Syphilis has an incubation period of about 2-3 weeks, and can usually be detected after one month, but a negative result cannot completely rule out infection. Syphilis one month usually refers to a month after the high-risk exposure behavior, because the incubation period of syphilis is relatively long, the average is two to three weeks, but it may be three months, so a month after the results are normal can not completely exclude syphilis infection, usually need further examination to be able to exclude infection, usually need to be reviewed in two months, three months, to do further exclusion. Syphilis infection in the incubation period will also have a certain degree of contagiousness, so not ruled out before the infection, must do a good job of isolation measures, to avoid infecting others, especially not in the absence of safety measures, sexual intercourse and not mixed with others daily necessities, it is recommended that timely compliance with the doctor’s advice treatment.