Syphilis is a chronic, systemic sexually transmitted disease caused by the pale (syphilis) spirochete. It is mainly transmitted through the sexual route and can be clinically manifested as stage I syphilis, stage II syphilis, stage III syphilis, latent syphilis and congenital syphilis (fetal syphilis). Syphilis is classified as a category B disease in the Prevention and Control of Infectious Diseases Law of the People’s Republic of China. What are the ways of syphilis transmission? The only source of infection of syphilis is the patient with syphilis. The spirochetes are present in the skin lesions, blood, semen, breast milk and saliva of the patient. 1. Sexual contact transmission: About 95% of patients are infected by sexual contact through tiny breaks in the skin and mucous membranes. Untreated patients are highly infectious within 1 to 2 years after infection, with the prolongation of the disease period, the infectiousness becomes less and less, and patients who have been infected for more than 4 years are basically not infectious. 2, vertical transmission: after 4 months of pregnancy TP can be transmitted from mother to fetus through the placenta and umbilical vein, which can cause miscarriage, premature birth, stillbirth or fetal syphilis, the infectiousness of which gradually decreases with the prolongation of the disease, the chances of vertical transmission of untreated stage I, early latent and late latent syphilis pregnant women are 70% to 100%, 40% and 10% respectively. Contact infection can also occur in the head and shoulder abrasions when the newborn passes through the birth canal during childbirth. 3, other ways: the blood of syphilis patients within 3 days of refrigeration is still infectious, the input of such blood can be infected; a small number of patients can be infected by the medical route, kissing, shaking hands, breastfeeding or contact with contaminated clothing, utensils.