Britain's epidemic of sexually transmitted infections reached record levels last year with more than 100,000 new cases of disease, mainly among young people.

Britain's epidemic of sexually transmitted infections reached record levels last year with more than 100,000 new cases of disease, mainly among young people.

The soaring rate was blamed on risky sexual behaviour and long delays in getting treatment because of a shortage of specialist clinics.

New diagnoses rose to 708,083, up 4 per cent on the previous year's 678,709 but 57 per cent up on the 1995 total of 449,666, the Health Protection Agency (HPA) said. The Family Planning Association said waiting times for genito-urinary medicine (GUM) clinics could be as long as six weeks, increasing the risk that infections would be spread.

An FPA survey found more than half of the 256 GUM clinics had opening times of less that 21 hours a week, meaning people had difficulty accessing services. Only two new clinics had opened since 2002.

Anne Weyman, the FPA chief executive, called on the Government to set a maximum wait of 48 hours. "Treating sexually transmitted infections and their consequences costs the NHS an estimated £1bn a year. Fast access to treatment is essential to prevent the spread of infection and makes economic sense."

In Birmingham, the Whittal Street GUM clinic said it had treated 26,000 people last year, 40 per cent up on the number five years ago. Jonathan Ross, director of the clinic, said: "The average wait for treatment is between four and five weeks, compared with three or four days a few years ago."

The HPA said gays and young people were the worst-hit. The commonest infection was chlamydia, which affects the fallopian tubes and can cause sterility. Cases were up 9 per cent last year to 89,918 and have almost trebled since 1995.

Almost three-quarters of chlamydia infections were found in women aged 16 to 24, a total of one in six of the female population. Chlamydia is often called the silent infection, because it has no symptoms in the early stages.

Syphilis, although rare, was up 28 per cent from 1,232 cases to 1,575, with outbreaks in Manchester and London. Incidence of the disease, which was a killer in the pre-antibiotic era, has risen more than ten-fold since 1995.

But there were chinks of light amid the gloom. Reductions in gonorrhoea in some regions reflected the impact of local campaigns and helped in a 3 per cent fall in cases nationally, the HPA said. Herpes cases were down by 2 per cent.

Sir William Stewart, the HPA chairman, said: "These are all preventable infections and it is a cause of considerable concern that we are still seeing increases across the UK. Unsafe sex is undoubtedly a main contributor to this.

"This is the time of year when many young people go on holiday, and these figures are a timely reminder of how important it is for people to take responsibility for their own, and their partners' sexual health, and to use a condom with new and casual sexual partners."

Professor Pat Troop, the HPA chief executive, said holiday companies should promote safe-sex messages in their brochures. A British Medical Journal survey last week found that only 3 per cent of travel brochures had such warnings. "There is a responsibility on the various travel companies to give out information about these matters," she said. Nick Partridge, the chief executive of the Terrence Higgins Trust, said treatment was inadequate. "It's no surprise that the figures are continuing to rise. The situation is shameful; we know how to tackle sexual ill-health, but a lack of national and local focus is stopping this."

Melanie Johnson, the minister for public health, said the Government was increasing capacity in sexual health services. "We have invested £26m to reduce waiting times and improve access to GUM clinics, with further funding to modernise buildings and develop GUM services in areas where there is little or no service," she said.