Syphilis infection can usually be detected two to four weeks after infection, mainly by drawing blood. Syphilis is a chronic infectious disease caused by syphilis spirochete infection. Clinically, it is mainly transmitted through sexual contact, mother-to-child transmission and blood transmission. Syphilis spirochete infection of the human body after the incubation period is generally 2-4 weeks, the longest up to 12 weeks, so if you draw blood to detect syphilis generally need to be in the high-risk behavior of two to four weeks after the test, if it is negative, can be reviewed again in 12 weeks. If the patient has high-risk behavior is worried about syphilis infection, it is recommended to go to the hospital in time to improve the relevant examination, if necessary, repeat the test, diagnosed by a professional doctor, so as not to delay the condition.