• Syphilis is a sexually transmissible infection (STI). Anyone who is sexually active is at risk of infection.
  • Syphilis is curable but, if left untreated, can lead to serious complications.
  • A simple blood test can detect syphilis.
  • It is important to let your sexual partner or partners know that you have syphilis so that they can be tested and treated. Your local doctor or sexual health centre can help you to do this.
  • Always have safe sex – use a condom, and water-based lubricant for all types of sex. Syphilis may also be spread through unprotected oral sex. 
  • Women can pass syphilis infection to their babies during pregnancy. Syphilis can cause miscarriage, serious birth defects in the baby and stillbirth (where a baby is born dead).

Syphilis is a sexually transmissible infection (STI) caused by a bacterium called Treponema pallidum. It can affect both men and women. Syphilis is transmitted through close skin-to-skin contact and is highly contagious when the syphilis sore (chancre) or rash is present.

The incubation period for syphilis ranges from 10 days to 3 months. You can pick up syphilis through unprotected oral, vaginal or anal sex with a person who is infected. 

It can also spread through skin-to-skin contact if the syphilis rash or sore is present. 

Syphilis can also be transmitted from mother to baby during pregnancy and at birth. This is called congenital syphilis.  Early treatment of syphilis is effective, but people may not have any symptoms or may not notice the symptoms of early syphilis and therefore may not seek medical advice.

Many years after it is acquired, untreated syphilis may lead to chronic brain or heart disease and can be fatal. 

Since 2002, the number of people with infectious syphilis in Victoria has increased rapidly, mainly among gay men and other men who have sex with men (MSM). An increase of syphilis in women (particularly in women of reproductive age) has also led to the re-emergence of congenital syphilis in Victoria since 2017.

Who is at risk of syphilis?

Regular sexual health check-ups (at least annually) are recommended for all sexually active people.  Some who are at increased risk of syphilis infection include: 

  • Men who have sex with men.
  • Female partners of men who have sex with men.
  • Pregnant women (as part of routine antenatal screening) and women of reproductive age (15-49 years).
  • Sexual partners of pregnant women.
  • Heterosexual men and women – particularly if they have multiple sexual partners, are travellers returning from countries where syphilis is more prevalent, or inject drugs.
  • Aboriginal and Torres Strait Islander people.
  • Sex workers.
  • Anyone diagnosed with an STI (such as HIV, gonorrhoea, chlamydia).

How often should I get checked for syphilis?

If you are sexually active, get a full sexual health check (including tests for syphilis, HIV, gonorrhoea and chlamydia) at least once a year. 

The frequency of sexual health checks depends on your STI risk. For example:

  • Men who have sex with men, and have more than 1 partner – are checked every 3 to 6 months.
  • A man who has sex with another man (has 1 partner) – is checked once a year. 
  • Pregnancy – syphilis testing is always done as part of routine antenatal screening. Women who at increased risk of syphilis should be tested multiple times during pregnancy and after their baby is born.

What are the symptoms of syphilis?

There are three stages of syphilis. Only the first 2 stages are infectious, and symptoms vary depending on the stage. 

You are more at risk of HIV infection during sexual contact if you have syphilis symptoms. 

First (or primary) stage syphilis symptoms

The first stage of syphilis usually occurs over 4 to 12 weeks. Some people may not notice they have syphilis because they have no symptoms. 

First stage syphilis is highly contagious, and symptoms usually begin as a sore (ulcer) on the genital area (including the penis or vagina), anus or mouth. 

The sore: 

  • May be difficult to notice as it is on hidden areas of the body or painless.
  • Can appear in areas where there has been sexual contact – such as the mouth, rectum, vagina or cervix.
  • Is likely to occur as a single sore but occasionally occurs as multiple sores.
  • Is usually painless.
  • Usually appears 3 to 4 weeks after infection (it can occur any time between 1 and 12 weeks). 
  • Usually heals completely within 4 weeks without any treatment.

If you are not treated for syphilis at this stage, you may go on to develop the second stage of the infection. 

Second (or secondary) stage syphilis symptoms 

The second stage begins around 2 to 4 months after contracting syphilis and (may last up to 2 years).  

This is a highly contagious stage and you may experience the following symptoms: 

  • A flat, red skin rash – on the soles of your feet, palms of your hands, or it may cover your entire body. 
  • Swollen lymph nodes.
  • Hair loss (especially of the eyebrows).
  • Joint pain. 
  • Flu-like illness. 
  • The rash may mimic other common skin conditions (such as measles). 

Diagnosis may be missed if a syphilis blood test is not done.

