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

Abstract

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.

Prevalence of hepatitis E virus in Chinese blood donors

“…[1][2][3][4]8 Since the majority of HEV infections are subclinical, 10 17 Scotland 4.7%). 18 The rate of anti-HEV IgG seropositivity in the present study (21.1%) was considerably higher than the rates described above, [11][12][13][14][15][16][17][18] irrespective of ALT concentrations. The anti-HEV IgM seropositivity rates in the present study were 0.9% and 0.0% for donors with and without elevated ALT, respectively.…”

Novel Approach for Detection of Hepatitis E Virus Infection in German Blood Donors

“…The seroprevalence rates observed in this study (donors with nonelevated ALT, 6%; donors with elevated ALT, 5.88%) are more comparable to rates which have been observed for Switzerland and Japan than to those observed for Germany so far. The seroprevalence rates of anti-HEV IgM have been measured less frequently, but studies in Chinese blood donors revealed a seroprevalence rate of 0.94 to 1.8% (11,21), comparable to 0.5 to 1.6% in Japan (18,20,42) and the 0.5% observed in this study. We also observed a considerably higher seroprevalence rate of 8.08% in donors with elevated ALT levels, according to data obtained by Fukuda et al (3.3%) (18).…”

“…The seroprevalence rates of anti-HEV IgM have been measured less frequently, but studies in Chinese blood donors revealed a seroprevalence rate of 0.94 to 1.8% (11,21), comparable to 0.5 to 1.6% in Japan (18,20,42) and the 0.5% observed in this study. We also observed a considerably higher seroprevalence rate of 8.08% in donors with elevated ALT levels, according to data obtained by Fukuda et al (3.3%) (18). However, comparison is rather difficult due to demographic differences in the study population and differences in the sensitivity of the commercially available assays used (27).…”

“…High anti-HEV IgG seroprevalence rates have already been demonstrated among blood donors in developed countries, with considerable differences: Germany, 14.2 to 15.5% (1, 28); Switzerland, 4.1 to 5.4% (27); Denmark, 20.6% (12); Italy, 2.6% (47); Spain, 7.3% (10); France, 3.2 to 16.6% (8,32); England, 10 to 15.8% (5,16); Japan, 3.4% (unselected donors) (44) and 3.2 to 6.6% (preselected study population of donors with elevated ALT levels) (18,42); China, 32.6% (21); and the United States, 18.3% (37). The seroprevalence rates observed in this study (donors with nonelevated ALT, 6%; donors with elevated ALT, 5.88%) are more comparable to rates which have been observed for Switzerland and Japan than to those observed for Germany so far.…”

Hepatitis-E-Virus

“…Retrospektive Untersuchungen von Spenden mit erhöhten Transaminasen (Untersuchungszeitraum 1991-2006) wiesen darauf hin, dass eine gleich bleibende Inzidenz von HEV-Infektionen bei japanischen Blutspendern zu beobachten war [175]. Nicht unerwartet ist, dass in den HEV-RNA-positiven Spenden die in Japan prävalenten Genotypen 3 und 4 nachweisbar waren.…”