There has been a dramatic increase in cases of the most common sexually transmitted disease in Scotland, according to official health figures.

The infection rate for Chlamydia has jumped by nearly 30% in the last year alone, according to the Scottish Centre for Infection and Environmental Health (SCIEH).

The rise in the recorded rate for the infection, which has been linked to cervical cancer, ectopic pregnancies and infertility, has been described as "very serious".

Over the past year there were 10,580 reports of genital Chlamydia trachomatis in comparison to 7,615 for 2000 and some 71% of infections were in women.

Those at greatest risk are the under 25s, especially the under 20s, with at least one in 10 carrying the infection Dr Gordon Scott

The greatest rise was in Lothians, where recorded incidents of Chlamydia more than doubled from 1,195 to 2,401 and one in 10 under 25-year-olds could be infected.

The next biggest jump in infection was recorded in Greater Glasgow, with a 28% increase from 1,300 in 2000 to 1,811 in 2001.

Dr Chris Redman, an epidemiologist at SCIEH, said: "This infection can lead to all sorts of complications if it isn't treated quickly, especially for women.

"It can cause ectopic pregnancies, pelvic inflammatory disease and infertility or scarring of the genital tract.

'Young in danger'

"The latest figures are very serious but they also indicate that sexual infection awareness campaigns are paying off and more people are coming to be tested."

The report reveals the incidence of Chlamydia between 2000 and 2001 increased steadily in all NHS board areas among both males and females, except in the Borders.

A SCIEH spokesman said the recorded rate of transmission of the infection in women leapt by 34% from last year and 45% for males over the same period.

And women, who can be left sterile by the disease, were 164% more likely than men to contract it, the study found.

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There has been a 300% increase in female reports of Chlamydia reported to SCIEH since 1995, compared to a 270% increase in male reports, the study recorded.

Dr Gordon Scott, of Edinburgh Royal Infirmary's genitourinary medicine clinic, warned that young people were most in danger.

He said: "Those at greatest risk are the under 25s, especially the under 20s, with at least one in 10 carrying the infection.

"Reasons for the increase include the introduction of more testing of those most at risk but it's also clear that the infection is spreading throughout the sexually active population."