Research and analysis

Spotlight on sexually transmitted infections in London: 2021 data

Updated 5 March 2024

Applies to England

Summary

This report focusses on sexually transmitted infections (STIs) in London reported in 2021, but 2022 data is presented for some infections where available. HIV is reported on separately. Please access the UK Health Security Agency (UKHSA)’s report on STIs and screening for chlamydia in England for a national perspective (1).

STIs remain an important public health problem in London. The region has the highest rate of new STIs in England.

More than 100,000 new STIs were diagnosed in London residents in 2021 (101,499), representing a rate of 1,127 diagnoses per 100,000 population, which is twice as high as the rate of 551 diagnoses per 100,000 population in England. Around a third of new STIs in England were diagnosed in London residents (33%).

Of the 20 upper tier local authorities in England with the highest sexually transmitted infection (STI) rates in 2021, 17 were in London. There is considerable geographical variation in rates across the capital. Rates by local authority ranged from 393 new STI diagnoses per 100,000 population in Sutton to 2,980 new STI diagnoses per 100,000 population in Lambeth.

The number of new STIs diagnosed in London residents in 2021 was 1% lower than in 2020 and 33% lower than in 2019. Between 2020 and 2021, the number of chlamydia diagnoses fell by 2%. Increases in diagnoses were reported in:

• genital warts (5%)
• syphilis (2%)
• gonorrhoea (less than 1%)
• genital herpes (less than 1%)

Overall, there was an increase in the number of consultations delivered by sexual health services (SHSs) in London in 2021 compared to 2020 (17% increase from 1,158,544 to 1,355,480).

Of all consultations in 2021:

• 48% (652,646) were via the internet (compared to 21% in 2019)
• 45% (611,821) were delivered face to face
• 7% (91,013) were via telephone

Compared to 2020, rises were seen in 2021 in consultations via the internet (29% increase), telephone (15% increase) and face to face (7% increase).

STI testing (excluding chlamydia in people aged under 25 years) in London increased by 20% between 2020 and 2021, but remained 11% lower than prior to the coronavirus (COVID-19) pandemic in 2019. There was a corresponding decrease in the STI positivity reported in London, from 9.2% in 2020 to 7.9% in 2021.

In 2021, the chlamydia detection rate among London residents aged 15 to 24 years (all recorded genders) was 1,673 per 100,000 residents, lower than the recommended detection rate indicator (DRI) prior to June 2021 of at least 2,300 per 100,000 residents aged 15 to 24 years (all recorded genders). The proportion of London residents aged 15 to 24 years screened for chlamydia increased from 19.5% in 2020 to 20.8% in 2021.

Men have higher rates of new STIs than women (1,479 and 747 per 100,000 residents, respectively).

Gay, bisexual and other men who have sex with men (GBMSM) experience health inequalities related to STIs. Where gender and sexual orientation are known, GBMSM account for 45% of London residents diagnosed with a new STI (excluding chlamydia diagnoses reported via Chlamydia Testing Activity Dataset (CTAD) surveillance system). They represent 84% of those diagnosed with syphilis and 72% of those diagnosed with gonorrhoea. The number of new STIs diagnosed in GBMSM in 2021 was similar to 2020.

STIs also continue to disproportionately affect young people. London residents aged between 15 and 24 years accounted for 30% of all new STI diagnoses in 2021. A steep decline (86% decrease) has been seen between 2017 and 2021 in genital warts diagnosis rates in females aged 15 to 19 years.

People in the black Caribbean ethnic group also experience health inequalities related to STIs. Although only 10% of new STIs are in the black Caribbean ethnic group, it has the highest rate (2,542 per 100,000), which is twice the rate seen in the white ethnic group. The white ethnic group has the highest number of new STI diagnoses (49,199; 56%).

Where country of birth was known, 56% of London residents diagnosed with a new STI in 2021 were UK-born (excluding chlamydia diagnoses reported via CTAD).

Mpox (monkeypox) is a zoonotic infection, caused by the monkeypox virus (MPXV), that previously occurred mostly in West and Central Africa. It is transmitted through close contact, including through sexual contact. Previous cases in the UK had been either imported from countries where mpox is endemic or contacts with documented epidemiological links to imported cases. In 2022, there was a very large outbreak of mpox in the UK, mainly in GBMSM. London was most affected, with 2,435 cases reported between 6 May and 19 December 2022 (69% of the England total) (2).

