Introduction

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Statistical sources

United Kingdom (UK) statistics on sexually transmitted infections (STIs) are based on diagnoses made at genitourinary medicine (GUM) clinics(1). These will underestimate true prevalence as diagnoses made in other healthcare settings such as family planning clinics and general practice are not included, and many infections such as genital chlamydia and gonorrhoea often show no symptoms and remain undiagnosed. 

Data for HIV diagnoses and AIDS are collated from a number of surveillance reports across the UK(2).

General trends

• In a survey of sexual attitudes and lifestyles in Great Britain(3), 10.8 per cent of men and 12.6 per cent of women aged 16–44 reported ever having a sexually transmitted infection.
• In 2008, there were 399,738 new sexually transmitted infection diagnoses at GUM clinics in the UK, an increase of 53 per cent on 1999(1).
• Between 2007 and 2008 the number of new diagnoses increased by 0.5 per cent.
• Between 1999 and 2008 the largest increases were seen in diagnoses of genital chlamydia which rose by 116 per cent, genital herpes by 65 per cent and syphilis by 1,032 per cent.

The overall rise in diagnoses over the years can be attributed to a number of factors including increased transmission, a greater awareness of sexually transmitted infections leading to more people coming forward for testing, improved acceptability of GUM clinics and the development of more sensitive diagnostic tests.

• In 2008, 1.2 million sexual health screens were carried out at GUM clinics in the UK, an increase of nearly 50 per cent since 2004.

Chlamydia

• Genital chlamydia remains the most common bacterial sexually transmitted infection seen at GUM clinics in the UK, with 123,018 diagnoses in 2008, a rise of 1 per cent since 2007.
• The overall rate of new diagnoses was 201.8 per 100,000 population.
• The highest rates of diagnoses were among women aged 16–19 (1,405.8 per 100,000) and 20–24 (1,168.4 per 100,000) and men aged 20–24 (1,163.3 per 100,000).
• Young people aged 16–24 years accounted for 65 per cent of all new diagnoses. 
• If diagnoses in other community settings are included, the total number of chlamydia diagnoses reported in the UK in 2008, was 200,959(4).

Obtaining accurate estimates of the true prevalence of chlamydia is difficult as the infection is often asymptomatic and is liable to remain undetected. A National Chlamydia Screening Programme (NCSP) for sexually active women and men under 25 years of age has been in operation in England since April 2003. By March 2008, all Primary Care Trusts were taking part. Scotland, Wales and Northern Ireland have not set up national chlamydia screening programmes.

• Over the first five years of the NCSP in England, around one in ten of those screened were found to be positive(5).
• If not treated, 10-40 per cent of women with genital chlamydial infection will develop pelvic inflammatory disease (PID). A significant proportion of chlamydia cases will have no, or only mild symptoms, so are likely to remain undetected. PID can result in tubal factor infertility, ectopic pregnancy and chronic pelvic pain(6).

Genital warts

• Genital warts are the most common viral sexually transmitted infection diagnosed at GUM clinics in the UK, with 92,525 diagnoses in 2008, a rise of 3.4 per cent since 2007.
• The overall rate of new diagnoses was 151.7 per 100,000 population.
• The highest rates of diagnoses were in women aged 16–19 (849.6 per 100,000) and men aged 20–24 (816.2 per 100,000).

Diagnoses of genital warts at GUM clinics across the UK have been slowly increasing, and many more cases are likely to be diagnosed and treated in other healthcare settings such as general practice.

Genital warts are the clinical visible manifestation of the human papilloma virus (HPV), mainly types 6 and 11. Some high-risk types of HPV are associated with cervical cancer; however these rarely show up as visible warts and are likely to remain undiagnosed.

Gonorrhoea

• There were 16,629 diagnoses of gonorrhoea at GUM clinics in the UK in 2008, a fall of 11 per cent since 2007. New cases are now at their lowest levels since 1999.
• The overall rate of new diagnoses was 27.3 per 100,000.
• The highest rates of diagnoses were in women aged 16–19 (134.8 per 100,000) and men aged 20–24 (151.8 per 100,000).
• Men accounted for 67 per cent of the overall diagnoses, with nearly a third of these occurring in men who have sex with men (MSM).

Rates for gonorrhoea are highest in predominantly urban regions, and higher in London (77.5 per 100,000) than any other part of the UK. This is likely to reflect the sub groups most at risk; in the UK these include MSM and black ethnic groups.

Syphilis

• There were 2,524 diagnoses of syphilis at GUM clinics in the UK in 2008, a fall of four per cent since 2007.
• Men accounted for 89 per cent of the diagnoses; the highest rate occurred in the 25–44 age group (16.0 per 100,000).
• In 2008, 62 per cent of all syphilis diagnoses in males were among MSM.

