Decline in hepatitis E virus antibody prevalence in the United States from 1988-1994 to 2009-2010

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.

Hepatitis E Virus (HEV) in Makkah, Saudi Arabia: A Population-Based Seroprevalence Study

BACKGROUND

The Hepatitis E virus (HEV) is a common cause of viral hepatitis worldwide. Little is known about the seroprevalence of HEV in the general population of Saudi Arabia.

METHODS

A community-based cross-sectional HEV seroprevalence study was conducted in Makkah, Saudi Arabia. Anti-HEV IgG antibodies were detected in sera using an in-house ELISA. The frequency of HEV sageerology and its correlation with demographic, and environmental factors were evaluated.

RESULTS

Enrollment consisted of 1329 individuals, ages ranged from 8 to 88 years, the mean age was 30.17 years, the median age was 28yrs, and the male: female ratio was 1.15. The overall seroprevalence was 23.8% (316/1329). Males had significantly higher seroprevalence than females (66.1 vs. 33.9%; p < 0.001). Seroprevalence had significant correlations with age, occupation, and lack of regular water supply and housing conditions.

CONCLUSIONS

This is the first HEV community-based seroprevalence study from Saudi Arabia. Results show that the HEV is endemic in Makkah and affects all age groups and occupations. HEV affects more males than females and those living in crowded accommodations without a regular supply of water. Further studies are required across all regions of Saudi Arabia to determine the country's seroprevalence of active or past infection using tests for HEV IgG, HEV IgM antibodies and/or HEV RNA and underlying determinants of transmission.

Hepatitis E prevalence and infection in solid-organ transplant recipients in the United States

Hepatitis E virus (HEV) is the most common cause of acute viral hepatitis worldwide. An increased risk for HEV infection has been reported in organ-transplant recipients, mainly from Europe. Prospective data on HEV prevalence in the United States (U.S.) organ transplant population are limited. To determine the prevalence and factors associated with HEV infection among solid organ transplant-recipients, we conducted a prospective, cross-sectional, multicentre study among transplant-recipients and age- and organ-matched waitlist patients. Participants answered a risk-exposure questionnaire and were tested for HEV-RNA (in-house PCR), HEV-IgG, and IgM (ELISA, Wantai). Among 456 participants, 224 were transplant-recipients, and 232 were waitlist patients. The mean age was 58 years, 35% female, and 74% White. HEV seroprevalence of the entire cohort was 20.2% and associated with older age (p < 0.0001) and organ transplantation (p = 0.02). The HEV seropositivity was significantly higher among transplant-recipients compared with waitlist patients (24% vs. 16.4%, p = 0.042). Among transplant recipients, relative-risk of being HEV seropositive increased with older age (RR = 3.4 [1.07-10.74] in patients >70 years compared with ≤50 years, p = 0.037); history of graft hepatitis (2.2 [1.27-3.72], p = 0.005); calcineurin inhibitor use (RR = 1.9 [1.03-3.34], p = 0.02); and kidney transplantation (2.4 [1.15-5.16], p = 0.02). HEV-RNA, genotype 3 was detected in only two patients (0.4%), both transplant-recipients. HEV seroprevalence was higher among transplant-recipients than waitlist patients. HEV should be considered in transplant-recipients presenting with graft hepatitis. Detection of HEV-RNA was rare, suggesting that progression to chronic HEV infection is uncommon in transplant-recipients in the U.S.

Incidence of Hepatitis E Infection in American Patients With Suspected Drug-Induced Liver Injury Is Low and Declining: The DILIN Prospective Study

INTRODUCTION

Hepatitis E virus (HEV) infection rarely causes icteric hepatitis, yet 10%-40% of adult Americans have serological evidence of previous infection. The aim of this study was to investigate the incidence, presentation, and outcome of acute and previous HEV infection in a large cohort of patients with suspected drug-induced liver injury (DILI).

METHODS

Serum samples from 2012 patients enrolled in the DILI Network were tested for anti-HEV immunoglobulin G (IgG). Those with detectable anti-HEV IgG underwent testing for anti-HEV IgM; those with detectable anti-HEV immunoglobulin m (IgM) were tested for HEV RNA.

RESULTS

Anti-HEV IgG was detected in 407 (20%) patients and associated with increasing subject age and earlier year of enrollment. The median age of seropositive subjects was more than a decade higher than seronegative subjects (59.8 vs 48.7 years). The overall prevalence of anti-HEV declined from 22% (2004-2011) to 18% (2012-2019), suggestive of a cohort effect. The frequency of acute hepatitis E (median ALT = 1231 IU/L) also decreased from 3% (2004-2008) to 1.2% (2009-2013) to 0.6% (2014-2019). These results suggest that acute HEV infection is usually subclinical and was much more frequent in this cohort before 2004.

DISCUSSION

Acute HEV infection accounts for less than 1% of suspected American DILI cases and is more frequent in older men. Previous HEV infection is also most commonly seen in older individuals. Clinicians should consider testing for unsuspected acute HEV infection in older adult patients with acute hepatocellular DILI and jaundice.

Hepatitis E virus infection and rejection in kidney transplant recipients

BACKGROUND

Hepatitis E virus (HEV) infection has been associated with immune-mediated kidney diseases in developing countries. However, its relationship with kidney transplant outcomes has never been studied. We investigated the association between HEV infection and kidney graft rejection among kidney transplant recipients (KTRs).

METHODS

We conducted a matched cohort and longitudinal study utilizing banked sera following kidney transplantation during 1988-2012. Studies with evidence of post-transplantation HEV infection were identified by positive ELISA tests (anti-HEV IgM or anti-HEV IgG seroconversion) or positive HEV PCR and matched to KTR controls with negative HEV ELISA and PCR tests in a 1:5 ratio by age, sex, crossmatch status, immunosuppression era, and time of HEV testing. Outcome data collected included time to first kidney graft rejection, transaminases, and glomerular filtration rates. Log-ranked test was used to analyze survival.

RESULTS

Of 271 KTRs, 9 (3%) had evidence of post-transplantation HEV infection and were compared to 45 negative, matched controls. Median age at transplantation was 46 years. Kidney graft rejection was reported in 8 (89%) of cases and 21 (47%) of controls. Median time to first episode of kidney graft rejection was 17.4 months in cases and 30.8 months in controls (p = 0.029), with a higher hazard of developing kidney graft rejection in cases (HR = 3.23, 95% CI: 1.19-8.79). Lower mean glomerular filtration rates over time were observed in cases (35 mL/min/1.73m²) versus controls (42.4 mL/min/1.73m²) but did not reach significance (p = 0.24).