Shigella is a gut infection that causes diarrhoea and is caused by a bacteria found in faeces. Sex that may involve anal contact or contact with faeces is one way that the infection can spread. GBMSM are at increased risk. Following a fall in 2020, the number of Shigella infections among presumptive GBMSM in London rose during 2021 and peaked in quarter 2 of 2022 at a higher number than seen in 2019.

Implications for prevention

STIs continue to show marked geographic and socioeconomic variation and they disproportionately impact upon GBMSM, black ethnic groups, and young people aged 15 to 24 years.

STI prevention efforts should include a range of measures. Proactive health promotion and high quality health education improve risk awareness and encourage safer sexual behaviour and testing. Consistent and correct condom use substantially reduces the risk of being infected with an STI. Immunisation reduces the risk of being infected with certain infections. STI screening, open access to SHSs for STI diagnosis and treatment and robust contact tracing, allows earlier diagnosis and reduces the length of time that people are infectious. Such measures need to be effectively commissioned, including targeting those groups highlighted above who are at greatest risk.

Following the disruptions in service delivery during the first year of the COVID-19 pandemic, the number of consultations at SHSs for London residents increased between 2020 and 2021 and now exceeds the number reported in 2019 (pre-COVID-19 pandemic). This provides evidence of a recovery in service provision, after the lifting of COVID-19 restrictions in the summer of 2021, partially driven by the continued widespread provision of online consultations. Online consultations now make up a higher proportion of consultations for London residents than face-to-face consultations. The rise in online consultations was likely facilitated by the London Sexual Health Programme (a partnership of many London boroughs) working together to commission open access sexual health services pre-COVID-19 pandemic, including establishing an online (self-sampling) service (3).

The number of sexual health screens (for chlamydia, gonorrhoea, syphilis and HIV) in London also increased between 2020 and 2021, although the overall number of STI diagnoses remained stable. The decline in positivity in 2021 may indicate more testing among lower risk populations.

The increase in sexual health screens may be a result of built-up demand for SHSs, a return to pre-COVID-19 pandemic levels of social and sexual mixing, and the substantial number of tests being accessed through online services (4 to 7). It will remain important to understand whether the changes in how people use services has affected the equity of access (8), (9).

The high rates of STIs among young people aged 15 to 24 years are likely to be due to greater rates of partner change (10). Implementation of Relationships Education in primary schools, as well as Relationships, Sex and Health Education (RSHE) in all secondary schools is expected to provide young people with the information and skills to prepare to look after their sexual health (11), (12), (13).

Many areas in England continue to provide condom schemes, which distribute condoms to young people (mostly aged under 20 years) and other groups most at risk through a variety of outlets (14) and condoms are provided free from sexual health clinics for all ages.

The National HPV Vaccination Programme introduced vaccination against human papillomavirus (HPV), the virus which causes genital warts, for young women in 2008 and young men in 2019. The programme has achieved high coverage in young women and has been successful in producing a longer-term decline in genital warts since 2009, which continued to fall in 2021 in those aged 15 to 19 years. However, the total number of genital warts diagnoses in all ages increased overall from 2020 to 2021, which may be due to improved diagnosis due to increased face-to-face consultations.

Also targeted at young people is the National Chlamydia Screening Programme (NCSP). This report relates to 2021, for the most part of which the NCSP recommended an offer of screening to all sexually active young people aged under 25 years. In June 2021, the NCSP changed to focus on reducing reproductive harm of untreated infection primarily in young women (15). This led to a change in the recommended chlamydia DRI included in the Public Health Outcomes Framework (PHOF). UKHSA recommends that local authorities work towards the revised PHOF benchmark DRI of 3,250 per 100,000 females aged 15 to 24 years.

In 2021, the population rates of STI diagnoses remained high among people of black ethnicity, but this varies within black ethnic groups. Research has found that when compared to all other ethnic groups, there were no unique clinical or behavioural factors explaining the disproportionately high rates of STI diagnoses among people of black Caribbean ethnicity; this ethnic disparity in STIs is likely influenced by underlying socioeconomic factors and the role they play in the structural determinants of the health of this community (16).

Among GBMSM, diagnoses of STIs did not increase overall in 2021, but remained high, particularly gonorrhoea and infectious syphilis diagnoses, which suggests that rapid STI transmission is occurring in dense sexual networks through condomless sex, including those living with HIV. Condomless sex increases the risk of infection of a range of infections that can be transmitted sexually, including hepatitis B and hepatitis C.

