The Northern Territory has seen the largest increase in syphilis rates in the country, as doctors call for more resources to combat the sexually transmitted infection.
The number of reported syphilis cases has jumped more than 16 times from just 14 cases in 2012 to 229 last year.
The STI was previously described as "almost eradicated" but has since been reported more times in the first month of 2017 than the entire year of 2012.
"There has been a syphilis outbreak across the north of Australia," Professor James Ward, head of Infectious Diseases Research Program for Aboriginal Health at the South Australian Health and Medical Research Institute, said.
"There are lots of efforts to bring the outbreak under control but unfortunately we haven't gotten on top of it yet," he said.
The outbreak is affecting Northern Australia from WA to Queensland, including Central Australia, Professor Ward said.
He said those most at risk included people aged between 15 and 29 living in remote communities, and pregnant women.
"There's been a massive increase in the number of new notifications of infectious syphilis among young Aboriginal and Torres Strait Islander people who live in remote communities," he said.
"We're making sure people who are diagnosed with syphilis are being treated appropriately, and making sure we are picking up syphilis in young women who are pregnant to ensure that it is not passed on to their babies.
"It really demonstrates that we must do much more and much more resources are required to bring it under control."
Health guidelines recommend being screened at least once a year, but it is very important to be tested as regularly as possible, Professor Ward said, especially for those who have recently changed partners, pregnant women, and young people aged 15 and 29.
"It's free, you'll get your results back quickly," he said.
"There's treatment readily available with very few side effects."