CONCLUSION

Subjects with evidence of post-transplantation HEV infection demonstrated earlier kidney graft rejection compared to controls.

Prevalence of hepatitis E infection among adults with concurrent chronic liver disease

While hepatitis E virus (HEV) infection can increase the risk of liver decompensation and death in patients with underlying chronic liver disease (CLD), prevalence of HEV in this cohort is not well reported. Using data from the 2011-2018 National Health and Nutrition Examination Survey, we aim to evaluate seroprevalence of HEV IgG among adults with non-alcoholic fatty liver disease (NAFLD), alcoholic liver disease (ALD), chronic hepatitis C virus (HCV) and chronic hepatitis B virus (HBV). HEV IgG seroprevalence between groups was evaluated with chi-square testing, and adjusted multivariate logistic regression models evaluated for predictors of seropositivity for HEV IgG. Seroprevalence of HEV IgG was 6.58% in ALD, 8.66% in HCV, 8.81% in NAFLD and 19.86% in HBV. We observed increasing HEV IgG seroprevalence over time in our study period, and in 2015-2018, seroprevalence was highest among the individuals with HCV (10.00%) and HBV (30.30%). Older age and being born outside of the United States were associated with seropositivity for HEV IgG in ALD, NAFLD, HBV, and for HCV, older age and being at or below poverty level were associated with seroprevalence for HEV IgG. In conclusion, we observed a relatively high prevalence of HEV among adults with CLD. These data highlight the need for greater awareness and education about the role of HEV in patients with underlying CLD, improving HEV test diagnostics, and revisiting the discussion about the potential role of HEV vaccines in CLD patients who are at higher risk of decompensation and death from acute HEV infection.

Assessment of subclinical effects of Hepatitis E virus infection in the United States

Some studies have exposed an increase in liver cirrhosis in hepatitis E seropositive individuals living with human immunodeficiency virus. The interrelation between HEV seroprevalence and risk of liver disease in immune-competent individuals remains under- investigated. Using the National Health and Nutrition Examination Survey (NHANES) data containing >30,000 subjects, we addressed if HEV exposure leads to subclinical effects that can influence liver health. We determined the association between HEV IgM and ALT and that of HEV IgG and Fib-4-a composite score reflecting potential liver fibrosis. These analyses were repeated in populations at risk for liver disease as well as among different races and ethnicities. The prevalence of HEV IgG was significantly associated with age as IgG positive individuals were, on average, 20 years older than IgG negative patients. We found a statistically significant increase in the likelihood of having a Fib-4 score >1.45 (significant fibrosis) in those positive for HEV IgG (RR: 1.03; 95% CI: 1.01-1.05). However, due to the small effect, it is unlikely that this association has clinical significance. Moreover, the effect was not present in those with pre-existing liver disease. We found no association between ALT levels and the presence of HEV IgM or IgG. This is the first study examining subclinical effects of HEV infection in the United States. Our study found that in the general US population, predominantly asymptomatic HEV infections do not contribute to the overall burden of liver disease.

Open reading frame 3 protein of hepatitis E virus: Multi-function protein with endless potential

Hepatitis E virus (HEV), a fecal-orally transmitted foodborne viral pathogen, causes acute hepatitis in humans and is responsible for hepatitis E outbreaks worldwide. Since the identification of HEV as a zoonotic agent, this virus has been isolated from a variety of hosts with an ever-expanding host range. HEV-open reading frame (ORF) 3, the smallest ORF in HEV genomes, initially had been perceived as an unremarkable HEV accessory protein. However, as novel HEV-ORF3 function has been discovered that is related to the existence of a putative third virion structural form, referred to as “quasi-enveloped” HEV particles, HEV is challenging the conventional virion structure-based classification scheme, which assigns all viruses to two groups, “enveloped” or “non-enveloped”. In this review, we systematically describe recent progress that has identified multiple pathogenic roles of HEV-ORF3, including roles in HEV virion release, biogenesis of quasi-enveloped virus, regulation of the host innate immune response, and interference with host signaling pathways. In addition, implications of HEV-ORF3-associated quasi-enveloped virions are discussed to guide future development of improved vaccines against zoonotic HEV infection.

Hepatitis E-Associated Hospitalizations in the United States: 2010-2015 and 2015-2017

Hepatitis E is considered rare in the United States (US) despite its widespread occurrence in Asian and African countries. The objective of this study was to describe the characteristics of hepatitis E-related pregnancies and acute-on-chronic liver failure and analyse trends for hepatitis E diagnosis among hospitalized patients in the US. We examined data from the 2010-2017 National Inpatient Sample from Healthcare Cost and Utilization Project to determine mortality, morbidity, pregnancy diagnoses, chronic liver disease diagnoses, and other conditions during hospitalization. Data were extracted for hospitalizations with hepatitis E as defined by ICD-9 codes 070.43 and 070.53 and ICD-10 code B17.2. Of 208,462,242 hospitalizations from 2010-2015, we identified 960 hepatitis E hospitalizations. The hospitalization rate of hepatitis E was 3.7 per 10 million in 2010 and 6.4 per 10 million in 2015 (β = 0.60, p = 0.011). From 2015 to 2017, the hospitalization appeared to increase with slope (β) of 0.50. Among those hospitalizations, 34 (4%) died and 85 (9%) had acute-on-chronic liver failure. Ninety-five (10%) had a diagnosis of pregnancy, there were no reports of maternal or foetus/neonate deaths, but there was a high proportion of adverse events for both during hospitalization. Having a chronic liver disease was associated with hepatic coma diagnosis (OR = 10.94, p = 0.002). Although the hospitalization rate of hepatitis E in the US is low, it appears to be increasing over time. Further studies are necessary in order to conclude a causal association of hepatitis E with adverse events and mortalities in pregnancy and chronic liver disease in the US.

Hepatitis E Virus Superinfection: an Underrecognized Trigger of Acute Hepatitis B Virus Flare

Hepatitis E virus (HEV) infection is a significant cause of acute hepatitis in endemic areas, such as parts of Asia, Africa, and Mexico, though HEV prevalence in the United States has been estimated between 6% and 20%. Chronic hepatitis B virus (HBV) infection affects about 1 per 1.4 million people in North America. Although well documented in Asia, HBV flare secondary to HEV superinfection is rarely reported in the United States. Here, we present a case of chronic undiagnosed HBV infection with acute flare secondary to HEV superinfection. 

