimating the prevalence of HEV infection and for the development of a hepatitis E vaccine. Although human HEV has four genotypes, all the viral strains are considered to belong to a single serotype. It is becoming increasingly clear that the innate and adaptive T-cell immune responses play critical roles in the clearance of the virus. Potent and multispecific CD4+ and CD8+ T cell responses to the ORF2 protein occur in patients with acute hepatitis E, and weaker HEV-specific CD4+ and CD8+ T cell responses appear to be associated with chronic hepatitis E in immunocompromised individuals.

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.

Is Hepatitis E Virus a Neglected or Emerging Pathogen in Egypt?

Though Egypt ranks among the top countries for viral hepatitis and death-related liver disease, Hepatitis E virus (HEV) is a neglected pathogen. Living in villages and rural communities with low sanitation, use of underground well water and contact with animals are the main risk factors for HEV infection. Domestic animals, especially ruminants and their edible products, are one source of infection. Contamination of water by either human or animal stools is the main route of infection. In addition, HEV either alone or in coinfection with other hepatotropic viruses has been recorded in Egyptian blood donors. HEV seropositivity among Egyptian villagers was 60-80%, especially in the first decade of life. Though HEV seropositivity is the highest among Egyptians, HEV infection is not routinely diagnosed in Egyptian hospitals. The initial manifestations of HEV among Egyptians is a subclinical infection, although progression to fulminant hepatic failure has been recorded. With the improvement in serological and molecular approaches and increasing research on HEV, it is becoming clear that HEV represents a threat for Egyptians and preventive measures should be considered to reduce the infection rate and possible complications.

Detection of Nonenveloped Hepatitis E Virus in Plasma of Infected Blood Donors

BACKGROUND

Transfusion-transmitted hepatitis E virus (HEV) infections have raised many concerns regarding the safety of blood products. To date, enveloped HEV particles have been described in circulating blood, whereas nonenveloped HEV virions have only been found in feces; however, no exhaustive studies have been performed to fully characterize HEV particles in blood.

METHODS

Using isopycnic ultracentrifugation, we determined the types of HEV particles in plasma of HEV-infected blood donors.

RESULTS

Nonenveloped HEV was detected in 8 of 23 plasma samples, whereas enveloped HEV was found in all of them. No association was observed between the presence of nonenveloped HEV and viral load, gender, or age at infection. However, samples with HEV-positive serology and/or increased levels of liver injury markers contained a higher proportion of nonenveloped HEV than samples with HEV-negative serology and normal levels of liver enzymes. These results were further confirmed by analyzing paired donation and follow-up samples of 10 HEV-infected donors who were HEV seronegative at donation but had anti-HEV antibodies and/or increased levels of liver enzymes at follow up.

CONCLUSIONS

The HEV-contaminated blood products may contain nonenveloped HEV, which may pose an additional risk to blood safety by behaving differently to pathogen inactivation treatments or increasing infectivity.

Calibrating Hepatitis E Virus Serological Assays Using Asymptomatic Specimens Obtained in Japan

This study aimed to calibrate hepatitis E virus (HEV) serological assays. We optimized the previously developed in-house HEV antibody enzyme-linked immunosorbent assay (ELISA) by setting the cutoff with an in-house serological performance panel consisting of broad HEV antibody titers and subtracting nonspecific background values for anti-HEV IgM, IgA, and IgG. We also compared the assay's performance with that of commercial serological assay kits (four kits for IgM, one for IgA, and two for IgG). Although all serological assays readily detected HEV antibodies at high titers in the symptomatic hepatitis E population, considerable variations between assays were observed in the asymptomatic population. The in-house ELISA showed a higher sensitivity for HEV IgM, IgA, and IgG than the commercial kits and detected the seroconversion of HEV IgM and IgG earlier when testing a commercially available HEV seroconversion panel. The low sensitivity of the commercial kits was due to the high setting of the original cutoff, which was demonstrated by receiver operating characteristic analysis. However, the corrected cutoff value reduced assay specificity. Background subtraction is essential to achieve high specificity because the in-house ELISA without background subtraction reduced its specificity. These results indicate that asymptomatic specimens and background subtraction contribute to the optimization of HEV serological assays. IMPORTANCE Accurate diagnosis of hepatitis E virus (HEV) infection is essential for public health surveillance and for preventing HEV-contaminated blood transfusion. Anti-HEV IgM or IgA is used as a reliable marker of recent HEV infection. However, considerable variability in the sensitivity and specificity of HEV antibody detection is observed among several commercially available assay kits. In addition, none of the HEV antibody detection methods have been approved by the U.S. Food and Drug Administration (FDA). Here, we show that the in-house enzyme-linked immunosorbent assay (ELISA) could detect HEV IgM and IgA more sensitively than commercial kits in the asymptomatic population. We also suggest that the assay performance of commercial kits might be improved by optimizing the cutoff and reducing nonspecific background noise. A sensitive serological (IgM or IgA) assay in addition to HEV RNA testing will contribute to accurate diagnosis of acute HEV infection because HEV RNA-positive duration is relatively short.

