Ongoing subclinical infection of hepatitis E virus among blood donors with an elevated alanine aminotransferase level in Japan

✍ Scribed by Yuhko Gotanda; Akiko Iwata; Hitoshi Ohnuma; Akira Yoshikawa; Hideaki Mizoguchi; Kazunori Endo; Masaharu Takahashi; Hiroaki Okamoto

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 143 KB
• Volume: 79
• Category: Article
• ISSN: 0146-6615
• DOI: 10.1002/jmv.20834

✦ Synopsis

Abstract

Ongoing subclinical infection of hepatitis E virus (HEV) has not been fully studied. In the present study, serum samples were collected from 6700 voluntary blood donors with an elevated alanine aminotransferase (ALT) level of 61‐476 IU/l at a Japanese Red Cross Blood Center, and were tested for the presence of IgG, IgM and IgA classes of antibodies to HEV (anti‐HEV) by in‐house ELISA and HEV RNA by nested RT‐PCR. Overall, 479 blood donors (7.1%) were positive for anti‐HEV IgG, including 8 donors with anti‐HEV IgM and 7 donors with anti‐HEV IgA. Among the nine donors with anti‐HEV IgM and/or anti‐HEV IgA, six had detectable HEV RNA. The presence of HEV RNA was further tested in 10‐sample minipools of sera from the remaining 6691 donors, and three donors including one without anti‐HEV IgG were found to be positive for HEV RNA. When stratified by ALT level, the prevalence of HEV RNA was significantly higher among the 109 donors with ALT ≥201 IU/l than among the 6591 donors with ALT of 61–200 IU/l (2.8% vs. 0.1%, P < 0.0001). The HEV isolates obtained from the nine viremic donors segregated into genotype 3, shared a wide range of identities of 85.6–98.5% and were 87.3–93.9% similar to the Japan‐indigenous HEV strain (JRA1), in the 412‐nucleotide sequence of open reading frame 2. This study suggests that approximately 3% of Japanese individuals with ALT ≥201 IU/l have ongoing subclinical infection with various HEV strains. J. Med. Virol. 79: 734–742, 2007. © 2007 Wiley‐Liss, Inc.