Syphilis Test FTA-ABS

Treponema pallidum, the bacterium which causes syphilis has four subspecies:

• Treponema pallidum pallidum, which causes syphilis
  
• T. pallidum endemicum, which causes bejel or endemic syphilis
  
• T. pallidum carateum, which causes pinta
  
• T. pallidum pertenue, which causes yaws
  

To detect antibodies to Treponema pallidum, the FTA-ABS (Fluorescent treponemal antibody absorbed), a blood serum screening test is done. This is sometimes also referred to as syphilis Immunofluorescent Assay (IFA). The FTA-ABS test is a second test to confirm the presence of the infection and is usually done after the RPR test and VDRL test results are positive. FTA-ABS test is used to detect syphilis infection at any stage except during the first 3 to 4 weeks after exposure and in tertiary stages of the disease. The test is more reliable for the secondary stage of syphilis. The test is done on a sample of blood or spinal fluid. A positive FTA-ABS usually indicates infection with syphilis and a negative or nonreactive result means there is no current or past infection with syphilis. The test requires no prior preparation on the part of the individual who is to be tested.