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

Abstract

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.

Keywords: acute hepatitis; hepatitis E virus; human population; phylogenetic analysis; zoonotic character.

Figure 1

Diagram of the study flow chart.

Figure 2

Phylogenetic tree based on the alignment of the generated sequences with the best hits to our sequences in GenBank and with the reference strains of each HEV3 subtype. The tree was constructed on the basis of a 348 bp fragment of the capsid protein-encoding region (ORF-2). The phylogenetic tree was built using the Maximum Likelihood method based on the Kimura 2-parameter model with 1,000 replicates. A human HEV-1 strain (EF530670.1/) was used as out group (the human HEV strains obtained in our study are highlighted by black bulleted; the gray diamonds indicated the wild boar HEV strains; the black triangles indicated the swine HEV strains previously characterized in eastern Romania).