Syphilis is a frequently diagnosed and reported sexually transmitted disease.

Syphilis is an infectious disease caused by the corkscrew-shaped bacterium (spirochete), Treponema pallidum. This type of bacteria causes infection when it gets into broken skin or mucus membranes, usually of the genitals. It is most often transmitted through sexual contact, although other means of transmission are possible.

Syphilis occurs worldwide. The rate of syphilis is higher in urban, rather than rural, areas, and the number of cases is rising most rapidly in men who have sex with men. Young adults, ages 15-25, are the highest-risk population. People have no natural resistance to syphilis.

Because people may be unaware that they are infected with syphilis, many states require tests for syphilis before marriage. All pregnant women who receive prenatal care are screened for syphilis to prevent the syphilis infection from passing from the mother to the newborn (congenital syphilis).

Syphilis has three stages:

• Primary syphilis
• Secondary syphilis
• Tertiary syphilis

Secondary syphilis, tertiary syphilis, and congenital syphilis are not seen as often in the United States as they were 20 or 30 years ago because of the availability of free, government-run sexually transmitted disease clinics, screening tests for syphilis, public education about STDs, and prenatal screening.

Primary syphilis symptoms include:

• Small, painless open sore or ulcer (called a chancre) on the genitals, mouth, skin, or rectum that should heal by itself in 3-6 weeks
• Enlarged lymph nodes in the area containing the chancre

The bacteria continues to multiply in the body, but there is little outward evidence of disease until the appearance of the second stage.

• Dark field examination of fluid from sore
• FTA-ABS fluorescent treponemal antibody test
• RPR
• STS (serologic test for syphilis -- any of the other tests may be used)
• VDRL