Seroprevalence of hepatitis E virus antibodies in adults and children from upstate New York: A cross-sectional study

Hepatitis E virus (HEV) is a major cause of viral hepatitis around the world, especially in developing countries. Recently, HEV has also been recognized as important cause of hepatitis in Europe and Japan, however, there is a paucity of clinical data from the United States. The overall seroprevalence of HEV antibodies is around 10% in the United States, but considerable variation is seen based on geographic location, year, and assay used. In this study, 63 adults and 417 children from New York State were tested for anti-HEV IgG antibodies using the commercially available Wantai IgG assay. The overall seroprevalence of HEV antibodies among adult participants was 9.52% (95% CI: 3.58–19.59%). Positive adults tended to be older than HEV negative adults, all positive adults were female. Only 3 (0.7%, 95% CI:: 0.15–2.09%) of the children were positive, all positive children were male. These results are consistent with global and United States trends in HEV seroprevalence.

Role of Hepatitis E Virus Infection in North American Patients With Severe Acute Liver Injury

INTRODUCTION

The aim of this study was to determine the role of hepatitis E virus (HEV) infection in a large cohort of prospectively enrolled patients with severe acute liver injury (ALI).

METHODS

Serum samples from 594 consecutive adults enrolled between 2008 and 2018 in the US Acute Liver Failure Study Group ALI registry were tested for anti-HEV IgM and anti-HEV IgG levels. Those with detectable anti-HEV IgM underwent further testing for HEV RNA using real-time polymerase chain reaction.

RESULTS

The median age of patients was 38 years; 41% were men and 72% Caucasian. Etiologies of ALI included acetaminophen hepatotoxicity (50%), autoimmune hepatitis (8.9%), hepatitis B virus (8.9%), and idiosyncratic drug-induced liver injury (7.9%). Overall, 62 patients (10.4%) were negative for anti-HEV IgM but positive for IgG, whereas only 3 men (0.5%) were positive for both anti-HEV IgM and IgG. These 3 cases were initially diagnosed as having indeterminate, HEV, and hepatitis B virus-related ALI. One of these patients had detectable HEV RNA genotype 3, and another anti-HEV IgM+ patient had detectable HEV antigens by immunohistochemistry on liver biopsy. On multivariate modeling, older (odds ratio: 1.99) and non-Caucasian subjects (odds ratio: 2.92) were significantly more likely to have detectable anti-HEV IgG (P < 0.0001).

DISCUSSION

Acute HEV infection is an infrequent cause of ALI in hospitalized North American adults. The anti-HEV IgG+ patients were significantly older and more likely to be non-Caucasian. These data are consistent with other population-based studies that indicate exposure to HEV in the general US population is declining over time and might reflect a cohort effect.

A Territorywide Prevalence Study on Blood-Borne and Enteric Viral Hepatitis in Hong Kong

BACKGROUND

Viral hepatitis epidemiological data are important for the World Health Organization plan of eliminating viral hepatitis. We aimed to document the prevalence of viral hepatitis A to E in Hong Kong.

METHODS

This community-based study was open to all Hong Kong Chinese citizens aged ≥18 years. Baseline data and risk factors were collected. Hepatitis A-E serology was measured, including hepatitis B e antigen, antibodies to hepatitis B e antigen, antibodies to hepatitis D, hepatitis B virus (HBV) DNA for hepatitis B surface antigen (HBsAg)-positive participants, and antibodies to hepatitis B surface antigen and antibodies to hepatitis B core antigen (anti-HBc) in HBsAg-negative participants. Hepatitis C virus (HCV) RNA and genotypes were determined in anti-HCV-positive participants.

RESULTS

A total of 10 256 participants were recruited from February 2015 to July 2016. Overall HBsAg seroprevalence was 7.8% (95% confidence interval [CI], 7.3%-8.3%), which was reduced significantly with HBV vaccination (odds ratio, 0.15 [95% CI, .11-.21]). Among HBsAg-negative participants, anti-HBc seroprevalence increased from 5.4% (<26 years) to 60.1% (>65 years). No hepatitis D virus (HDV) cases were detected. Anti-HCV positivity was 0.5% (95% CI, .3%-.6%). Prevalence of antibodies to hepatitis A virus (anti-HAV) and hepatitis E virus (anti-HEV) was 65.2% (95% CI, 64.2%-66.1%) and 33.3% (95% CI, 32.4%-34.2%), respectively, and were influenced by age, family income, and being born in mainland China.

CONCLUSIONS

HBV seroprevalence remained high despite universal vaccination. High anti-HBc seroprevalence underlines the potential issue of HBV reactivation during profound immunosuppression. HCV and HDV remained uncommon. Anti-HAV seroprevalence had decreased whereas anti-HEV seroprevalence had risen.

Low seroprevalence of hepatitis E on Reunion island

Objective

Hepatitis E virus (HEV) has been scarcely investigated in the Indian Ocean. Following a nationwide serosurvey among blood donors, we conducted a population-based serosurvey to assess the magnitude of HEV exposure on Reunion Island.

Methods

Four hundred and sixty-six archived frozen human sera from the 2009 CoPanFlu-RUN cohort were analysed using the Wantai HEV IgG enzyme immunoassay. HEV seropositivity was defined as an IgG titre ≥5 UI/ml. Raw and weighted seroprevalences were assessed to account for the discrepancy between the CoPanFlu-RUN subset and the general community. Prevalence proportion ratios (PPR) were measured using log-binomial models.

Results

The raw and the weighted seroprevalences of HEV were 9.01% (95% CI 6.41–11.61) and 6.73% (95% CI 4.47–8.98), respectively. The presence of HEV IgG antibodies was associated with increasing age (P < 0.001). In a survey-adjusted model minimizing the sampling bias and adjusting for age, males were more likely to be seropositive than females (adjusted PPR 2.59, 95% CI 1.07–6.25). Seropositivity was spatially heterogeneous across the island (P < 0.01). Living in the neighbourhood of a pig farm within a low to intermediate slope area was associated with seropositivity in several models adjusting for age, gender, altitude of residency and interaction between slope and pig farms.

Conclusion

Reunion Island is a low endemic area for HEV exposure. Despite limitations related to the retrospective study design, our findings confirm the roles of cumulative lifetime exposure and male gender in HEV exposure. The risk associated with neighbouring pig farms might also suggest environmental contamination in this setting.

