YOUNG women in the North-East are being warned about the spread of a sexually transmitted disease that could leave them infertile.

Cases of chlamydia in the UK have doubled in the past six years.

Between 1995 and 2000, reported cases of the disease rose from 30,877 to 64,000.

Figures released by Tees Health Authority in November showed the number of people diagnosed had doubled on Teesside during the 1990s.

In County Durham, the number of reported cases soared from 189, in 1995, to 603 in 2001 - a threefold increase.

Dr Conrad White, consultant in genito-urinary medicine for County Durham and Darlington Health Authority, said: "In 2000, 17 per cent of females and 11 per cent of males who visited the GU clinic in Durham were diagnosed.

"These are serious numbers, and I suspect there are pockets within the region where the figures are even higher or where people don't get tested.

"This is particularly true for young men who are notoriously bad at accessing health services."

Chlamydia can be treated with antibiotics but, undiagnosed, it can cause irrevocable damage to the reproductive system and result in infertility among women.

There are no obvious symptoms, and many sufferers do not realise they have contracted the disease until it is too late.

Men can also contract the disease and pass it on to their sexual partners.

Family planning campaigners blame unprotected sex and increased availability of the morning-after pill for the spread of the disease.

The Government is launching a multi-million campaign to raise awareness.

There are plans for GP surgeries to carry out routine tests, possibly in conjunction with cervical smear tests, and women attending family planning clinics will be checked for the disease.