Syphilis is a sexually transmitted disease (STD) caused by a bacterium called Treponema pallidum. The initial infection causes an ulcer at the site of infection; however, the bacteria move throughout the body, damaging many organs over time. Medical experts describe the course of the disease by dividing it into four stages -- primary, secondary, latent, and tertiary (late). An infected person who has not been treated may infect others during the first two stages, which usually last one to two years. In its late stages, untreated syphilis, although not contagious, can cause serious heart abnormalities, mental disorders, blindness, other neurologic problems, and death.
The bacterium spreads from the initial ulcer of an infected person to the skin or mucous membranes of the genital area, the mouth, or the anus of a sexual partner. It also can pass through broken skin on other parts of the body. The syphilis bacterium is very fragile, and the infection is almost always spread by sexual contact. In addition, a pregnant woman with syphilis can pass the bacterium to her unborn child, who may be born with serious mental and physical problems as a result of this infection. But the most common way to get syphilis is to have sex with someone who has an active infection.
Reprinted from the National Institute of Allergy and Infectious Diseases
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