Enterically Transmitted Non-A, Non-B Hepatitis and the Discovery of Hepatitis E Virus

The recognition of hepatitis E as a discreet disease entity in the late 1970s followed the development of serological tests for hepatitis A and the discovery that large waterborne outbreaks of hepatitis in India were not caused by hepatitis A virus (HAV). These "enterically transmitted non-A, non-B hepatitis" outbreaks had distinctive epidemiologic features, including the highest attack rates among young adults, little secondary household transmission of infection, and severe disease in pregnant women. The responsible agent, hepatitis E virus (HEV), was identified several years later in extracts of feces from a self-inoculated virologist. Multiple genetically related HEV genotypes are now known to exist, two of which are common in domestic swine herds and the cause of sporadic cases of acute hepatitis in economically well-developed countries. HEV genotypes possess impressive genetic and biologic diversity, and present many unanswered questions concerning their natural host range, potential for zoonotic transmission, and disease pathogenesis.

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.

Prevalence and Impact of Hepatitis E Virus Infection Among Persons With Chronic Hepatitis B Living in the US and Canada

Background

Patients with chronic hepatitis B virus (HBV) may experience spontaneous biochemical flares of liver disease activity. This study aimed to determine (i) the prevalence of prior and possible acute hepatitis E virus (HEV) infection among persons with chronic HBV and (ii) whether HEV infection is associated with liver disease flares among persons with chronic HBV.

Methods

Serum from a random sample of 600 adults in the Hepatitis B Research Network Cohort Study was tested for HEV RNA and anti-HEV IgM and IgG. Logistic regression models were used to estimate crude and adjusted odds ratios of anti-HEV prevalence for participant characteristics.

Results

Anti-HEV IgG and IgM seroprevalence was 28.5% and 1.7%, respectively. No participants had detectable HEV RNA. Of the 10 anti-HEV IgM+ participants, only 1 had elevated serum ALT at seroconversion. The odds of anti-HEV seropositivity (IgG+ or IgM+) were higher in older participants, males, Asians, less educated people, and those born outside the United States and Canada.

Conclusions

Acute HEV infection is a rare cause of serum ALT flares among persons with chronic HBV. The high seroprevalence of anti-HEV IgG among the chronic HBV patients is strongly associated with various demographic factors in this largely Asian American cohort.

Epidemiology and Transmission of Hepatitis A Virus and Hepatitis E Virus Infections in the United States

There are many similarities in the epidemiology and transmission of hepatitis A virus (HAV) and hepatitis E virus (HEV) genotype (gt)3 infections in the United States. Both viruses are enterically transmitted, although specific routes of transmission are more clearly established for HAV than for HEV: HAV is restricted to humans and primarily spread through the fecal-oral route, while HEV is zoonotic with poorly understood modes of transmission in the United States. New cases of HAV infection have decreased dramatically in the United States since infant vaccination was recommended in 1996. In recent years, however, outbreaks have occurred among an increasingly susceptible adult population. Although HEV is the most common cause of acute viral hepatitis in developing countries, it is rarely diagnosed in the United States.

Probable transmission of hepatitis E virus (HEV) via transfusion in the United States

BACKGROUND

Hepatitis E virus (HEV) can inapparently infect blood donors. To assess transfusion transmission of HEV in the United States, which has not been documented, a donor-recipient repository was evaluated.

STUDY DESIGN AND METHODS

To identify donations that contained HEV RNA and were linked to patient-recipients with antibody evidence of HEV exposure, we assayed samples from the Retrovirus Epidemiology Donor Study (REDS) Allogeneic Donor and Recipient repository that represents 13,201 linked donations and 3384 transfused patients. Posttransfusion samples, determined to contain IgG anti-HEV by enzyme-linked immunosorbent assay, were reassayed along with corresponding pretransfusion samples for seroconversion (incident exposure) or at least fourfold IgG anti-HEV increase (reexposure). HEV-exposed patients were linked to donations in which HEV RNA was then detected by reverse-transcription quantitative polymerase chain reaction, confirmed by transcription-mediated amplification, and phylogenetically analyzed as subgenomic cDNA sequences.

RESULTS

Among all patients, 19 of 1036 (1.8%) who had IgG anti-HEV before transfusion were reexposed; 40 of 2348 (1.7%) without pretransfusion IgG anti-HEV seroconverted. These 59 patients were linked to 257 donations, 1 of which was positive by reverse-transcription quantitative polymerase chain reaction and transcription-mediated amplification. Plasma from this donation contained 5.5 log IU/mL of HEV RNA that grouped with HEV genotype 3, clade 3abchij. The patient-recipient of RBCs from this donation had a greater than eightfold IgG increase; however, clinical data are unavailable.

CONCLUSIONS

This is the first report of probable HEV transmission via transfusion in the United States, although it has been frequently observed in Europe and Japan. Additional data on the magnitude of the risk in the United States are needed.

Meta-Analysis of Human IgG anti-HEV Seroprevalence in Industrialized Countries and a Review of Literature

Although Hepatitis E is increasingly described as a major cause of liver disease in industrialized countries, the epidemiology is far from being fully elucidated. We provide here a comprehensive review of documented clusters of cases, and of serological studies conducted in populations with distinct types of exposure. Seroprevalence rates range from <5% to >50% depending on the countries and the groups of population. Such discrepancies can be attributed to the type of serological assay used, but this solves only a part of the problem. We performed a meta-analysis of studies performed with the broadly used Wantai HEV-IgG ELISA and found striking differences that remain difficult to understand with the current knowledge of transmission pathways.

Seroprevalence of hepatitis E in adults in Brazil: a systematic review and meta-analysis

BACKGROUND

Hepatitis E virus (HEV) is a member of the Hepeviridae family; it has four main genotypes and one serotype. While genotypes 1 and 2 cause epidemic hepatitis and are transmitted via water and the fecal-oral route, genotypes 3 and 4 are zoonotic. In the various seroprevalence studies of hepatitis E in Brazil, the numbers reported vary widely and are difficult to interpret. The aim of this study was to analyze existing seroprevalence studies of hepatitis E in adults in Brazil.

MAIN TEXT

We searched the PubMed, Latin American and Caribbean Health Sciences and Embase databases for studies published from inception to May 12, 2018 concerning infection by HEV in Brazil without time period or language restrictions. We included studies that presented data concerning hepatitis E seroprevalence in adults in Brazil, had a sample size ≥50 patients and whose method used for the detection of anti-HEV was standardized and commercialized. We also evaluated the quality of the articles using a list of criteria that totalized 9 items. Of the 20 studies ultimately analyzed, 10 (50%) were from the southeast region of Brazil, 3 (15%) were from the central-west region, 3 (15%) were from the northern region, 2 (10%) were from the northeast region and 2 (10%) were from the southern region. Regarding the quality evaluation of the studies, the mean score was 5.6 (range: 4-8). The estimated overall seroprevalence of HEV infection in the adult population was 6.0% (95% CI: 5.0-7.0); in subgroup analyses, we observed that the prevalence of anti-HEV antibodies in blood donors was 7.0% (95% CI: 5.0-8.0), whereas in the general population, it was 3.0% (95% CI: 2.0-4.0).

