STI jump in SA prompts call for condom use

Using condoms when having sex is the way to go, South Australia's peak health body is warning, following a spike in diagnoses of chlamydia and gonorrhoea.

SA Health says 3454 people in the state have been diagnosed with chlamydia so far this year, compared with 3454 at this time in 2015.

There's been an even bigger boost in the number of gonorrhoea cases, with 735 being diagnosed this year, up from 523 a year ago.

People in their early 20s are the most likely to be affected by the diseases.

SA Health says the infections often don't show any symptoms, and could remain in the body for years doing unseen damage if they go untreated.

"For women in particular, chlamydia can affect the entire reproductive system and cause serious and permanent damage which may result in infertility," SA Health chief medical officer Paddy Phillips said.

He noted that while men and women are equally susceptible to STIs, chlamydia is diagnosed among women more often and gonorrhoea more frequently in men.

"Almost 2000 women have been diagnosed with chlamydia this year, compared to less than 1500 men ... and of more than 700 diagnoses of gonorrhoea, just over 250 of those have been in women," he said.

"These are preventable and what you can do is easy; use a condom and practise safe sex."