If you are infected with syphilis and do not seek treatment at this stage, you may develop the third stage of the infection.

Third (or tertiary) stage of syphilis

The third stage of syphilis may occur 10 to 30 years after the initial infection. This stage affects around one third of untreated people. 

It can affect various organs, mainly the brain and heart. Severe complications may occur. 

Syphilis is not infectious at this stage, but is still treatable.

What is congenital syphilis?

Congenital syphilis occurs when a mother with syphilis passes the infection on to her baby during pregnancy or at birth.

Congenital syphilis can have serious health impacts on your baby. This depends on how long you had syphilis and if, or when, you were treated for the infection.

Left untreated, syphilis during pregnancy can cause:

Congenital syphilis symptoms in babies

While some babies may have no congenital syphilis symptoms at birth, others may be born with:

  • bone deformities 
  • severe anaemia (low red blood cell count)
  • issues with their vital organs (liver and kidneys)
  • jaundice (yellowing of the skin or eyes)
  • brain and nerve problems (like vision or hearing loss) 
  • skin rashes. 

Early congenital syphilis symptoms (up to 2 years of age) may include:

  • a runny nose
  • skin eruptions
  • bone abnormalities
  • eye, liver or kidney problems. 

Late congenital syphilis symptoms (which presents after 2 years) may include: 

  • a variety of skeletal problems
  • dental defects
  • eye problems
  • hearing loss. 

How does syphilis spread?

Syphilis is spread (transmitted) through close skin-to-skin contact. 

You can catch syphilis by having unprotected oral, vaginal or anal sex with a person who is in the first 2 stages of the infection. 

Syphilis is highly contagious when the sore or rash is present. 

Pregnant women who have syphilis can pass on the infection to their baby during pregnancy or at birth. 

Syphilis can also be passed through infected blood. However, blood used in blood donations is routinely screened for syphilis in Australia.

How is syphilis diagnosed? 

A regular sexual health check-up with your local GP (doctor) or sexual health centre can detect syphilis. Just ask your doctor or nurse for a test. 

Syphilis is easy to detect using: 

  • a simple blood test
  • a swab test – if there are sores present. 

Getting your syphilis test results

Test results are normally available within a week.

How is syphilis treated?

Penicillin is a very effective treatment for all stages of syphilis (including congenital syphilis). 

Other treatments are available if you are allergic to penicillin, or you may be able to undergo a desensitisation procedure that safely allows you to be given penicillin. 

Early treatment helps to prevent further complications and to avoid passing the infection on to sexual partners or to an unborn baby during pregnancy. 

Avoid sexual contact until your treatment is completed. 

Although the treatment is straightforward, it is important to have repeat blood tests to check that the treatment has worked. Follow-up blood tests may be recommended at 3, 6 and 12 months after treatment.

Can you get reinfected with syphilis?

Having syphilis once does not protect you from getting it again. Even after you’ve been successfully treated, you can still be reinfected by having sex with a partner who has syphilis.

Letting partners know you have syphilis 

It is important to let your sexual partner or partners know that you have syphilis. Most people will appreciate being told they may have an infection and it is an important step in preventing further infection in the community. If your partner is treated it will also prevent you from getting the infection again.

Your local GP and sexual health centre can help you inform your partners and let them know that they need a test. This process is called ‘partner notification’. It can be done anonymously, and your confidentiality is always respected. 
Letting your partners know will also prevent you from getting the infection again.

You can also anonymously notify your sexual partners of the need to get tested and treated for syphilis via the Let Them Know website if you feel unable to speak to them personally. 

There are also nurses (called partner notification officers) who can help you anonymously notify your partners. They can be contacted on (03) 9096 3367.

Reducing syphilis transmission

Ways to reduce your risk of catching syphilis include: 

  • Practise safe sex – use condoms and water-based lubricant (lube) for all types of sex. Female, (or internal) condoms can also be used for vaginal or anal sex. 
  • If you are sexually active, get a full sexual health check (including tests for syphilis, HIV, gonorrhoea and chlamydia) at least once a year.
  • If you are at greater risk of STIs, get tested regularly.  Men who have sex with men get a syphilis test and tests for other STIs at least yearly, and up to 4 times a year if you have several partners.
  • Seek early medical advice for oral, genital or anal sores, or rashes on your body that are related to recent sexual contact.
  • If you are pregnant or planning a family, you and your partner should have an STI test to prevent any infections being passed onto your baby.
  • Remember, syphilis may be spread through unprotected oral sex. 

Where to get help

More information

Sexually transmissible infections

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This page has been produced in consultation with and approved by: Melbourne Sexual Health Centre

Last updated: November 2020

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