Gonorrhoea cases up have shot up by 45 per cent, according to National Notifiable Diseases Surveillance System (NNDSS) data.
There has also been a 24 per cent rise in chlamydia cases.
The data compares confirmed cases between this year and 2021.
Experts said young people aged 15 to 29 made up 67 per cent of all chlamydia infections and half of gonorrhoea cases.
Pathology Awareness Australia has urged Australians to get tested if they were worried, and said the infections could have longer term health impacts.
“Chlamydia and gonorrhoea are highly transmissible and have long-term ramifications, making them of high public health importance,” Microbiologist and Pathology Awareness Australia ambassador Associate Professor Caitlin Keighley said.
“If left undiagnosed, both can have long-term negative health consequences, such as infertility and pelvic inflammatory disease.”
However, symptoms – which can include bleeding and painful urination – don’t always show up.
Professor Keighley said Aussies should have regular STI tests if they could be at risk, and practice safe sex.
She blamed the pandemic for a lack of education on the issue.
“There was a lack of sexual health education that occurred during the pandemic period due to difficulty communicating these messages effectively online,” she said.
“In addition, there was a decrease in GP attendance, which resulted in undiagnosed infections, therefore transmitted, and overall decreased vigilance or concern about contracting an STI.”