Research and analysis

Spotlight on sexually transmitted infections in the South East: 2023 data

Updated 15 July 2025

Applies to England

Summary

This report focuses on sexually transmitted infections (STIs) in the South East. HIV is reported on separately. Please access the UK Health Security Agency (UKHSA) report on STIs and screening for chlamydia in England for a national perspective (1).

While this report primarily focuses on the trend between 2022 and 2023, some trends relative to 2019 or earlier are included to provide a comparison to sexual health service (SHS) provision and STI diagnoses prior to the COVID-19 pandemic. For England, the numbers of consultations, sexual health screens and STI diagnoses in 2020 and 2021 are lower than preceding years and any trends in diagnoses between 2021 and 2022 must be interpreted in that context.

STIs represent a significant public health problem in the South East. More than 46,000 new STIs were diagnosed in South East residents in 2023, representing a rate of 507 diagnoses per 100,000 population. This is lower than the overall rate in England (740 per 100,000). Rates by upper-tier local authority (UTLA) ranged from 318 new STI diagnoses per 100,000 population in West Berkshire to 1,610 in Brighton and Hove.

The number of new STIs diagnosed in South East residents increased by 11% between 2022 and 2023. During this time, there was an increase in the number of diagnoses of:

• gonorrhoea (15%)
• genital herpes (10%)
• chlamydia (8%)
• genital warts (2%)

There was a slight fall in the number of syphilis diagnoses (1%). The rise in gonorrhoea was seen for gay, bisexual and other men who have sex with men (GBMSM) (14%), among heterosexual men (15%) and heterosexual women (21%). A sharp increase in genital herpes (26%) and lymphogranuloma venereum (LGV) (122%) was also seen among GBMSM. Additionally, there was an increase in Mycoplasma genitalium among GBMSM (19%), heterosexual men (37%) and heterosexual women (52%).

Compared to 2019, there were 20% fewer new STIs in South East residents in 2023. Over the 5-year period, genital warts have almost halved (48% reduction), chlamydia has decreased by 23%, and genital herpes fell by 17%. However, a rise was seen in gonorrhoea (16%) with the largest increase among GBMSM (21%) and heterosexual women (19%). Syphilis increased by 3%.

Of the 603,653 SHS consultations in 2023, 51% (306,304) were delivered face-to-face, 36% (219,526) online and 13% (77,823) via telephone. There was a 7% increase in the number of consultations from 2022 (566,802) to 2023. Compared to 2019 (pre-pandemic year), there was a 24% decrease in face-to-face consultations, and a rise in both online (2.5-fold) and telephone (6-fold) consultations.

The largest proportion of consultations in 2023 were among women (60%) for all medium of SHS consultations, in the South East. The numbers of consultations for both GBMSM and heterosexual men were considerably less (14% and 18% respectively).

STI testing in the South East (excluding chlamydia in the under 25-year-olds as this is the age group targeted by the National Chlamydia Screening Programme (NCSP)) increased 10% from 2022. Testing among GBMSM increased by 8% and testing in both heterosexual males and all females increased by 11% in 2023 compared to the previous year.

Partner notification (PN) is the process where the sexual contact of an index patient, who was diagnosed with an STI, is informed that they may be at risk of infection (2). PN aims to actively find and treat undiagnosed infection and is an essential component of STI control (2). The proportion of patients presenting as a result of partner notification to a specialist SHS, that were diagnosed with an STI in the South East was highest for chlamydia (22%), gonorrhoea (26%) and trichomoniasis (10%). Not all services report on PN.

UKHSA recommends that local areas should be working towards achieving a chlamydia detection rate no lower than 3,250 per 100,000 among females aged 15 to 24 years. This is an indicator in the Public Health Outcomes Framework. In 2023, the chlamydia detection rate among South East female residents aged 15 to 24 years was below this at 1,637 per 100,000 residents (1,531 in 2022).

Rates of new STIs are higher among men than women (538 and 456 per 100,000 residents, respectively) in the South East.

