Syphilis cases surge to record levels in Australia, prompting national health response

Australia's record-high syphilis cases in 2024—5,866 diagnoses, roughly double the level from a decade ago—underscore a widening sexual health crisis, with about 80 percent of cases in men and rising diagnoses among women of reproductive age.

Congenital syphilis has more than doubled since 2015, with 34 infant deaths linked to the infection. In response, Australia's Chief Medical Officer Professor Michael Kidd declared syphilis a Communicable Disease Incident of National Significance, a move designed to mobilize resources across health services to expand testing and treatment. Jessica Michaels, Deputy CEO of the Australasian Society for HIV, Viral Hepatitis, and Sexual Health Medicine, said the epidemic will require a sustained and coordinated response from government, researchers, the clinical workforce, and the community.

Testing remains simple and widely available, with blood tests or swabs offered at GP clinics, sexual health clinics, or community health services. Treatment is typically antibiotics, most commonly penicillin, effective if the infection is caught early. The Kirby Institute data also show gonorrhoea diagnoses reached 44,210 in 2024, doubling over the past decade, with about 70 percent of cases among men, a sign that transmission among men who have sex with men is a key driver. Professor Andrew Grulich noted that the higher share of gonorrhoea among men suggests more frequent transmission in male-to-male sex.

Chlamydia remains the most common STI in Australia, with more than 101,000 cases in 2024, particularly among young adults aged 20-29. Dr. Skye McGregor said while chlamydia diagnoses are not rising as fast as syphilis or gonorrhoea, it remains the country's most common STI and testing is crucial for those who are sexually active. A test for chlamydia is straightforward, and treatment is typically a single antibiotic dose.

HIV diagnoses have fallen by about 27 percent over the past decade, but experts caution that complacency could jeopardize progress toward reduced domestic transmissions by 2030. Scott Harlum, president of the National Association of People with HIV Australia, emphasized that continued testing and prevention efforts are essential.

Public health officials say testing remains accessible and effective treatments exist when infections are detected early. A new prevention option, Doxy PEP, is now available for gay and bisexual men to help prevent syphilis and chlamydia when taken within 72 hours of sex. Public health authorities say regular testing, open discussions about sexual health, and sustained investment across government, researchers, clinicians, and communities are key to turning the tide on the STI surge.