Abstract: Objective Compared automated chemiluminescent microparticle immunoassay (CLIA) with conventional methods to analyze the results of CLIA for the screening of syhilis.Methods 36 000 serum samples were tested by CLIA for screening of syphilis, and the positive samples would be subjected to TPPA for furhter confirmation. Then the sensibility, specificity, positive prediction value and negative prediction value were calculated. Results The sensitivity and specificity of CLIA were 100% and 99.7%, respectively. When the value of S/CO value was 1.08, the Youden index reached maximum, the sensitivity and specificity of CLIA were 100% and 94.8%, respectively. Conclusion CLIA is suggested as a screening test for the diagnosis of syphilis.

Key words: automated chemiluminescent microparticle immunoassay, Treponema pallidum, sensitivity, specificity