Where gender and sexual orientation are known, GBMSM account for 23% of South East residents diagnosed with a new STI (78% of those diagnosed with syphilis and 47% of those with gonorrhoea). These data exclude chlamydia diagnoses reported via the CTAD Chlamydia Surveillance System.

STIs disproportionately affect young people. South East residents aged between 15 and 24 years accounted for 45% of all new STI diagnoses in 2023. This proportion was more than in London (27%), similar to East of England and the West Midlands and less than the remaining regions in England. A steep decline of 74% has been seen in genital warts diagnosis rates in females aged 15 to 19 between 2019 and 2023. This follows the introduction for girls and boys, in 2008 and 2019 respectively, of vaccination against human papillomavirus (HPV), the virus which causes genital warts.

The white ethnic group has the highest number of new STI diagnoses: 29,649 (80.1%). Although only 1.8% (675) of new STIs are in the black Caribbean ethnic group, they have the highest rate: 1,551 per 100,000, which is 4.2 times the rate seen in the white ethnic group.

Where country of birth was known, 80% of South East residents diagnosed with a new STI in 2023 (excluding chlamydia diagnoses reported via CTAD) were UK-born.

The rate of new STIs among people who live in the most deprived areas (732 per 100,000) was 2.1 times higher than the rate for people who live in the least deprived areas (348 per 100,000).

Conclusion

STIs increasing

From 2022 to 2023, the number of gonorrhoea, genital herpes, chlamydia and genital warts diagnoses increased. However, when compared to 2019, only gonorrhoea and syphilis were higher in 2023. The increase in gonorrhoea diagnoses is the most striking. Despite the increases, diagnosis rates in the South East remain lower than the rates for England and most other regions. The overall South East STI diagnosis rate is a third of its neighbour, London.

A steep fall in the rates of genital warts was observed in the youngest age group (15 to 19 years) from 2019 to 2020, and rates have continued to remain low. This is likely due to the HPV vaccine introduced for girls in September 2008 and for boys in September 2019.

Inequalities

There are marked health inequalities in STIs in the South East. STI rates in Brighton and Hove remain significantly higher than the overall rate in the South East and in England. Some other Unitary Authorities (Portsmouth, Reading and Southampton) also have higher rates than England overall. Rates of new STIs increased significantly with increasing deprivation, with rates in the most deprived deciles almost double those in the least deprived.

STI rates remain high among the younger age groups and there has been a doubling of gonorrhoea rates in those aged 20 to 24 from 2021 to 2023.

Rates of new STIs increased among both GBMSM and heterosexual men and women from 2022 to 2023; the percent increase of gonorrhoea was higher among heterosexuals.

All STI diagnosis rates were higher in 2023 compared to 2022 for GBMSM and approximately 80% of all syphilis diagnoses in 2023 were in GBMSM.

Rates of new STIs among black Caribbean and black African groups are significantly higher than other ethnic groups, however over 80% of cases are in the white ethnic group. Additionally, 80% of diagnoses in the South East are in people born in the UK.

Accessing services

The way people are accessing sexual health services remains significantly altered from before the COVID-19 pandemic. The proportion and number of online consultations continue to rise annually, and face-to-face consultations remains significantly below that in 2019. Additionally, despite the increased provision of telephone and online services, the overall testing rate of STIs in the South East remains lower than pre-pandemic levels and continues to be consistently lower than the England rate. It is not clear to what extent these changes are driven by service provision versus service-user behaviour, but it is possible that some groups may be disadvantaged by these changes (such as those living in shared households and those without internet access).

The chlamydia detection rate, among 15 to 24 year old women, remains significantly lower than the target for all local authorities in the South East. The South East region (1,637 out of 100,000 population) had the third lowest rate in England (1,962 out of 100,000).

UKHSA’s main messages

Commissioners and providers of SHSs have an important role in communicating messages about safer sexual behaviours and how to access services.

Main prevention messages

Using condoms consistently and correctly protects against HIV and other STIs such as chlamydia, gonorrhoea, and syphilis – condoms can also be used to 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 – and in addition:

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

HIV pre-exposure prophylaxis (PrEP) is available for free from specialist SHSs and can be used to reduce an individual’s risk of acquiring HIV.

