Syphilis Serology

Serological testing for syphilis for syphilis can be classified into two categories—treponemal and non treponemal. As the name suggests, the treponemal tests are aimed at detecting an antigen or an antibody of the T.pallidum bacteria (This is the bacteria that causes syphilis). However, a positive treponemal test cannot necessarily be indicative of an active syphilis infection. This is because antibodies remain in the bloodstream even after several years since contraction of syphilis. Non-treponemal tests on the other hand, looks for indirect indications of the infection, like the presence of cardiolipins. This is released when a treponeme bacteria damages cells. So, if cardiolipin is found in the blood sample, it indicates an active infection. However, one then needs to take a treponemal test to confirm that increased cardiolipin is in fact a result of a syphilis infection.