Evaluation Of Hepatitis B Virus Screening Strategy In Blood Donors After The Implementation Of NAT

Objectives Hepatitis B virus infection is both one of serious public health problems worldwide,and the main transfusion-associated contagion. How to minimize the risk of transfusion transmitted HBV to ensure the safety of blood and blood products has become the major problem faced by the researchers in this field. It?s to study the possible risk of delete one of the two rounds of HBsAg ELISA screening after the nucleic acid testing(NAT) was implemented in donor screening and to evaluate whether the screening strategy of one ELISA reagent and one NAT reagent is better than the strategy of two ELISA reagents,exploring the screening strategy which is more suitable for the HBV epidemic status in our country. Methods 616 unqualified blood samples, which were screened by two different HBsAg ELISA kits(xinchuang and BIOMERIEUX), were collected. Samples were further tested by NAT, five HBV complementally serological tests and HBsAg Confirmatory test. Donors with one kind of ELISA+ and NAT- but confirmed HBsAg positive were followed and followed samples were tested for the same tests. The false negative risk which single ELISA Kit took was analyzed. Results Among 616 samples, 35.7%(220/616) had qualified results by Xinchuang ELISA reagent, of which, 31 were NAT- but HBsAg Confirmatory test +. Therefore, if specimens were screened by Xinchuang ELISA reagent and NAT, 5%(31/616) confirmed HBsAg+ samples of the original two round ELISA unqualified samples would not be detected. Thus, 16 confirmed HBs Ag+ cases per 100000 donors would be missed, which was estimated based on the average 0.32% HBsAg positive rate in donors. On the other hand, among 616 samples, 15.3%(94/616) had qualified results by BIOMERIEUX ELISA reagent, of which, 3 were NAT- but HBsAg Confirmatory test +. Therefore, if specimens were screened by BIOMERIEUX ELISA reagent and NAT, 0.5%(3/616) confirmed HBsAg+ samples of the original two round ELISA unqualified samples would not be detected. Thus, 1.6 confirmed HBsAg+ cases per 100000 donors would be missed, which was also estimated based on the average 0.32% HBsAg positive rate in donors. This value is significantly lower than that of removing BIOMERIEUX reagent and retain Xinchang reagent(16/100000χ2=23.713,P=0.000). Given that added single NAT from the original two round ELISA qualified samples, 121 HBV NAT+ cases per 100000 donors would be detected. 119.4 cases per 100000 and 105 cases per 100000 donors would be detected by the screening strategy of one import ELISA reagent and one NAT reagent or one domestic ELISA reagent and one NAT reagent instead of the strategy of two ELISA reagents.Besides, NAT detection rate(18.6%) among samples with single BIOMERIEUX unqualified is significantly higher than that of samples with single Xinchang unqualified(2.1%)(χ2=15.187,P=0.000). The positive rate of HBsAg confirmatory(17.3%)among samples with NAT- but single BIOMERIEUX unqualified is significantly higher than that of samples with NAT- but single Xinchang unqualified(3.3%)(χ2=10.945,P=0.001),it indicates that the sensitivity and specificity of the import HBsAg ELISA reagent were superior to the domestic reagent. Among samples with NAT- but single reagent reactive, the research data showed that there were 2 confirmed HBsAg+ samples in 19 with BIOMERIEUX reagent grey area.Conclusions The screening strategy of one ELISA reagent and one NAT reagent can provide a much more HBV safety than the strategy of two ELISA reagents. ELISA reagent with better sensitivity and better specificity should be remained. the grey area setting of ELISA detection still has a certain sense to some extent.