Syphilis for health professionals

Syphilis and congenital syphilis are notifiable conditions1

ALL sexual health checks should include comprehensive STI testing, including blood testing for syphilis and HIV.

Universal repeat screening for syphilis at the first antenatal appointment, 26 to 28 weeks and 36 weeks is now recommended in ALL pregnancies.

Locating, testing, and treating partners of infectious syphilis cases is critical for controlling syphilis transmission.

After completing treatment, it is critical to repeat RPR testing of cure at 3 months, 6 months and 12 months.

Syphilis is a sexually transmissible infection (STI) caused by a bacterium called Treponema pallidum.

There is an increased prevalence of syphilis in South Australia (SA) affecting multiple population groups across metropolitan and country SA.

How syphilis is transmitted

Syphilis is highly infectious during the first two years of infection, and can be transmitted through unprotected vaginal, anal and oral sex, and through skin-to-skin contact.

Syphilis can also be transmitted during pregnancy and childbirth (congenital syphilis).

Having syphilis increases the risk of both acquiring and transmitting HIV.

Signs and symptoms

Untreated syphilis has four stages: primary, secondary, latent and tertiary.

It can take up to 90 days for symptoms of syphilis to show (if at all). Symptoms of syphilis can vary depending on the stage of infection.

For further information about the symptoms of syphilis see:

Congenital syphilis

If a pregnant person has an untreated syphilis infection or reinfection during pregnancy or childbirth, it can lead to foetal death, premature delivery, or severe, permanent disability in the child.

Neurosyphilis

Is a life-threatening condition affecting a person’s central nervous system. Neurosyphilis can occur at any time after initial syphilis infection and can cause a range of severe outcomes including loss of vision or hearing, palsies and dementia.

Syphilis reinfection

Is a common issue in some groups. Reinfections are more likely to be asymptomatic and therefore harder to detect. Repeat testing for cure after treatment is critical.

Who should be tested for syphilis?

Pregnant people

  • In all pregnancies test pregnant people at:
    • the first antenatal appointment (ideally <10 weeks)
    • 26-28 weeks
    • 36 weeks.
  • In addition to the above, testing at birth and at the six week postnatal check is recommended for pregnant people at increased risk for syphilis in pregnancy. Refer to the South Australian Perinatal Practice Guidelines for further information about Populations at Increased Risk.

Please note that the South Australian Perinatal Practice Guidelines and the South Australian Pregnancy Record were updated in January 2025 to reflect these changes to universal screening for syphilis in pregnancy.

Symptomatic patients

  • People with any signs and symptoms of infectious syphilis
  • People with any signs and symptoms of neurosyphilis
  • People with signs or symptoms of any other STI.

Asymptomatic patients

Treatment and management

All medical practitioners:

  • If assistance with interpretation of syphilis serology results is required, contact SA Pathology on (08) 8222 3000, or Adelaide Sexual Health Centre on (08) 7117 2800.
  • For treatment of pregnant people with syphilis refer to the SA Perinatal Practice Guideline for Syphilis in Pregnancy and Infants.
  • Ongoing sexual contacts of pregnant people are the highest priority and must be presumptively treated as soon as possible to prevent re-infection during pregnancy.
  • Treat infectious syphilis (duration <2 years) with intramuscular (IM) benzathine benzylpenicillin (Bicillin® L-A) 2.4 million units (MU), administered as two injections, one in each buttock, stat.
  • Treat patients likely to have had untreated syphilis for longer than 2 years, or of unknown duration, with IM Bicillin® L-A 2.4 MU administered as two injections, one in each buttock, weekly for 3 weeks.

  • Collect serology for syphilis on the day of treatment and other STI tests as indicated.

  • Presumptively treat all sexual contacts from the last 3 months of patients with primary or secondary syphilis, regardless of serology, with IM Bicillin® L-A 2.4 MU administered as two injections, one in each buttock, stat.
  • Test and treat for syphilis on the same day of presentation for all people with genital ulcers – do not wait for a positive result.
  • If there is a history of allergy to penicillin, soy or peanut, consult with an Infectious Diseases or Sexual Health Physician.
  • Initiate and document a discussion about partner notification (contact tracing). Partner notification is essential to prevent re-infection and reduce transmission. The diagnosing doctor is responsible for this. Refer to the Australasian Contact Tracing Guidelines: Syphilis for further information.
  • Notify cases of syphilis to the Communicable Disease Control Branch by:
    • Downloading and faxing the maroon notification form to fax: (08) 7425 6696, or
    • Notifying by phone on 1300 232 272 if public health advice is required.

The SA Syphilis Register

The SA Syphilis Register is a secure, confidential, single statewide database that includes all laboratory positive syphilis cases diagnosed in Aboriginal and Torres Strait Islander South Australians that meet the syphilis national case definition.

Register staff may undertake or assist with partner notification (also known as contact tracing) for all contacts of Aboriginal and Torres Strait Islander cases, regardless of Aboriginality. Register staff contact partners (or coordinate the contacting of partners) with the aim of coordinating syphilis screening and treatment, where appropriate.

Congenital Syphilis Case Reviews

Five cases of congenital syphilis have been notified in SA since 2017, occurring in the context of an ever-increasing trend for cases of both syphilis and congenital syphilis in SA and nationally. Prior to 2017, congenital syphilis had not been reported in SA since the 1990s.

Each occurrence of a congenital syphilis case is a sentinel event reflecting potential missed opportunities for prevention in the public health, antenatal and primary health care systems.

Communicable Diseases Network Australia’s (CDNA) national guidelines for syphilis recommend the consistent and systematic investigation of all congenital syphilis cases.

In SA, the process of undertaking a public health review of each congenital syphilis case was established in 2020. With the overarching aim of minimising the risk of future cases of congenital syphilis, the specific purposes of a congenital syphilis case review are to:

  • Review the clinical and public health management of a congenital syphilis case
  • Identify areas for health service and health system improvement
  • Identify opportunities to update relevant clinical, antenatal, and public health guidelines
  • Identify opportunities to raise awareness and educate health care staff about syphilis and congenital syphilis
  • Identify issues or solutions for inclusion in relevant statewide strategies.

Case Review Reports:

More information

Clinical information about infectious syphilis

General information about infectious syphilis

Other health promotion and educational resources

1 In South Australia the law requires doctors and laboratories to report some infections or diseases to SA Health. These infections or diseases are commonly referred to as 'notifiable conditions'