CONCLUSIONS

The results of this systematic review indicate that there should be national investment in the prevention of hepatitis E virus infection in Brazil, including the implementation of improvements in basic sanitation and guidance regarding the appropriate handling of animal waste and the optimal cooking of vegetables, meat and their derivatives.

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 seroprevalence in the Americas: A systematic review and meta-analysis

BACKGROUND & AIMS

While hepatitis E virus infections are a relevant topic in Europe, knowledge about epidemiology of hepatitis E virus infections in the USA and Latin America is still limited. Aim of this study was to estimate anti-hepatitis E virus IgG seroprevalence in the Americas and to assess whether low socioeconomic status is associated with hepatitis E virus exposure.

METHODS

We performed a systematic review and meta-analysis. Literature search was performed in PubMed for articles published 01/1994-12/2016. Prevalence was estimated using a mixed-effects model and reported in line with PRISMA reporting guidelines.

RESULTS

Seroprevalence was significantly higher in the USA than in Latin America, independently of assay, patient cohort, methodological quality or study year (OR: 1.82 (1.06-3.08), P = .03). Patients in the USA had a more than doubled estimated seroprevalence (up to 9%, confidence interval 5%-15.6%) than those in Brazil (up to 4.2%, confidence interval 2.4%-7.1%; OR: 2.27 (1.25-4.13); P = .007) and Mixed Caribbean (up to 1%, OR: 8.33 (1.15-81.61); P = .04). A comparison with published data from Europe demonstrated that anti-hepatitis E virus seroprevalence in the USA and Europe did not differ significantly (OR: 1.33 (0.81-2.19), P = .25), while rate in South America was significantly lower than that in Europe (OR: 0.67 (0.45-0.98), P = .04).

CONCLUSIONS

Hepatitis E virus is common in the USA. Surprisingly, the risk of hepatitis E virus exposure was low in many South American countries. Seroprevalence did not differ significantly between Europe and the USA. Hence, hepatitis E virus is not limited to countries with low sanitary standards, and a higher socioeconomic status does not protect populations from hepatitis E virus exposure.

Hepatitis E seroprevalence in the United States: Results for immunoglobulins IGG and IGM

BACKGROUND

Previous research identified a decline in hepatitis E virus (HEV) seroprevalence in US in 1988-1994 and 2009-2010. We investigated most recent HEV epidemiology.

METHOD

Using a nationally representative sample (7656 persons in the National Health and Nutrition Examination Survey [NHANES] 2013-2014 and 7124 persons in NHANES 2015-2016), we compared the weighted seroprevalence of HEV (immunoglobulin G [IgG]/immunoglobulin M [IgM]) among people from the US (aged ≧ 6 years) between these two time periods. Sampling-weighted multivariate logistic regression models were used to identify factors associated with HEV seropositivity.

RESULTS

The median participant age was 37 years (interquartile range = 17-58 years); 51.17% of them were female. Among US-born individuals, HEV seropositivity (IgG/IgM) increased from 4.5% (95% confidence interval [CI] = 3.5%-5.5%) in 2013-2014 to 8.1% (95%CI = 6.5%-9.7%) in 2015-2016. Recent HEV infection (IgM) has nearly doubled in all US-born people. For participants born in and outside of the US, the overall weighted HEV (IgG/IgM) seropositivity increased from 5% (95%CI = 3.9%-6.1%) during 2013-2014 to 7.7% (95%CI = 7.2%-10.5%) during 2015-2016. In "non-Hispanic Asian" females, HEV seropositivity (IgG/IgM) rose from 8.4% (95%CI = 5.6%-11.1%) during 2013-2014 to 20.7% (95%CI = 15.8%-25.7%) during 2015-2016. In "non-Hispanic Asian" males, HEV seropositivity (IgG/IgM) increased from 9.3% (95%CI = 6.9%-11.8%) during 2013-2014 to 16.8% (95%CI = 12.5%-21.2%) during 2015-2016. HEV (IgG/IgM) seropositivity was significantly associated with "non-Hispanic Asian" ethnicity (odds ratio [OR] = 1.69; CI = 1.12-2.56), female (OR = 1.2, CI = 1.06-1.38), and age (OR = 1.058, CI = 1.05-1.06). No clear etiologic agent was found.

CONCLUSION

The combined and strata-specific HEV weighted seroprevalence increased from 2013-2014 to 2015-2016. Although prior studies had found increasing age as the only significant factor associated with HEV, the attribute of "non-Hispanic Asian" had a stronger association with HEV seropositivity than the age factor alone.

Ingesting Self-Grown Produce and Seropositivity for Hepatitis E in the United States

Background

Hepatitis E virus (HEV) is a major cause of hepatitis in developing and industrialized countries worldwide. The modes of HEV transmission in industrialized countries, including the United States, remain largely unknown. This study is aimed at evaluating the association between HEV seropositivity and consumption of self-grown foods in the United States.

Methods

Cross-sectional data was extracted from the 2009–2012 National Health and Nutrition Examination Survey (NHANES). Data from the dietary interview and the serum HEV IgG and IgM enzyme immunoassay test results were linked and examined. Univariate and multivariable logistic regression models were used to evaluate the significance and effect size of an association between self-grown food consumption and hepatitis E seropositivity.

Results

The estimated HEV seroprevalence in the civilian, noninstitutionalized US population was 6.6% in 2009–2012, which corresponds to an estimated hepatitis E national seroprevalence of 17,196,457 people. Overall, 10.9% of participants who ingested self-grown foods had positive HEV antibodies versus 6.1% of participants who did not consume self-grown foods (P < 0.001; odds ratio (OR) 1.87; 95% CI 1.41–2.48). In the age-stratified multivariable analysis, the correlation between ingesting self-grown foods and HEV seropositivity was significant for participants 40–59 years old, but not overall, or for those < 40 years or ≥60 years.

Conclusions

Ingesting self-grown food, or simply the process of gardening/farming, may be a source of zoonotic HEV transmission.