HIV post-exposure prophylaxis (PEP) can be used to reduce the risk of acquiring HIV following some sexual exposures – PEP is available for free from most specialist SHSs and most emergency departments.

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 human papillomavirus (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 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 up to and including 45 years can obtain the HPV vaccine from specialist SHSs
• routine childhood vaccination (hepatitis B and HPV), including catchup for those who have missed vaccinations at school, is important in preventing STIs

Specialist sexual health services are free and confidential and offer testing and treatment for HIV and STIs, condoms, vaccination, HIV PrEP and PEP:

• clinic-based services are commissioned for residents of all areas in England.
• online self-sampling for HIV and STIs is widely available
• information and advice about sexual health including how to access services is available at NHS.UK 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, 2023

Data sources: GUMCAD, CTAD

Figure 1 is a bar chart showing the rate of new STI diagnosis in the South East (506.6 per 100,000 population). The South East rate is the fourth lowest among the English regions in 2023.

Figure 2. Number of diagnoses of the 5 main STIs, South East residents, 2019 to 2023

Data sources: GUMCAD, CTAD

Notes:

It is important to consider whether there have been any changes to testing or vaccination practices when interpreting increases or decreases in STIs:

• 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 for the number of diagnoses of the 5 main STIs for South East residents from 2019 to 2023. The highest number of diagnoses was in chlamydia. This was followed by gonorrhoea, genital warts, genital herpes and syphilis.

Figure 3. Diagnosis rates of the 5 main STIs, South East residents, 2019 to 2023

Data sources: GUMCAD, CTAD

Figure 3 shows a trend line of the rate of diagnosis per 100,000 population of the five main STIs in the South East from 2019 to 2023. The highest rate of diagnosis is in chlamydia. This is followed by gonorrhoea, genital warts, genital herpes and syphilis.

Table 1. Percentage change in new STI diagnoses, South East residents

Diagnoses	2023	Percentage change 2019 to 2023	Percentage change 2022 to 2023
New STIs	46,041	-20%	11%
Syphilis	857	3%	-1%
Gonorrhoea	7,574	16%	15%
Genital Warts	3,934	-48%	2%
Genital Herpes	3,871	-17%	10%
Chlamydia	22,398	-23%	8%

Data sources: GUMCAD, CTAD

See notes for Figure 2.

Table 1 shows a 20% decrease in new STIs, over the 5 years, from 2019 to 2023 but a 11% increase from 2022 to 2023. Between 2019 and 2023, syphilis and gonorrhoea increased, but genital warts, genital herpes and chlamydia decreased. From 2022 to 2023, there was an increase in gonorrhoea (15%), and also increases in genital herpes (10%), chlamydia (8%) and warts (2%). During this time period there was a 1% decline in syphilis.

Figure 4. Rates of new STIs per 100,000 South East residents by age group (for those aged 15 to 64 years only) and gender, 2023

Data sources: GUMCAD, CTAD

Figure 4 is a bar chart showing rates of new STIs by age group (15 to 64 years old) and gender. The rates of new STIs per 100,000 were highest among both females and males in the group aged 20 to 24 years (3,162 and 2,397 per 100,000 respectively). Rates were also high among females aged 15 to 19 years (1,752 per 100,000) and males aged 25 to 34 years (1,462 per 100,000).

Figure 5. Rates of gonorrhoea per 100,000 residents by age group [Note 1] (for those aged 15 to 64 years only) in the South East, 2019 to 2023

Data sources: GUMCAD

Note 1: 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 the South East from 2019 to 2023. Rates were highest among those aged 20 to 24 years and lowest among those aged 45 to 64 years. Although rates increased for all age-groups from 2022 to 2023, the largest increases, of over 20%, were among the older age groups (aged 35 to 64 years). The largest increase in rates of gonorrhoea over the 5 years were among the under 25’s and the 45 to 64 year group.

