Standardising surveillance of hepatitis E virus infection in the EU/EEA: A review of national practices and suggestions for the way forward

Temporal changes in the genotypes of Paslahepevirus balayani in southern Spain and their possible link with changes in pig trade imports

Introduction

Paslahepevirus balayani (HEV) is an endemic zoonotic disease ranked as a major cause of acute hepatitis in Europe. Most infections occurring in Europe are due to the endemic several subtypes of genotype 3, through the consumption of raw or undercooked pork, observing a genotype geographical distribution pattern among countries Because of global changes in the pig and pork trading markets, subtype distribution might vary. We aimed to evaluate the temporal distribution of HEV genotypes in patients from southern Spain with acute hepatitis to determine whether these changes were related to the pig import trade during the study period between 2018 and 2022.

Methods

Prospective longitudinal study including patients with acute hepatitis from southern Spain between 2018 and 2022. HEV RNA and antibodies was tested in all patients. In patients with detectable HEV RNA, genotype was obtained. To determine the number of imported pigs and their origins, we checked the official data from the Spanish statistics on international trade of Spanish Minister of Industry during by country of origin during the same study period.

Results

A total of 659 patients with acute hepatitis were included in the study. Among them, 162 (24.5%) had at least one marker (IgM or RNA) of acute HEV infection. Among the 71 patients with detectable viral RNA, genotypes could be obtained for 58 (81.6%). The most prevalent HEV genotype was 3f (n = 48; 78.6%), showing a decreasing prevalence of over time, from 100% in 2018 to 70.6% in 2022. Since 2021, the emergence of other genotypes has been determined. A significant increase in the number of animals imported was observed since the beginning of the study. Denmark experienced a significant rise, from 0.03% in 2018 of total imports to 10.4% in 2022.

Conclusions

HEV molecular diversity is changing in Spain, could be linked to changes in fattening pig import origin.

Seroprevalence of Anti-Hepatitis E Virus Antibodies among Patients from a Tertiary Hospital from Northeast Romania

Background and Objectives. Being an enterically transmitted pathogen with a growing prevalence in developed countries, hepatitis E virus (HEV) infection remains an underdiagnosed disease in Eastern Europe. As far as Romania is concerned, only a few studies address this issue. Our goal was to estimate the prevalence of serum anti-HEV IgA/IgM/IgG antibodies in a group of patients admitted to the Clinical Hospital for Infectious Diseases “St. Parascheva” Iasi. Materials and Methods. The cross-sectional study consisted of enrollment of 98 patients admitted to the clinic for COVID-19 over a period of three months in 2020. Results. The median age in our study was 73 years, with an equal gender ratio and with a predominance of people from the urban environment (75%). The overall HEV antibody seroprevalence was 12.2%. The main risk factors associated with HEV infection were consumption of water from unsafe sources (58.3% HEV-positive patients vs. 26.7% HEV-negative patients, p = 0.026) and improperly cooked meat (58.3% HEV-positive patients vs. 23.2% HEV-negative patients, p = 0.01). Zoonotic transmission was an important criterion in our study, with patients reporting contact with pigs, poultry, rats, or other farms animals, but no significant differences were found between HEV antibody positive and negative groups. Conclusions. The seroprevalence rate of HEV antibodies was similar to other previous reports from our area but higher than in most European countries. The fact that HEV antibodies were detected in patients without identifiable risk factors for hepatitis E is evidence of subclinical infection as a silent threat.

Molecular epidemiology and genotype-specific disease severity of hepatitis E virus infections in Germany, 2010-2019

Zoonotic hepatitis E virus (HEV) is endemic in Europe. Genotype 3 (HEV-3) is predominant but information on subtype distribution, trends and clinical implications in Germany is scarce. We analysed 936 HEV RNA positive samples of human origin and corresponding national surveillance data from 2010 to 2019. Samples were referred to the National Consultant Laboratory and sequenced in at least one of four genomic regions. Sequences were analysed using bioinformatics methods and compared to the latest HEV reference set. 1,656 sequences were obtained from 300 female, 611 male and 25 of unknown sex aged 3–92 years (median 55 years). HEV-3c was predominant (67.3%) followed by HEV-3f, HEV-3e and HEV-3i(-like) with 14.3%, 9.7% and 4.0% (other subtypes ≤1.1%). The proportion of HEV-3 group 2 (3abchijklm) strains increased over time. Jaundice, upper abdominal pain, fever, hospitalization, and death due to HEV were significantly more often reported for patients infected with HEV-3 group 1 (3efg) compared to group 2. Larger spatio-temporal clusters of identical sequences were not observed. HEV-3 group 1 infections are more severe as compared to the predominant group 2. Detection of group 2 strains increased over the last years, possibly due to more frequent diagnosis of asymptomatic and mild courses. The diversity of strains and the space–time distribution is compatible with a foodborne zoonosis with supra-regional distribution of the infection vehicle (pork products).

Risk assessment of hepatitis E transmission through tissue allografts

Hepatitis E virus (HEV) is a small non-enveloped single stranded RNA virus whose genotypes 3 and 4 have been associated with zoonotic transmission in industrialized countries. HEV infection is considered the main cause of acute hepatitis worldwide. In some cases, transfusion of blood components or organ transplantation have been reported as the source of infection. We have conducted a literature review on the risk of transmission through cell and tissue allografts. Although no case was found, measures to control this risk should be taken when donor profile (based upon geographical and behavioural data) recommended it. Issues to be considered in donor screening and tissue processing to assess and to reduce the risk of HEV transmission are approached.

