Analysis of results of determination of syphilis from blood donors with different methods

Objective To investigate the morbidity and distribut ion of blood donors with positive syphilis antibody (PSA) in the donor population o f Shenzhen City and improve the ability for syphilis antibody screening i n the donor population. Method The blood samples were assayed by parallel methods of TRUST and ELISA. If the sample was PSA with one assay, it w i ll be measured with another assay. If the sample was positive again, it will be measured by TPPA method for specific validation of syphilis antibody ( above 1:8 0 as PSA). Results The samples from 12600 cases of donors had been assayed with TRUST and ELISA,and 62 and 118 positives were detected with th e positive rates of 0.49% and 0.94%,respectively. 116 cases were positive wi th TPPA assay. The valid positive rate was 0.92 % . The positive rate with TRUST method was obviously lower than that with ELISA and TPPA methods. Conclusion The results suggest that the fal se negative syphilis antibody may occur in the screening blood donors with single TRUST assay, which and there wou ld be potential risk for safe use of blood .