A rise in titer after syphilis treatment may be a recurrence of syphilis and may also be a reinfection. Serologic tests for syphilis include specific and non-specific antibodies. A positive TRUST test result for non-specific antibodies is presented as an antibody titer, the higher the titer the more active the virus is. The test can also be used during and after treatment for syphilis. An increase in titer suggests that syphilis may be recurring or that the patient may be re-infected. 1. Syphilis relapse: this may be the stage of development of syphilis to the second or third stage of syphilis. The main treatment for syphilis is penicillin, such as procaine penicillin, and for those who are allergic to penicillin, ceftriaxone, doxycycline and other drugs can be used. During the treatment period, regular follow-ups to check the serum titer are carried out in accordance with the doctor’s instructions. 2. Reinfection: If the syphilis treatment has reached a clinical cure, but the sexual partner has latent syphilis or has unclean sex, it may be re-infected with syphilis, and the titer will rise, so it is necessary to check as soon as possible to make a clear diagnosis. If the titer rises after syphilis treatment, you should follow the doctor’s advice for further examination and treatment, so as to avoid delaying the condition.