Official Statistics

Quality and methodology information for the sexually transmitted infections and National Chlamydia Screening Programme data release for England

Updated 4 June 2024

About this report

This report outlines the quality and methodology information (QMI) relevant to the sexually transmitted infections and National Chlamydia Screening Programme official statistics release published by the UK Health Security Agency (UKHSA). This QMI report supports users in understanding the strengths and limitations of these statistics, ensuring UKHSA is compliant with the quality standards stated in the Code of Practice for Statistics. The report covers the following areas:

1. The strengths and limitations of the data used to produce the statistics.
2. The methods used to produce the statistics.
3. The quality of the statistical outputs.

About the statistics

Sexually transmitted infections (STIs) are caused by a variety of organisms including bacteria, viruses and protozoa, when they are primarily transmitted through sexual contact. STIs are a major public health concern due to the potentially severe impact on the health and wellbeing of individuals, the risks of antimicrobial resistance for bacterial STIs such as gonorrhoea, and pressures on healthcare services to provide testing and treatment; STIs are also a major source of health inequality given higher diagnosis rates among young people; gay, bisexual and other men who have sex with men (GBMSM); and some ethnic minority groups. If left undiagnosed and untreated, common STIs can cause a range of complications and long-term health problems including pelvic inflammatory disease, infertility, adverse pregnancy outcomes, neonatal infections, and irreversible cardiovascular and neurological damage.

The primary aim of England’s National Chlamydia Screening Programme (NCSP) is to reduce the reproductive harm of untreated infection in young women and other people with a womb or ovaries. As chlamydia is a largely asymptomatic infection, increases in the number of infections detected and treated is an indication of improved chlamydia control. 

More information on STIs is available on NHS.UK. More information on the NCSP is available on GOV.UK.

Geographical coverage: England

Publication frequency: Annual

Changes to this document

4 June 2024: QMI report first published

Contact

Lead analyst: Dr Stephanie Migchelsen

Contact information: gumcad@ukhsa.gov.uk and ctad@ukhsa.gov.uk

Suitable data sources

Statistics should be based on the most appropriate data to meet intended uses.

This section describes the data used to produce the statistics.

Data sources

Two data sources are used for these official statistics. Firstly, data on STI tests and diagnoses are submitted by all local authority commissioned sexual health services (SHSs) in England to UKHSA through the GUMCAD STI Surveillance System. GUMCAD is a pseudonymised and depersonalised data set of all face to face attendances, and remote (telephone and online) consultations at SHSs – this means that the data cannot be used to reveal anyone’s identity. STIs are not notifiable diseases, but reporting of STI tests and diagnoses using GUMCAD is mandatory as specified in the Department of Health and Social Care’s SHS service specification.

Secondly, data on all publicly provided chlamydia tests and diagnoses are submitted by primary diagnostic laboratories in England to UKHSA through the CTAD Chlamydia Surveillance System – this includes chlamydia testing provided outside of specialist STI related care such as general practices and pharmacies. CTAD is also a pseudonymised and depersonalised data set.

In combination, the data from GUMCAD and CTAD provide a comprehensive picture of STI service provision and diagnosis trends in England. These systems are detailed below.

GUMCAD

The GUMCAD STI Surveillance System was established in 2008 as an electronic surveillance system to collect pseudonymised, individual service user level data from SHSs. The data set includes:

• STI tests and diagnoses
• demographic data including age, ethnicity, gender identity and sexual orientation
• sexual behaviour
• outcomes of partner notification and management
• provision of HIV pre-exposure prophylaxis (PrEP)

Services reporting to GUMCAD

The following SHSs report GUMCAD data to UKHSA each quarter:

• SHSs providing specialist (Level 3) and non-specialist (Level 2) STI related care – these services may also provide SRH care as an integrated service
• online services providing non-specialist (Level 2) STI related care

Details on the levels of sexual health service provision are provided in Appendix B of the British Association for Sexual Health and HIV’s Standards for the Management of STIs.

