Syphilis: why it’s rising, and how to get tested

Why it matters now

Australia had 5,986 infectious syphilis diagnoses in 2025, and the diagnosis rate has risen by more than half in a decade. Most are in men, but syphilis is rising much faster in women: up 167% over the same time, against 39% in men. Syphilis in pregnancy can pass to the baby, and congenital syphilis has caused 40 infant deaths in the past decade. In August 2025, Australia’s Chief Medical Officer declared syphilis a Communicable Disease Incident of National Significance.

The signs, by stage

The guidelines say around half of people with syphilis have no symptoms and are only found by testing. When it does show:

• Primary: a sore (chancre) on the genitals, anus or mouth, usually around 3 weeks after infection (anywhere from 10 to 90 days). It’s often painless and can be hidden, so it’s easy to miss, and it heals by itself.
• Secondary: usually more than 6 weeks after infection, a rash, often across the body or on the palms and soles, sometimes with fever, swollen glands or patchy hair loss.
• Latent: no symptoms. It’s infectious to partners for about the first 2 years, and untreated, it can damage the brain, nerves, heart and eyes years later.

If you have a sore or rash like this, see a sexual health clinic (opens in new tab) or GP clinic (opens in new tab) in person.

Who should test

• Anyone having STI testing. The Australian STI Management Guidelines (opens in new tab) recommend including syphilis whenever STI testing is done.
• Men who have sex with men, every time you test for HIV, which is every 3 months for many. See STI testing for gay, bi and other men who have sex with men.
• Anyone pregnant, as part of antenatal care, at the first visit and again later in pregnancy.
• Anyone with an unexplained sore, rash or a partner with syphilis.

How the test works

Syphilis is tested with a blood sample from a vein, which the lab checks for antibodies. If a sore is present, a swab of it can be tested by PCR too, which can find syphilis before the blood test does.

The antibody test usually stays positive for life after syphilis has been treated, so tell the doctor if you’ve had it before. A second blood test, the RPR, shows whether an infection is active and is used to check treatment has worked.

The window period is around 12 weeks. If you’ve had a recent exposure, test now and again at 12 weeks. See how soon after sex you can test.

Treatment

Early syphilis is treated with a single long-acting penicillin injection, given as two injections at once. Syphilis that’s been there longer, or for an unknown time, needs one each week for 3 weeks. A shortage of the injection means some people are treated with a 2- or 4-week course of doxycycline tablets instead. Follow-up blood tests at 3, 6 and 12 months check it’s worked.

Partners from the last 3 to 12 months, depending on the stage, need testing and treatment too, and syphilis is reported to the state or territory health department.

Where to get tested

A GP clinic (opens in new tab) or sexual health clinic (opens in new tab) can request a syphilis blood test, which is taken at a pathology collection centre. Sexual health clinics are free, and many GPs bulk bill.

Prickly doesn’t test for syphilis yet, because it needs blood from a vein rather than samples you collect at home. If you test for chlamydia, gonorrhoea and HIV with Prickly, ask a GP or clinic to add syphilis so your check is complete.

How at-home testing works with Prickly

Prickly is an Australian at-home STI testing service for people without symptoms. It tests for chlamydia and gonorrhoea, with an optional HIV self-test. Syphilis isn’t included yet, so pair it with a blood test at a clinic or GP.

• Request online. Complete a five-minute online request, or book a short call with a doctor – bulk billed with Medicare. Either way, a doctor confirms that at-home STI testing is suitable for you.
• Receive your equipment. Collection equipment tailored to your exposures ships the same or next business day in an unmarked mailer box with Australia Post tracking.
• Collect at home. Follow the included STI testing self-collection guide – swabs and urine for the lab, and, if you’ve added HIV testing, a fingerprick HIV self-test you read at home in 15 minutes.
• Post to the lab. Post your lab samples back the same day using the included prepaid return label – at any Australia Post Office, red street posting box or Parcel Locker.
• Get your results. A doctor reviews every lab test result and emails you privately. Telehealth follow-up included – with help accessing treatment and telling partners, if needed.

The same steps are on the home page under How it works, and fees are under Pricing.

When at-home testing isn’t right

See someone in person at a sexual health clinic (opens in new tab), GP clinic (opens in new tab) or urgent care clinic (opens in new tab) instead if you have symptoms or if you’re under 16. And if you may have been exposed to HIV in the last 72 hours, don’t wait for a test – visit www.getpep.info (opens in new tab) or go to a sexual health clinic (opens in new tab) or emergency department (opens in new tab) as soon as you can. If something happened without your consent, 1800RESPECT (opens in new tab) is also available 24/7 for free, confidential support.