Figure 6. Rates of genital warts per 100,000 residents aged 15 to 19 years by gender in the South East, 2019 to 2023

Data sources: GUMCAD

Figure 6 shows trend lines for the rates of genital warts among residents aged 15 to 19 years by gender in the South East. It shows that rates have fallen steeply for both males and females from 2019 to 2020, and the rate in females have gradually decreased from 18.4 per 100,000 in 2020 to 15.9 per 100,000 in 2023 and in males from 26.2 per 100,000 to 19.0 per 100,000 respectively.

Figure 7. Rates of new STIs by ethnic group per 100,000 residents in the South East, 2023

Data sources: GUMCAD, CTAD

Figure 7 is a bar chart showing rates by ethnic group per 100,000 population of South East residents diagnosed with a new STI in 2023. It shows the rate of new STIs is significantly higher among the black Caribbean ethnic group (1,551 per 100,000) and the black African ethnic group (1,114 per 100,000) compared to the white (370 per 100,000) and other ethnic groups (464 per 100,000).

Table 2. Percentage of South East residents diagnosed with a new STI by ethnic group, 2023

Ethnic group	Number	Percentage (excluding unknown)
all other ethnic groups combined	4,991	13.5%
black African	1,677	4.5%
black Caribbean	675	1.8%
white	29,649	80.1%
unknown	9,049

Data sources: GUMCAD, CTAD

Table 2 shows the number and relative proportion of South East residents diagnosed with a new STI by ethnicity in 2023. It shows that the number of new STIs were highest in the white ethnic group (29,649, 80% of total). Where ethnicity was known, the black African ethnic group made up 4.5% of the total, and the black Caribbean group made up 1.8%. As there were 9,049 new STI diagnoses with ethnicity data recorded as unknown, there is an opportunity to improve reporting of ethnic group in these data.

Figure 8. Percentage of South East residents diagnosed with a new STI by world region of birth [note 2], 2023

Data sources: GUMCAD data only

Note 2: 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 South East residents diagnosed with a new STI by world region of birth in 2023. It shows that 80% of South East residents diagnosed with a new STI were born in the UK, 7% were born in the European Union (EU) (excluding UK), 4% born in Sub-Saharan Africa and 2% born in the Caribbean or Central and South America.

Figure 9. Rates of new STIs per 100,000 residents by decile of deprivation [note 3] in South East residents, 2023

Data sources: GUMCAD, CTAD

Note 3: deciles run from 1 to 10 in order of decreasing deprivation, with 1 being the decile for the most deprived area.

Figure 9 is a column chart which shows the new STI diagnosis rate by 100,000 population for each decile of deprivation in 2023. Deciles run from 1 to 10 in order of decreasing deprivation and are calculated at the level of lower super output area (LSOA) of residence, a unit of geography containing around 1,500 residents, across England. All new STI diagnoses in South East residents reported with an LSOA of residence code that could be linked to Index of Multiple Deprivation (IMD) data for 2019 are included. The rates are not adjusted for the underlying population demographics e.g. age distribution.

The chart shows that new STI diagnosis rates are highest in LSOAs which fall into the decile of highest deprivation (decile 1, 732 per 100,000 population) and then fall with each decile, bar decile 3, reaching 348 per 100,000 population for the decile of lowest deprivation (decile 10). The rate in decile 1 is approximately twice that in deciles 9 and 10.

Figure 10. Diagnoses of the 5 main STIs among GBMSM [note 4], South East residents, 2019 to 2023

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 and exclude chlamydia diagnoses via online services.

It is important to consider whether there have been any changes to testing or vaccination practices when interpreting increases or decreases in STIs:

• increases in gonorrhoea may be due to the increased use of highly sensitive NAATs and additional screening of extra-genital sites in GBMSM
• decreases in genital wart diagnoses may be due to the moderately protective effect of HPV-16/18 vaccination.
• increases in genital herpes diagnoses may be due to the use of more sensitive NAATs

Figure 10 shows trend lines for the number of diagnoses of the 5 main STIs in sexual health clinics among GBMSM, from 2019 to 2023. Gonorrhoea diagnoses increased by 69% among GBMSM from 1,970 in 2021 to 3,331 in 2023. Over the five years from 2019 to 2023, syphilis and genital herpes diagnoses have increased slightly (by 9% and 12%), genital warts have decreased by 45% and the number of chlamydia diagnoses has fallen by 23%.