Incorporation of Social Determinants of Health in the Peer-Reviewed Literature: A Systematic Review of Articles Authored by the National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention

OBJECTIVES

Social determinants of health (SDHs) are the complex, structural, and societal factors that are responsible for most health inequities. Since 2003, the National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention (NCHHSTP) has researched how SDHs place communities at risk for communicable diseases and poor adolescent health. We described the frequency and types of SDHs discussed in articles authored by NCHHSTP.

METHODS

We used the MEDLINE/PubMed search engine to systematically review the frequency and type of SDHs that appeared in peer-reviewed publications available in PubMed from January 1, 2009, through December 31, 2014, with a NCHHSTP affiliation. We chose search terms to identify articles with a focus on the following SDH categories: income and employment, housing and homelessness, education and schooling, stigma or discrimination, social or community context, health and health care, and neighborhood or built environment. We classified articles based on the depth of topic coverage as "substantial" (ie, one of ≤3 foci of the article) or "minimal" (ie, one of ≥4 foci of the article).

RESULTS

Of 862 articles authored by NCHHSTP, 366 (42%) addressed the SDH factors of interest. Some articles addressed >1 SDH factor (366 articles appeared 568 times across the 7 categories examined), and we examined them for each category that they addressed. Most articles that addressed SDHs (449/568 articles; 79%) had a minimal SDH focus. SDH categories that were most represented in the literature were health and health care (190/568 articles; 33%) and education and schooling (118/568 articles; 21%).

CONCLUSIONS

This assessment serves as a baseline measurement of inclusion of SDH topics from NCHHSTP authors in the literature and creates a methodology that can be used in future assessments of this topic.

Hepatitis E virus seroprevalence, seroincidence and seroreversion in the German adult population

A steep rise in Hepatitis E diagnoses is currently being observed in Germany and other European countries. The objective of this study was (i) to assess whether this trend mirrors an increase in infection pressure or is caused by increased attention and testing and (ii) estimate individual and population-based Hepatitis E Virus (HEV) seroconversion and seroreversion rates for Germany. We measured anti-HEV IgG prevalence in 10 407 adults participating in two linked, population-representative serosurveys (total n = 12 971) conducted in 1998 and 2010. In this period, we found a moderate but statistically significant decline of overall anti-HEV IgG prevalence from 18.6% to 15.3%. At both time points, seroprevalence increased with age and peaked in persons born between 1935 and 1959 suggesting a past period of increased infection pressure. Paired samples of individuals participating in 1998 and 2010 (n = 2564) revealed respective seroconversion and seroreversion rates of 6.2% and 22.6% among seronegative and seropositive individuals during 12 years, or 5.2 and 2.9 per 1000 inhabitants per year. This corresponds to a total of 417 242 [95%CI: 344 363-495 971] new seroconversions per year in the German population. While anti-HEV seroprevalence has decreased in the last decade, infection pressure and seroincidence remains high in Germany. Continuously rising numbers of Hepatitis E diagnoses in Europe are likely due to an increased awareness of clinicians and indicate that still there is a gap between incident and diagnosed cases. Studies on the true burden of the disease, specific risk factors and sources of autochthonous infections as well as targeted prevention measures are urgently needed.

Disparities in detection of antibodies against hepatitis E virus in US blood donor samples using commercial assays

BACKGROUND

Reported hepatitis E virus (HEV) antibody assay performance characteristics are variable. Using a subset of surplus US blood donation samples, we compared assays for detecting anti-HEV immunoglobulin M (Ig)M and IgG or total anti-HEV antibodies.

STUDY DESIGN AND METHODS

Samples from 5040 random blood donations, all HEV-RNA negative, collected primarily in the midwestern United States in 2015 were tested for anti-HEV IgM and IgG or total anti-HEV using assays manufactured by Diagnostic Systems, Wantai, and MP Biomedicals.

RESULTS

Overall, the percentage of detection for anti-HEV IgG and total anti-HEV was 11.4%, and for anti-HEV IgM was 1.8%. Nine samples were reactive for anti-HEV IgM by all assays, giving a recent infection rate of 0.18%. Anti-HEV IgG/total anti-HEV detection rates increased with age. Interassay agreement was higher among the IgG anti-HEV/total anti-HEV assays (84%) than the IgM assays (22%). Regression analyses of signal-to-cutoff ratios from IgG/total antibody assay were heteroskedastic, indicating no constant variance among these assays, suggesting they may detect different epitopes or were affected by waning or less avid antibodies in the US donor population.

CONCLUSIONS

Although similar percentages of IgG anti-HEV/total anti-HEV detection were observed across the three commercial assays, each assay detected a unique sample subpopulation and was heteroskedastic when compared pairwise. Discordance was higher among anti-HEV IgM assays, but a recent HEV infection rate of at least 0.18% was estimated based on assay concordance.

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.

Seroprevalence of Hepatitis E Virus Antibodies in Portuguese Children

BACKGROUND

Hepatitis E virus (HEV) has become a growing public health concern in industrialized countries. Most of the HEV seroprevalence studies have focused on adult populations, and reports regarding HEV seroepidemiology among children are scarce in these countries. The aims of this work were to perform a nationwide seroprevalence study on HEV infection in Portuguese children and to compare the HEV seropositivity in this 2015 children cohort with results in sera performed 20 years earlier.

METHODS

Sera (N = 352) from children collected in 2015 from all regions of Portugal were screened for anti-HEV IgG and IgM using the commercial enzyme-linked immunosorbent assay recomWell HEV IgG/IgM (2015 version; Mikrogen, Neuried, Germany), and positive samples were retested by immunodot assay recomLine HEV IgG/IgM (2015 version; Mikrogen, Neuried, Germany). For the comparative assessment of HEV seropositivity of the 2 children cohorts, children's sera (N = 71) archived since 1995 were screened for anti-HEV IgG and results were compared with that of the 2015 cohort, matched by sex, age and region.

RESULTS

Anti-HEV antibodies were detected in 4 children giving an overall HEV seroprevalence in the 2015 cohort of 1.1%. A healthy 10-15-year-old female was found positive for anti-HEV IgM indicating a current or recent HEV infection. No statistically significant difference was observed in HEV seroprevalence regarding gender, age group and region of residence. Comparison of the HEV seropositivity of the 2 children cohorts showed a statistical significant decrease with time (P = 0.024).

CONCLUSIONS

This is the first national study of HEV seroprevalence in Portuguese children and the first to demonstrate a decrease of anti-HEV antibodies in this age group over time.

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.

