Syphilis is a sexually transmitted disease caused by the spirochetal (spirochete) bacterium Treponema pallidum subspecies pallidum. The route of transmission of syphilis is almost always through sexual contact, although there are examples of congenital syphilis via transmission from mother to child in utero or at birth.Citation neededdate=May 2010

The signs and symptoms of syphilis are numerous; before the advent of serological testing, precise diagnosis (medical diagnosis) was very difficult. In fact, the disease was dubbed the "Great Imitator (great imitator)" because it was often confused with other diseases, particularly in its tertiary stage.Citation neededdate=May 2010

Syphilis can generally be treated with antibiotics, including penicillin. If left untreated, syphilis can damage the heart, aorta, brain, eyes, and bones. In some cases these effects can be fatal.Citation neededdate=May 2010