Hepatitis E virus isolated from chronic hepatitis B patients in Malaysia: Sequences analysis and genetic diversity suggest zoonotic origin

Abstract

Background: Zoonotically acquired HEV has been described as one of the most successful zoonotic viral infections in human history.

Aim: In this study we characterized HEV comparative genomic analysis as it relates to swine HEV.

Materials and methods: A total of 82 chronic hepatitis B patients were recruited from May 2015 to May 2016 for this study. We conducted a serological and molecular investigation of HEV among these patients. The detected HEV were sequenced and the genomes and deduced amino acids were characterized using molecular evolutionary genetic analysis software version 7.

Results: Of the 82 chronic hepatitis B patients that were tested, 9.8% (8/82) were found to be HEV positive. Phylogenetic analysis of the HEV RNA sequences showed they are of genotype 4 and demonstrated high sequence identity with a swine isolate from China, with variation in amino acids at position 22, where leucine was present in the Malaysian human isolate while phenylalanine was present in the China swine isolate.

Conclusion: Comparative analysis of the human HEV ORF-2 nucleotide sequence suggest zoonotic origin.

Keywords: Co-infection, Chronic hepatitis B, Hepatitis E virus, Zoonotic HEV, Malaysian HEV isolate