As GBMSM continue to experience high rates of STIs, they remain a priority for targeted STI prevention and health promotion beyond HIV prevention, including immunisation against hepatitis A, hepatitis B, HPV and mpox.

There is a continued need to strengthen public health measures to reduce transmission of syphilis across the city. National clinical guidelines recommend frequent testing in high-risk GBMSM (17), but surveillance data suggests this is not uniformly carried out, especially in GBMSM living with HIV. There are also concerns about poor knowledge and awareness of syphilis among GBMSM (18). The Syphilis Action Plan includes recommendations to address the increase in syphilis diagnoses in England (19).

The rise in Shigella infections among presumptive GBMSM from 2021 into 2022 may reflect normalisation of mixing and health care seeking behaviour after COVID-19 pandemic restrictions were reduced. This rise in infections in the context of reports of extensively drug resistant infection (20) must result in a continued focus on promoting messages designed for GBMSM regarding practicing good hygiene during and after sex (21).

The 2022 mpox outbreak predominantly affected GBMSM. SHSs were instrumental in responding, including delivering vaccination to protect high risk GBMSM. The UK strategy for mpox control was published in December 2022 and outlines the UK’s plan to continue reducing mpox transmission (22).

Several established HIV prevention activities may also impact on wider STI control. The London HIV Prevention Programme (LHPP) is a London-wide sexual health promotion initiative, funded by London local authorities, aiming to promote combined prevention choices for Londoners (23). The Department of Health and Social Care (DHSC) commissioned Terrence Higgins Trust to deliver the National HIV Prevention Programme from November 2021 to March 2024. The programme aims to improve knowledge, understanding and uptake of combination HIV prevention interventions among populations most at risk of HIV in England, particularly aimed at GBMSM and people of black ethnicity and other groups that have a higher or emerging burden of infection (24).

UKHSA’s main messages

Providers and commissioners have an important role in communicating messages about safer sexual behaviours and how to access services.

Important prevention messages

Using condoms consistently and correctly protects against HIV and other STIs such as chlamydia, gonorrhoea, and syphilis, and can prevent unplanned pregnancy.

Regular screening for STIs and HIV is essential to maintain good sexual health. Everyone should have an STI screen, including an HIV test, on at least an annual basis if having condomless sex with new or casual partners.

In addition:

• women and other people with a womb or ovaries under the age of 25 years who are sexually active should have a chlamydia test annually and on change of sexual partner
• GBMSM should have an annual test for HIV and STIs or every 3 months if having condomless sex with new or casual partners

HIV pre-exposure prophylaxis (PrEP) can also be used to provide protection to people at risk of HIV while HIV post-exposure prophylaxis (PEP) can be used after condomless sex if someone has potentially been exposed to HIV, to reduce the risk of contracting HIV. Both of these can be obtained from specialist SHSs.

People living with diagnosed HIV who are on treatment and have an undetectable viral load are unable to pass on the infection to others during sex. This is known as ‘Undetectable = Untransmittable’ or ‘U=U’.

Vaccination against MPXV, HPV, hepatitis A and hepatitis B will protect against disease caused by these viruses and prevent the spread of these infections:

• GBMSM can obtain the mpox, hepatitis A and hepatitis B vaccines from specialist SHSs; these vaccines are also available for other people at high risk of exposure to the viruses
• GBMSM aged 45 years and under can also obtain the HPV vaccine from specialist SHSs

SHSs are free and confidential and offer testing and treatment for HIV and STIs, condoms, vaccination, HIV PrEP, and PEP:

• online self-sampling for HIV and STIs is widely available
• information and advice about sexual health including how to access services is available at Sexwise and from the national sexual health helpline on 0300 123 7123

Charts, tables and maps

Figure 1. New STI diagnosis rates by UKHSA region of residence, England, 2021

Data sources: GUMCAD (previously known as Genitourinary Medicine Clinic Activity Dataset) STI surveillance system, CTAD

Figure 1 is a bar chart showing the rate of new STI diagnosis in London (1,127.5 per 100,000 population). The London rate is the highest among English regions in 2021.

Figure 2. Number of diagnoses of the 5 main STIs, London residents, 2017 to 2021

Data sources: GUMCAD, CTAD

[note 1] Any increase in gonorrhoea diagnoses may be due to the increased use of highly sensitive nucleic acid amplification tests (NAATs) and additional screening of extra-genital sites in GBMSM. Any decrease in genital wart diagnoses may be due to a moderately protective effect of HPV-16/18 vaccination. Any increase in genital herpes diagnoses may be due to the use of more sensitive NAATs. Increases or decreases may also reflect changes in testing practices.

