At a glance

• No vaccine available – read more about prevention
• Nationally notifiable disease

About syphilis

Syphilis is an STI caused by bacteria called Treponema pallidum.

It’s easy to treat if found early. But it can cause serious health problems if you don’t get treatment.

If untreated, syphilis can progress through different stages:

• primary syphilis
• secondary syphilis
• latent syphilis
• tertiary syphilis.

If you have syphilis while pregnant, it can spread to the baby. This is called congenital syphilis, and can cause severe health problems for the baby or even death.

Symptoms depend on the stage of your infection. But not everyone gets symptoms, and sometimes syphilis can mimic other conditions. 

Syphilis screening tests are very effective at detecting infections. It is important to get tested regularly if you are at risk of exposure. 

If you’ve previously had syphilis and recovered, you’re not immune – you can get it again. 

You can take steps to protect yourself from syphilis infection.

Why it matters to public health

Syphilis can cause serious health problems if untreated, and congenital syphilis has severe consequences for babies. Adults and babies in Australia are still dying from untreated syphilis and congenital syphilis. 

Some groups are at much higher risk, especially those who may have limited access to health care, such as Aboriginal and Torres Strait Islander people living in remote and very remote areas. 

Syphilis is preventable and easily treated in the early stages. Yet, over the past 20 years, the number of cases in Australia has significantly increased. 

Congenital syphilis is also on the rise.

The factors that contribute to the rise in syphilis cases include:

• limited access to healthcare services, including early testing and treatment
• limited access to culturally appropriate care
• stigma
• lack of awareness.

Because of this, we:

• monitor and report on cases of syphilis and congenital syphilis infection in Australia
• are implementing the National Syphilis Response Plan 2023 to 2030
• develop and implement national STI strategies.

Symptoms

If you’re looking for advice about your own health or treatment options, see healthdirect or speak with a qualified healthcare professional. Our role is to provide public health advice – information and guidance that helps prevent disease, protect communities and improve wellbeing at a population level. 

Some people with syphilis have no symptoms, so you may not know you have it unless you get tested.

healthdirect’s symptom checker can help you decide whether to see a health professional.

Check your symptoms

Primary syphilis

Common signs and symptoms of primary syphilis include:

• firm, painless sores in or on the mouth, anus, penis, vagina or cervix
• swollen and usually painless lymph nodes in the groin area.

The sores usually go away without treatment after 2 to 6 weeks, so you might not notice those signs and symptoms. But you can still infect others, even after the sores have disappeared.

Signs and symptoms usually show between 10 and 90 days after infection.

Secondary syphilis

Common signs and symptoms of secondary syphilis include:

• a rash, usually in the
  • palms of the hands
  • soles of the feet
  • chest area
  • back area
• white or grey lesions (snail trail) in the mouth or genital area
• fever
• fatigue
• headache
• enlarged glands in the armpits and groin
• hair loss.

Signs and symptoms can show between 4 and 10 weeks after infection.

Latent syphilis

Latent syphilis is when someone is untreated for syphilis but has no symptoms. Only a blood test can identify infection.

If you have previously recovered from syphilis, and get it again, you are more likely to have latent syphilis.

Latent syphilis can progress to tertiary syphilis.

Tertiary syphilis

Signs and symptoms of tertiary syphilis depend on which body system is affected, and might include:

• heart disease
• neurological problems, including
  • headaches
  • difficulty coordinating muscle movements
  • paralysis
  • numbness
  • dementia
• visual impairment and blindness
• soft, tumour-like growths (called gummas) that can appear on the skin, bones or internal organs.

Signs and symptoms usually start years after an untreated infection. 

If not treated, tertiary syphilis can result in death. 

Congenital syphilis

Congenital syphilis is serious and can result in miscarriage or stillbirth.

Once a baby is born, common signs and symptoms include:

• prematurity
• low birthweight
• enlarged liver
• enlarged spleen
• jaundice
• dental abnormalities
• skeletal abnormalities
• central nervous system disease, such as hydrocephalus and cranial nerve palsies
• neurological problems
• hearing loss.

Signs and symptoms usually appear in the first 2 to 8 weeks of life, but can also appear later in childhood.

Read more about symptoms, diagnosis and treatment of syphilis.

Onset of symptoms

The first symptoms of syphilis usually show between 10 and 90 days after infection.

How it spreads

Syphilis most often spreads through unprotected skin-to-skin contact during vaginal, anal or oral sex. 

