Comparison of CAPTIA syphilis G enzyme immunoassay with rapid plasma reagin test for detection of syphilis.

The CAPTIA Syphilis G enzyme-linked immunosorbent assay compared favorably with the rapid plasma reagin test when used to screen for syphilis in a low-risk population. The sensitivity and specificity of the CAPTIA Syphilis G test were 100 and 97.8%, respectively, for 646 routine specimens and 100 and 99.2%, respectively, for 265 specimens from obstetrics patients. Overall, for 911 specimens, the CAPTIA Syphilis G test showed a sensitivity of 100%, a specificity of 98.2%, and positive and negative predictive values of 78.9 and 100%, respectively. For the same population, the rapid plasma reagin test showed a sensitivity and a specificity of 96.4 and 97.5%, respectively, and positive and negative predictive values of 72 and 99.8%, respectively.