Figure 2 shows trend lines of the number of diagnoses of the 5 main STIs for London residents from 2017 to 2021. The highest number of diagnoses over the 5 years was in chlamydia. This was followed by gonorrhoea, genital warts and genital herpes.

Figure 3. Diagnosis rates of the 5 main STIs, London residents, 2017 to 2021

Data sources: GUMCAD, CTAD

See [note 1] above.

Figure 3 shows trend lines of the rate of diagnosis per 100,000 population of the 5 main STIs in London from 2017 to 2021. The highest rate of diagnosis is in chlamydia. This is followed by gonorrhoea, genital warts and genital herpes.

Table 1. Percentage change in new STI diagnoses, London residents

Diagnoses	2021	Percentage change from 2017 to 2021	Percentage change from 2020 to 2021
New STIs	101,499	-14%	-1%
Syphilis	3,640	7%	2%
Gonorrhoea	25,041	24%	0%
Chlamydia	43,191	-10%	-2%
Genital herpes	5,463	-32%	1%
Genital warts	7,216	-43%	5%

Data sources: GUMCAD, CTAD

See [note 1] above.

Table 1 shows a 14% drop of new STIs from 2017 to 2021 and a 1% drop from 2020 to 2021.

Between 2017 and 2021, the largest proportional rise was seen in gonorrhoea (24% increase) and syphilis (7% increase), with the largest fall being in genital herpes (32% decrease) and genital warts (43% decrease).

From 2020 to 2021, falls were seen in chlamydia (2% decrease) and rises in genital warts (5% increase), genital herpes (1% increase) and syphilis (2% increase).

Figure 4. Rates of new STIs per 100,000 residents by age group (for those aged 15 to 64 years only) and gender in London, 2021

Data sources: GUMCAD, CTAD

Figure 4 is a bar chart showing the rate of new STIs by age group. The rate of new STIs per 100,000 were highest among both males and females aged 20 to 24 years (3,956.8 and 4,098 per 100,000 respectively). Rates are also high among males aged 25 to 34 years (3,657.1 per 100,000) and females aged 15 to 19 years (2,150.5 per 100,000).

Figure 5. Rates of gonorrhoea per 100,000 residents by age group [note 2] in London, 2017 to 2021

Data sources: GUMCAD

[note 2] Age-specific rates are shown for those aged 15 to 64 years only.

Figure 5 shows trend lines for rates of gonorrhoea per 100,000 in London from 2017 to 2021. Rates were highest among those aged 20 to 24 years and those aged 25 to 34 years. Rates of gonorrhoea declined in the last 2 years among those aged 15 to 19 years.

Figure 6. Rates of genital warts per 100,000 residents aged 15 to 19 years by gender in London, 2017 to 2021

Data sources: GUMCAD

Figure 6 shows trend lines for the rates of genital warts among residents aged 15 to 19 years by gender in London. It shows that rates have fallen steeply for females from 2017 to 2021 and fallen for males from 2018 to 2021.

Figure 7. Rates of new STIs by ethnic group per 100,000 residents in London, 2021

Data sources: GUMCAD, CTAD

Figure 7 is a bar chart showing rates by ethnic group per 100,000 population of London residents diagnosed with the new STI in 2021. It shows the rate of new STIs per 100,000 is higher among the black Caribbean ethnic group compared to the other ethnic groups.

Table 2. Proportion of London residents diagnosed with a new STI by ethnicity, 2021

Ethnic group	Number	Percentage excluding unknown
White	49,199	56%
Black Caribbean	8,759	10%
Black African	8,174	9%
All other ethnic groups combined	22,344	25%
Unknown	13,023

Data sources: GUMCAD, CTAD

Table 2 shows the number and proportion of London residents diagnosed with a new STI by ethnicity in 2021. It shows the number and proportion of new STIs were highest in the white ethnic group (49,199). Where ethnicity was known, the black Caribbean ethnic group made up 10% of the total new STIs, and the black African ethnic group made up 9%.

Figure 8. Proportion of London residents diagnosed with a new STI by world region of birth [note 3], 2021

Data sources: GUMCAD data only

[note 3] Data on country of birth is not collected by CTAD. All information about world region of birth is based on diagnoses made in specialist and non-specialist services, which report to GUMCAD.

