Identification of Hepatitis E Virus Genotypes 3 and 7 in Israel: A Public Health Concern?

Rachel Shirazi,Paolo Pozzi,Marina Wax,Michal Linial,Orna Mor,Yael Gozlan,Ella Mendelson,Svetlana Bardenstein,Yaniv Lustig

doi:10.3390/v13112326

Abstract

Background: Hepatitis E (HEV) is an emerging cause of viral hepatitis worldwide. Swine carrying hepatitis E genotype 3 (HEV-3) are responsible for the majority of chronic viral hepatitis cases in developed countries. Recently, genotype 7 (HEV-7), isolated from a dromedary camel in the United Arab Emirates, was also associated with chronic viral hepatitis in a transplant recipient. In Israel, chronic HEV infection has not yet been reported, although HEV seroprevalence in humans is ~10%. Camels and swine are >65% seropositive. Here we report on the isolation and characterization of HEV from local camels and swine. Methods: Sera from camels (n = 142), feces from swine (n = 18) and blood from patients suspected of hepatitis E (n = 101) were collected during 2017–2020 and used to detect and characterize HEV sequences. Results: HEV-3 isolated from local swine and the camel-derived HEV-7 sequence were highly similar to HEV-3f and HEV-7 sequences (88.2% and 86.4%, respectively) related to viral hepatitis. The deduced amino acid sequences of both isolates were also highly conserved (>98%). Two patients were HEV-RNA positive; acute HEV-1 infection could be confirmed in one of them. Discussion: The absence of any reported HEV-3 and HEV-7 infection in humans remains puzzling, especially considering the reported seroprevalence rates, the similarity between HEV sequences related to chronic hepatitis and the HEV genotypes identified in swine and camels in Israel.

Highlights

Hepatitis E virus (HEV) is a major cause of enterically transmitted hepatitis
We showed that the swine are highly seropositive, the virus is endemic in local farms, and its sequence is most similar to the published HEV-3f sequences [9]
Initial phylogenetic analysis based on a 2508 nucleic acid-long gene fragment amplified from the 3 segment of the genome, revealed that this sequence clustered with camelid HEV-7 sequences KJ496143 and KJ496144, and with a HEV sequence from a patient with viral hepatitis (KT818608), all retrieved from GenBank

Summary

Introduction

Hepatitis E virus (HEV) is a major cause of enterically transmitted hepatitis. Of the eight genotypes of HEV, genotype 3 is the most abundantly distributed worldwide, associated with both acute and chronic hepatitis. Genotype 7, a new genotype identified in dromedary camels, was recently reported to cause chronic hepatitis in an immunocompromised patient [2]. Swine carrying hepatitis E genotype 3 (HEV-3) are responsible for the majority of chronic viral hepatitis cases in developed countries. Genotype 7 (HEV-7), isolated from a dromedary camel in the United Arab Emirates, was associated with chronic viral hepatitis in a transplant recipient. Results: HEV-3 isolated from local swine and the camel-derived HEV-7 sequence were highly similar to HEV-3f and HEV-7 sequences (88.2% and 86.4%, respectively) related to viral hepatitis. Discussion: The absence of any reported HEV-3 and HEV-7 infection in humans remains puzzling, especially considering the reported seroprevalence rates, the similarity between HEV sequences related to chronic hepatitis and the HEV genotypes identified in swine and camels in Israel

Methods

Results

Conclusion