CTAD

The CTAD Chlamydia Surveillance System is a universal disaggregate data set that collects chlamydia data from all laboratories commissioned by local authorities or the NHS to carry out chlamydia testing. This report includes the chlamydia data from tests and diagnoses occurring in community-based testing services.

Services reporting to CTAD

Chlamydia testing from all healthcare settings, covering community services (level 1), non-specialist STI care (level 2) and specialist STI care (level 3).

Data quality

The data that we use to produce statistics must be fit for purpose. Poor quality data can negatively impact surveillance and can hinder effective decision making.

We have assessed the quality of the source data against the data quality dimensions in the Government Data Quality Framework.

This assessment covers the quality of the data that was used to produce the statistics, not the quality of the final statistical outputs. The ‘Quality summary’ section below assesses the quality of the final statistical outputs.

Strengths and limitations of the data

The following strengths of the data have been identified:

• CTAD and GUMCAD data reporting to UKHSA is mandatory so, in combination, they are a comprehensive source of STI testing and diagnoses in England
• CTAD and GUMCAD data are submitted quarterly and therefore provide timely data on STI testing and diagnoses, and reporters can retrospectively update previous submissions
• data validation rules (applied at the point of submission) ensure that all fields are completed properly
• Additional data reviews, enhancement and quality assurance checks are carried out on a quarterly basis and for each annual official statistics release of STI and NCSP data
• tests and diagnosis data are reported with depersonalised geographical information about where the tests were provided, and the area of residence of the person tested

The following limitations of the data have been identified:

• GUMCAD data is only reported by SHSs – a small number of people are tested for STIs in GPs but, in the case of chlamydia testing, these tests are reported by laboratories through CTAD
• CTAD and GUMCAD data are depersonalised so it is not possible to identify individual people – it is not therefore possible to link individuals between data sets or, to link people between different services within each data set
• neither data set collects data from private providers of sexual healthcare
• we cannot definitively rule out a small degree of over or under-reporting of activity or diagnoses due to miscoding by reporters – to mitigate this risk, we conduct data quality workshops, at least annually, with UKHSA’s regional Sexual Health Facilitators to review and improve the quality of data reported

CTAD and GUMCAD are the most appropriate sources of data for these statistics. The design of both data sets helps ensure that the data is accurate and valid.

Accuracy

Accuracy is about the degree to which the data reflects the real world. This can refer to correct demographic and clinical data.

Every effort is made to ensure accuracy and completeness of the data, including web-based reporting with integrated checks on data quality. However, responsibility for the accuracy and completeness of data lies with the data submitter and service providers.

GUMCAD and CTAD data reporters are required to evaluate their own data content prior to submission to UKHSA to ensure that data is accurate and representative of full service provision. To further facilitate accuracy of reporting, UKHSA applies automated ‘data validation’ rules at the point of submission that enforce data coding and formatting requirements. Data submissions that do not comply with the GUMCAD and CTAD data specification (as defined by the GUMCAD technical guidance and the CTAD technical guidance) may be rejected (where correction and resubmission is then required). Additionally, UKHSA conducts quarterly reviews of data content to ensure consistency in ongoing trends. Anomalies in trends are followed up directly with data reporters to either confirm the data content is correct, or to ensure corrected data is resubmitted.

Completeness

Completeness describes the degree to which records are present.

For a data set to be complete, all records are included, and the most important data is present in those records. This means that the data set contains all the records that it should and all essential values in a record are populated.

Completeness is not the same as accuracy as a full data set may still have incorrect values.

CTAD and GUMCAD only contain mandatory fields, all of which must be completed in order to submit data. This ensures that all the necessary information is recorded for each service or test provided, but reporters may report some data as either ‘not known’ or ‘not specified’ (which would be classified as ‘incomplete’ data).

Chlamydia diagnoses are recorded in both GUMCAD and CTAD data sets. Records are deduplicated within the 2 data sets as part of data cleaning to prevent overestimation prior to publication.