Figure 8 is a bar chart showing the proportion of London residents diagnosed with a new STI by world region of birth in 2021. It shows that 56% of London residents diagnosed with a new STI were born in the UK, 19% were born in Europe (excluding UK), 6% born in Central and South America, 5% born in Sub-Saharan Africa, 2% born in the Caribbean, 2% born in south Asia and 1% born in North America.

Figure 9. Diagnoses of the 5 main STIs among GBMSM [note 4], London residents, 2017 to 2021

Data sources: GUMCAD data only

[note 4] Data on sexual orientation is not collected by CTAD. All information about GBMSM is based on diagnoses made in specialist and non-specialist services, which report to GUMCAD.

Any increase in gonorrhoea diagnoses may be due to the increased use of highly sensitive NAATs and additional screening of extra-genital sites in GBMSM. Any decrease in genital wart diagnoses may be due to a moderately protective effect of HPV-16/18 vaccination. Any increase in genital herpes diagnoses may be due to the use of more sensitive NAATs. Any increase or decrease may reflect changes in testing.

Figure 9 shows trend lines for diagnoses of the 5 main STIs in specialist sexual health clinics among GBMSM, from 2017 to 2021. It shows that the largest increase was in gonorrhoea. There were smaller numbers of syphilis, genital warts and genital herpes diagnoses over the 5 years.

Table 3. Percentage change in new STI diagnoses in GBMSM residents in London

Diagnoses	2021	Percentage change from 2017 to 2021	Percentage change from 2020 to 2021
New STIs	31,679	8%	0%
Syphilis	2,701	-9%	-8%
Gonorrhoea	16,315	30%	2%
Chlamydia	7,898	-1%	-3%
Genital herpes	638	-9%	-8%
Genital warts	740	-40%	13%

Data sources: GUMCAD

See [note 4] above.

Table 3 shows the number of the main STI diagnoses among GBMSM London residents in 2021 and the percentage change since 2017 and 2020.

From 2017 to 2021, the percentage increase among GBMSM was highest for gonorrhoea and the percentage decrease was greatest for genital warts. Between 2020 and 2021, the percentage increase was highest for genital warts (13%) and decrease greatest for both syphilis (8%) and genital herpes (8%).

Figure 10a. Rate of new STI diagnoses per 100,000 population among London residents by local authority of residence, 2021

Data sources: GUMCAD, CTAD

Figure 10a is a bar chart showing the rate of new STI diagnoses per 100,000 population among London residents by local authority of residence in 2021. It shows that the rate of new STIs for all ages was highest in Lambeth (2,980). Seven local authorities had rates below the England average (Richmond upon Thames, Bromley, Hillingdon, Redbridge, Havering, Bexley and Sutton).

Figure 10b. Rate of new STI diagnoses (excluding chlamydia diagnoses in people aged 15 to 24 years) per 100,000 population aged 15 to 64 years among London residents by local authority of residence, 2021

Data sources: GUMCAD, CTAD

Figure 10b is a bar chart showing the rate of new STI diagnoses (excluding chlamydia diagnoses in people aged 15 to 24 years) per 100,000 population aged 15 to 64 years among London residents by local authority in 2021. The rate of new STIs for all ages was highest in Lambeth (3,502) and lowest in Sutton (459).

Figure 11. Chlamydia detection rate per 100,000 population aged 15 to 24 years in London residents by local authority of residence, 2021

Data sources: GUMCAD, CTAD

Figure 11 is a bar chart showing the chlamydia detection rate per 100,000 population aged 15 to 24 years in London by local authority of residence in 2021. The chlamydia detection rate among 15 to 24 year olds was highest in Lambeth (3,063).

Figure 12. Rate of gonorrhoea diagnoses per 100,000 population in London residents by local authority of residence, 2021

Data sources: GUMCAD

Figure 12 is a bar chart showing the rate of gonorrhoea diagnoses per 100,000 population in London by local authority of residence in 2021. It shows the rate of gonorrhoea was highest among residents in Lambeth (1,006) and lowest in Sutton (52).

Figure 13. Map of new STI rates per 100,000 residents by local authority in London, 2021

Data sources: GUMCAD, CTAD. Contains Ordnance Survey data © Crown copyright and database right 2021. Contains National Statistics data © Crown copyright and database right 2021.

Figure 13 shows a map of new STI rates per 100,000 residents by local authority in 2021. The map shows the rate of new STIs for all ages was higher in the inner London areas and lower in the outer London areas.

