There is no gold standard and no culture technique is available. Diagnosis must rely on the following:
Identification of T. pallidum from lesions using darkfield microscopy
It measures immunoglobulin M (IgM) and immunoglobulin G (IgG) antibody directed against cardiolipin—lecithin- cholesterol antigen.
It is nonspecific for T. pallidum.
It is used to determine antibody titer and monitor therapy. Rising titer indicates an active infection that may be any one of the following:
Reactivation of the latent disease
Types of tests include the following:
Venereal Disease Research Laboratory (VDRL)
Rapid plasma reagin (RPR)
Measures IgM and IgG antibody against T. pallidum— specific antigens
Types are as follows: –
Fluorescent treponemal antibody test (FTA-ABS).
- pallidum—hemogiutinatisag antibody tests (MHA-TP, TPHA)
- Specific treponemal antibody tests may remain active after adequate therapy.