Nearly half a million people were diagnosed with STIs last year, with those aged under-25 experiencing the highest rates of infection, according to new figures released today.

Health experts have warned that the rise in STIs shows too many young people are still putting themselves at risk by failing to practice safe-sex.

Last year there were 448,422 diagnoses, which was a rise of five per cent from 2011, said Public Health England (PHE).

Almost half of all infections were chlamydia, amounting to 46 per cent of total STI diagnoses.

The number of new gonorrhoea diagnoses increased by 21 per cent, which is a particular cause for concern among health officials as the global threat of antibiotic resistance grows.

People aged under-25 accounted for 64 per cent of all chlamydia and 54 per cent of genital warts diagnoses in 2012.

The UK has some of the most aggressive and early sex education of any Western country. But all of this effort to educate young people hasn’t reduced the amount of sexual activity at all. When young people learn about the mechanics of sex, and are taught that recreational sex is normal and healthy, then they have more of it. Young people aren’t able to assess risks like adults can. They think that nothing will happen to them. No amount of sex education can cure youthful recklessness.