Congenital syphilis gets passed on to the baby during pregnancy through the placenta or during delivery.

Syphilis can less commonly spread by:

• non-penetrative sex
• blood contamination
• needle-stick injury
• sharing injecting equipment.

Infectious period

Syphilis is most contagious during the primary, secondary and early latent stages (within 2 years of infection). 

Generally, people are not considered infectious during tertiary and late latent stages (after 2 years of infection).

Transmission to a baby during pregnancy can occur at any stage of syphilis infection.

Prevention

Protecting yourself

There is no vaccine for syphilis.

The best way to protect yourself against syphilis is to:

• get regular sexual health checks
• avoid sexual activity with anyone with syphilis symptoms until they have sought medical advice and testing
• practise safe sex
• get tested if you are pregnant – your healthcare professional will tell you when to get this done
• know the symptoms and what to do if you develop them
• speak to your healthcare professional to discuss other prevention and treatment options for syphilis.

Congenital syphilis is preventable. The best way to protect your baby is to get tested at least 3 times if you are pregnant. Your healthcare professional will tell you when to get this done.

Protecting others

If you’ve been diagnosed with syphilis, you should:

• not have any sexual contact for 7 days after you complete your treatment or until symptoms have resolved (whichever is longer)
• get regular sexual health check-ups, even after you have been treated because you can still get it again
• tell anyone you have had sex with during the past 12 months, so that they can get tested and treated – you can do this anonymously through:
  • Let them know
  • The drama down under
  • Better to know
• not have sex with current or previous partners until they all:
  • have been tested
  • have been treated, if necessary
  • are no longer infectious. 

Priority groups and settings

Some people are at greater risk of getting syphilis or of getting very sick from it.

Syphilis can also spread within sexual networks and in settings with frequent sexual activity between different partners, such as:

• venues that offer sex on premises
• parties or other social events where intimate contact occurs.

If you are at greater risk, it is especially important to take steps to protect yourself and see a healthcare professional if you are exposed to syphilis or develop symptoms.

If you are pregnant, it is important to get tested and follow your health professional’s advice. This is because untreated syphilis during pregnancy can put your baby at risk of getting congenital syphilis. 

People at greater risk of severe disease

Those at greater risk of severe illness include:

• people with syphilis who do not receive appropriate antibiotic treatment, particularly in the early stages
• people who have both syphilis and HIV
• babies born to someone with untreated syphilis during their pregnancy.

People at greater risk of exposure

Those at greater risk of infection include:

• people who have unprotected vaginal, anal or oral sex with someone infected with syphilis
• babies born to a person who has not been tested for syphilis, or has untreated syphilis during their pregnancy.

Diagnosis and treatment

Your healthcare professional can diagnose syphilis by:

• assessing your symptoms and medical history
• referring you for a blood test
• taking a swab from your sore (if you have any) and sending it for testing. 

Your healthcare professional may consider other diagnosis methods if you have complications.

You can use healthdirect’s directory to find a health service near you.

Find a health service

Your healthcare professional will:

• prescribe and administer antibiotics called penicillin to treat syphilis, if appropriate
• ask you to come back for another test to make sure the treatment is working.

Depending on the stage of infection, treatment can take up to 3 weeks.

If you are pregnant, it is important to seek early advice from your healthcare professional, and get tested and treated (if necessary) to protect you and your baby.

You should tell anyone you have had sex with during the past 12 months, so that they can get tested and treated. You can do this anonymously.

If you’ve previously been treated for syphilis, you’re not immune – you can get it again.

Read more about how to manage or treat syphilis.

Surveillance and reporting

Syphilis is a nationally notifiable disease – these are diseases that present a risk to public health.

Health authorities in each state and territory report new confirmed and probable cases to us daily through the National Notifiable Diseases Surveillance System.

This is part of our surveillance activities, which help us monitor case numbers around the country and understand disease patterns.

We analyse the data and report on case numbers and other data through our:

• quarterly national syphilis monitoring reports
• data visualisation tool, where you can filter and search the latest information.

Outbreaks

The states and territories are responsible for responding to syphilis outbreaks in their jurisdictions.

Public health units might respond to a syphilis outbreak by:

• providing information about syphilis and its symptoms
• providing access to testing and treatment services
• engaging early with local communities.

Read more about how the Australian Government defines and plans for outbreaks and pandemics.

