Quick facts:

  • Syphilis is a complex yet curable sexually transmissible infection that can cause serious health problems if left untreated.
  • There are 4 stages of syphilis infection with each stage presenting different symptoms.
  • A simple blood test can detect syphilis.
  • Infectious syphilis is a significant public health concern worldwide. Notifications in Queensland have increased rapidly over the last 20 years, from 112 cases in 2001 to 1,049 cases in 2021.
  • Of added concern is the risk of the syphilis infection passing to a baby during pregnancy (congenital syphilis).
  • Practicing safe sex, timely and adequate testing, treatment and contact tracing of sexual partners is paramount for reducing notifications, risk of infection and burden of disease.

Syphilis is a curable sexually transmissible infection (STI) caused by the Treponema pallidum bacteria. There are four stages of syphilis with each having different signs and symptoms.

Crucially, all early stages of syphilis are infectious, and the infection can be passed on to sexual partners for up to two years if the person is not treated. If left untreated, syphilis can lead to serious health complications from damage to organ systems, most commonly the brain and heart.

Since 2011 there has been an ongoing infectious syphilis outbreak in northern Queensland that has seen Aboriginal and Torres Strait Islander populations disproportionally affected. More recently, notifications among heterosexual women of reproductive age have substantially increased. This poses an increased risk of congenital syphilis and adverse pregnancy outcomes.

Signs and symptoms

Primary syphilis

Syphilis can initially cause sores or ulcers around the genital area, mouth, or throat 10–90 days (average 21 days) after infection. These sores, called chancres, can be any size or shape. They are often painless, don't bleed, and can feel like a hard button on the skin. Sometimes these sores may be internal and go unnoticed. This is called the primary stage of syphilis. If not treated, the sores usually heal and disappear after a few weeks, however, the syphilis infection remains in the body and the person can still pass the infection on.

Secondary syphilis

Two to six months after getting infected, the secondary stage of syphilis occurs. Symptoms may include a flu-like illness, a rash on the trunk, palms, and soles of the feet, swollen glands, wart like lumps around the moist areas of the body, and hair loss. Some people also get headaches, tiredness and pains in the bones, muscles and joints. Even when these symptoms resolve on their own the person can still pass the infection on.

Early latent syphilis

This means that the person does not have any signs or symptoms but is still infectious. The only way they would know they have syphilis is to have a blood test.

Late latent syphilis

This means the person is not infectious. The only way the person would know they have syphilis is to have a blood test.

Tertiary syphilis

Tertiary syphilis can develop years after the infection was first acquired. If left untreated, the bacteria can damage major organ systems including the heart, brain, spinal cord, eyes and bones, resulting in heart disease, mental illness, blindness, deafness and neurological problems. At this stage, syphilis can still be treated and the person is not infectious.


A simple blood test is used to diagnose syphilis. If a person has an ulcer or sore this can also be tested with a swab. There is a short period after exposure to syphilis when tests may not pick up the early stages of infection, so tests may need to be repeated. Sometimes people with syphilis have other STIs. It is therefore considered best practice to test for other STIs at the same time as syphilis testing.

How often you test depends on your lifestyle and how sexually active you are. For sexually active people under 30, it is recommended to get checked at least once each year, but there are situations where getting tested more regularly is advised.

Pregnant mothers should be tested for syphilis during routine antenatal screening; in the first trimester of pregnancy and between 26–28 weeks, or if presenting for the first time in late pregnancy without previous antenatal care. Repeat testing throughout gestation is required for mothers at high risk of STIs and in all mothers presenting at any stage of pregnancy with the clinical signs of any other STI.

If you are concerned you have an STI, have had sexual contact with someone who has an STI, or require routine testing you should discuss with your local doctor, family planning clinic, or sexual health clinic and avoid having sex until you have received medical advice.

If you test positive for syphilis, anyone you have had sex with in the past 12 months should be tested and may need treatment. Sample conversations and services that help with telling partners in a confidential and anonymous way (if desired) are available online:

Advising sexual partners that they have been exposed to an STI is important for their health and the health of any other people they may have sex with.


