TPPA negative means that no syphilis-specific antibodies are detected, but a false negative may occur. TPPA refers to the syphilis spirochete particle agglutination test, which is a method of detecting syphilis-specific antibodies. If the TPPA is positive, it means that you are infected with the spirochete or have had a previous infection with the spirochete. a negative TPPA means that no syphilis-specific antibodies have been detected on this occasion, but it does not rule out the diagnosis and a false negative may occur. Infection with S. syphilis does not produce antibodies immediately; there is a window period during which the TPPA may be negative, but the person may already be infected with S. syphilis. For those who have high-risk behaviors, retesting can be done after 2 to 4 weeks to confirm the diagnosis of syphilis infection.