Evaluation of TP-ELISA Screening Combined with TRUST and TPPA in Diagnosis of Syphilis

Objective To explore the value of using ELISA as a routine screening method combined with TRUST and TPPA for the diagnosis of syphilis,and establish the system of test and report for serological diagnosis of treponema infection in our laboratory.Methods The clinical specimens underwent routine treponema pallidum antibody screening with ELISA method.All positive samples and the suspicious samples that S/CO value was between 0.7 and 0.99 by TP-ELISA were further tested by TRUST and TPPA.Results Among 145 treponema pallidum antibody screening positive specimens,141 positive and 4 negative results were retested by TPPA.The positive coincidence rate of ELISA and TPPA was 97.24 %.91 positives results were detected with TRUST,which were the same positives results as with TPPA.Among 54 TRUST negative samples,50 positives results were detected with TPPA.4 positives results were detected with TPPA for 20 suspicious samples that S/CO value was between 0.7 and 0.99 by ELISA.TPPA was more sensitive than ELISA by 4 positive samples in the dilution test.Conclusions TP-ELISA screening test exist several false positives and false negative results.ELISA screening positive specimens should be firstly detected with TRUST.All TRUST negative samples and the suspicious samples that S/CO value is between 0.7 and 0.99 by ELISA should be further tested by TPPA,which can greatly reduce the erroneous or escape diagnosis of Syphilis.