Syphilis

What is syphilis?

Syphilis is a highly contagious sexually transmitted infection (STI) caused by a type of bacteria called Treponema pallidum.

It can be treated and cured with antibiotics. However, if left untreated, syphilis can lead to serious health issues.

Syphilis can affect anyone.

What are the symptoms?

There are three stages of syphilis infection:

• early infectious syphilis – including primary, secondary and early latent infection
• late latent syphilis
• tertiary syphilis.

Symptoms vary depending on the stage.

Often, people will have no symptoms and syphilis will only be picked up with a sexual health check-up blood test.

If they do happen, symptoms may include:

• a sore (ulcer), or multiple sores, which can appear on areas of sexual contact (such as the mouth, bottom, vulva, vagina or cervix). The sore/s may be painless and may go unnoticed.
• swollen lymph nodes
• fever
• headache
• rash on the body, sometimes involving the palms of the hands and soles of the feet
• hair loss
• lumps in/around the bottom and genital area
• neurological symptoms such as visual changes, deafness or ringing in the ears, altered behaviour, paralysis or numbness.

If syphilis has been left untreated for many years the bacteria can damage almost any part of the body including the heart, brain, spinal cord, eyes and bones, which can cause serious health issues including mental illness, heart disease, neurological problems and even death.

Syphilis during pregnancy can cause:

• severe birth defects and sometimes death of the baby
• miscarriage (losing the baby during pregnancy)
• stillbirth (a baby born dead)
• premature labour (a baby born early)
• low birth weight.

How is syphilis spread?

Syphilis can be passed on:

• through unprotected vaginal, anal, or oral sex with someone who has the infection.
• through close skin-to-skin contact, especially when a sore or rash is present.
• from pregnant person to baby during pregnancy or childbirth (called ‘congenital syphilis’).

Syphilis is highly infectious for a long time, especially when a sore or rash is present but even after the early symptoms have gone. Some people may not have any symptoms but can still pass on the infection.

Syphilis can be passed on to a baby during pregnancy, which can lead to severe birth defects and even death of the baby.

How is syphilis tested?

A regular sexual health check-up can detect syphilis. Just ask your doctor or nurse for a syphilis test.

Syphilis can be detected using a blood test.

The blood test measures your body’s response to syphilis infection and looks for current and past infection. Your doctor can interpret the blood results and explain them to you.

Syphilis can also be detected with a swab test if there are sores or a rash present.

When should I have a syphilis test?

All sexually active people are at risk of infection.

You should have a syphilis test if:

• you have had unprotected sex
• you have recently changed sexual partner/s
• you have more than one current sexual partner
• you have signs or symptoms of genital infection, an unusual sore or an unexplained rash
• you have been diagnosed as having another STI, for example chlamydia, herpes or warts
• you have a sexual partner who has been diagnosed as having syphilis or another STI
• you are pregnant.

Syphilis in pregnancy

Syphilis should be tested for at the beginning of pregnancy and at regular intervals (at least three times total) throughout pregnancy to prevent infection of unborn babies.

 

Pregnant people who are at higher risk of syphilis also need another syphilis test at the time of birth, and again at 6 weeks after birth.

 

There are particular criteria in local guidelines to help health professionals assess who is at higher risk.

 

You can be treated safely for syphilis while pregnant.

How is syphilis treated?

Syphilis is treated with antibiotics given as an injection.
Often only one injection is needed, although this depends on the stage of infection.

The sooner you seek treatment for syphilis, the better. Early treatment helps to prevent further complications and to avoid passing the infection on to sexual partners or to an unborn baby during pregnancy.

It’s important to avoid sex (even with a condom) for one week after treatment so that you don’t pass on the infection or become reinfected yourself.

You will need to have a few follow up blood tests to make sure the treatment has worked and the infection has gone.

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.

Your recent sexual partner/s will need to be notified so they can also be tested and treated. Your health professional can help you with notifying sexual partner/s and there are websites where partner notification can be done anonymously.

Syphilis is a notifiable STI. This means that the doctor has a legal requirement to notify SA Health of the syphilis infection. This information will be confidential.

Prevention of syphilis

• Use condoms/dams and water-based lubricant for all types of sex.
• Get tested regularly.
• Avoid sex with sexual partners who have symptoms of an STI.
• Make sure semen, blood, vaginal or anal fluid are not passed between partners.
• Let your sexual partner/s know that you have had syphilis so they can be tested and treated. Your doctor or sexual health centre can help you to do this.
• Seek early medical advice for oral, genital or anal sores, or rashes that are related to recent sexual contact.

Where can I get more information?

• You can visit SHINE SA for further information, testing and treatment.
• Make an appointment with your local doctor, health care provider or Aboriginal Health Service.
• You can also contact Adelaide Sexual Health Centre:
  260 Currie Street, Adelaide
  Tel: 71117 2800
  www.sahealth.sa.gov.au/adelaidesexualhealthcentre

Updated March 2025