Figure 14. Map of new STI rates per 100,000 residents by middle super output area (MSOA) in London, 2021

Data sources: GUMCAD, CTAD

Figure 14 shows a map of new STI rates per 100,000 residents by middle super output area in 2021. The map shows the rate of new STIs for all ages was higher in the inner London areas (particularly in South London) and lower in the outer London areas.

Figure 15. STI testing rate (excluding chlamydia in those aged under 25 years) per 100,000 population in London residents aged 15 to 64 years, 2017 to 2021

Data sources: GUMCAD, CTAD

Figure 15 shows trend lines for the STI testing rate (excluding chlamydia in those aged under 25 years) per 100,000 population in London and England residents aged 15 to 64 years from 2017 to 2021. The STI testing rate in London remains higher than the England rate for residents over the 5 years, with both increasing between 2017 and 2021. Testing rates in both England and London fell between 2019 and 2020, before increasing again in 2021, but to below the level seen in 2019.

Figure 16. STI testing positivity rate [note 5] (excluding chlamydia in those aged under 25 years) in London residents, 2017 to 2021

Data sources: GUMCAD, CTAD

[note 5] The numerator for the STI testing positivity rate now only includes infections, which are also included in the denominator. These are chlamydia (excluding diagnoses in those aged under 25 years), gonorrhoea, syphilis and HIV. Up to 2018 (data for 2017), it included all new STIs.

Figure 16 shows trend lines for the STI testing positivity rate (excluding chlamydia in those aged under 25 years) in London and England residents from 2017 to 2021. It shows the STI testing positivity rate in the London was higher than the England rate over the 5 years, with the positivity falling since 2020 in London.

Table 4. Number of diagnoses of new STIs by UKHSA region of residence, data source and data subset 2021

UKHSA region of residence	GUMCAD specialist SHSs	GUMCAD non-specialist SHSs [note 6]	CTAD [note 7]	Total
East Midlands	10,622	6,275	3,974	20,871
East of England	15,809	4,238	5,608	25,655
London	69,545	8,162	23,792	101,499
North East	7,495	1,580	2,718	11,793
North West	23,693	3,789	7,954	35,436
South East	26,578	1,960	8,287	36,825
South West	13,797	2,444	4,782	21,023
West Midlands	16,890	3,867	4,804	25,561
Yorkshire and Humber	16,031	2,050	7,724	25,805

Data sources: GUMCAD, CTAD

[note 6] Diagnoses from enhanced GPs reporting to GUMCAD are included in the ‘non-specialist sexual health services’ total.

[note 7] Including site type 12 chlamydia from GUMCAD.

Table 4 shows the number of diagnoses of new STIs by UKHSA region of residence, data source and data subset in 2021. It shows London had a total of 101,499 new STI diagnoses in 2021. 69% of new STI diagnoses in London residents were made at specialist SHSs.

Table 5. Number of diagnoses of the 5 main STIs in London by STI, data source and data subset 2021

5 main STIs	GUMCAD specialist SHSs	GUMCAD non-specialist SHSs [note 8]	CTAD [note 9]	Total
Syphilis	3,621	19		3,640
Gonorrhoea	18,175	6,866		25,041
Chlamydia	18,908	491	23,792	43,191
Genital herpes	5,240	223		5,463
Genital warts	6,968	248		7,216

Data sources: GUMCAD, CTAD

[note 8] Diagnoses from enhanced GPs reporting to GUMCAD are included in the ‘Non-specialist sexual health services (SHSs)’ total.

[note 9] Including site type 12 chlamydia from GUMCAD.

Table 5 shows the number of diagnoses of the 5 main STIs in London by STI, data source and data subset in 2021. It shows that apart from chlamydia, the majority of the 5 main STIs were diagnosed in specialist SHSs.

Figure 17. Shigella diagnoses in London residents presumed GBMSM by year and quarter, 2017 to quarter 3 of 2022

Data source: Second Generation Surveillance System

Figure 17 shows a trend line for the number of diagnoses of Shigella by year and quarter of diagnosis over the 6 year period from 2017 to 2022. It shows that, after falling from a mid-2019 high to lower levels during the COVID-19 pandemic period, Shigella diagnoses in London residents started to increase again in 2021. By quarter 2 2022, they were higher than seen in 2019.

Figure 18. Level 2 or 3 SHS consultations by consultation medium, London residents, 2017 to 2021

Data source: GUMCAD, CTAD

Figure 18 is a bar chart that shows the number of consultations in London residents attending SHSs (levels 2 or 3) over the 5 year period from 2017 to 2021 by the consultation medium. It shows that the number and proportion of consultations that took place online almost doubled between 2019 and 2020, the first year of the COVID-19 pandemic. It also shows that online consultations now make up nearly half of all consultations for London residents, but that face-to-face consultations have started to increase again in 2021. Telephone consultations have also increased but make up a far smaller proportion of all consultations than the other 2 mediums.

