Syphilis can be transmitted through saliva, but the chances of transmission are very small, mainly through sexual contact and mother-to-child transmission. Since the skin and mucous membranes of syphilis patients contain syphilis spirochetes, an uninfected person can get the disease if there is a slight break in the skin or mucous membranes during sexual contact with a syphilis patient. Pregnant women with syphilis transmit the infection to the fetus through the placenta, causing intrauterine infection, and some of these infections can lead to fetal syphilis transmission. There are other ways of transmission, such as blood transfusion, kissing, sharing contaminated clothing, including towels, toothbrushes, razors, cutlery, etc., but these last have particularly low chances, and are mainly transmitted through the first two ways.