Although syphilis remains a relatively rare condition, there was a substantial increase in the number of diagnoses between the late 1990s and 2005, mainly due to localised outbreaks, particularly in Bristol, London, Brighton and Manchester. Many of the cases were among MSM, however heterosexual men and women have also been affected. Although numbers of diagnoses are relatively small, transmission in heterosexuals is of concern because it increases the likelihood of congenital syphilis.

Genital herpes

• There were 28,957 diagnoses of first episode genital herpes simplex at GUM clinics in the UK in 2008, an increase of 10 per cent since 2007.
• The overall rate of new diagnoses was 47.5 per 100,000.
• The highest rates of diagnoses were in women aged 16–19 (228.7 per 100,000) and 20–24 (251.4 per 100,000).

Diagnoses of genital herpes made at GUM clinics are likely to underestimate true prevalence as many people will be diagnosed and treated in other healthcare settings or may not seek treatment at all.

Genital herpes is caused by the herpes simplex virus (HSV) which has two subtypes, 1 (HSV-1) and 2 (HSV-2). Both types can cause symptoms on the genitals but also on the face (cold sores). Changes in sexual behaviour where oral sex is becoming more common(7) and a decreased immunity in young people to HSV-1 have been identified as a contributing factor to a rise in incidence of genital herpes(8). Greater use of highly sensitive molecular tests may also contribute to the more recent rises. 

HIV/AIDS

By 31 December 2008(9):

• 7,370 new diagnoses of HIV in the UK had been reported, compared with 7,660 in 2007. Due to delays in reported diagnoses, this figure is expected to rise
• 57 per cent of infections were acquired through heterosexual intercourse. Three quarters of these were acquired outside the UK
• 38 per cent of infections were acquired through sex between men. MSM remain most at risk of acquiring HIV within the UK
• there were 529 AIDS diagnoses and 484 HIV-related deaths, compared with 818 diagnoses and 514 HIV-related deaths in 1998.

In 2007 there were an estimated 77,400 people living with HIV in the UK, with more than a quarter (28 per cent) being unaware of their infection(10). Highly active antiretroviral therapies (HAART) have resulted in substantial reductions in AIDS incidence and deaths in the UK, which, in turn, has led to an increase in the number of people needing long-term treatment.

Government policy

Governments in each UK country have all published policy documents which address sexual health issues, including the need to reduce the incidence of STIs.(11, 12, 13, 14)

References

1 Health Protection Agency, ‘STIs annual data’, accessed 3 August 2009.

2 Health Protection Agency, ‘HIV’, accessed 3 August 2009.

3 Fenton K et al, ‘Sexual behaviour in Britain: reported sexually transmitted infections and prevalent genital Chlamydia trachomatis infection’, Lancet , vol 358, (2001), 1851–1854.

4 Health Protection Agency, Chlamydia diagnoses reported in the UK and England: 2008 (London: Health Protection Agency, 2009).

5 National Chlamydia Screening Programme, NCSP: Five Years. The fifth annual report of the National Chlamydia Screening Programme 2007/08 (London: National Chlamydia Screening Programme, 2008).

6 British Association of Sexual Health and HIV, UK National Guideline for the Management of Genital Tract Infection with Chlamydia trachomatis (London: British Association of Sexual Health and HIV, 2006).

7 Johnson AM, ‘Sexual behaviour in Britain: partnerships, practices, and HIV risk behaviours’, Lancet, vol 358, (2001), 1835–1842.

8 Gupta R et al, ‘Genital herpes’, Lancet, vol 370, (2007), 2127–2138. 

9 Health Protection Agency Centre for Infections et al, United Kingdom HIV New Diagnoses to the end of December 2008 (London: Health Protection Agency, 2009).

10 Health Protection Agency, HIV in the United Kingdom: 2008 report. (London: Health Protection Agency, 2008).

11 Department of Health, National Strategy for Sexual Health and HIV (London: Department of Health, 2001).

12 National Assembly for Wales, A Strategic Framework for Promoting Sexual Health in Wales (Cardiff: National Assembly for Wales, 2000).

13 Scottish Executive, Respect and Responsibility. Strategy and action plan for improving sexual health (Edinburgh: Scottish Executive, 2005).

14 Northern Ireland Department of Health, Social Services and Public Safety, Sexual Health Promotion: Strategy and Action Plan 2008–2013 (Belfast: Northern Ireland Department of Health, Social Services and Public Safety, 2008).

Further information

For further information on the material covered in this factsheet, and other subjects related to sexual health, contact the FPA Library and Information Service. Email: libraryandinformation@fpa.org.uk. Tel: 020 7608 5282.

sexual health direct is supported by the Department of Health.