Support

For information about syphilis in your state or territory see:

• Australian Capital Territory
• New South Wales
• Northern Territory
• Queensland
• South Australia
• Tasmania
• Victoria
• Western Australia.

If you need mental health support, see a list of organisations, websites and services that offer support, counselling and information.

Quick links

• National Guidelines for Public Health Units
• Surveillance case definition for
  • congenital syphilis
  • less than 2 years duration
  • more than 2 years or unknown duration
• Laboratory case definition
• National response plan

Disease

Infectious agent

Syphilis is caused by the bacterium Treponema pallidum, subspecies pallidum.

Clinical presentation

Many people infected with syphilis have no symptoms.

The clinical features of syphilis vary and can present similarly to many other conditions. The disease can progress through different stages if left untreated.

At any stage of pregnancy (or during delivery), syphilis can spread to the unborn baby and cause congenital syphilis.

Primary syphilis

Symptoms usually start 10 to 90 days after infection. They are localised and typically include:

• one or more firm ulcers, known as chancres, at the site of infection – these may not be apparent, and people may not notice any lesions; the chancres are usually painless and heal on their own within a few weeks (even if untreated)
• enlarged lymph nodes (usually painless) in the groin area.[1] 

Secondary syphilis

Symptoms can start 4 to 10 weeks after primary syphilis. They can be widespread throughout the body and typically include:

• diffuse rash, which often involves the
  • palms of the hands
  • soles of the feet
  • chest
  • back
• white or grey lesions (condylomata lata) in the mouth or anogenital area
• fever
• lymphadenopathy
• alopecia.

Latent syphilis

Latent syphilis is asymptomatic and can be divided into 2 categories:

• early latent syphilis – where infection was acquired less than 2 years ago
• late latent syphilis – where infection was acquired more than 2 years ago.[2] 

People who have previously recovered from syphilis are more likely to have latent syphilis if reinfected.[3] [4]

Latent syphilis can also progress to tertiary syphilis. [5] [6]

Tertiary syphilis

Tertiary syphilis usually starts years to decades after untreated infection. Clinical features vary depending on which body system is affected, and can include:

• cardiovascular syphilis (aortic aneurysms and aortitis)
• neurosyphilis (headaches, difficulty coordinating muscle movements, paralysis, numbness and dementia)
• gummatous lesions (soft, tumour-like growths, called gummas, that can appear on the skin, bones or internal organs).[1]

Untreated tertiary syphilis can also result in death.

Congenital syphilis

Congenital syphilis is serious and can result in miscarriage or stillbirth.

In live-born infants, clinical features usually start in the first 2 to 8 weeks of life, but can also appear later in childhood.[7] They include:

• prematurity
• low birthweight
• enlarged liver (hepatomegaly)
• enlarged spleen (splenomegaly)
• jaundice
• dental abnormalities
• skeletal abnormalities
• hearing loss
• central nervous system disease (neurosyphilis), such as hydrocephalus and cranial nerve palsies. [8] [9] [10]

Read more about symptoms, diagnosis and treatment of syphilis.

Public health importance

Syphilis is a significant public health issue that can cause serious illness and even death. Although it is easily cured when diagnosed and treated early, cases have continued to rise steadily in Australia.

Early detection is critical. Diagnostic tests are highly effective, and timely antibiotic treatment cures the infection and prevents further transmission.

If left untreated, syphilis can lead to serious health complications. During pregnancy, untreated syphilis can cause congenital syphilis, which can result in severe health issues or death in babies.

Each case of congenital syphilis reflects missed opportunities for early testing and treatment, and points to broader systemic barriers in healthcare access.

The factors that contribute to the ongoing increase in syphilis cases include: 

• limited access to healthcare, including timely testing and treatment
• limited access to culturally appropriate sexual health services
• social stigma
• lack of awareness of syphilis risk among healthcare professionals and the public.[11] [12] [13] [14]

Effectively addressing syphilis involves implementing:

• public health actions at a population level, including supporting prevention, testing, treatment and safe sex
• targeted and culturally appropriate efforts towards priority population groups
• equitable access to antenatal care programs for pregnant people, including syphilis screening
• measures to address social determinants of health contributing to the continued spread of syphilis.

Because of this, we:

• monitor and report on cases of syphilis and congenital syphilis in Australia
• are implementing the National Syphilis Response Plan 2023 to 2030
• develop and implement national STI strategies.