Table 3: Percentage change in new STI diagnoses in GBMSM [note 5] residents in the South East

Diagnoses	2023	Percentage change 2019 to 2023	Percentage change 2022 to 2023
New STIs	7,508	2%	12%
Syphilis	632	9%	2%
Gonorrhoea	3,331	21%	14%
Genital Warts	229	-45%	10%
Genital Herpes	219	12%	26%
Chlamydia	2,074	-12%	2%

Data sources: GUMCAD data only

Note 5: see notes for Figure 10.

From 2019 to 2023, the percentage increase in new diagnoses among GBMSM was highest for gonorrhoea (21% increase) and the percentage decrease was greatest for genital warts (45% decrease) followed by chlamydia (12% decrease). The percentage increase from 2022 to 2023 was highest for genital herpes (26% increase) followed by gonorrhoea (14% increase) and genital warts (10% increase). Additionally, LGV increased by 122% (from 48 to 107 diagnoses) and M. genitalium increased by 19% (from 109 to 130 diagnoses) from 2022 to 2023.

Figure 11. Diagnoses of the 5 main STIs among heterosexual men and heterosexual/bisexual women [note 6], South East residents, 2019 to 2023

Data sources: GUMCAD data only

Note 6: data on sexual orientation is not collected by CTAD. All information about heterosexual men and heterosexual/bisexual women is based on diagnoses made in specialist and non-specialist services which report to GUMCAD and exclude chlamydia diagnoses via online services.

It is important to consider whether there have been any changes to testing or vaccination practices when interpreting increases or decreases in STIs:

• increases in gonorrhoea may be due to the increased use of highly sensitive NAATs and additional screening of extra-genital sites in GBMSM
• decreases in genital wart diagnoses may be due to the moderately protective effect of HPV-16/18 vaccination
• increases in genital herpes diagnoses may be due to the use of more sensitive NAATs

Figure 11 shows trend lines for diagnoses of the 5 main STIs in sexual health clinics among heterosexual men and heterosexual and bisexual women, from 2019 to 2023. Gonorrhoea diagnoses continue to increase among this group (by 18%) from 2022 to 2023. Over the 5 years from 2019 to 2023, genital warts and chlamydia diagnoses have decreased by 50%, there was a fall of 21% in genital herpes and of 12% in syphilis. Gonorrhoea diagnoses increased by 17% from 3,180 to 3,709 from 2019 to 2023.

Table 4. Percentage change in new STI diagnoses in heterosexual men and heterosexual/bisexual women [note 7] resident in the South East

Diagnoses	2023	Percentage change 2019 to 2023	Percentage change 2022 to 2023
New STIs	24,020	-35%	13%
Syphilis	172	-12%	-2%
Gonorrhoea	3,709	17%	18%
Chlamydia	7,498	-50%	12%
Genital Herpes	3,362	-21%	10%
Genital Warts	3,419	-50%	1%

Data sources: GUMCAD data only

Note 7: see notes for Figure 11.

From 2019 to 2023, there was a 35% fall in new STI diagnoses among heterosexual men and heterosexual/bisexual women. However, there was an increase in gonorrhoea (of 17%) among this group. There was a decrease for genital warts, chlamydia (both 50%) and herpes (21% decrease). The percentage increase from 2022 to 2023 was highest for gonorrhoea (18%) followed by chlamydia (12%) and genital herpes (10%).

Figure 12a. Rate of new STI diagnoses per 100,000 population by UTLA of residence, South East residents, 2023

Data sources: GUMCAD, CTAD

Figure 12a is a bar chart showing the rate of new STI diagnoses per 100,000 population among South East residents by UTLA of residence in 2023. It shows that the rate of new STIs for all ages was highest in Brighton and Hove (1,610/100,000). This rate is more than double all but one other UTLA in the South East. Four UTLAs had rates above the England average (Brighton and Hove, Portsmouth, Reading and Southampton).

