What is the difference between FTA-ABS test and VDRL test?

Question

Hello doctor,

I recently did an fluorescent treponemal antibody absorption test (FTA-ABS) test for syphilis. It showed reactive with a titer 1:1. But after a week and a half, I took a venereal disease research laboratory (VDRL) test, and it was non-reactive. Now I am confused. The doctor was not so clear while explaining the difference in the result. Kindly help. Thanks.

Answer 1

Hi,

Welcome to icliniq.com. Thanks for writing in, and I understand your concern. If FTA-ABS (fluorescent treponemal antibody test absorption) test is positive, it will remain positive for lifetime. It suggests that you have been infected with syphilis. It could have been in the past or present. However, VDRL (venereal disease laboratory test) suggests present disease activity. VDRL non-reactive means, at present, infection is not active.

Answer 2

Hello,

Welcome back to icliniq.com. Syphilis is a sexually transmitted disease that is usually a consequence of unprotected sexual activity. venereal disease research laboratory (VDRL) reflects disease activity in syphilis, and titers above 1:8 are considered significant. FTA-ABS test is a specific test that detects antibodies developed against the bacteria after an infection. Hence it remains positive for a lifetime as antibodies are present in the body for the entire life. If you have never been treated for syphilis, you could repeat the VDRL test after four weeks and 12 weeks and check for a rising trend. If increasing, I suggest taking the appropriate antibiotic.

Regards.