Information on data sources

Find more information on local sexual health data sources on GOV.UK.

These slides are based on data from the GUMCAD and CTAD surveillance systems published on 4 October 2022 (data to the end of calendar year 2021).

GUMCAD surveillance system

This disaggregate reporting system collects information about attendances and diagnoses at specialist (level 3) and non-specialist (level 2) sexual health services. Information about the patient’s area of residence is collected along with demographic data and other variables. GUMCAD superseded the earlier KC60 system and can provide data from 2009 onwards. GUMCAD is the main source of data for this report.

Due to limits on how much personally identifiable information sexual health clinics are able to share, it is not possible to deduplicate between different clinics. There is a possibility that some patients may be counted more than once if they are diagnosed with the same infection (for infection specific analyses) or a new STI of any type (for new STI analyses) at different clinics during the same calendar year.

CTAD surveillance system

CTAD collects data on all NHS and local authority or NHS-commissioned chlamydia testing carried out in England. CTAD is comprised of all chlamydia (NAATs) tests for all ages (with the exception of conjunctival samples), from all venues and for all reasons. CTAD enables unified, comprehensive reporting of all chlamydia data, to effectively monitor the impact of the NCSP through estimation of the coverage of population screening, proportion of all tests that are positive and detection rates.

For services that report to GUMCAD and for which CTAD does not receive data on the patient’s area of residence (for example SHSs), information about chlamydia diagnoses is sourced from GUMCAD data.

New STIs

New STI diagnoses comprise diagnoses of the following:

• chancroid
• lymphogranuloma venereum (LGV)
• donovanosis
• chlamydia
• gonorrhoea
• genital herpes (first episode)
• HIV (acute and AIDS defining)
• molluscum contagiosum
• non-specific genital infection (NSGI)
• non-specific pelvic inflammatory disease (PID) and epididymitis
• chlamydial PID and epididymitis (presented in chlamydia total)
• gonococcal PID and epididymitis (presented in gonorrhoea total)
• scabies
• pediculosis pubis
• syphilis (primary, secondary and early latent)
• trichomoniasis and genital warts (first episode)
• mycoplasma genitalium
• Shigella

Calculations

Confidence intervals were calculated using Byar’s method.

Office of National Statistics (ONS) mid-year population estimates for 2020 were used as a denominator for rates for 2021. ONS estimates for 2011 were used as a denominator for rates for 2021 as these reports were produced before the estimates for 2021 (the first produced since 2011) were published.

Further information

As of 2020, all analyses for this report include data from non-specialist (level 2) SHSs and enhanced GP services as well as specialist (level 3) SHSs.

For further information, access the online Sexual and Reproductive Health Profiles.

Find more information on local sexual health data sources on GOV.UK.

Local authorities have access to the Summary Profile of Local Authority Sexual Health (SPLASH) Reports (accessible from the Sexual and Reproductive Health Profiles) and the SPLASH supplement reports via the HIV and STI Data exchange.

For an Annual Epidemiological Spotlight on HIV in London, contact fes.seal@ukhsa.gov.uk

About the Field Service

The Field Service was established in 2018 as a national service comprising geographically dispersed multi-disciplinary teams integrating expertise in Field Epidemiology, Real-time Syndromic Surveillance, Public Health Microbiology and Food, Water and Environmental Microbiology to strengthen the surveillance, intelligence and response functions of UKHSA.

You can contact your local Field Service team at fes.seal@ukhsa.gov.uk

If you have any comments or feedback regarding this report or the Field Service, contact josh.forde@ukhsa.gov.uk

Acknowledgements

We would like to thank:

• local SHSs for supplying the SHS data
• local laboratories for supplying the CTAD data
• UKHSA Blood Safety, Hepatitis, Sexually Transmitted Infections (STI) and HIV Division for collection, analysis and distribution of data

References

1. Migchelsen S, Sonubi T, Ratna N, Harb AK, Enayat Q, Anderson A, Charles H, Green F, Dunn J, Shaw D, Walker S, Sinka K, Folkard K, Mohammed H and contributors. Sexually transmitted infections and screening for chlamydia in England, 2021 UK Health Security Agency (UKHSA) October 2022 (viewed on 22 February 2023)

