Syphilis Fact Sheet

Updated August 2025

Definition

Syphilis is a sexually transmitted infection (STI) caused by the bacterium Treponema pallidum.

Signs and Symptoms

Many people who have syphilis have no symptoms. They can pass the infection to their sexual partner(s) without even knowing it. The disease goes through a few stages when the bacteria enter the body.

Primary Stage

3-90 days after exposure, a painless sore called a chancre may appear on the penis, anus, vagina, throat or any other part of the body where the bacteria entered. Many people do not notice the sore because it is painless and goes away on its own without treatment. However, without treatment the infection can advance to the next stage.

Secondary Stage

2-12 weeks after infection, a rash may develop on the palms of the hands, soles of the feet or on any part of the body. In some cases, there are other symptoms like fever, patchy hair loss, muscle or joint pain or swollen glands. Again, these symptoms may disappear without treatment. Without treatment the infection will continue to the next stage.

Latent Stage

There are no symptoms in this stage. If a person has the infection for less than a year, they are in the early latent phase. Once a person has had the infection for one year or more, they are in the late latent stage. They are no longer able to pass the infection on to others, but the infection may begin to damage their body.

Tertiary Stage

Some people who have never received treatment may enter the tertiary stage of syphilis 10 to 20 years after they were first infected. However, if a person also has HIV these tertiary stage symptoms can appear earlier. The tertiary stage of syphilis can cause serious heart, brain, liver, eye and bone disease.

Diagnosis

A blood test is used to diagnose syphilis. It can take 2 to 12 weeks for the infection to appear in the blood. Syphilis is not a routine blood test. If you think you may have been infected, ask your health care provider for a syphilis blood test. In addition, your health care provider will discuss your sexual health history, assess your symptoms and conduct a physical exam to help diagnose the infection.

Complications (that may arise)

Without treatment the symptoms will go away, but the disease may continue to spread through the body. Many years later it may cause severe damage to the heart, brain, liver, bones and eyes.

A pregnant woman can pass the infection to her unborn baby. If not treated, the baby can have serious health problems or make it more likely that the baby will be born early or stillborn.

Risk Factors

Anyone who is sexually active can be infected with syphilis. People at increased risk are gay, bisexual, and other men who have sex with men (gbMSM), sexual contacts of a known case of syphilis, or people who use drugs. Having multiple sexual partners, having a STI in the past, not using condoms/barriers during sex, and being a sexual partner of anybody in these higher-risk groups increases your risk as well.

Treatment

It is important to treat syphilis as early as possible. Treatment will prevent serious complications. It will also keep you from passing the infection to someone else. Antibiotics, usually given as injections, will cure syphilis. Intravenous (IV) treatment is required for syphilis that has infected the nervous system (neurosyphilis). Once you have been treated for a syphilis infection, if you have syphilis blood tests in the future, there will always be evidence of a history of syphilis. Your blood test result will be “positive” or “reactive”.

Prevention

Here are a few important points to remember:

• Avoid anal, vaginal or oral sex with anyone who has a sore(s) in the genital or mouth area.
• If you already have syphilis, avoid anal, vaginal or oral sex, even with a condom until 7 days after treatment.
• If you have an untreated STI like syphilis, it is easier to get HIV from a person who has it.
• Do not share needles.
• All pregnant women should be tested for syphilis at least once during pregnancy.
• It is possible to have more than one infection at a time, so it is important to be tested for other STIs including HIV.
• Use condoms correctly every time you have sex to lower your chance of getting an STI.

Self-care

Follow-up blood tests for syphilis are very important. The results of these blood tests will show if the treatment was effective or if you need further treatment. They will also indicate if you have been infected again, either from an untreated partner or a new partner.

Public Health Role

Syphilis infection is reportable to your local public health department. Your health information will be kept confidential. A public health nurse will work closely with your health care provider to ensure you are aware of your infection, receive the correct treatment, answer any questions you have and discuss notifying your partners. A public health nurse can help an infected person notify their partner(s). Your name will be kept confidential.

Transmission/Spread

Syphilis is spread from person to person through unprotected oral, anal, or vaginal sex, or sharing sex toys. Syphilis may also be transmitted to an infant during pregnancy and birth.

Information for Sexual Partners (for STIs)

All sexual and needle sharing partners need to be tested and treated if they are infected.

• In the primary stage, it is important to tell partners within the past 3 months, even if they have no symptoms.
• In the secondary stage, all partners within the past 6 months need to be told.
• In the early latent stage, all partners within 1 year of diagnosis need to be told.
• In the late latent stage, long-term partners should be told. Children may also need to be tested.
• If there have been no partners in the notification period, the last partner should be contacted.