Syphilis cases rise in Australia despite fall in testing for STIs during pandemic

There has been a concerning rise in syphilis cases despite a drop in the number of Australians tested for sexually transmissible infections during the pandemic, data published by the Kirby Institute on Thursday shows.

In 2021 there were 86,916 diagnoses of chlamydia, 26,577 of gonorrhoea and 5,570 of infectious syphilis in Australia, according to the report titled HIV, Viral Hepatitis and Sexually Transmissible Infections in Australia.

There were reductions in total chlamydia and gonorrhoea diagnoses nationally. But Kirby Institute modelling shows most chlamydia and gonorrhoea cases are undiagnosed and untreated, and the report authors said the decrease in cases is likely a reflection of a drop in the numbers of Australians having a test for sexually transmissible infections (STIs). Chlamydia and gonorrhoea tests are down 14% from pre-pandemic levels.

In contrast syphilis diagnoses increased in 2021, after falling between 2019 and 2020. There have been steady rises in syphilis among gay and bisexual men and among Aboriginal and Torres Strait Islander people, and among women of reproductive age.

Kirby Institute researchers are now working to understand what proportion of pregnant women are not receiving adequate screening, she said.

Diagnoses of genital warts among heterosexuals aged under 21 attending sexual health clinics declined to less than 1% among females and 0% among males under 21 years, reflecting the success of the national HPV vaccination program.

The medical director of Sexual Health Victoria, Dr Kathleen McNamee, said the report reflects what is being seen in clinics.