Syphilis is a sexually transmissible infection (STI) usually caused by having vaginal, oral or anal sex with a person who is infected.

Both men and women can be infected. It can also be passed on during pregnancy from mother to child.


The first sign of primary syphilis is usually a painless sore (chancre), which appears where the infection has occurred; this is usually on the genitals or mouth. The sore may be less prominent with repeat infections.

Sometimes the chancre may occur inside the vagina or anus where you do not notice it. The chancre will heal within 2-6 weeks even without treatment. However, the person will still have syphilis and need treatment.

After about 6 weeks the person will get what is known as secondary syphilis. They may be unwell and feel like they have the flu. A rash on their hands, feet and other parts of the body may appear. They may also develop soft, moist lumps on the warm, moist areas of the body (genitals, around the anus, under the breasts, armpits) or ulcers in the mouth or on the genitals. 

The outward symptoms of secondary syphilis will also disappear without treatment but the person will still have syphilis and still need treatment.

Syphilis can be spread by skin contact with the chancre, the skin lumps and sometimes by contact with the rash or genital lumps.

Using a condom is an important way of preventing infection. But because not all of these areas with syphilis will be covered by the condom, it may not give 100% protection.

Other problems it can cause

After the secondary syphilis heals, the person will feel fine and not know that they are carrying the infection. This is called the latent stage, where there are no visible signs of the illness.

However, without treatment, tertiary syphilis may develop anytime between 5-30 years later. This can seriously affect the brain, spinal cord or heart and can lead to death.

Having primary or secondary syphilis can make it easier for a person to become infected with HIV or to pass HIV on to someone else.


Usually syphilis is diagnosed by having a blood test. Sometimes a swab may be taken from the skin sores or lumps to look for the germ that causes syphilis.

Babies born with syphilis

If a pregnant woman has untreated syphilis, her baby can be infected even if she does not have any symptoms herself. Syphilis can also cause a miscarriage or stillbirth. Or it may cause problems with the baby’s bones, skin, blood, eyes, ears, teeth or brain. These problems may be present at birth or only appear after a few weeks or even years.

Congenital syphilis is extremely easy to prevent by doing a blood test in all pregnant women and treating the infected mothers-to-be (and their partners) if needed.


Syphilis is usually treated with an injection of antibiotics.

It is important that treatment for syphilis be completed and the person has a follow-up blood test to make sure the infection is completely cured.

Sexual partners need to be told so they can also be tested and treated.


For more information contact the Centre for Disease Control's Clinic 34 or the Syphilis Register.

Last updated: 12 May 2016

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