But as the high-profile public health campaigns came and went so attitudes to safe sex seem to have relaxed. New generations of sexually active young people have emerged without the spectre of the Aids tombstone which was etched on young people in the '80s and as a result, other sexually transmitted infections (STIs) are on the rise.

Some of this increase is down to better testing, screening and recording, but as the young pregnancy figures prove, more young people are having unprotected sex.

The most prevalent STI is chlamydia with one in 10 of the general population infected, rising to one in eight in inner city areas.

The problem with chlamydia is that it doesn't quite have the stigma of gonorrhea, despite people being more likely to catch it. Also, on the whole, it is without symptoms and very easy to catch. Left untreated it can lead to women suffering Pelvic Inflammatory Disease which can result in infertility.

There is also some evidence that it can also lead to infertility in men.

As well as being the most common STI, it is also one of the easiest to treat with normally just one dose of antibiotics. And yet it is still a struggle to get young people to come forward for testing.

Yorkshire is leading the way in trying to tackle this huge problem. Four years ago, Leeds was one of the first cities in the country to introduce a free chlamydia screening programme where young people under the age of 25 accessing sexual health services were tested for the infection.

Sheila McNerney, co-ordinator of the Leeds Chlamydia Screening Programme, said the aim was to eventually screen 50 per cent of sexually active young people under 25 – this year's target is 17 per cent.

"Chlamydia figures are on the increase, but we do have better recording and testing," says Mrs McNerney. "Until we are reaching the 50 per cent screening of the target population we will not have an accurate picture."

As well as screening, Leeds PCT has introduced other innovative ways for people to get tested for chlamydia in a bid to reduce the figures. During the recent Kaiser Chiefs concert at Elland Road, the PCT's sexual health team offered free chlamydia testing to concert goers.

In the only project of its kind, young people aged 16 to 24 in the city are able to pick up free self-testing kits from 19 pharmacies.

The kits allow them to perform a simple self-test, either a urine sample or vaginal swab, at home and then post back the sample free of charge. Those who test negative will be sent a text message informing them of the result and those who are tested positive will be seen quickly for simple treatment with antibiotics.

"We are keen to encourage young people to get themselves tested for chlamydia and are aware that not many will visit clinic settings," says Mrs McNerney.

"Therefore, we are making it easier for young people to take better care of their health while ensuring that they can access these services confidentially and without fear of embarrassment.

"Many young people who may have chlamydia may not be aware of it as there are often no signs and symptoms, however, if identified early enough it can be easily treated."

n For further details of the pharmacies providing testing kits or to order one to be sent to your home address, log on to www.leedssexual
health.com. Anybody aged over 25 who would like to be tested for chlamydia should make an appointment to visit their local GP.

CHLAMIDYIA: THE FACTS

Chlamydia is a sexually transmitted infection (STI) caused by the bacterium chlamydia trachomatis.

In the UK, the number of new diagnoses has been steadily increasing each year since the mid-1990s, and it is now the most commonly diagnosed STI.

Between 2004 and 2005, the number of confirmed cases of chlamydia rose by five per cent, from 104,733 to 109,958.

Sexually active women aged under-25 have a one in 10 chance of getting chlamydia, and men who are aged between 20 and 30 are most at risk of becoming infected.

As chlamydia sometimes has no symptoms, it can often go undiagnosed, unless it leads to complications. However, once the infection has been diagnosed, it can be easily treated with antibiotics.