Tejal Somvanshi
Australia’s rates of gonorrhoea and syphilis have risen by more than 50% over the past decade, according to new data released by the Kirby Institute at UNSW. The numbers are the largest, most detailed picture of sexual health in the country — and they show a story more complicated than a single national trend.
The Numbers
In 2025, Australia recorded:
Compared to a decade ago, both syphilis and gonorrhoea diagnosis rates have risen by more than 50%. These are notifications — confirmed cases reported to health authorities — not estimates.
Men account for the large majority of diagnoses: 78% of syphilis cases and 73% of gonorrhoea cases. That reflects, in part, that gay and bisexual men remain the population group with the highest testing rates and the highest notification numbers.
What This Means for You
If you are an Australian adult who is sexually active and not regularly tested, these numbers are relevant to you personally — not as a news item, but as a health prompt.
Syphilis and gonorrhoea can be asymptomatic for extended periods. A person can carry and transmit either infection without knowing. Both are curable with antibiotics when caught early; both can cause serious complications when left untreated. Syphilis in pregnancy is particularly serious — it can be passed to an unborn baby, causing congenital syphilis, which can lead to stillbirth or severe illness in a newborn.
The practical message from the data is straightforward: regular STI testing is the only reliable way to know your status.
Who Is Most Affected
Women and pregnancy
The Kirby Institute data shows a concerning rise in syphilis among women of reproductive age. In 2025, 43% of congenital syphilis cases were diagnosed in First Nations infants — a figure that reflects both the disparity in testing access and the ongoing challenges of antenatal care in some communities.
Congenital syphilis is preventable. It requires detecting the infection in a pregnant person early enough to treat it before transmission to the baby. The data is a direct argument for routine syphilis testing during pregnancy, particularly in communities where access to antenatal care is inconsistent.
First Nations communities
The disparity in STI rates between First Nations and non-Indigenous Australians is a persistent feature of the data. Experts have called for more comprehensive testing in First Nations communities and more accessible pathways to treatment.
Gay and bisexual men
This group has historically had the highest STI notification rates, partly because they are also the most tested. But the Kirby Institute data contains a more positive signal here: recent declines in infectious syphilis and chlamydia among gay and bisexual men suggest that targeted prevention measures — including doxy-PEP, a post-exposure antibiotic treatment — may be having an effect.
That matters for how the national story is read. The 50% decade-long increase is real. But within that, some groups are seeing recent improvement while others are seeing continued deterioration.
The Counter-Trend That Changes the Story
The headline figure of 50% over a decade is accurate, but it flattens a more textured picture. Among gay and bisexual men — who represent the largest share of historical diagnoses — syphilis and chlamydia rates have recently declined. That is not a small footnote. It suggests that when prevention tools reach a population group effectively, they work.
The challenge is extending that reach. The groups currently experiencing rising rates — women, First Nations communities, younger Australians — are the ones where testing and prevention resources need to be directed next.
Frequently Asked Questions
What is causing the rise in syphilis and gonorrhoea in Australia?
The Kirby Institute attributes the longer-term rise to a combination of factors including expanded screening, increased awareness, and genuine increases in transmission in some populations. Among gay and bisexual men, recent declines in syphilis and chlamydia are encouraging and may reflect the uptake of prevention measures including doxy-PEP. Overall national rates, however, remain high.
What is congenital syphilis and why does it matter?
Congenital syphilis occurs when syphilis is transmitted from a pregnant person to their baby during pregnancy or childbirth. It can cause stillbirth, premature birth, and serious illness in newborns. It is preventable through testing and treatment during pregnancy. In 2025, 43% of congenital syphilis cases in Australia were in First Nations infants.
Should I get tested for STIs if I have no symptoms?
Yes. Syphilis and gonorrhoea are commonly asymptomatic — a person can carry and transmit them without knowing. Regular testing is the only reliable way to detect infections early, when they are straightforward to treat with antibiotics.
What Comes Next
The Kirby Institute releases its sexual health surveillance data annually. The next round will show whether recent declines in some population groups continue, and whether the overall national trend begins to stabilise. Australian health authorities have called for increased testing and prevention resources, particularly in communities where access remains limited.
