Immunofluorescent Assay (IFA)
The FTA-ABS is a specific treponemal assay to detect antibody to t. Pallidum. The FTA-ABS becomes reactive 4-6 weeks after infection. Unlike the nontreponemal tests, once the FTA-ABS test becomes reactive, it will remain reactive for many years. Since the reactivity found with the FTA-ABS does not indicate response to therapy, it is not suitable for monitoring treatment. The FTA-ABS test does not distinguish between syphillis and other treponematoses such as yaws, pinta and bejil.
Treponemal pallidum, Fluorescent Treponemal Antigen, Syphilis