A nationwide survey for prevalence of hepatitis E virus antibody in qualified blood donors in Japan

Background and Objectives In previous studies, we reported the transmission of hepatitis E virus (HEV) by transfusion, and the frequent detection of HEV markers in Japanese blood donors with elevated ALT levels. For the current study, we carried out a nationwide survey of the prevalence of IgG anti-HEV in qualified blood donors throughout Japan. Materials and Methods The 12 600 samples from qualified blood donors were collected from seven blood centres (1800 per centre) representing nearly all regions of Japan. Samples were from age- and sex-matched blood donors who tested negative for all the current blood screening tests. The samples were screened using the in-house IgG anti-HEV ELISA. Sequentially, the positive samples were tested by the commercial IgG anti-HEV ELISA. Results Of 12 600 samples, 431 (3 center dot 4%) were regarded as positive for IgG anti-HEV. The prevalence of IgG anti-HEV was higher in eastern Japan (5 center dot 6%) than in western Japan (1 center dot 8%) (P < 0 center dot 001), and was also age-dependent and higher in men (3 center dot 9%) than in women (2 center dot 9%) (P = 0 center dot 002). Conclusion The spread of the domestic infection of HEV was observed in qualified blood donors in Japan. A higher prevalence of IgG anti-HEV was observed in male donors, older donors and in donors residing in eastern Japan. Further studies are necessary to clarify the potential risk of transfusion-transmission of HEV in Japan.