Treponemal tests work by identifying the presence of specific antibodies in the blood, which are produced in response to T. pallidum infection. Unlike nontreponemal tests like the Rapid Plasma Reagin (RPR) or Venereal Disease Research Laboratory (VDRL) tests, treponemal tests remain positive for life even after successful treatment. This makes them useful for confirming a diagnosis but less so for determining treatment efficacy or recent infection.