Epidemiology

Syphilis cases have significantly increased across Australia over the past decade.

The number of infectious syphilis cases in Australia has increased:

• almost 3-fold over the past 10 years
• almost 10-fold over the past 20 years.

Syphilis is no longer limited to specific groups or regions, with increases seen across urban, regional and remote areas of Australia.

Aboriginal and Torres Strait Islander people continue to be disproportionately affected, with rates 7 times higher than for non-Indigenous people in 2024.

Rates among people who can become pregnant have also increased, coinciding with historical high notifications of congenital syphilis in recent years.

Between 2016 and 2024:

• 99 cases of congenital syphilis were reported
• 33 congenital syphilis-related deaths were reported
• congenital syphilis rates per 100,000 live births among Aboriginal and Torres Strait Islander infants were, on average, more than 16 times higher than among non‑Indigenous infants.

For the latest information on syphilis incidence, severity, transmission and virology in Australia see:

• our national syphilis monitoring reports
• the National Notifiable Diseases Surveillance System (NNDSS) data visualisation tool
• the Kirby Institute’s annual surveillance reports.

Spread of infection

Transmission

Person-to-person transmission most commonly occurs by direct contact with skin lesions or mucous membranes during vaginal, anal or oral sex.

Less commonly, syphilis can be spread by:

• non-sexual direct contact with infected lesions
• infected blood (such as via injection drug use)
• accidental direct inoculation (such as needle stick injury).

Vertical transmission to babies can occur at any time during pregnancy (congenital syphilis).

Incubation period

The clinical features of primary syphilis are usually apparent from 10 to 90 days after exposure (most commonly around 21 days).

Infectious period

People are most infectious during primary, secondary and early latent syphilis.

Generally, people are not considered infectious during late latent and tertiary syphilis.

Vertical transmission can occur at any stage of syphilis infection.

Priority populations

People at greater risk of severe disease

In Australia, efforts to address syphilis are focused on:

• people who can become pregnant
• babies of pregnant people who have syphilis
• Aboriginal and Torres Strait Islander people who live in outbreak regions.

Syphilis poses a greater risk of severe illness for:

• people who do not receive appropriate antibiotic treatment, particularly in the early stages of their infection
• people with concurrent HIV infection
• babies born to people with untreated syphilis during their pregnancy.

Read more about measures people can take to protect themselves.

People at greater risk of exposure

People are more likely to be exposed to syphilis in areas with ongoing community transmission.

Those at greater risk of infection include:

• people who have unprotected vaginal, anal or oral sex with someone infected with syphilis
• babies of people who had untreated syphilis during their pregnancy.

In Australia, there is continued high prevalence of syphilis in:

• remote Aboriginal and Torres Strait Islander communities
• non-Indigenous gay or bisexual males and other men who have sex with men in major cities.

See what measures people can take to protect themselves.

Settings at increased risk of spread

Sexually transmitted infections, including syphilis, can spread within sexual networks and in settings with frequent sexual activity between different partners, such as:

• venues that offer sex on premises
• parties or other social events where intimate contact occurs.

The risk is higher in areas where syphilis is circulating in the community.

Taking steps to prevent syphilis is particularly important in these settings.

Prevention

There is no vaccine against syphilis.

Healthcare professionals can help prevent syphilis infection by:

• encouraging regular sexual health checks
• providing education to support people to practise safe sex
• educating people on the symptoms of syphilis and what to do if they develop them
• advising people to avoid sexual activity with anyone with syphilis symptoms until they have sought medical advice and testing
• advising people who test positive to tell their sexual partners to also get tested and treated for syphilis to avoid reinfection
• ensuring syphilis screening during pregnancy, within recommended timeframes outlined in the Australian Pregnancy Care Guidelines
• considering the use of doxycycline post-exposure prophylaxis (Doxy-PEP), in line with the Doxy-PEP Decision Making Tool.

Prevention among priority populations

Healthcare professionals should proactively recommend screening for priority populations as outlined in the Australian STI management guidelines for use in primary care.

Diagnosis and clinical management

Diagnosis

Syphilis is primarily diagnosed by:

• serological testing through a blood test (treponemal specific and non-treponemal tests)
• nucleic acid amplification test of lesion specimens (such as anogenital lesions or ulcers) if present.

Other diagnosis methods include tissue diagnosis and analysis of cerebrospinal fluid. 