Chronic hepatitis E: Advancing research and patient care

The hepatitis E virus (HEV) was initially thought to exclusively cause acute hepatitis. However, the first diagnosis of chronic hepatitis E in transplant recipients in 2008 profoundly changed our understanding of this pathogen. We have now begun to understand that specific HEV genotypes can cause chronic infection in certain immunocompromised populations. Over the past decade, dedicated clinical and experimental research has substantiated knowledge on the epidemiology, transmission routes, pathophysiological mechanisms, diagnosis, clinical features and treatment of chronic HEV infection. Nevertheless, many gaps and major challenges remain, particularly regarding the translation of knowledge into disease prevention and improvement of clinical outcomes. This article aims to highlight the latest developments in the understanding and management of chronic hepatitis E. More importantly, we attempt to identify major knowledge gaps and discuss strategies for further advancing both research and patient care.

Hepatitis E virus is effectively inactivated by methylene blue plus light treatment

BACKGROUND AND OBJECTIVES

Photodynamic treatment with methylene blue (MB) and visible light is a well-established pathogen inactivation system for human plasma. This technique is routinely used in different countries. MB/light treatment was shown to inactivate several transfusion-transmittable viruses, but its efficiency for the inactivation of the quasi-enveloped hepatitis E virus (HEV) has not yet been investigated.

MATERIALS AND METHODS

Plasma units were spiked with cell culture-derived HEV and treated with the THERAFLEX MB-Plasma system using various light doses (30, 60, 90, and 120 J/cm² ). HEV titers in pre- and post-treatment samples were determined by virus titration and a large-volume plating assay to improve the detection limit of the virus assay.

RESULTS

THERAFLEX MB-Plasma efficiently inactivated HEV in human plasma. Even the lowest light dose of 30 J/cm² inactivated HEV down to the limit of detection, with a mean log reduction factor of greater than 2.4 for the total process.

CONCLUSION

Our study demonstrates that the THERAFLEX MB-Plasma system effectively inactivates HEV in human plasma.

Fulminant Transfusion-Associated Hepatitis E Virus Infection Despite Screening, England, 2016-2020

In England, all blood donations are screened in pools of 24 by nucleic acid test (NAT) for hepatitis E virus (HEV) RNA. During 2016-2020, this screening successfully identified and intercepted 1,727 RNA-positive donations. However, review of previous donations from infected platelet donors identified 9 donations in which HEV RNA detection was missed, of which 2 resulted in confirmed transmission: 1 infection resolved with ribavirin treatment, and 1 proceeded to fatal multiorgan failure within a month from infection. Residual risk calculations predict that over the 5-year study period, HEV RNA detection was missed by minipool NAT in 12-23 platelet and 177-354 whole-blood donations, but transmission risk remains undetermined. Although screening has been able to largely eliminate infectious HEV from the blood supply in England, missed detection of low levels of HEV RNA in donated blood can lead to a severe, even fulminant, infection in recipients and could be prevented by more sensitive screening.

Long-term liver allograft fibrosis: A review with emphasis on idiopathic post-transplant hepatitis and chronic antibody mediated rejection

Liver transplantation (LT) is a life-saving surgical procedure and the current standard of care for most patients with end stage liver disease. With improvements in organ preservation techniques, perioperative care, and immunosuppression, there is better patient and graft survival following LT, and assessment of the liver allograft in long-term survivors is becoming increasingly important. Recurrent or de novo viral or autoimmune injury remains the most common causes of chronic hepatitis and fibrosis following liver transplantation in adults. However, no obvious cause can be identified in many adults with controlled recurrent disease and the majority of pediatric LT recipients, as they have been transplanted for non-recurrent liver diseases. Serial surveillance liver biopsies post LT have been evaluated in several adult and pediatric centers to identify long-term pathological changes. Pathological findings are frequently present in liver biopsies obtained after a year post LT. The significance of these findings is uncertain as many of these are seen in protocol liver biopsies from patients with clinically good allograft function and normal liver chemistry parameters. This narrative review summaries the factors predisposing to long-term liver allograft fibrosis, highlighting the putative role of idiopathic post-LT hepatitis and chronic antibody mediated rejection in its pathogenesis.

