Hepatitis E virus in donor plasma collected in Japan.
OBJECTIVE
Human hepatitis E virus (HEV) is prevalent worldwide. Iatrogenic HEV has recently been identified based on the reports of transfusion-transmitted cases. The detection rate of HEV-RNA and seroprevalence of HEV-IgG/IgM have been regionally evaluated in Japan, and donor plasma collected in Hokkaido is currently screened by nucleic acid amplification testing. However, the detection rate of HEV-RNA in blood donors in Japan outside of Hokkaido has not been reported.


METHODS
A total of 620 140 qualified donor plasma samples from Japanese regions excluding Hokkaido were tested for HEV-RNA (pools of 50 or 500) between 2004 and 2014. HEV-RNA-positive plasma bags were identified, and the HEV viral load, genotype and anti-HEV immunoglobulin (Ig)G/IgM were evaluated.


RESULTS
The detection rate of HEV-RNA (pools of 50) was 1/15 075 and higher in eastern than in western Japan. All 36 HEV-RNA-positive samples were genotype 3 with viral load ranging from <1·69 to 7·22 log10 copies/ml.


CONCLUSIONS
Our detection rate of HEV-RNA in donor populations in Japan outside Hokkaido (1/15 075 donations) is generally lower than reported in Europe and lower than previously reported for Hokkaido (1/8173 donations). As methods varied, we cannot exclude that these differences are reflective of differing RNA detection limits. In contrast to Hokkaido where genotype 4 has been reported among blood donations, all our positive donations were genotype 3, which is less pathogenic.
Quality Control, Kyoto Plant, Japan Blood Products Organization, Kyoto, Japan.
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T
Minagi
Quality Control, Kyoto Plant, Japan Blood Products Organization, Kyoto, Japan.
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H
Okamoto
Quality Control, Kyoto Plant, Japan Blood Products Organization, Kyoto, Japan.
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M
Ikegawa
R & D Division, Japan Blood Products Organization, Tokyo, Japan.
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S
Ideno
R & D Division, Japan Blood Products Organization, Tokyo, Japan.
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K
Takahashi
R & D Division, Japan Blood Products Organization, Tokyo, Japan.
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Sakai
Graduate School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido, Japan.
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Hagiwara
R & D Division, Japan Blood Products Organization, Tokyo, Japan. yunoki-mikihiro@jbpo.or.jp.|Graduate School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido, Japan. yunoki-mikihiro@jbpo.or.jp.
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M
Yunoki
R & D Division, Japan Blood Products Organization, Tokyo, Japan.
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A
Wakisaka
D001782:Blood Donors; D005838:Genotype; D006508:Hepatitis Antibodies / Q000097:blood; D016751:Hepatitis E / Q000453:epidemiology* / Q000517:prevention & control; D016752:Hepatitis E virus / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007564:Japan / Q000453:epidemiology; D057230:Limit of Detection; D015995:Prevalence; D012367:RNA, Viral / Q000097:blood; D060888:Real-Time Polymerase Chain Reaction; D012698:Serologic Tests; D019562:Viral Load
D006508:Hepatitis Antibodies; D007074:Immunoglobulin G; D012367:RNA, Viral

HEV
; NAT testing; blood donors; serological testing