Syphilis, a chronic bacterial infection caused by the spirochete Treponema pallidum subsp. pallidum, remains a public health concern worldwide. Syphilis control is largely dependent upon early identification and prompt treatment. The diagnosis of syphilis is mainly based on laboratory tests, especially serology and dark-field microscopy. In recent years, recombinant Treponema pallidum antigen-based rapid tests, polymerase chain reaction, and immunoglobulin M antibody detection have also shown certain sensitivities and specificities for syphilitic patients at different stages.