A new study confirms, Chlamydia, the sexually transmitted disease has increased 10% from 2007 to last year, putting more women at risk of potentially dangerous ectopic pregnancy and infertility.

Australia's latest figures on sexually transmitted infections released today i. e. over 58,000-cases, equivalent to 270 per 100,000 Australians reveal, while HIV has stabilised, the numbers of reported chlamydia cases is rising.

Considered a mild illness, even when there are symptoms, about 70% of people fail to notice the bacterial infection.

However, if left untreated, the infection can cause pelvic inflammatory disease, ectopic pregnancy or infertility in women.

A medical emergency, ectopic pregnancy is caused when a fertilised embryo implants itself outside the uterus, often in the fallopian tube.

One of the reasons for the continued strong rise in chlamydia infections, particularly evident among young Australians aged 16 to 24, is that they are the most likely to change partners frequently, and the likely not to use condoms.

The report also looked at gonorrhoea rates, which have remained stable at 36 per 100,000 people over the past four years, and syphilis, which showed a slight decline last year after doubling between 2004 and 2007.

As well, the study found infection rates for all three STIs were far higher in Aboriginal and Torres Strait Islander communities compared to non-Indigenous Australia.