Data is updated on an annual basis due to clinic/laboratory resubmissions and improvements to data cleaning. Data may differ from previous publications.

The tables below show trends in key demographic data quality for CTAD and GUMCAD presented by the percentage of data completeness (data reported with a specified value).

GUMCAD

Table A1. GUMCAD consultation number and percentage of demographic data completeness, 2019 to 2023

Demographic variables	2019	2020	2021	2022	2023
Number of consultations	3,869,725	3,573,471	4,034,768	4,392,466	4,610,410
Gender %	98.3	97.6	95.8	94.4	95.5
Age %	99.9	99.9	100	100	100
Sexual orientation %	88.9	90.2	89.9	91.4	91.2
Ethnicity %	91.3	89.5	91.8	93.1	94.6
Country of birth %	80.3	78.9	79.4	84.2	91.8

The table shows trends in data quality by showing the percentage complete (reported with a specified value as compared to ‘not known’ or ‘not specified’) for each demographic variable by year.

Missing submissions

No missing submissions.

Imputed data

The number of STI diagnoses among GBMSM in 2021, as presented in the accompanying data tables, is unadjusted and underestimated because of incomplete data quality that year – but the overall trend in diagnoses in all people (irrespective of gender and sexual behaviour) is unaffected. Please refer to the ‘Technical note’ in the main report for further details

GUMCAD data may be imputed (estimated) where there are gaps in total coverage due to late submissions or data quality issues. Data is imputed by using the most recent quarterly submission as an appropriate proxy to maintain current trends (based on data reported since 2008 and given the increasing trends in STI tests and diagnoses since then, this is usually a conservative assumption). Imputed data is replaced with real data submissions in the next available data release.

The current official statistics release for 2023 contains 1% of imputed GUMCAD data for England – which relates to 8 submissions from 4 clinics in the North West region and 5 submissions from 5 clinics in London (a total of 13 submissions from 9 clinics).

A data quality issue has been identified in Leeds local authority (within the Yorkshire and the Humber region) that affects the New STI total for 2023 – therefore the New STI total in Leeds local authority has been suppressed for 2023 (a data quality note has been added to the data). No other data, for any other local authority, region or for any other years, is affected.

CTAD

Table A2. CTAD test number (non-specialist) and percentage of demographic data completeness, 2019 to 2023. Test numbers are deduplicated to present one test per 6 week’s episode per patient.

Demographic variables	2019	2020	2021	2022	2023
Number of CTAD Tests: Tests coded as ‘non-Specialist’	1,821,270	1,525,340	1,743,128	1,904,160	1,992,035
Gender %	99.2	99.5	99.5	98.9	98.3
Age %	99.8	99.8	100	99.9	99.9
Postcode of residence %	90.5	93.3	92.3	92.7	90.5
Ethnicity %	61.7	66.5	68.1	69.4	69
Testing service Type %	97.3	97.4	97.8	98.5	98.5

Missing submissions

No missing submissions.

Uniqueness

Uniqueness describes the degree to which there is no duplication in records. This means that the data contains only one record for each entity it represents, and each value is stored once.

CTAD and GUMCAD conduct deduplication as part of quarterly data enhancement routines to ensure that tests and diagnoses are only counted once within a single episode of patient care (to prevent double-counting).

Given the depersonalised nature of CTAD and GUMCAD data, unique individuals are identified using an alphanumeric code (patient ID) issued by their SHS – without revealing their identity. This enables UKHSA to assess testing and diagnoses in unique individuals within a single SHS but not between different SHSs. This is an acceptable limitation to ensure public trust in the confidentiality of SHSs and the GUMCAD data they report to UKHSA – especially as SHSs are regarded as anonymous access providers under the Health and Social Care (Safety and Quality) Act 2012.

Consistency

Consistency describes the degree to which values in a data set do not contradict other values representing the same entity.