2. UKHSA. Mpox (monkeypox) outbreak: epidemiological overview, 20 December 2022 (viewed on 22 February 2023)

3. Sexual Health London. London has the highest prevalence of STIs and HIV in the country

4. Mitchell KR, Shimonovich M, Bosó Pérez R, Dema E, Clifton S, Riddell J and others. Initial Impacts of COVID-19 on sex life and relationship quality in steady relationships in Britain: Findings from a large, quasi-representative Survey (Natsal- COVID) Journal of Sex Research March 2022: pages 1 to 12 (viewed on 11 August 2022)

5. Howarth A, Saunders J, Reid D, Kelly I, Wayal S, Weatherburn P, Hughes G and Mercer C. Stay at home ….: Exploring the impact of the COVID-19 public health response on sexual behaviour and health service use among men who have sex with men: findings from a large online survey in the United Kingdom Sexually Transmitted Infections July 2022: pages 346 to 352 (viewed on 11 August 2022)

6. Dema E, Gibbs J, Clifton S and others. Initial impacts of COVID-19 on sexual and reproductive health service use and unmet need in Britain: findings from a large, quasi-representative survey (Natsal-COVID) Lancet Public Health 2022: volume 7, pages e36 to 47

7. Sonnenberg P, Menezes D, Freeman L and others. Intimate physical contact between people from different households during the COVID-19 pandemic: a mixed-methods study from a large, quasi-representative survey (Natsal-COVID) British Medical Journal Open 2022: volume 12, issue 2 (viewed on 11 August 2022)

8. Ratna N, Dema E, Conolly A and others. O16 Ethnic variations in sexual risk behaviour, sexual health service use and unmet need during the first year of the COVID-19 pandemic: an analysis of population-based survey and surveillance data Sexually Transmitted Infections 2022: volume 98, pages A8 to A9 (viewed on 11 August 2022)

9. Sumray K, Lloyd KC, Estcourt CS, Burns F and Gibbs J. Access to, usage and clinical outcomes of, online postal sexually transmitted infection services: a scoping review Sexually Transmitted Infections June 2022: pages 1 to 8 (viewed on 11 August 2022)

10. Mercer CH and others. ‘Changes in sexual attitudes and lifestyles in Britain through the life course and over time: findings from the National Surveys of Sexual Attitudes and Lifestyles (Natsal)’ Lancet 2013: volume 382, issue 9,907, pages 1,781 to 1,794

11. Macdowall W, Jones KG, Tanton C, Clifton S, Copas AJ, Mercer CH and others. ‘Associations between source of information about sex and sexual health outcomes in Britain: findings from the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3)’ British Medical Journal Open 2015: volume 5 issue 3, e007837

12. Sex Education Forum. Sex and Relationship Education (SRE) – the evidence 2015 (viewed 24 December 2021)

13. Department for Education. ‘Policy statement: relationships education, relationships and sex education, and personal, social, health and economic education’ 2017

14. Ratna N, A N, Hadley A, Brigstock-Barron O. Condom Distribution Schemes in England 2015 to 2016 Public Health England (PHE) 2017 (viewed on 1 December 2021)

15. NCSP: programme overview (viewed on 31 January 2023)

16. Bardsley M, Wayal S, Blomquist P, Mohammed H, Mercer CH, Hughes G. Improving our understanding of the disproportionate incidence of STIs in heterosexual-identifying people of black Caribbean heritage: findings from a longitudinal study of sexual health clinic attendees in England Sexually Transmitted Infections 2022: volume 98, pages 23 to 31 (viewed on 17 August 2022)

17. Clutterbuck D and others. ‘2016 United Kingdom national guideline on the sexual health care of men who have sex with men’ International Journal of STD and AIDS 2018: page 95,646,241,774,689

18. Datta J and others. ‘Awareness of and attitudes to sexually transmissible infections among gay men and other men who have sex with men in England: a qualitative study’ Sexual Health 2019: volume 16, issue 1, pages 18 to 24

19. Addressing the increase in syphilis in England: PHE Action Plan June 2019 (viewed on 31 January 2023)

20. UKHSA press release. Rise in extremely drug-resistant Shigella in gay and bisexual men

21. UKHSA. Shigella: leaflet and poster for men who have sex with men

22. UKHSA. UK strategy for mpox control, 2022 to 2023 December 2022 (viewed on 31 January 2023)

23. London HIV Prevention Programme. Four sure ways to prevent HIV

24. HIV prevention England (viewed on 1 December 2021)