Syphilis is usually treated with benzathine penicillin injections. You should not have sex for 7 days after treatment (not even with a condom) and until all signs and symptoms of syphilis have cleared as you could still pass the infection to your partners.

It is important to have blood tests at three, six and twelve months after syphilis treatment to check that the treatment has worked. Even after treatment, some of the blood tests will remain positive for syphilis. This does not mean that the person is still infected. It just shows that they have had syphilis in the past.

It is important that all your sexual partners get treated to prevent getting re-infected and the infection from spreading in the community


Syphilis is spread by unprotected vaginal, anal and oral sex. A person can also be infected through intimate skin to skin contact with an infected person. Syphilis can also increase the risk of HIV transmission.

If syphilis is untreated or inadequately treated during pregnancy, then it can be passed on to an unborn baby via the placenta.

In Australia, groups at increased risk of syphilis include:

  • gay, bisexual and other men who have sex with men
  • female sexual partners of bisexual and other men who have sex with men
  • Aboriginal and Torres Strait Islander people (especially those) who live in an outbreak declared area
  • transgender people
  • people who have sex in countries with high rates of syphilis
  • babies of mothers who have not had adequate antenatal care, including syphilis testing and treatment during pregnancy.


    Practise safe sex, talk to your partners about sexual health, and make sure you get enthusiastic consent. Condoms are the best way to prevent STIs and using them with a water-based lubricant will be more pleasurable and reduce the risk of the condom breaking. Avoid having sex if you or your sexual partner have visible signs of ulcers or sores on the genitals and/or mouth.

    The only way to know that you do not have an infection is to get a sexual health check. If you have sex with new or different partners and do not use condoms, you'll need to have more frequent sexual health checks.

    If you are planning a family, you and your partner should have an STI test to prevent any infections being passed onto your baby. If you're pregnant, you should have an STI screen (which includes a syphilis test) at the first antenatal visit (preferably before 12 weeks) and another syphilis test between 26–28 weeks. This can be done at the same time as the glucose tolerance test.

    Previous infection and previous treatment do not protect a person from getting syphilis again.

    Health outcome

    If the infection is not treated, the signs will go away, although some may come and go for up to a year. Regardless, the syphilis infection remains in the body and can still be passed to sexual partners.

    If late latent syphilis is not treated, over time (which may be many years), the syphilis infection can affect different parts of the body. It can cause problems with nerves, the brain and the large vessels near the heart.

    Untreated syphilis in pregnant mothers can cause miscarriage, serious birth defects in the baby and stillbirth. A syphilis infection can pass from mother to baby for a much longer period than for sexual partners.

    Help and assistance

    Get qualified health advice 24/7 for the cost of a local call. 13 HEALTH (13 43 25 84).

    This factsheet provides general information and is not intended to replace the need to see a health professional or have a sexual health check. For more information on syphilis or sexual health please talk to a healthcare provider. A doctor, nurse or health worker can assist with:

    • providing appropriate tests, treatment and information about how to prevent STIs
    • providing advice about risks and repeat STI testing recommendations during pregnancy
    • helping people to ensure that their sexual partners get tested and treated.

      Other resources

      • For short animations about common STIs, see Queensland Health's YouTube channel Your Sexual Health.
      • For comprehensive information about safe sex, STIs, testing and treatment for young adults see Stop the Rise of STIs.
      • For information and resources about syphilis during pregnancy see Lady Peeps
      • For information and resource about syphilis for men who have sex with men see Let's treat syphilis.
      • For videos and resources developed with Aboriginal and Torres Strait Islander communities see Young Deadly Free.
      • For information on syphilis in Arabic, Chinese, Filipino, Japanese, Korean, Spanish, Thai, or Vietnamese go to StaySTIFree website. Other translated resources about STIs are available from the Ethnic Communities Council of Queensland.

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