Final answer:
The confirmatory assay used for syphilis is treponemal-specific. Treponemal serologic tests detect antibodies to T. pallidum antigens using different methods.
Step-by-step explanation:
The confirmatory assay used for syphilis is treponemal-specific. Treponemal serologic tests measure antibodies directed against T. pallidum antigens using various methods such as particle agglutination, immunofluorescence, enzyme reactions, and chemiluminescence immunoassays. These tests are used for confirmatory testing because they specifically detect antibodies to the syphilis spirochete antigens.