Sexual attitudes research

14% of men and 2% of women did not tell their main partner they had an STI 42% of men and just under 60% of women believe gay sex is rarely or never wrong 19% of women and 37% of men believe a one night stand is rarely or never wrong Source: Sexually Transmitted Infections

It makes a raft of recommendations on how to tackle the problem, including:

• a more proactive approach in schools
• more clinics to enable faster diagnosis
• a call for popular TV soaps and series to reflect the true nature of sexual relationships, including the risk of infection
• the British Broadcasting Standards Commission should conduct a survey of popular TV series aimed at teenagers which have a sexual content
• government to invest in sex education and training of GPs

There is quite clear evidence that young people in particular have not even heard the message about safe sex

Dr Vivienne Nathanson

In just one year, 1999-2000, gonorrhoea rose by 31% in males and 26% in females.

In the same year, chlamydia, one of the major causes of infertility in women, rose by 17% - and the number of cases has doubled in just six years.

Chlamydia is a particularly dangerous disease because in many cases symptoms do not become apparent for some time.

Failure to treat the condition increases the risk of infertility, or of life-threatening ectopic pregnancy.

It is estimated that 9% of sexually active women under 25 have chlamydia. The infection could be responsible for a third of all infertility cases.

Media campaigns

The BMA says part of the problem may be the lack of high profile campaigns to highlight sexual health risks and encourage safer behaviour among the general population.

There was a decline in the number of STIs in the late 1980s and early 1990s in the wake of the government's publicity campaign about HIV epidemic.

However, many sexually active teenagers now have no recollection of the campaign.

Sexually transmitted infections

New cases seen in specialist UK clinics nearly doubled in the last decade STIs such as chlamydia or gonorrhoea may go undiagnosed because often there are no obvious symptoms

The National Survey of Sexual Attitudes and Lifestyles published last autumn showed that people were first having sex at a younger age than ever before, and that more people were regularly switching sexual partners, and having concurrent sexual relationships.

The BMA's head of ethics Dr Vivienne Nathanson said: "There is quite clear evidence that young people in particular have not even heard the message about safe sex.

"There is a lot of young people who don't recognise the risk, and who are coming forward with a variety of new infections."

Schools lagging behind

Dr Nathanson said sex education in UK schools was not as frank and open as elsewhere in Europe.

The rise in STI cases has also made it difficult for some people to obtain treatment quickly as clinics struggle to cope with increased demand.

Researchers from Southampton University found that 20% of patients with acute symptoms of a sexually transmitted disease could not obtain an appointment at a specialist clinic within the recommended 48 hours.

Colin Dixon, of the HIV charity the Terrence Higgins Trust, said: "Sexually transmitted infections are preventable.

"It is ridiculous that we are still so afraid of talking about sex that we can allow our young people to remain ill-informed about simple ways to protect themselves from STIs, HIV and unwanted pregnancies."