Confirmatory test for Syphilis is: September 2010 March 2013

Ans. C: FT-ABS T. pallidum cannot be grown in vitro Diagnostic tests for syphilis: Tests include serologic tests for syphilis (STS), which consist of screening (reaginic) and confirmatory (treponemal) tests, and dark field microscopy. Reaginic tests use lipid antigens (cardiolipin from bovine heas) to detect reagin (human antibodies that bind to lipids). The Venereal Disease Research Laboratory (VDRL) and rapid plasma reagin (RPR) tests are sensitive, simple, and inexpensive reaginic tests that are used for screening but are not specific for syphilis. Results may be presented qualitatively (e.g., reactive, weakly reactive, borderline, or nonreactive) and quantitatively as titers (e.g., positive at 1:16 dilution). Many disorders other than treponemal infections (e.g., SLE, antiphospholipid antibody syndromes) can produce a positive (biologically false-positive) reagin test result. CSF reaginic tests are reasonably sensitive for early disease but less so for late neurosyphilis. CSF reagin tests can be used to diagnose neurosyphilis or to monitor response to treatment by measuring antibody titers. Treponemal tests detect antitreponemal antibodies qualitatively and are very specific for syphilis. They include the following: - Fluorescent treponemal antibody absorption (FTA-ABS) test - Microhemagglutination assay for antibodies to T. pallidum (MHA-TP) T. pallidum hemagglutination assay (TPHA)