Implementation of nucleic acid test in blood screening in Xi'an

Objective To analyze the necessity and feasibility on implementation of nucleic acid testing( NAT) in blood screening in Xi'an blood center for improving blood safety.Methods With pooling 6 samples each,175 268 ELISA screening negative samples and 1 043 single ELISA reagent screening positive samples were tested by NAT on Roche Cobas s 201 Nucleic acid amplification testing system to determine the HBV DNA,HCV RNA and HIV RNA.The positive samples would be tested for each specific pathogen,respectively.Results Totally 29 286 pools were tested by NAT in 175 268 ELISA negative samples.195 positive pools were found,as 0.67%( 195 /29 286),and 116 samples were determined positive with NAT in individual tests,as a positive rate of 0.066%( 116 /175 268).81 samples were determined to be HBV DNA positive,and the other 35 cases were determined to be inconclusive in these 116 positive samples,while no HCV RNA and HIV RNA were found.In addition,7 HBV DNA positive samples were found in 1 043 single ELISA reagent positive samples as the positive rate of 0.67%.Conclusion The implementation of NAT can effectively shorten window period in virus screening,while some reactive samples could be found by NAT in serological test negative specimens.It is suggested by this study that it could reduce the risk of Occult HBV Infection( OBI) and improve blood safety with the NAT initiated in our blood center.