An Illawarra health official is warning sexually active young people to get tested for chlamydia as the rate of infection rises across the Illawarra.
Last year the Illawarra Shoalhaven Local Health District recorded 1114 notifications of chlamydia, compared with 659 in 2008.
"The number of notified chlamydia cases among males and females has risen substantially in the last five years, primarily among young people," the health district's sexual health service director, Katherine Brown, said yesterday.
Most concerning was that the sexually transmitted infection - common in people aged 15-25 - is easily treated and prevented.
"Young people are not realising they are at risk," Associate Professor Brown said.
"There are often no symptoms, so people don't actually think to go see a doctor and get a check-up if they don't have any symptoms," she said.
"We suggest that if you have had a partner change it's wise to get a check-up. You need to wait a week, because the day after can be too soon for the infection to show up."
Prof Brown said the Illawarra spike in chlamydia cases was reflected nationally.
Between 2007 and 2011, the number of notified cases of chlamydia in NSW also increased by 8046 - up from 12,406 notified cases to 20,452.
About 60 per cent of chlamydia notifications in the state in 2011 were among 15-25 year olds.
"This increase suggests that the message of getting tested for STIs [sexually transmitted infections] is getting through," Prof Brown said.
"Chlamydia, like many STIs, is easy to test for and easily treated with a simple dose of antibiotics, but it's better to have never had it at all," she said.
"It is easily prevented by practising safe sex. But if untreated it can result in serious health problems in men and women, including pelvic inflammatory disease and female infertility."
Prof Brown said symptoms could occur within two to 14 days after infection, but a person may have chlamydia for months or even years without knowing it.
For confidential and free sexual health information call 1800 451 624.