Evaluation of the serodia Treponema pallidum particle agglutination, the Murex Syphilis ICE and the Enzywell TP tests for serodiagnosis of syphilis.

We evaluated the Treponema pallidum haemagglutination assay (TPHA), a treponemal test, with three other treponemal tests, the Serodia T. pallidum particle agglutination assay, the Murex Syphilis ICE IgG + IgM enzyme immunoassay (EIA) and the Enzywell TP IgG + M EIA (a new rapid EIA) for use in conjunction with the rapid plasma reagin test (RPR), a non-treponemal test, for serodiagnosis of syphilis. In all, 124 serum samples were found reactive with RPR and/or TPHA after testing by the routine laboratory protocol. Twenty-three (18.5%) of them were positive only by RPR test and were evaluated as biologically false-positive, 16 were positive only by the TPHA and 84 by both the RPR and TPHA tests; one sample was non-specific (heterophile reaction) in the TPHA. Agreements of the TPHA with the Serodia TPPA, the Murex Syphilis ICE and the Enzywell TP tests were 96.7%, 100% and 99.1%, respectively. We conclude that each one of the tests, the Serodia TPPA, the Murex Syphilis ICE and the Enzywell TP, is an appropriate substitute for screening for serodiagnosis of syphilis.