Syphilis is a sexually transmitted infection caused by the bacterium Treponema pallidum. Syphilis is spread through sexual contact and pregnant woman can also pass the infection to the fetus. If untreated, syphilis can cause problems throughout the body, including the brain, after many years of infection. A blood test can detect the infection. Syphilis can be treated with doses of a single antibiotic medication.
Information about syphilis in pregnancy and congenital syphilis.