Prevalence of hepatitis E viruses in patients with acute hepatitis and characterization of the detected genotype 4 hepatitis e virus sequences in Ulaanbaatar, Mongolia

Abstract

Background: Hepatitis E is considered to be a worldwide public health problem. Although the prevalence of hepatitis E virus (HEV) antibodies in healthy individuals is noted to be 11%, no patients with acute hepatitis E have previously been identified in Mongolia. Materials and Methods: Three hundred two consecutive patients who were clinically diagnosed with sporadic acute hepatitis in Ulaanbaatar, Mongolia, were studied. Results: By serological and/or molecular approaches, 12 (4.0%) of the patients were diagnosed with acute hepatitis of type E. The 12 hepatitis E patients had no history of travel abroad in the 3 months before the onset of disease, and lived separately in fixed or movable houses with water supplied via pipe, tank or well, denying transmission from a common water supply. The 12 HEV isolates obtained from the patients showed high nucleotide identities of 99.7–100%, and a representative HEV isolate, MNE13-227, was closest to the Chinese isolates of genotype 4, with the highest identity of 97.3% in the 304-nt ORF2 sequence and 92.1% over the entire genome. Conclusion: The present study revealed the occurrence of autochthonous acute hepatitis E in Mongolia, caused by a monophyletic genotype 4 HEV strain.