Markers for Ongoing or Previous Hepatitis E Virus Infection Are as Common in Wild Ungulates as in Humans in Sweden

Abstract

Hepatitis E virus (HEV) is a human pathogen with zoonotic spread, infecting both domestic and wild animals. About 17% of the Swedish population is immune to HEV, but few cases are reported annually, indicating that most infections are subclinical. However, clinical hepatitis E may also be overlooked. For identified cases, the source of infection is mostly unknown. In order to identify whether HEV may be spread from wild game, the prevalence of markers for past and/or ongoing infection was investigated in sera and stool samples collected from 260 hunted Swedish wild ungulates. HEV markers were found in 43 (17%) of the animals. The most commonly infected animal was moose (Alces alces) with 19 out of 69 animals (28%) showing HEV markers, followed by wild boar (Sus scrofa) with 21 out of 139 animals (15%), roe deer (Capreolus capreolus) with 2 out of 30 animals, red deer (Cervus elaphus) with 1 out of 15 animals, and fallow deer (Dama dama) 0 out of 7 animals. Partial open reading frame 1 (ORF1) of the viral genomes from the animals were sequenced and compared with those from 14 endemic human cases. Phylogenetic analysis revealed that three humans were infected with HEV strains similar to those from wild boar. These results indicate that wild animals may be a source of transmission to humans and could be an unrecognized public health concern.

Hepatitis E Virus Genotype 3 Genomes from RNA-Positive but Serologically Negative Plasma Donors Have CUG as the Start Codon for ORF3

“…HEV is mainly transmitted by the faecal-oral route, but blood transmission may occur [2]. HEV1 and HEV2 cause sporadic cases or large waterborne outbreaks in developing countries, while HEV3 and HEV4 have zoonotic reservoirs, mainly pigs and wild boar, and probably cause most endemic human HEV3 infections by faecaloral spread [2,3]. There are nine HEV3 subtypes in two major phylogenetic clades, 3I by subtypes abchij, and 3II by efg [4,5].…”

“…Nucleic acids were extracted from 250 μL of plasma from the 18 donors as described [3]. Viral RNA was detected in 17 by an in-house TaqMan qPCR assay [3].…”

“…A plasmid with the target region was used to set the threshold to measure the C t value for product quantification. Five microlitres of extracted RNA were reversely transcribed to DOI: 10.1159/000491926 cDNA and detected by PCR [3]. Sets of primers were used to amplify the complete genome of five selected HEV strains (online suppl.…”

“…Viral RNA was detected in 17 by an in-house TaqMan qPCR assay [3]. A plasmid with the target region was used to set the threshold to measure the C t value for product quantification.…”

Seroprevalence of hepatitis E virus in Lithuanian domestic pigs and wildlife

“…The HEV is unique among known hepatitis (A, B, C, D) viruses because domestic pigs, wild boar, deer, and other animal species are considered to be possible reservoirs of HEV. Up to date, at least seven genotypes of HEV have been reported, and five of them have been described in humans (HEV-1 and HEV-2 anthroponotic, HEV-3 and HEV-4 zoonotic, HEV-7 zoonotic potential is still being questioned) (Roth et al 2016). In contrast to humans, pigs and wild boar infected by HEV do not show obvious clinical manifestations.…”