Interpretation of syphilis serology is complex – past testing and treatment history, clinical assessment and specialist microbiologist advice are often needed. 

See the Australian STI management guidelines for use in primary care for guidance on diagnosis.

A syphilis point-of-care treponemal specific test is available in some parts of Australia. This can help identify and treat cases early, when used in combination with laboratory-based serology and treatment history information.

Laboratory case definition

Clinical management

Syphilis is treated with antibiotics. Follow up with repeat testing is important to monitor whether the patient is responding to treatment.

Pregnant people who test positive for syphilis should be referred for urgent specialist advice and be treated during pregnancy to minimise the risk of vertical transmission.

Sexual partners of people infected with syphilis should also be tested and treated if they test positive.

Successful treatment of previous syphilis infection does not protect against reinfection.[4]

Read more about the clinical management of syphilis.

Notification and reporting

Surveillance case definition

The Communicable Diseases Network Australia (CDNA) has published surveillance case definitions for:

• confirmed or probable cases of syphilis (less than 2 years duration)
• confirmed cases of syphilis (more than 2 years or unknown duration)
• confirmed or probable cases of congenital syphilis.

National notification and reporting

Confirmed and probable cases of syphilis are nationally notifiable in Australia. This means certain health professionals must report diagnoses through their relevant health authorities.

Check how to report syphilis cases in your state or territory:

• Australian Capital Territory
• New South Wales
• Northern Territory
• Queensland
• South Australia
• Tasmania
• Victoria
• Western Australia.

State and territory health authorities report new cases to us daily through the National Notifiable Diseases Surveillance System, as part of our surveillance activities.

We report case numbers and activity through our:

• quarterly national syphilis monitoring reports
• data visualisation tool, where you can filter and search the latest information.

This helps us to:

• identify trends in syphilis activity and impact
• assess the effectiveness of syphilis control programs
• develop policies to minimise the impact of syphilis.

Public health response

National public health guidelines

Management of cases

Public health units work with treating clinicians to investigate syphilis cases, with a focus on appropriate antibiotic treatment and contact tracing.

People with syphilis should be provided information about how to prevent spread to others including advice to:

• not have any sexual contact for 7 days after treatment is completed or until symptoms have resolved (whichever is longer)
• not have sexual contact with current or previous sexual partners until all partners:
  • have been tested and treated, if necessary (see management of contacts)
  • are no longer infectious (as previous infection and recovery from syphilis does not protect against reinfection)
• get regular sexual health checks.

Physical isolation of people infected with syphilis is not required.

Management of contacts

Public health units work with primary health and sexual health clinicians to undertake contact tracing to:

• identify all potential contacts who have been exposed to syphilis, including babies of pregnant people infected with syphilis
• clinically assess and test contacts for infection
• provide advice and public health education
• provide antibiotic treatment, where appropriate.

Public health messaging focuses on advising contacts to abstain from sexual activity for 7 days after completing antibiotic treatment or until they test negative to syphilis (whichever is earlier).

See the Australian Contact Tracing Guidelines for detailed guidance on contact tracing.

Online tools that can assist with contact tracing include:

• Let them know
• The drama down under
• Better to know.

Outbreak response

How public health agencies respond to syphilis cases and outbreaks depends on:

• state or territory legislation
• local reporting requirements
• the nature of the cases or outbreak
• available resources.

Syphilis preparedness and response initiatives involve:

• engaging early and establishing trust with local community and health services, including Aboriginal and Torres Strait Islander community-controlled health organisations
• consulting with communities to co-design syphilis control strategies and programs.

Additional control measures used during outbreaks may include:

• providing tailored public health education and messaging to the community and health staff about syphilis, including its symptoms and how to prevent spread
• providing access to appropriate testing and treatment services.

Special situations and high-risk settings

High-risk settings and certain population groups might require extra infection and control actions to reduce syphilis infection.

Read more about prevention and outbreak response.

Resources

See the:

• National Syphilis Response Plan 2023 to 2030
• Australian STI management guidelines for use in primary care
• ASHM’s Syphilis Decision Making Tool
• national syphilis monitoring reports
• healthdirect syphilis page
• Young Deadly Free
• Make STI testing your Beforeplay.

For more information relevant to your state or territory, see:

• Australian Capital Territory
• New South Wales
• Northern Territory
• Queensland
• South Australia
• Tasmania
• Victoria
• Western Australia.