Sexually transmitted infections factsheet

Last updated November 2010

Sexually transmitted infections factsheet (PDF)

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Contents

Sources

United Kingdom (UK) statistics on sexually transmitted infections (STIs) are chiefly based on diagnoses made at genitourinary medicine (GUM) clinics(1). Chlamydia is also diagnosed in a variety of community settings.

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

This factsheet provides UK data. A variety of other sources provide country and regional data: England(1),(3),Wales (4),Scotland(5),(6),Northern Ireland(7).

In 2009 for the first time STI data were also made available by area of residence in England, rather than by clinic attended. These include overall figures by PCT of residence, and by ethnic group, continent of birth, gender, male sexual orientation and SHA of residence. This provides a truer picture of the sexual health of the population of an area(1).

General trends

  • In 2009 there were 482, 696 new STI diagnoses in the UK, 3 per cent more than in 2008.
  • Young people aged 15-24 years continue to be the group most affected by STIs in the UK. In 2009, around two thirds of new STI diagnoses in women were in those aged under 25, and over half of new diagnoses in men were in under 25s.
  • Rates of acute STIs were highest in residents of urban areas, particularly in London. This is likely to reflect higher incidence of socio-economic deprivation and higher concentrations of groups of the population who are at most risk of infection, such as young people and men who have sex with men.
  • The overall rise in diagnoses over the years can be attributed to a number of factors including: increased transmission through unsafe sex; improved availability of community-based chlamydia screening; increasing use of more sensitive diagnostic tests.

Chlamydia

  • Genital Chlamydial trachomatis is the most common STI diagnosed in the UK.
  • In 2009 there were 217, 570 new chlamydia diagnoses made at any clinical setting, 7 per cent more than in 2008. Three quarters of these were in the 15-24 age group.
  • The rate of new diagnoses was 348.7 per 100,000 population, compared with 326.1 in 2008.
  • The recent numbers and rates appear higher than those published in previous years as, for the first time in 2009, the data included diagnoses made in all settings rather than GUM clinics only.

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. 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(8).
  • 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(9).

Genital warts

  • Genital warts are the most common viral STI in the UK, with a gradual increase in cases since recording first began in the early 1970s.
  • There were 91, 257 new cases diagnosed in 2009, a slight decrease since 2008 (-0.3 per cent), the first such decrease for many years.
  • The overall rate of new diagnoses was 148.7 per 100,000 population, with the highest rates in women 16-19 (810.7) and men aged 20-24 (802.2).
  • There were 5,356 new diagnoses in the over 45 age group, 36 per cent more than in 2000. The rate increased from 16.1 to 21.1 per 100,000 population between 2000 and 2009.

Genital warts are the clinical visible manifestation of the human papilloma virus (HPV), mainly types 6 and 11.

Gonorrhoea

  • There were 17, 385 new cases diagnosed in 2009, 6 per cent more than in 2008. This was the first increase in several years.
  • The overall rate of new diagnoses was 27.7 per 100,000 population, with the highest rates in men aged 20-24 (151.0) and women aged 16-19 (123.4).
  • There were 1,225 diagnoses in the over 45 age group, 8 per cent more than in 2000. The rate increased from 4.7 to 4.8 per 100,000 population between 2000 and 2009.
  • Gonorrhoea is treated with antibiotics but laboratory tests show that the bacteria are becoming less sensitive to these drugs, which could make gonorrhoea increasingly difficult to treat in the future.

Syphilis

  • There were 3, 273 new cases diagnosed in 2009, a slight decrease since 2008 (-1 per cent). While numbers are relatively low, they have increased by over 600 per cent in the last 10 years.
  • Men accounted for 88 per cent of the diagnoses. Just over half of these cases were in men who have sex with men.
  • The overall rate of new diagnoses was 3.8 per 100,000 population. The highest rates were in men aged 25-34 (15.7) and 35-44 (14.6).
  • There were 535 diagnoses in the over 45 age group, 14 per cent more than in 2000. The rate increased from 1.9 to 2.1 per 100,000 population between 2000 and 2009.

Genital herpes

  • There were 30,126 new cases diagnosed in 2009, 5 per cent more than in 2008.
  • The overall rate of new diagnoses was 49.1 per 100,000 population. The highest rates were in women aged 20-24 (264.0) and 16-19 (219.7).
  • There were 3,025 diagnoses in the over 45 age group, 83 per cent more than in 2000. The rate increased from 6.8 to 11.9 per 100,000 population between 2000 and 2009.

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(10) 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(11). Greater use of highly sensitive molecular tests may also contribute to the more recent rises.

HIV/AIDS

  • In 2009, 6,630 new diagnoses of HIV in the UK were reported, compared with 7,388 in 2008(12). These were the diagnoses reported by the end of June 2010. Due to delays in reported diagnoses, this figure is expected to rise.
  • 54 per cent of infections were acquired through heterosexual intercourse. Two thirds (68 per cent) of these were acquired outside the UK.
  • 42 per cent of infections were acquired through sex between men. This group remains most at risk of acquiring HIV within the UK.
  • There were 547 AIDS diagnoses and 516 HIV-related deaths in 2009.

In 2008 there were an estimated 83,000 people living with HIV in the UK, with more than a quarter (27 per cent) being unaware of their infection(13). 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 Wales, Scotland and Northern Ireland have published policy documents which address sexual health issues, including the need to reduce the incidence of STIs (14,15,16). The Government in England is currently considering how to improve the nation’s sexual health and has commissioned a review (17).

References

1 Health Protection Agency, ‘STIs annual data tables’, accessed 20 September 2010.

2 Health Protection Agency, ‘HIV’, accessed 20 September 2010.

3 Health Protection Agency, ‘Sexual health profiles TREND map’. accessed 20 September 2010.

4 Public Health Wales, Health Protection Division, ‘Sexual Health and Blood Borne Viruses’, accessed 20 September 2010.

5 ISD Scotland, ‘STI (GUM) data’. accessed 22 September 2010.

6 Health Protection Scotland, ‘Blood Borne Viruses and Sexually Transmitted Infections’, accessed 22 September 2010.

7 Communicable Disease Surveillance Centre Northern Ireland, ‘Sexually Transmitted Infections’, accessed 22 September 2010.

8 National Chlamydia Screening Programme, NCSP: Five Years. The fifth annual report of the National Chlamydia Screening Programme2007/08, London:National Chlamydia Screening Programme, 2008.

9 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).

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

11 Azwa A and Barton SE, ‘Aspects of herpes simplex virus: a clinical review ’ (PDF), Journal of Family Planning and Reproductive Health Care, vol 35, no 4, (2009), 237-242.

12 Health Protection Agency Centre for Infections et al, United Kingdom New HIV Diagnoses to the end of June 2010 (London: HPA, 2010).

13 Health Protection Agency, HIV in the United Kingdom: 2009 report (London: HPA, 2009).

14 Welsh Assembly Government, Sexual Health and Wellbeing Action Plan for Wales, 2010-2015 (Cardiff: Welsh Assembly Government, 2010).

15 Scottish Executive. Respect and Responsibility. Strategy and Action Plan for Improving Sexual Health. Edinburgh: Scottish Executive, 2005.

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

17 HM Government, Department of Health response to the public’s comments on The Coalition: Our Programme for Government on Public health (London: HM Government, 2010).