Seroprevalence of Hepatitis E Among Boston Area Travelers, 2009-2010

AbstractWe determined the prevalence of IgG antibodies to hepatitis E virus (anti-HEV IgG) among travelers attending Boston-area travel health clinics from 2009 to 2010. Pre-travel samples were available for 1,356 travelers, with paired pre- and post-travel samples for 450 (33%). Eighty of 1,356 (6%) pre-travel samples were positive for anti-HEV IgG. Compared with participants who had never lived in nor traveled to a highly endemic country, the pre-travel prevalence odds ratio (POR) of anti-HEV IgG among participants born in or with a history of previous travel to a highly endemic country was increased (POR = 4.8, 95% CI = 2.3-10.3 and POR = 2.6, 95% CI = 1.4-5.0, respectively). Among participants with previous travel to a highly endemic country, anti-HEV IgG was associated with age > 40 years (POR = 3.7, 95% CI = 1.3-10.2) and travel history to ≥ 3 highly endemic countries (POR = 2.7, 95% CI = 1.2-5.9). Two participants may have contracted HEV infection during their 2009-2010 trip.

Hepatitis E in Singapore: A Case-Series and Viral Phylodynamics Study

AbstractThe incidence of hepatitis E in Singapore appears to be increasing. A retrospective case-series study of patients diagnosed with hepatitis E in a tertiary hospital from 2009 to 2013 was conducted. Of 16 cases, eight (50%) were solid-organ transplant recipients (SOTRs), and 14 (88%) were found infected by genotype 3 hepatitis E virus (HEV-3). Bayesian inferences based on HEV subgenomic sequences from seven cases suggest that HEV-3 strains were introduced to Singapore as two principal lineages. Within limitations of the study, it can be inferred that one lineage, in the 3efg clade, emerged about 83 years ago, probably originating from Japan, whereas the other, in the 3abchij clade, emerged about 40 years ago, from the United States. Establishment and subsequent transmissions of strains from these two lineages likely contribute to the current endemicity of hepatitis E in Singapore.

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.

Acute Hepatitis E: Two Sides of the Same Coin

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

Hepatitis E virus infection in patients with acute non-A, non-B, non-C hepatitis in Central Brazil

Hepatitis E virus (HEV) infection has a worldwide distribution and represents an important cause of acute hepatitis. This study aims to investigate the occurrence of HEV infection and factors associated with this infection in patients with acute non-A, non-B, non-C hepatitis in Central Brazil. From April 2012 to October 2014, a cross-sectional study was conducted among 379 patients with acute non-A, non-B, non-C hepatitis in the City of Goiania, Central Brazil. Serum samples of all patients were tested for serological markers of HEV infection (anti-HEV IgM and IgG) by ELISA. Positive samples were confirmed using immunoblot test. Anti-HEV IgM and IgG positive samples were tested for HEV RNA. Of the 379 serum samples, one (0.3%) and 20 (5.3%) were positive for anti-HEV IgM and IgG, respectively. HEV RNA was not found in any sample positive for IgM and/or IgG anti-HEV. After multivariate analysis, low education level was independently associated with HEV seropositivity (p = 0.005), as well as living in rural area, with a borderline p-value (p = 0.056). In conclusion, HEV may be responsible for sporadic self-limited cases of acute hepatitis in Central Brazil.

Low transfusion transmission of hepatitis E among 25,637 single-donation, nucleic acid-tested blood donors

BACKGROUND

Hepatitis E virus genotype-3 (HEV-gt-3) causes autochthonous infections in western countries, with a primary reservoir in animals, especially pigs. HEV transfusion transmission has been reported, and HEV-gt-3 prevalence is high in some European countries. The prevalence of HEV RNA was investigated among Danish blood donors, and the prevalence of HEV transfusion-transmitted infection (TTI) was investigated among recipients.

STUDY DESIGN AND METHODS

Samples from 25,637 consenting donors collected during 1 month in 2015 were screened retrospectively using an individual-donation HEV RNA nucleic acid test with a 95% detection probability of 7.9 IU/mL. HEV-positive samples were quantified by real-time polymerase chain reaction and genotyped. Transmission was evaluated among recipients of HEV RNA-positive blood components. Phylogenetic analyses compared HEV sequences from blood donors, symptomatic patients, and swine.

RESULTS

Eleven donations (0.04%) were confirmed as positive for HEV RNA (median HEV RNA level, 13 IU/mL). Two donations were successfully genotyped as HEV-gt-3. Only one donor had a travel history outside Europe. Nine of 11 donors were male, but the gender ratio was nonsignificant compared with the total donor population. Seven available recipients tested negative for HEV RNA and anti-HEV immunoglobulin M in follow-up samples. One recipient was HEV RNA-negative but anti-HEV immunoglobulin G-positive. HEV TTI was considered unlikely, but a transfusion-induced secondary immune response could not be excluded. Phylogenetic analysis showed relatively large sequence differences between HEV from donors, symptomatic patients, and swine.

CONCLUSIONS

Despite an HEV RNA prevalence of 0.04% in Danish blood donations, all HEV-positive donations carried low viral loads, and no evidence of TTI was found.

Hepatitis E Virus Does Not Contribute to Hepatic Decompensation Among Patients With Advanced Chronic Hepatitis C

BACKGROUND & AIMS

Hepatitis E (HEV) can cause acute-on-chronic liver failure in persons with pre-existing liver disease. We investigated whether HEV infection contributes to hepatic decompensation in patients with previously stable, advanced chronic hepatitis C.

METHODS

We performed a case-control study using stored serum samples from subjects enrolled in the randomized phase of the Hepatitis C Antiviral Long-Term Treatment Against Cirrhosis Trial (n = 1050; mean age, 51 y; 70% male; 40% with cirrhosis at baseline). Cases were subjects who developed hepatic decompensation within a 24-week period. Controls (3 per case) were subjects without hepatic decompensation matched for fibrosis stage and followed up for a similar period. A serum sample obtained within 6 months after the decompensation event in cases and the same follow-up period in controls were tested for anti-HEV IgG. Subjects with a positive result had a baseline sample similarly tested for anti-HEV IgG. We measured levels of anti-HEV IgM and HEV RNA in blood samples from incident cases.

RESULTS

Of the 1050 subjects analyzed, 314 (30%) experienced a clinical event. Of the 314 subjects who experienced decompensation as defined, 89 (28%) were tested for anti-HEV, along with 267 controls (without decompensation). Similar proportions of cases and controls tested positive for anti-HEV (22.5% and 20.6%, respectively; P = .70). Ten incident HEV infections were identified-4 in cases (4.5%) and 6 in controls (2.2%) (P = .28). HEV RNA was not detected in blood samples from the 10 incident infections. Only 2 of the 4 incident infections among cases were related temporally to the decompensation event.

