Impact of chemiluminescent enzyme immunoassay screening for human parvovirus B19 antigen in Japanese blood donors

Background To reduce the risk of human parvovirus B19 (B19V) transmission through contaminated blood for transfusion and plasma-derived products, the Japanese Red Cross (JRC) Blood Centers introduced B19V antigen screening by chemiluminescent enzyme immunoassay (CLEIA-B19V) in 2008. Study Design and Methods Donor samples that were positive by CLEIA-B19V screening were tested for B19V DNA. The sensitivity of CLEIA-B19V was tested using samples of all three genotypes and B19V DNA–positive donations. B19V DNA–positive donations and pooled plasma were quantitatively assayed for B19V DNA. B19V DNA–positive donations were phylogenetically analyzed by polymerase chain reaction direct sequencing. Results The sensitivity of CLEIA-B19V was inferred to be approximately 6.3 log IU/mL with the genotype samples and 6.4 log IU/mL with B19V DNA–positive donor samples. Of 417 CLEIA-B19V–positive samples from 1,035,560 donations in Hokkaido, Japan, 101 were positive for B19V DNA. The 198 strains of B19V DNA–positive donations in Hokkaido over the past 15 years clustered exclusively with Genotype 1. After introduction of CLEIA-B19V, the viral load for B19V DNA in all 772 pooled plasma for fractionation from donors in nationwide Japan did not exceed 4 log IU/mL. Conclusion CLEIA-B19V can detect all three genotypes of B19V (viral load >6.3 log IU/mL) and limit the viral load (