For example, there are multiple internal validation checks within GUMCAD to ensure consistency – such as ensuring that gender specific diagnoses are reported with the appropriate gender identity, and age specific diagnoses are reported with the correct age.

CTAD data is based on tests with confirmed positive and negative results only. Tests with equivocal, inhibitory, and insufficient results have been excluded as most people with these results are retested.

It is possible that the number of diagnoses used to calculate the chlamydia detection rate indicator for (all) persons has a different value than the total of women and men diagnoses; this is because the total number of diagnoses includes tests where sex or gender was reported as indeterminate or unspecified.

Data reported with an unknown gender may be included in the data total (therefore the total may not equal the sum of women and men. In NCSP statistical products, women includes both cisgender and transgender women. Men includes both cisgender and transgender men.

Timeliness

Timeliness describes the degree to which the data is an accurate reflection of the period that it represents, and that the data and its values are up to date. 

Data is timely if the time lag between collection and availability is appropriate for the intended use. Both CTAD and GUMCAD data are reported to UKSHA on a quarterly basis – which minimises the reporting burden for providers while providing sufficiently timely STI surveillance data to guide local, regional and national public health action, and to support the commissioning of SHSs and chlamydia screening. CTAD and GUMCAD submission deadlines are set 6 weeks after the end of each quarter. This allows SHSs and laboratories sufficient time to process test results and ensure that data entry is complete, which facilitates a high rate of timely submissions. If there are gaps in submissions that would negatively impact data reporting, GUMCAD data is imputed (estimated) to ensure it is a more complete reflection of annual trends (please see the ’Completeness’ section for more information on imputed data).

Validity

Validity describes the degree to which the data is in the range and format expected.

Detailed technical guidelines are available for both CTAD and GUMCAD that clearly define the data coding and formatting requirements. Additionally, automated data validation rules are applied at the point of submission which enforce the data coding and formatting requirements. Data that does not comply may be rejected (where correction and resubmission is then required).

Sound methods

Statistical outputs should be made using the best available methods and recognised standards.

This section describes how the statistics were produced and quality assured.

Data set production

The official statistics are produced using automated calculations in standard software packages (such as Stata, SQL, MS Access and MS Excel) which reduces the risk of human error via manual calculations. All calculations are independently verified via multiple quality assurance checks.

Quality assurance

CTAD and GUMCAD data go through a rigorous data validation and evaluation process. The initial data submissions have automated data validation rules applied at point of submission (enforcing coding and formatting requirements) and are also subject to quarterly data enhancement routines and quality assurance checks (such as deduplication of test and diagnosis data and ensuring consistency in data trends).

The official statistics (the written report, data tables, slides and indicators) are produced using automated calculations which are prepared and tested in advance. Additionally, each statistical product is produced by a member of the CTAD or GUMCAD team, then is independently validated by another member of the team – regional breakdowns are also reviewed by regional UKHSA colleagues (the Field Service epidemiology scientist and Sexual Health Facilitator for each region); these steps are taken to ensure the accuracy of calculations and the written text in the report. Any data queries that are raised via review are investigated and actioned appropriately – where data may be confirmed as correct or may require the addition of specific data notes or caveats to explain the data content. All of these quality assurance checks ensure that outputs are robust and reliable.

Confidentiality and disclosure control

UKHSA’s responsibilities include collecting surveillance data on STIs. We use this information to help improve the nation’s sexual health and wellbeing, to understand more about people’s access to care and the effectiveness of interventions such as PrEP or human papillomavirus (HPV) vaccination, and to monitor outbreaks of STIs and HIV across the nation.

The sexual health and HIV privacy notice explains the STI surveillance that we conduct and how we use the data from these surveillance systems. All UKHSA staff with access to surveillance data must complete mandatory information governance training, which must be refreshed every year. Information is stored on computer systems that are kept up-to-date and regularly tested to make sure they are secure and protected from viruses and hacking. UKHSA staff do not store data on their own laptops or computers. Instead, data is stored centrally on secure UKHSA servers.

