ABBR: STS

Nonspecific blood tests for syphilis. Three general types are available: (1) Procedures that identify the presence of a nontreponemal antibody against a lipoidal agent that is generated in response to infection with Treponema pallidum, i.e., a reagin. These tests include the Wassermann, the Venereal Disease Research Laboratory (VDLR), and the rapid plasma reagin tests. (2) An antibody-specific test, the fluorescent treponemal antibody absorption (FTA-ABS) procedure. Because of a high rate of false-positive findings by the nonspecific antibody tests, diagnosis of syphilitic infection is established by the more accurate FTA test. (3) Polymerase chain reaction testing for T. Palladium DNA, although not yet approved for use in the U.S., can detect some cases of otherwise occult infection with syphilis.