Everything you need to know about syphilis testing in Australia
What this page covers. Syphilis is a bacterial infection that comes and goes through several stages over months and years if left untreated, and rates in Australia have risen substantially over the past decade. This page covers what a syphilis test involves (it is a blood test, not a swab), when the test is reliable after exposure, what positive and negative results actually mean, and what a current syphilis diagnosis looks like in practice in Australia.
What syphilis is. Syphilis is caused by the bacterium Treponema pallidum. It progresses through stages: primary syphilis (a painless ulcer at the site of infection, usually 3 weeks after exposure), secondary syphilis (rash, fever, swollen glands, weeks to months later), latent syphilis (no symptoms but the infection is still present, can last years), and rarely tertiary syphilis (long-term damage to the heart, brain, and other organs, decades after the initial infection). The infection is treatable at all stages, but earlier treatment is simpler.
The test itself. The syphilis test is a blood test, not a urine sample or swab. The lab uses a combination of tests: a screening test (usually a treponemal antibody test, which detects antibodies to the syphilis bacterium itself), and a confirmation test (an RPR or VDRL, which measures non-specific antibodies that correlate with disease activity). The screening test tells you whether you have ever had syphilis. The confirmation test, if both are positive, tells you whether the infection is current and how active it is.
How long after exposure before the test is reliable. Syphilis antibodies take 3 to 6 weeks to develop after the initial infection. The test is reliable from about 6 weeks after the last possible exposure. Testing earlier is reasonable if symptoms are present (a painless ulcer, for instance) because the test may already be positive, but a negative test before 6 weeks does not rule the infection out. For people with no symptoms who want a routine screen, 6 weeks after the last exposure is the standard wait. See when to test after exposure for the full timing guide across all STIs.
Why syphilis is back. Syphilis was rare in Australia for decades. From around 2010 onwards, rates have risen, first in men who have sex with men, then in heterosexual networks particularly in regional and Indigenous communities, and more recently in women of reproductive age. Congenital syphilis (passed from mother to baby during pregnancy) is the most concerning trend because it causes serious harm or death to the baby if untreated. Australian guidelines now recommend syphilis screening at the first antenatal visit for every pregnancy and at a follow-up point depending on risk.
Symptoms to know about. Primary syphilis classically presents as a single painless ulcer (called a chancre) at the site of infection — on the penis, vulva, vagina, anus, or mouth. The ulcer heals on its own in 3 to 6 weeks, but the infection has not gone away. Secondary syphilis can include a rash that often involves the palms and soles, fever, sore throat, hair loss, and patchy mucous patches. The challenge is that ulcers can be painless and unnoticed, and the secondary rash is non-specific and often misdiagnosed. Most people only realise they have syphilis when a routine test comes back positive in the latent stage with no symptoms at all.
Who should test. Current Australian guidelines recommend syphilis testing for: sexually active gay, bisexual, and other men who have sex with men (3 to 6 monthly screening for those with multiple partners), anyone with a recent diagnosis of another STI, anyone with symptoms suggesting primary or secondary syphilis (ulcer, rash that includes palms and soles, unexplained fever in someone who has had unprotected sex), all pregnant people at the first antenatal visit, and people from communities with rising heterosexual rates per local public health advice. A syphilis test is included in the standard comprehensive STI panel by default.
A positive screening test. A positive treponemal screen means antibodies to syphilis are present. This can mean current infection or past infection that has already been treated — antibodies persist for life even after successful treatment. The RPR (or VDRL) result tells you whether the infection is currently active and quantifies how active. A four-fold drop in the RPR titre after treatment indicates the treatment has worked. Interpretation matters and the Specialist GP can talk you through what the specific result means for you, particularly if you have been treated for syphilis in the past.
What treatment looks like. Syphilis is treated with an intramuscular injection of a long-acting antibiotic. For early syphilis (primary, secondary, or early latent) a single dose works. For late latent or unclear-stage syphilis, three weekly injections are standard. The injection cannot be given by telehealth alone — an in-person visit is needed. See syphilis treatment for the full clinical detail on the regimen, follow-up retest timing, and partner notification.
Pregnancy and syphilis. Untreated syphilis during pregnancy can cause stillbirth, premature birth, low birth weight, and a range of birth defects (congenital syphilis). Australian antenatal care includes syphilis testing at the first antenatal visit. People at higher risk are usually retested in later pregnancy. Treatment in pregnancy is safe and effective when given early enough. If you are pregnant and have a positive syphilis test, this is a clinical priority and the Specialist GP coordinates urgently with your maternity team.
Partner notification. Sexual partners from the past 3 months (for primary syphilis), 6 months (for secondary), or up to a year (for early latent) should be informed so they can test and be treated. The exact lookback period depends on what stage of syphilis you have. The Specialist GP can help you find the words for direct notification or direct you to anonymous online notification services. Partner notification is particularly important for syphilis because the infection can be present and infectious for months without symptoms.
A negative test. A negative syphilis test taken at the right time (at least 6 weeks after the last possible exposure) is reliable. If the test was earlier than 6 weeks and there is any clinical concern, the standard advice is to repeat the test in another 4 weeks. A persistently negative test, with no symptoms, after the full window has passed, rules out current syphilis.
Co-infections. A syphilis diagnosis is a strong trigger for a broader screen. Chlamydia and gonorrhoea co-infection is common in the same sexual networks where syphilis is rising, and HIV testing is essential after a syphilis diagnosis because the two share transmission patterns and HIV alters the syphilis treatment response. See comparison of STI tests for the broader screening context. A comprehensive screen also covers hepatitis B — see 5-infection STI screen.
Confidentiality. Syphilis is a notifiable infection in Australia. The lab notifies the state public health authority for surveillance and partner-notification support, but the report does not usually include your full identifying details unless additional follow-up is needed (rare, only for outbreak management or congenital syphilis prevention). All testing through Clinic365 is otherwise confidential between you and the Specialist GP.
Want to discuss your situation? A Specialist GP phone consult can discuss your situation, what test makes sense, the timing relative to any exposure, and what a positive or negative result would mean for you. See the hero section above for booking. For Melbourne residents, see syphilis testing in Melbourne. For pathology collection across Australia, see pathology collection centres.
