Two of the world's oldest known bacterial infections are making a dramatic comeback in Australia, with new analysis revealing reported cases of syphilis and gonorrhoea have each surged by more than half over the past decade — prompting urgent calls for better education, expanded testing, and genuine investment in community-controlled health services.
Figures from the Kirby Institute at the University of New South Wales show that in 2025 there were 42,393 gonorrhoea notifications and 5,986 infectious syphilis notifications nationally — representing a 57 per cent increase in gonorrhoea and a 56 per cent rise in syphilis compared with a decade earlier. The scale of the problem has been serious enough that syphilis was formally declared a communicable disease of national significance in late 2025.
A disease that hides in plain sight
Both infections are ancient in origin and, today, straightforward to treat with antibiotics. The challenge is that neither reliably announces itself. Syphilis and gonorrhoea can present with mild or no symptoms at all, meaning many Australians are unknowingly living with — and transmitting — the infections.
Left untreated, syphilis is particularly dangerous. It moves through distinct stages and can eventually spread to the brain, heart, eyes and other organs, causing neurological damage including paralysis and dementia, as well as tumour-like growths on the skin, bones or internal organs. In its most advanced form, tertiary syphilis can be fatal.
Australia's Chief Medical Officer, Professor Michael Kidd, has called on all Australians — including healthcare professionals — to be aware of the risk and to get tested, stressing that awareness across the entire community is now essential.
Women and pregnant people bearing a growing burden
One of the most striking trends in the data is the disproportionate rise among women. Infectious syphilis notification rates for women increased by 170 per cent between 2016 and 2025, compared with a 39 per cent rise among males over the same period.
That shift carries serious consequences for pregnancy. Syphilis transmitted from mother to baby — known as congenital syphilis — can result in miscarriage or stillbirth, and babies who survive may face premature birth, low birthweight and lasting developmental abnormalities.
Kirby Institute epidemiologist Dr Skye McGregor described congenital syphilis as a persistent and troubling problem. Between 2016 and 2025, there were 113 recorded cases, including 14 in 2025 alone, with 40 resulting in infant deaths. More than half of those deaths over the decade involved First Nations infants.
"This is an entirely preventable outcome with early diagnosis, testing and treatment of pregnant people," Dr McGregor said.
First Nations communities disproportionately affected
The data points to a stark and persistent disparity. First Nations Australians are diagnosed with gonorrhoea at more than four times the rate of non-Indigenous people, and with syphilis at more than six times the rate.
Kim Gates, community relations lead in the Kirby Institute's First Nations Point-Of-Care Program, said these gaps reflect much deeper inequities within the broader healthcare system. She noted that many First Nations people have a complex and often difficult relationship with health services, and "have good reasons to be sceptical of top-down services and approaches."
"This is why Aboriginal-led services are so important," Gates said.
Australia currently has 149 Aboriginal Controlled Community Health Services providing culturally safe, comprehensive care — but Gates acknowledged there remain areas these services do not reach. For her, sustained investment in community-led initiatives such as the First Nations Molecular Point-of-Care Testing Program is the most effective path to reducing STI rates in Indigenous communities. Understanding how structural inequities shape health outcomes for First Nations Australians is central to this challenge — an issue explored further in coverage of First Nations perspectives on Australian society and policy.
What needs to happen next
Health authorities are urging all sexually active Australians to consider routine STI testing, particularly given how often these infections go undetected. Early diagnosis remains the single most effective tool — not only for individual health outcomes, but to prevent onward transmission and, in the case of syphilis during pregnancy, to protect unborn children.
The message from experts is consistent: these are treatable conditions, but only if they are found. With case numbers continuing to climb, the window to get on top of the outbreak is narrowing.