CONCLUSIONS

HEV does not appear to be a significant cause of hepatic decompensation among persons with previously stable, advanced chronic hepatitis C in the United States.

A nationwide survey of hepatitis E viral infection in French blood donors

Most cases of hepatitis E viral (HEV) infection in developed countries are autochthonous. Nevertheless, the reported seroprevalence of HEV varies greatly depending on the geographical area and the performance of the immunoassay used. We used validated assays to determine the prevalence of anti-HEV immunoglobulin G (IgG) and IgM among 10,569 French blood donors living in mainland France and three overseas areas. Epidemiological information was collected using a specific questionnaire. We found an overall IgG seroprevalence of 22.4% (8%-86.4%) depending on the geographical area (P < 0.001). The presence of anti-HEV IgG was associated with increasing age (P < 0.001) and eating pork meat (P = 0.03), pork liver sausages (P < 0.001), game meat (P < 0.01), offal (P < 0.001), and oysters (P = 0.02). Conversely, drinking bottled water was associated with a lower rate of anti-HEV IgG (P = 0.02). Overall IgM seroprevalence was 1% (0%-4.6%). The frequency of anti-HEV IgM was higher in donors living in a high anti-HEV IgG seroprevalence area (1.9% versus 0.7%, P < 0.001) and in those eating pork liver sausage (1.4% versus 0.7%, P < 0.01), pâté (1% versus 0.4, P = 0.04), and wild boar (1.3% versus 0.7%, P < 0.01).

CONCLUSION

HEV is endemic in France and hyperendemic in some areas; eating habits alone cannot totally explain the exposure to HEV, and contaminated water could contribute to the epidemiology of HEV infection in France.

Acute and Chronic Hepatitis E Virus Infection in Human Immunodeficiency Virus-Infected U.S. Women

Exposure to hepatitis E virus (HEV) is common in the United States, but there are few data on prevalence of HEV/human immunodeficiency virus (HIV) coinfection in U.S.

POPULATIONS

We tested 2,919 plasma samples collected from HIV-infected (HIV(+)) women and men enrolled in U.S. cohort studies for HEV viremia using a high-throughput nucleic acid testing (NAT) platform. NAT(+) samples were confirmed by real-time polymerase chain reaction. Samples were selected for testing primarily on the basis of biomarkers of liver disease and immune suppression. Prevalence of HEV viremia was 3 of 2,606 and 0 of 313 in tested plasma samples collected from HIV(+) women and men, respectively. All HEV isolates were genotype 3a. Based on follow-up testing of stored samples, 1 woman had chronic HEV infection for >4 years whereas 2 women had acute HEV detectable at only a single study visit.

CONCLUSIONS

To our knowledge, this is the first reported case of chronic HEV infection in an HIV(+) U.S. individual. We also confirm that chronic HEV infection can persist despite a CD4(+) count >200 cells/mm(3). Overall, though, these data suggest that HEV infection is rare in the HIV(+) U.S. population.

Hepatitis E Virus Infection Among Solid Organ Transplant Recipients at a North American Transplant Center

Background.  Autochthonous hepatitis E virus (HEV) infection has been reported in over 200 solid organ transplant (SOT) recipients since 2006, yet little is known about the burden of HEV among SOT recipients in North America. We performed a retrospective, cross-sectional study to investigate the prevalence and risk factors associated with HEV infection among SOT recipients at our institution. Methods.  Children and adults (n = 311) who received allografts between 1988 and 2012 at the Johns Hopkins Hospital were assessed for evidence of HEV infection by testing posttransplantation serum samples for HEV antibody by enzyme immunoassay and HEV RNA by reverse transcription quantitative polymerase chain reaction. Individuals with evidence of posttransplant HEV infection (presence of anti-HEV immunoglobulin [Ig]M antibody, anti-HEV IgG seroconversion, or HEV RNA) were compared with individuals without evidence of infection and assessed for risk factors associated with infection. Results.  Twelve individuals (4%) developed posttransplant HEV infection. Posttransplant HEV infection was associated with an increased risk for graft rejection (odds ratio, 14.2; P = .03). No individuals developed chronic infection. Conclusions.  Solid organ transplant recipients in the United States are at risk for posttransplant HEV infection. Further studies are needed to characterize environmental risk factors and the risk of HEV infection after SOT in North America.

Hepatitis E virus seroprevalence in pregnant women in Jiangsu, China, and postpartum evolution during six years

Background

China is an endemic area for hepatitis E virus (HEV). The previous surveys of anti-HEV seroprevalence are cross-sectional. This study aimed to investigate the prevalence of infection among pregnant women and their children in Jiangsu, China, and to observe postpartum anti-HEV evolution.

Methods

Sera from 497 women collected during pregnancy and 6-year postpartum and from their 497 children were screened for anti-HEV by ELISA and confirmed by Western blotting. HEV RNA was detected by reverse transcription-nested PCR.

Results

Of the pregnant women, 3 (0.6 %) were anti-HEV IgM positive and 55 (11.1 %) were IgG positive. At 6-year postpartum, 18 anti-HEV IgG positive samples became negative and 18 others became IgG positive; the accumulated prevalence in this cohort of women was at least 14.7 % (73/497). Of the 497 children, the positive rates of anti-HEV IgM and IgG were 0.2 % and 0.4 %, respectively. None of the 18 children from mothers with anti-HEV IgG seroconversion was anti-HEV IgG positive.

Conclusions

Our data indicate that the constant seroprevalence of anti-HEV IgG in adults may be resulted from the balance of negative seroconversion due to waning immunity and positive seroconversion due to novel infections, and the risk of intra-family transmission of HEV was low. The data also imply that cross-sectional seroepidemiological survey may underestimate the prevalence of HEV infection, due to the natural decay of pathogen-specific IgG.

Is hepatitis E virus an emerging problem in industrialized countries?

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

Hepatitis E virus infection: Epidemiology and treatment implications

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

Variability of hepatitis E serologic assays in a pediatric liver transplant recipient: challenges to diagnosing hepatitis E virus infection in the United States

Hepatitis E virus (HEV) is an emerging cause of viral hepatitis among immunocompromised individuals in developed countries. Yet the diagnosis of HEV infection in the United States remains challenging, because of the variable sensitivity and specificity of currently available tests, and the lack of a US Food and Drug Administration-approved test. We report a case of multiple discordant HEV serology results in a pediatric liver transplant recipient with idiopathic hepatitis, and review the challenges to diagnosis of HEV infection in the United States.