Burden of most STIs in the UK falls on young people

Between 1995 and 2000 new episodes of sexually transmitted infections seen at GUM clinics in England, Wales and Northern Ireland rose from 887,760 to 1,185,285.

• Uncomplicated gonorrhoea rose by 102%
• Genital chlamydial infection rose by 107%
• Infectious syphilis rose by 145%

According to a new report from the Public Health Laboratory Service the burden of sexually transmitted infections falls upon teenage women and men aged 20 to 24 years old. A study in three urban GUM clinics showed that between 20% and 30% of teenage females diagnosed with an STI were subsequently diagnosed with another STI within 18 months.

The most common STI diagnosed in GUM clinics is anogenital warts, with 66,044 new diagnoses being made in 2000. The rate is highest among those under 24 and infections are distributed uniformly across the country.

The most common bacterial STI seen in 2000 was genital chlamydial infection, with over 64,000 new diagnoses. Again this infection is distributed evenly across the country, and the tendency is for it to be concentrated in young people under 24 years of age. Currently 1% of 16 to 19 year old females were diagnosed with genital chlamydial infection at a GUM clinic. Genital chlamydial infection is the dominant cause of pelvic inflammatory disease, which can lead to infertility and has been associated with an increased risk of ovarian cancer.

The National Strategy for Sexual Health and HIV proposes to begin a programme of screening for chlamydia for targeted groups in 2002. Much of the 47.5 million pounds investment that accompanies the strategy is believed to have been set aside for work around chlamydia.

Anogenital HSV infection is the commonest ulcerative STI in England. Anogenital HSV infection can cause severe disease in people with compromised immunity and its presence may facilitate HIV transmission. Rates of first episode genital HSV infection have remained relatively stable in the period 1995-2000. Genital HSV infection can be caused by both HSV-1 and HSV-2. HSV-2 prevalence is low and HSV-1 is now the commonest cause of genital HSV infection in GUM clinics. The increase in HSV-1 infection has been particularly pronounced in young women, and oral sex has been suggested as an increasingly important route for transmission.

Unlike genital warts, genital chlamydial infection and genital HSV infection, new diagnoses of gonorrhoea are concentrated in urban regions, with London being the most affected city. Gay men and people from black ethnic minorities are disproportionately affected by gonococcal infection.

In women, the highest rates of gonorrhoea are in those aged 16 to 19,with 41% of all female diagnoses being concentrated in those under 20 years of age.

In 2000, 20% of gonorrhoea diagnoses in males overall, and 24% of those in London were known to be homosexually acquired.

Rates of syphilis have increased dramatically in males aged 20 to 44 years old and in females aged 16 to 34 years old. This reflects the emergence of several regional outbreaks since 1996. Outbreaks in London, Brighton and Manchester were among gay men, some of whom were also HIV-positive. The rise of ‘sexual marketplaces’ such as saunas and the internet has increased the opportunity to acquire new partners, and recent research has reported an increase in unsafe sex among gay men, particularly with a partner of unknown HIV status in London.

The National Strategy for Sexual Health and HIV has highlighted the need for the provision of better services aimed at young people. Since detailed, accurate, timely surveillance data are necessary to underpin sexual health initiatives in the UK, the report recommends that “a new suveillance initiative is required that will provide data to estimate the population burden of disease, monitor intervention strategies and evaluate risk factors associated with infection”.

Currently the dataset collected in GUM clinics in the UK is limited to gender and region; male sexual orientation and age group are only collected for certain conditions.