LONDON: Cases of chlamydia have risen by almost 250 per cent in Britain during the past 10 years, prompting fears of a sexual health crisis among the young, says a report published in The Independent. Official figures to be published this week will show that more than 105, 000 Britons were diagnosed last year with the sexually transmitted disease, compared with 32, 288 in 1995.The startling rise in cases of the infection, which can lead to infertility and ectopic pregnancies, has alarmed health professionals, who blame increased casual and unprotected sex among young people for the rise. It will also disappoint government health ministers, who have made tackling STDs a priority.

The figures, to be published by the Health Protection Agency, will increase fears of a lurking ''silent time bomb'', as chlamydia does not often have symptoms. Chlamydia is most prevalent in people aged 15 to 24.It can be treated easily by a course of antibiotics, but about 70 per cent of women who have the infection do not realise they are carrying it. Infertility caused by the untreated infection can be devastating, and costs the NHS more than $100 million a year.

The Independent quoted Marie Stopes health organisation senior nurse Pauline Beddoes as saying the clinics had seen a sharp rise in the detection of the disease in the past year. ''In females, about 80 per cent have no symptoms and most people only act when they have symptoms, '' she said. ''It's sleeping with more partners and the lack of condoms that has led to the increase. ''.