Assessment of ELISA and TRUST in detection of syphilis from blood donors.

Objective To observe the reliability of ELISA and TRUST in diagnosis of Treponema pallidum by screening syphilis from large batches of blood donors. Methods Blood donors were screened by using TP-ELISA and TRUST (or TP-ELISA). The positive samples detected with any kind of reagents would be confirmed by TPPA. The differences of sensitivity among ELISA, TRUST and TPPA would be compared and the false positive rate and negative rate would be calculated. Results Totally 94 770 blood donors altogether were determined including the first batch of 47 803 blood donors detected with TP-ELISA and TRUST separately, second 46 967 blood donor were detected with TP-ELISA. 242 positives were detected from the first batch of blood donors with the positive rate of 0.18% (87/47 803 ) by TRUST and 0.49%(233/47 803) by TP-ELISA, respectively. 284 positives were detected from the second batch of blood donors by TP-ELISA made by two manufacturer with the positive rates of 0.57% (269/46 967) and 0.55% (260/46 967), respectively. TP-ELISA was obviously more sensitive than TPPA and TRUST (P0.01). If the results of test is confirmed with TPPA, TP-ELIS was obviously more sensitive than TRUST, the false negative rate of TRUST was as high as 59.5% and the false negative and positive rates of TP-ELISA were only 0%～2.7% and 0.06%～ 0.1%, respectively, and a sensitivity of as high as 97.3～100%. Conclusion The sensitiveness of TRUST is very low and it can't be used in the screening of syphilis from blood donor. For increasing sensitiveness in screening Treponema pallidum,TP-ELISA should be used in first screening of syphilis from blood donors or rescreening or clinical screening of syphilis.