Syphilis is a sexually transmitted disease caused by Treponema pallidum. The disease has been known under many names during history, including the "French disease", "Great Pox", and "The Black Lion." Syphilis has had a prominent role in history and literature for the last several hundred years. The route of transmission of syphilis is almost always by sexual contact. However, there are examples of congenital syphilis via transmission from mother to child in utero. The signs and symptoms of syphilis are numerous; before the advent of serological testing, precise diagnosis was very difficult. In fact, the disease was dubbed the "Great Imitator" because it was often confused with other diseases.
Syphilis (unless it has become antibiotic-resistant) can be easily treated with antibiotics including penicillin. The oldest, and still most effective, method is an intramuscular injection of benzathine penicillin. If not treated, syphilis can cause serious effects such as damage to the heart, aorta, brain, eyes, and bones. In some cases these effects can be fatal. In 1998, the complete genetic sequence of T. pallidum was published which may aid understanding of the pathogenesis of syphilis.