Abstract: Objective To analyze the results of blood virus screening by both nucleic acid test （NAT） and ELISA to evaluate the significance of NAT in improving blood safety. Methods We randomly collected 19 464 blood samples from volunteers between 2015 and 2016. The blood samples were detected by ELISA for screening of anti-HIV,anti-HCV and HBsAg,followed by PCR fluorescence detection for nucleic acids of HBV,HCV and HIV in the samples which had showed negative reactions in ELISA. The comparative results were evaluated for the efficiency and significance in laboratory diagnoses and blood safety ensurance. Result The positive rate of HBV was 16.0% by NAT compared with 11.0% by ELISA （P<0.05）. HCV detected by NAT revealed a positivity of 1.8% ,which is obviously higher than 0.5% by ELISA （P<0.05）. The positive rate of HIV,however,was 1.9% by NAT whereas 1.7% by ELISA,no significant difference was noted between the two methods （P>0.05）. Conclusion Pre-examination of blood samples with ELISA followed by NAT verification is recommended for blood screening which may help avoid missing or misdetection of samples in ELISA and help improve sensitivity and accuracy in the safety of blood transfusion.

Key words: Blood virus screening, Nucleic acid detection, Enzyme-linked immunosorbent assay