Hepatitis E virus in blood donors from Argentina: A possible source of viral infection?

BACKGROUND

The hepatitis E virus (HEV) causes acute hepatitis, which can progress to chronicity in immunosuppressed patients. It is transmitted mainly by the fecal-oral or zoonotic routes, but there is current evidence that it can be transmitted by blood transfusions. The objective of the study was to investigate HEV infections in blood donors in Argentina, within the framework of a hemovigilance program.

METHODS

A total of 547 samples from Argentinean blood donors, collected in 2016, 2019 and 2020 was studied for IgG and IgM anti-HEV by ELISA (Diapro) and RNA HEV by RT-real time PCR and RT-Nested-PCR.

RESULTS

The prevalence of IgG anti-HEV was 3.47% (19/547). No significant differences were registered according to the year studied, sex or age. The presence of RNA HEV was observed in 0.18% (1/547) of the donors studied without serological evidence of infection.

CONCLUSIONS

This is the first molecular detection in blood donors from Argentina, showing a molecular prevalence within the range described for RNA-HEV in blood donors from other non-endemic countries, in which immunocompetent RNA-HEV positive donors without serological evidence of infection were identified. The presence of viraemic donors could imply transfusion transmission, which deserves further attention and study.

Viral hepatitis: A narrative review of hepatitis A–E

Viral hepatitis continues to be a major health concern leading to hepatic decompensation ranging from acute hepatitis to cirrhosis and hepatocellular carcinoma. The hepatic and extrahepatic manifestations are not only debilitating but also associated with a significant economic burden. Over the last two decades, the field of virology has made significant breakthroughs leading to a better understanding of the pathophysiology of viral hepatitis, which in turn has led to new therapeutic options. The advent of direct-acting antiviral agents changed the landscape of hepatitis C virus (HCV) therapy, and new drugs are in the pipeline for chronic hepatitis B virus (HBV) treatment. There has also been a significant emphasis on screening and surveillance programs, widespread availability of vaccines, and linkage of care. Despite these efforts, significant gaps persist in care, and there is a pressing need for increased collaboration and teamwork across the globe to achieve a reduction of disease burden and elimination of HBV and HCV.

Serology versus nucleic acid amplification to diagnose acute hepatitis E, United Kingdom, 2014-18

OBJECTIVES

Diagnosing hepatitis E infection usually involves specific IgM testing, but sensitivity/specificity concerns mean many guidelines and practices include confirmatory tests. We studied whether additional information confirmatory tests provide justifies their use.

METHODS

We examined 9,131 records of anti-hepatitis E IgM assays, 7,615 of IgG assays, and 1,726 of RT-PCR assays from our regional laboratory, spanning October 2014-October 2018. We paired 495 IgM assay results with a RT-PCR result. We examined whether IgM results predicted PCR results, reviewed discrepant pairs, and investigated the correlation between IgG and PCR results in patients with strongly reactive IgM assays.

RESULTS

Anti-hepatitis E IgM titres are bimodal. A high cut-off value optimises prediction of RNA detectability. 7/404 low-IgM samples had detectable RNA, 6 from immunosuppressed patients. 26/91 high-IgM samples did not have detectable RNA. In high-IgM samples, RNA detectability was not associated with IgG titre (one-tailed Mann-Whitney U test, p=0.14).

CONCLUSIONS

In immunocompetent patients, tests beyond IgM seldom add clinically useful information. In patients with immunocompromise, IgM and RNA could contribute information. Additional tests' extra costs/intervention delays cannot be justified. IgM assay cut-offs should reflect titres' bimodal distribution, with values standardised using international units.

Viral hepatitis: Past, present, and future

Each hepatitis virus-Hepatitis A, B, C, D, E, and G-poses a distinct scenario to the patient and clinician alike. Since the discovery of each virus, extensive knowledge regarding epidemiology, virologic properties, and the natural clinical and immunologic history of acute and chronic infections has been generated. Basic discoveries about host immunologic responses to acute and chronic viral infections, combined with virologic data, has led to vaccines to prevent Hepatitis A, B, and E and highly efficacious antivirals for Hepatitis B and C. These therapeutic breakthroughs are transforming the fields of hepatology, transplant medicine in general, and public and global health. Most notably, there is even an ambitious global effort to eliminate chronic viral hepatitis within the next decade. While attainable, there are many barriers to this goal that are being actively investigated in basic and clinical labs on the local, national, and international scales. Herein, we discuss pertinent clinical information and recent organizational guidelines for each of the individual hepatitis viruses while also synthesizing this information with the latest research to focus on exciting future directions for each virus.