Figure 12b. Rate of new STI diagnoses (excluding chlamydia diagnoses in residents aged under 25 years) per 100,000 population by UTLA of residence, the South East, 2023

Data sources: GUMCAD, CTAD

Note: prior to 2023, this figure showed rates for the population aged 15 to 64 years, excluding chlamydia in those aged 15 to 24 years.

Figure 12b 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 South East residents by UTLA in 2023. The rate of new STIs for all ages was highest in Brighton and Hove (1,249 per 100,000) and lowest in West Berkshire (210 per 100,000). The rate in Brighton and Hove was more than double the UTLA with the next highest rate.

Figure 13. Chlamydia detection rate per 100,000 female residents aged 15 to 24 years by UTLA of residence, the South East, 2023

Data sources: GUMCAD, CTAD

Note: prior to 2023, this figure showed rates for the whole population aged 15 to 24 years, regardless of gender.

Figure 13 is a bar chart showing the chlamydia detection rate per 100,000 female residents, aged 15 to 24 years in the South East by UTLA of residence in 2023. The chlamydia detection rate among 15 to 24 year old females was highest in Portsmouth residents (2,779 per 100,000) and lowest in Slough (984 per 100,000). Portsmouth and Brighton and Hove had chlamydia detection rates higher than the England rate (1,962 per 100,000). All local authorities in the South East have a detection rate significantly lower than the target of at least 3,250 per 100,000.

Figure 14. Rate of gonorrhoea diagnoses per 100,000 population by UTLA of residence, South East residents, 2023

Data sources: GUMCAD

Figure 14 is a bar chart showing the rate of gonorrhoea diagnoses per 100,000 population in South East residents by UTLA of residence in 2023. It shows the rate of gonorrhoea was highest among residents in Brighton and Hove (292 per 100,000) and lowest in Isle of Wight (35 per 100,000). Brighton and Hove had a rate significantly above the England rate (149 per 100,000) and more than double the rate in all other UTLAs in the South East.

Figure 15. Map of new STI rates per 100,000 residents by UTLA in the South East, 2023

Data sources: GUMCAD, CTAD

Figure 15 shows a map of new STI rates per 100,000 residents by UTLA in 2023. The map shows that the rate of new STIs for all ages was highest in Brighton and Hove (1,610 per 100,000). and lowest in West Berkshire (318 per 100,000). Rates tended to be higher in more densely populated urban areas.

Figure 16. STI testing rate (excluding chlamydia in under 25 year olds) per 100,000 population in South East residents aged 15 to 64 years, 2012 to 2023

Data sources: GUMCAD, CTAD

Figure 16 shows trend lines for the STI testing rate (excluding chlamydia in those aged under 25 years) per 100,000 population in South East compared to all England residents aged 15 to 64 years from 2012 to 2023. The STI testing rate in the South East increased again in 2023, but remained lower than the (pre-COVID pandemic) rate in 2019. The testing rate in the South East was consistently lower than the England rate.

Figure 17. STI testing positivity rate [note 8] (excluding chlamydia in under 25 year olds) in South East residents, 2012 to 2023

Data sources: GUMCAD, CTAD

Note 8: 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
• HIV

Up to 2018 (data for 2017) it included all new STIs.

Figure 17 shows trend lines for the STI testing positivity rate (excluding chlamydia in those aged under 25 years) in South East compared to all England residents from 2012 to 2023. Although there was an increase in the STI positivity rate in South East residents to 5.8% in 2022, the rate fell to 5.7% in 2023 and remains lower than the England rate over the 13 years shown.

Table 5. Number of diagnoses of new STIs by UKHSA region of residence, data source and data subset 2023

Data sources: GUMCAD, CTAD

UKHSA region of residence	GUMCAD Specialist SHSs	GUMCAD Non-specialist SHSs [note 9]	CTAD [note 10]	Total
East Midlands	14,758	8,212	5,029	27,999
East of England	18,062	4,855	7,409	30,326
London	87,279	12,689	28,444	128,412
North East	11,007	2,045	2,743	15,795
North West	35,993	4,742	11,742	52,477
South East	31,875	2,495	11,671	46,041
South West	17,956	3,944	6,017	27,917
West Midlands	20,031	4,588	5,183	29,802
Yorkshire and Humber	21,991	2,478	7,895	32,364

Note 9: diagnoses from SRH reporting to GUMCAD are included in the ‘non-specialist SHSs’ total.

