Unchanged high prevalence of antibodies to hepatitis E virus (HEV) and HEV RNA among blood donors with an elevated alanine aminotransferase level in Japan during 1991-2006.
Hepatitis E is rare in Japan but is occurring more frequently than previously thought. To investigate whether de novo subclinical infection of hepatitis E virus (HEV) has recently increased in Japan, HEV RNA was assayed in serum samples obtained from 4019 Japanese voluntary blood donors with alanine aminotransferase (ALT) of > or =61 IU/l, who are likely to have ongoing HEV infection, during 1991-2006. The overall rates of IgG-class antibody to HEV (anti-HEV IgG), anti-HEV IgM/IgA and HEV RNA among 3185 donors in 2004-2006 were comparable with those among 594 donors in 1998 (5.3 vs. 5.2%, 0.2 vs. 0.5%, and 0.2 vs. 0.3%, respectively). Among blood donors with ALT > or = 201 IU/l in three groups according to the year of blood collection (1991-1995 [n = 156], 1996-1999 [n = 116] and 2004-2006 [n = 61]), there were no appreciable differences in the prevalence of anti-HEV IgG (5.8, 4.3, and 6.6%, respectively), anti-HEV IgM/IgA (1.9, 3.4, and 3.3%, respectively) and HEV RNA (1.3, 3.4, and 3.3%, respectively). The eleven HEV isolates obtained in the present study differed from each other by 1.7-22.8% in the ORF2 sequence and segregated into genotype 3 or 4. The occurrence rate of subclinical infection with divergent HEV strains has essentially remained unchanged during 1991-2006 in Japan.
Fukuda
S
S
Japanese Red Cross Tochigi Blood Center, Tochigi, Japan.
Ishikawa
M
M
Ochiai
N
N
Suzuki
Y
Y
Sunaga
J
J
Shinohara
N
N
Nozawa
K
K
Tsuda
F
F
Takahashi
M
M
Okamoto
H
H
D000328:Adult; D000410:Alanine Transaminase / Q000097:blood*; D001782:Blood Donors; D005260:Female; D006508:Hepatitis Antibodies / Q000097:blood*; D016751:Hepatitis E / Q000453:epidemiology* / Q000821:virology; D016752:Hepatitis E virus / Q000235:genetics / Q000276:immunology*; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008969:Molecular Sequence Data; D010802:Phylogeny; D015995:Prevalence; D012367:RNA, Viral / Q000097:blood* / Q000235:genetics; D017422:Sequence Analysis, DNA; D012727:Sex Characteristics
D006508:Hepatitis Antibodies; D012367:RNA, Viral; D000410:Alanine Transaminase