An Evaluation of Hepatitis E Virus Molecular Typing Methods

BACKGROUND

Hepatitis E virus (HEV) is a major cause of acute viral hepatitis. Better understanding of HEV subtypes involved in hepatitis E infections is essential. Investigation of sources and routes of transmission and the identification of potential clusters/outbreaks rely upon molecular typing of viral strains. A study was carried out to evaluate the ability of laboratories to undertake molecular typing with genotype and subtype determination.

METHODS

A blinded panel of 11 different Orthohepevirus A strains was distributed to 28 laboratories performing HEV sequence analysis. Laboratories used their routine HEV sequencing and genotyping methods.

RESULTS

Results were returned by 25 laboratories. Overall, 93% samples were assigned to the correct genotype and 81% were assigned to the correct subtype. Fragments amplified for typing ranged in size and the sequencing assays targeted both the structural and non-structural protein-coding regions. There was good agreement between the reported sequences where methods targeted overlapping fragments. In some cases, incorrect genotypes/subtypes were reported, including those not contained in the panel, and in one case, a genotype was reported for a blinded control sample containing Zika virus; collectively these data indicate contamination problems.

CONCLUSIONS

In general, identification of genotypes was good; however, in a small number of cases, there was a failure to generate sequences from some of the samples. There was generally broad agreement between the use of online typing tools such as the one provided by HEVnet and curated lists of published HEV reference sequences; however, going forward harmonization between these resources is essential.

Genetic Diversity of Hepatitis E Virus Type 3 in Switzerland-From Stable to Table

Simple Summary

The main hosts of hepatitis E virus (HEV) genotype 3 are porcine species. Transmission of the virus to humans, for example via undercooked meat, may cause acute or chronic hepatitis. To determine sources and routes of infection, comparing the viruses present in humans to the ones present in main hosts is a helpful tool. However, it requires knowledge of the genetic diversity of the circulating viruses. Therefore, we tested Swiss pigs and wild boars for HEV and determined the virus subtype and part of its genome. In addition, we determined the HEV subtype present in 11 positive meat products. One pig liver from the slaughterhouses (0.3%) and seven livers from a carcass collection (13%) as well as seven wild boar livers (5.8%) were found HEV positive. The same virus subtypes were found in Swiss pigs, wild boars, and meat products. Most of the viruses belonged to a Swiss-specific cluster within the subtype 3h. In addition, one pig liver and one wild boar liver were found positive for 3l and two meat products from Germany for 3c. Our data indicate that Switzerland has its “own” HEV viruses that circulate independent from the rest of Europe.

Abstract

Hepatitis E caused by hepatitis E viruses of the genotype 3 (HEV-3) is a major health concern in industrialized countries and due to its zoonotic character requires a “One Health” approach to unravel routes and sources of transmission. Knowing the viral diversity present in reservoir hosts, i.e., pigs but also wild boars, is an important prerequisite for molecular epidemiology. The aim of this study was to gain primary information on the diversity of HEV-3 subtypes present along the food chain in Switzerland, as well as the diversity within these subtypes. To this end, samples of domestic pigs from slaughterhouses and carcass collection points, as well as from hunted wild boars, were tested for HEV RNA and antibodies. HEV positive meat products were provided by food testing labs. The HEV subtypes were determined using Sanger and next generation sequencing. The genetic analyses confirmed the predominance of a Swiss-specific cluster within subtype HEV-3h in pigs, meat products, and wild boars. This cluster, which may result from local virus evolution due to the isolated Swiss pig industry, supports fast differentiation of domestic and imported infections with HEV.

Case-Control Study of Risk Factors for Acquired Hepatitis E Virus Infections in Blood Donors, United Kingdom, 2018-2019

Hepatitis E virus (HEV) is the most common cause of acute viral hepatitis in England. Substantial yearly increases of autochthonous infections were observed during 2003–2016 and again during 2017–2019. Previous studies associated acute HEV cases with consumption of processed pork products, we investigated risk factors for autochthonous HEV infections in the blood donor population in England. Study participants were 117 HEV RNA–positive blood donors and 564 HEV RNA–negative blood donors. No persons with positive results were vegetarian; 97.4% of persons with positive results reported eating pork products. Consuming bacon (OR 3.0, 95% CI 1.7–5.5; p<0.0001), cured pork meats (OR 3.5, 95% CI 2.2–5.4; p<0.0001), and pigs’ liver (OR 2.9, 95% CI 1.0–8.3; p = 0.04) were significantly associated with HEV infection. Our findings confirm previous links to pork products and suggest that appropriate animal husbandry is essential to reduce the risk for HEV infection.

Common European Origin of Hepatitis E Virus in Human Population From Eastern Romania

The purpose of this research was to improve the epidemiological data on HEV infection in the human population in Romania. The analysis targeted hospitalized subjects with acute hepatitis (n = 94) of unknown etiology from the Infectious Diseases Regional Hospital in Iasi. Moreover, patients without liver disease (n = 40) from a different county hospital located in Eastern Romania were included. The presence of HEV infection and first characterization of human HEV strains was determined using serological and molecular assays. The apparent HEV seroprevalence varied between 29.16% (95% CI, 16.31–42.03) and 32.5% (95% CI, 17.98–47.02) according to patient grouping. Molecular analysis enhanced the detection of two HEV isolates, that clustered in subtype HEV-3c, the most commonly identified subtype in Europe. Identification of acute hepatitis E cases, together with the first detection and molecular characterization of human HEV in Romania represent the originality attributes of the present study.