Note 10: including site type 12 chlamydia from GUMCAD.

Table 5 shows the number of diagnoses of new STIs by UKHSA region of residence, by data source and data subset in 2023. The South East had a total of 46,041 new STI diagnoses in 2023, 69% of which were made at specialist SHSs. The South East has the highest proportion of cases reported to GUMCAD from specialist SHSs compared to non-specialist SHS (93%).

Table 6. Number of diagnoses of the 5 main STIs in the South East by STI, data source and data subset 2023

5 main STIs	GUMCAD Specialist SHSs	GUMCAD Non-specialist SHSs [Note 1]	CTAD [Note 2]	Total
Chlamydia	10,397	330	11,671	22,398
Genital Herpes	3,819	52	N/A	3,871
Genital Warts	3,873	61	N/A	3,934
Gonorrhoea	5,856	1,718	N/A	7,574
Syphilis	846	11	N/A	857

Data sources: GUMCAD, CTAD

Note 11: diagnoses from SRH reporting to GUMCAD are included in the ‘non-specialist sexual health services (SHSs)’ total. It is possible 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.

Note 12: including site type 12 chlamydia from GUMCAD.

Table 6 shows the number of diagnoses of the 5 main STIs in the South East by STI, data source and data subset in 2023. Although the majority of the 5 main STIs were diagnosed in specialist SHSs, almost one-quarter of gonorrhoea (23%) were diagnosed in non-specialist SHS.

Figure 18. Consultations by service medium: South East residents, 2019 to 2023

Data sources: GUMCAD

Figure 18 is a bar chart that shows the number of sexual health service consultations in South East residents over the 5-year period from 2019 to 2023 by the medium of consultation. It shows that the number of consultations which took place over the telephone trebled in 2020, the first year of the COVID-19 pandemic, compared to 2019. It then doubled again in 2021, compared to 2020. Online consultations increased 2.5-fold over the 5-year period. In 2023, just over half of consultations in South East residents were face to face (51%), over a third were online (36%) and around 13% were over the telephone.

Information on data sources

Find more information on local sexual health data sources in the UKHSA guide.

This report is based on data from the GUMCAD and CTAD surveillance systems published on 6 June 2024 (data to the end of calendar year 2023).

GUMCAD surveillance system

This disaggregate reporting system collects information about attendances and diagnoses at specialist (Level 3) and non-specialist (Level 2) SHSs. 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 (chlamydia) 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 which 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.

CTAD does not collect information about sexual orientation or country of birth. Reports from CTAD are excluded from figures in this report which relate to analyses by sexual orientation or world region of birth.

Chlamydia diagnoses in people aged 15 to 25 years old may be excluded in some data analysis or graphs as these individuals are in the age group targeted by the NCSP.

New STIs

New STI diagnoses comprise diagnoses of the following:

• chancroid
• 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.

ONS mid-year population estimates for 2022 were used as a denominator for rates (other than by ethnic group) for 2023. ONS estimates of population by ethnic group for the year 2019 were used as a denominator for rates by ethnic group for 2023. This is the first time that new estimates of population by ethnic group have been available since 2011. This must be considered if comparing rates for 2023 in this report with rates by 2022 in last year’s report, as the rates in the last report used the 2011 estimates.

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.

For more information on local sexual health data sources, see the UKHSA guide.

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. Please contact GUMCAD@ukhsa.gov.uk for further information regarding access to the Data Exchange.

For an Annual Epidemiological Spotlight on HIV in the South East, 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 and Public Health Microbiology to strengthen the surveillance, intelligence and response functions of UKHSA.

You can contact your South East and London Field Service team at FES.SEaL@ukhsa.gov.uk

Acknowledgements

We would like to thank the following:

• 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. UK Health Security Agency, 2024. Sexually transmitted infections and screening for chlamydia in England: 2023 report (Accessed: 19 September 2024).

2. UK Health Security Agency, 2024. STI Prioritisation Framework (Accessed: 24 October 2024).