Which test is most likely to be positive in the tertiary stage of syphilis?

Which test is most likely to be positive in the tertiary stage of syphilis?

• A. FTA-ABS
• B. RPR
• C. VDRL
• D. Reagin screen test (RST)

Answer: (A)

In the tertiary stage of syphilis, the FTA-ABS (Fluorescent Treponemal Antibody Absorption) test is the most likely to be positive. This test is a treponemal assay that detects antibodies specific to Treponema pallidum, the bacterium that causes syphilis. By the time the disease has progressed to the tertiary stage, treponemal tests like FTA-ABS are more reliable in detecting antibodies, which can remain positive for life even after treatment. While the RPR (Rapid Plasma Reagin), VDRL (Venereal Disease Research Laboratory), and reagin screen test are non-treponemal tests that measure non-specific antibodies produced in response to cell damage caused by the infection, these tests are less reliable in later stages of syphilis. They can yield false negatives in late-stage disease, as the antibody levels may decline in some patients. Consequently, in tertiary syphilis, the specificity and sensitivity of the FTA-ABS make it the preferred test for confirming the infection.

In the tertiary stage of syphilis, the FTA-ABS (Fluorescent Treponemal Antibody Absorption) test is the most likely to be positive. This test is a treponemal assay that detects antibodies specific to Treponema pallidum, the bacterium that causes syphilis. By the time the disease has progressed to the tertiary stage, treponemal tests like FTA-ABS are more reliable in detecting antibodies, which can remain positive for life even after treatment.

While the RPR (Rapid Plasma Reagin), VDRL (Venereal Disease Research Laboratory), and reagin screen test are non-treponemal tests that measure non-specific antibodies produced in response to cell damage caused by the infection, these tests are less reliable in later stages of syphilis. They can yield false negatives in late-stage disease, as the antibody levels may decline in some patients. Consequently, in tertiary syphilis, the specificity and sensitivity of the FTA-ABS make it the preferred test for confirming the infection.