Over the past 30 years, Australia has seen a troubling surge in sexually transmitted infections (STIs) such as chlamydia, gonorrhoea, and syphilis. Despite the availability of testing and treatment, these bacterial infections continue to climb — often silently and without immediate symptoms.
In 2004, Australia recorded around 35,700 cases of chlamydia. By 2024, that number had nearly tripled to over 102,000, according to government data. Rates of gonorrhoea and syphilis have also risen dramatically — from 7,047 to over 44,000 and from 660 to nearly 6,000 cases annually, respectively.
Dr Skye McGregor, an epidemiologist at the Kirby Institute at UNSW, says the data confirms chlamydia remains the most frequently notified STI in the country — a trend with significant public health implications.
Why This Matters
While bacterial STIs are generally treatable with antibiotics, they pose serious health risks when left undetected. These include:
- Infertility
- Congenital transmission from mother to child
- Organ damage in severe cases of syphilis
Antibiotic resistance compounds the problem. Some strains of gonorrhoea have developed resistance to azithromycin and ceftriaxone, both first-line treatments. In 2023, NSW Health issued a public warning about rising drug-resistant gonorrhoea cases.
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“It makes infections harder to treat, which increases the risk of transmission, illness and even death,” said Dr McGregor.
Understanding the Drivers: No Single Cause
Despite the well-documented increase, the reasons behind rising STI rates are not straightforward.
“There’s a range of factors. We can’t just point to one thing and go, ‘This is the main reason we’re seeing an increase in STIs,’” Dr McGregor explained.
Some of these contributing factors include:
- The asymptomatic nature of many infections (especially chlamydia)
- Declining condom use
- Changes in sexual behaviour due to medical advances like PrEP (pre-exposure prophylaxis), which protects against HIV but may lead to reduced condom usage
Is Awareness the Missing Link?
Dr McGregor believes that limited public understanding of STIs like chlamydia, gonorrhoea, and syphilis is part of the issue. Campaigns that once targeted HIV and hepatitis C had government backing and public visibility — and infection rates for those diseases have declined.
“It’s complex, but if you take into account where the reductions have been, there’s a reason for it,” she said.
Unfortunately, STI awareness campaigns have not kept pace, leaving a knowledge gap among sexually active Australians.
A Broader View on Testing Gaps
Sexual health physician Dr Jason Ong from the Melbourne Sexual Health Centre says the issue may also lie in who gets tested.
Traditionally, public health efforts have focused on high-risk groups, such as men who have sex with men (MSM) and Indigenous communities. But STIs are now spreading across all age, gender, and sexuality demographics.
“Maybe we’re not testing the right populations,” Dr Ong said. “Within certain groups, we know there are people who are not testing.”
Stigma and Cost: Hidden Barriers to Testing
Many people still avoid STI testing due to social stigma, embarrassment, or fear of judgment. A 2021 meta-analysis co-authored by Dr Ong found that stigma and limited awareness were major reasons young people in wealthy countries avoided getting tested.
“If we can address that stigma piece, I think that will help a lot,” said Dr Ong.
Cost is another concern. With bulk-billing in decline, some Australians now face out-of-pocket costs just to see a GP.
“It’s now expensive for people to go to the GP,” said Professor David Lewis of the University of Sydney. “You can do health promotion, but if you don’t make the testing accessible, then it’s a challenge.”
New Strategies: At-Home Testing and Accessibility
One solution may lie in replicating successful interventions used in HIV prevention. For example, at-home rapid HIV tests have been available since 2019 and are now offered for free through NSW pilot programs.
In late 2023, Australia approved at-home test kits for chlamydia and gonorrhoea, but they’re not yet part of any government distribution initiative. Experts believe expanding access to self-testing kits — especially in rural or conservative communities — could help overcome both stigma and logistical barriers.
“It’s not just a question of promotion and education,” Professor Lewis said. “It’s also about making the testing easy, private, and non-judgmental.”
A Holistic Approach Is Needed
Professor Mark Stoové from the Burnet Institute emphasises that the most effective sexual health programs don’t just reduce sexual risk, but also encourage health-seeking behaviour.
“Particularly in the space of sexual health education, if we’re putting a campaign out there, people need to recognise that the campaign is speaking to them,” he said.
That means interventions must be:
- Culturally appropriate
- Economically accessible
- Regionally targeted
- Inclusive of all demographics, not just traditional “high-risk” groups
The Path Forward: Prevention, Investment, and Innovation
Ultimately, education and prevention remain the first line of defence. More investment in large-scale awareness campaigns, such as those used to tackle HIV in the 1990s, could yield similar results in the fight against rising STI rates.
Health experts also suggest exploring preventive antibiotics. For instance, some researchers have proposed a “morning-after” antibiotic like doxycycline for post-exposure STI prevention, though it comes with caveats around antibiotic resistance.
Australia’s STI surge is not unsolvable — but it demands urgent, inclusive, and innovative solutions.
“These interventions need to be tailored,” said Professor Stoové. “The right message, in the right voice, at the right time — that’s how we get people tested and treated.”
