Estimation of hepatitis B-positive rates in Chinese blood donors by combining predonation and postdonation screening results.

Background Chinese blood centers use Hepatitis B surface antigen (HBsAg) rapid test (RT) in pre-donation and two rounds of screening with different enzyme-linked immunosorbent assays in post-donation. Nucleic acid testing (NAT) on screening non-reactive (SC-) donations has been gradually implemented since 2010. Yet RT+ and SC-/NAT+ donors are seldom included in hepatitis B virus (HBV) positive rate estimates in Chinese blood donors. Methods We performed HBsAg neutralization test (NT) on whole blood (WB) with pre-donation RT+ results and post-donation screening reactive (SC+) samples from Mianyang and Chongqing in 2015. The annual totals of pre- and post-donation NT+ donors were combined with the annual totals of SC-/NAT+ donors to derive the estimated HBV positive rates. Result In Mianyang and Chongqing, 59.4% and 68.2% of RT+ donors in Jan-Aug 2015 contributed for NT, 95.5% and 97.2% of which were NT+ respectively. In 2015, 422 and 667 donors from Mianyang and Chongqing respectively were HBsAg RT+, yielding estimated 403 and 648 pre-donation RT+/NT+ deferrals. 411 and 668 post-donation SC+ samples were NT tested from Mianyang and Chongqing, of which 249 and 323 were NT+ respectively. An estimated 63 donors in Mianyang and 88 donors in Chongqing were SC-/NAT+. The estimated HBV confirmed positive rate in blood donors are 1.59% in Mianyang and 1.01% in Chongqing. Conclusion Pre-donation HBsAg RT effectively intercepts donations from HBV infected donors. Using NT confirmatory results from RT+, SC+ and SC-/NAT+ donors, this study provides a model for more accurate estimation for HBV positive rates in China.