Updated December 2016

What is syphilis?

Syphilis is the oldest recognized STI and remains a common, although serious, infection that can be debilitating and even result in death if left untreated. It is caused by corkscrew-shaped bacteria called Treponema pallidum. 

Is it common?

According to the CDC, in 2020, 133,945 cases (all stages) of syphilis were reported.

How is it transmitted?

The syphilis bacteria are transmitted by having direct contact with a syphilis sore. These sores can be found in the external genital area, the vagina, anus, rectum, on the lips and in the mouth. You can get and spread syphilis through oral, anal, and vaginal sex or through other intimate sexual contact including kissing. You can have syphilis without knowing it and pass it on to others. Syphilis may also be transmitted during pregnancy from mother to fetus through the placenta.

What are the symptoms and how long after exposure will they appear?

Syphilis has three stages and there are different symptoms that are associated with each stage. The stages may overlap with one another and an infected person may not always experience the symptoms in the same sequence. It is important to note that like other STIs, it is common that a person infected with syphilis will not show any symptoms. If you think you are infected, avoid any sexual contact and visit Health Services or a local STI clinic or your medical provider immediately.

During the first stage, if a person does experience symptoms, a painless sore called a chancre may appear at the spot where the bacteria first entered the body. The chancre is usually firm, round, and small and will appear within 2 to 12 weeks after sexual contact with an infected person. This sore may appear around or in the vagina, on the penis, on the lips or inside the mouth or anus. Sores are often unnoticed and may disappear on their own if not treated, but the bacterial infection remains.

The second stage occurs from 3 weeks to 3 months after the primary stage and symptoms include fever, swollen lymph glands, sore throat, patchy hair loss, headaches, weight loss, muscle aches, and fatigue. Some people experience a rash on the palms of their hands and soles of their feet, as well as over their entire body. But the rash may be faint enough not to be noticed and may disappear on its own even without treatment. During these first 2 phases, an infected person is highly contagious and can easily pass the infection to sex partners.

If untreated, the third stage of syphilis can appear 3 to 10 years or more after the first and second stages. Symptoms of this stage may include skin lesions, mental deterioration, loss of balance and vision, loss of sensation, shooting pains in the legs, and heart disease. 

How is it diagnosed?

Your medical provider will either examine material from an infectious sore or s/he will perform a simple blood test to determine whether or not you have syphilis. However, if you were infected within 2 to 3 weeks before your blood test, the test might not be sensitive enough to find evidence of the bacteria.

How is it treated?

Fortunately, all stages of syphilis can be treated with antibiotics but damage caused by the disease in the third stage cannot be undone. The most common treatments are penicillin injections. Be sure that any partner(s) are tested and treated and avoid all sexual contact until the infection is cured.

Can a syphilis infection be dangerous?

Left untreated, a syphilis infection can be fatal. In the third stage of the infection, a person may experience internal organ damage, paralysis, numbness, gradual blindness and dementia. This damage may be serious enough to cause death. If you think you have any risk of exposure to syphilis, get tested and get treatment.

If a pregnant person has been infected, they have a high chance of having a stillbirth or of giving birth to a baby that dies shortly after birth. If not treated immediately, an infected baby may be born without symptoms but could develop them within a few weeks. These signs and symptoms can be very serious. Untreated babies may become developmentally delayed, have seizures, or die. Because of this, every person giving birth should have the blood test to eliminate the risk. 

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