Syphilis is a curable sexually transmissible infection (STI) caused by the Treponema pallidum bacteria. Syphilis of less than two years duration can present with signs and symptoms (this is called primary or secondary syphilis) or without signs and symptoms (this is called early latent syphilis). Syphilis of more than two years duration is called late latent syphilis and is usually asymptomatic.

All of these stages are infectious and syphilis can be passed on to sexual partners for up to two years if the person is not treated. Not everyone who has syphilis has signs of infection, so a person can have it and pass it on without knowing.

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 is still infectious.

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. When these symptoms go the person is still infectious.

Early latent syphilis

This means that the person does not have any signs or symptoms but is infectious. The only way they would know they had 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.

What happens if syphilis is not treated?

If the infection is not treated, the signs and symptoms will go away, although some of them may come and go for up to a year. However, the syphilis infection still remains in the body and people can pass syphilis onto their sexual partners during this time for up to two years.

If a pregnant woman has untreated syphilis, the infection can pass, via the placenta, to her unborn baby. This can seriously affect the baby. Infection can pass from mother to baby for a much longer period than for sexual partners. It is believed to be a risk for any pregnancy for up to eight years after initial infection if that infection was not treated.

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.


A simple blood test is usually used to diagnose syphilis. If a person has an ulcer or sore this can also be tested for syphilis with a swab for a PCR test. There is a short period after exposure to syphilis when the tests may not pick up the early stages of infection and repeat tests may be necessary. If a person has contracted syphilis they will test positive by blood tests three months after infection, and usually much earlier.

Sometimes people with syphilis have other sexually transmissible infections. It is considered best practice to test for other STIs at the same time as syphilis testing.

Syphilis is usually managed with benzathine penicillin injections which treat the infection in seven days. For cases of confirmed infectious syphilis of less than two years duration, one dose of benzathine penicillin by intra-muscular injection is required. For probable cases of infectious syphilis or syphilis of more than two years or unknown duration, a course of three doses benzathine penicillin by intra-muscular injection, 7 days apart, is required

A person with syphilis should abstain from sexual activity for seven days after completing their course of treatment and all signs and symptoms of syphilis have cleared. Your sexual partners should also be treated for syphilis and abstain from sexual activity for seven days after completing treatment.

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 sexual partners get treated to stop re-infection and to prevent the infection spreading in the community. A person with syphilis can help by advising sexual partners to get tested and treated for syphilis. This can be done by talking with partners or asking the doctor, nurse or health worker to inform partners. This is a confidential process and names will not be mentioned. Some people use an on-line notification website such as:


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 during sex. Syphilis can also increase the risk of HIV transmission.

A pregnant woman with untreated or inadequately treated syphilis can pass syphilis on to her unborn baby via the placenta during pregnancy.

Who is at risk?

There is an ongoing outbreak of infectious syphilis occurring predominantly among young Aboriginal and Torres Strait Islander people aged 15—29 years in Northern Australia, including in north Queensland. The outbreak currently affects Queensland, Northern Territory, Western Australia and South Australia.

There continues to be increasing notifications of infectious syphilis in south-east Queensland occurring among men who have sex with men. There is also increasing infectious syphilis notifications across the state among bisexual men, young heterosexual, non-Indigenous men and women, and transgender people.

In Australia, groups at increased risk of syphilis include:

  • Gay men
  • Men who have sex with men
  • Female sexual partners of 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.

In Australia, the risk of getting syphilis from a woman involved in sex work is very low.


The safest ways to protect against syphilis are to:

  • Always use condoms and water based lubricant. Condoms are the best way of protecting against syphilis and other STIs.
  • Avoid having sex with someone who has a visible ulcer or sore on their genitals and/or mouth.
  • Have a relationship where neither partner has other sexual partners.
  • Have fewer sexual partners.
  • Have regular STI check-ups, especially if partners change. You can organise to have a reminder for an STI check-up sent to you via SMS or email at:
  • If diagnosed with an STI, complete the recommended course of treatment.

All women should have a syphilis test in the first 12 weeks of pregnancy or at the first antenatal visit. The earlier syphilis is treated during the pregnancy, the lower the risk of the baby being affected by syphilis.

There is no vaccine for syphilis. Previous infection and previous treatment do not protect a person from getting syphilis again.

Other resources: 

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Help and assistance: 

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

A doctor, nurse, health worker or sexual health clinic is responsible for:

  • Providing appropriate tests, treatment and information about how to prevent STIs.
  • Helping people to ensure that their sexual partners get tested and treated.