A study released at the Australasian Sexual Health Conference in Darwin shows girls as young as 12 are testing positive to the sexually transmitted infection chlamydia.

The research found 13 per cent of girls aged 12 to 15 years who were tested had a positive result, a higher proportion than those aged 15 to 24.

Burnet Institute lead researcher Carol El-Hayek said the high result may be explained by the testing of the younger girls being more selective.

She says the figures do show that safe-sex campaigns and future research must better target girls under 16.

“Young people as young as 12 are sexually active,” she said.

They are having sex and they are probably having unsafe sex.”

“People who are under 16-years-old who are sexually active need to be included in all research, testing guidelines and all that sort of thing,” she said.

New figures also show one in 20 young Australians have chlamydia, many going untreated.

In females, untreated chlamydia can lead to pelvic inflammatory disease, which can eventually cause infertility.