What is syphilis?

Syphilis is a sexually transmitted disease (STD) caused by a bacterium.

Syphilis can cause long-term complications and/or death if not adequately treated.

How common is syphilis?

CDC estimates that, annually, 55,400 people in the United States get new syphilis infections.

There were 46,042 reported new cases of syphilis in 2018, compared to 48,298 estimated new diagnoses of HIV infection and 321,849 cases of gonorrhea in 2018. Of new cases of syphilis, 13,970 cases were of primary and secondary (P&S) syphilis, the earliest and most infectious stages of syphilis.

How do people get syphilis?

Syphilis is transmitted from person to person by direct contact with syphilis sores. Sores occur mainly on the external genitals, vagina, anus, or in the rectum.

Sores also can occur on the lips and in the mouth. Syphilis can be transmitted during vaginal, anal, or oral sexual contact. Pregnant women with the disease can pass it to their unborn children. 

What are the symptoms in adults?

See all syphilis symptoms

How does syphilis affect a pregnant woman and her baby?

A pregnant woman with syphilis can pass the disease to her unborn baby. Babies born with syphilis can have many health problems.

This may lead to low birth weight, premature delivery or even having a stillbirth (a baby born dead).

To protect their babies, pregnant women should be tested for syphilis regularly during the pregnancy and at delivery and receive immediate treatment, if positive. An infected baby may be born without signs or symptoms of disease. However, if not treated immediately, the baby may develop serious problems within a few weeks. Untreated babies can have many health problems (such as cataracts, deafness, or seizures), and they can die. 

Who should be tested for syphilis?

Providers should routinely test persons who:

    • are pregnant

    • are men who have sex with men

    • have HIV infection

    • have partner(s) who have tested positive for syphilis