CTAD and GUMCAD data are both pseudonymised and depersonalised data sets – this means that these data cannot be used to reveal anyone’s identity. Additional controls are applied to the outputs included in the official statistics to minimise the risk of deductive disclosure. These controls include the masking of small numbers (counts of 1 to 4) when the relevant population size is less than 10,000 people. These controls are described in UKHSA’s HIV and STI data publication guidelines.

Geography

The data in these official statistics are provided at national (England), regional (UKHSA Regions), and upper and lower tier local authority level; all local authority level data are published to the Sexual and Reproductive Health and Public Health Outcomes Framework Profiles, while regional and national data are provided in the report, data tables, and slide set.

Most UKHSA Regions are consistent with the former Government Office Regions (GORs). The major difference between regions is Milton Keynes, which is in the UKHSA South East region, but is in the East of England GOR.

Quality summary

The Code of Practice for Statistics states that quality means that statistics:

• fit their intended uses
• are based on appropriate data and methods
• are not materially misleading

Quality requires skilled professional judgement about collecting, preparing, analysing, and publishing statistics and data in ways that meet the needs of people who want to use the statistics.

This section assesses the statistics against the European Statistical System dimensions of quality.

Relevance

Relevance is the degree to which the statistics meet user needs in both coverage and content.

There is a clear need for timely, high quality STI and NCSP statistics; Google Analytics data shows that during 2023, the STI and NCSP statistics were viewed nearly 31,000 times. The statistics are used to monitor trends and inequalities in STIs, the coverage of chlamydia screening through the NCSP, and the impact of public health interventions such as human papillomavirus vaccination and HIV PrEP.

The statistics are published annually to prioritise completeness and accuracy of reporting. England has experienced rising rates of STIs since the early 2000s, with the largest annual number of diagnoses of gonorrhoea reported in 2022.

The STI and NCSP statistics are primarily used by people in local public health teams, and by the providers and commissioners of SHSs and chlamydia screening in local authorities. The uses of these data include monitoring of trends including inequalities in STIs, evaluation of interventions, local strategic needs assessments and commissioning.

We have continued to make changes to the publication to meet user needs. We now publish the following products as part of the statistical release:

1. Sexually transmitted infections and screening for chlamydia in England: 2023 report
2. Sexually transmitted infections (STIs): annual data tables
3. NCSP: chlamydia testing data in 15 to 24 year olds in England, 2019 to 2023
4. STI Slide Set
5. Sexual and Reproductive Health Profiles: STI and NCSP data by local authority
6. Public Health Outcomes Framework; STI and NCSP data by local authority
7. This QMI report, first published in June 2024

By providing this range of different outputs, we can better cater to the needs of different users from a range of backgrounds, in line with the Office for National Statistics user personas.

UKHSA regularly meets with key sexual health stakeholders to share epidemiological updates on STIs and to understand how to best meet their needs. This includes meetings with the English Sexual Health and HIV Commissioners’ Group, and with the British Association for Sexual Health and HIV (BASHH). These discussions are used to inform the data we publish through official statistics.

Accuracy and reliability

Accuracy is the proximity between an estimate and the unknown true value. Reliability is the closeness of early estimates to subsequent estimated values.

The accuracy of the statistics is largely dependent on the accuracy of the source data submitted by SHSs and laboratories. We have assessed the source data to be accurate (see the ‘Data quality’ section) as the design of CTAD and GUMCAD helps prevent data entry errors, and guidance given to users helps ensure the right information is collected in the proper format. The statistics report on STI testing and diagnoses, which are mandatory through CTAD and GUMCAD. The statistics therefore represent all STI diagnoses at SHSs in England.

Timeliness and punctuality

Timeliness refers to the time gap between publication and the reference period. Punctuality refers to the gap between planned and actual publication dates.

These official statistics aim to provide timely and up-to-date figures of important epidemiological indicators to inform ongoing STI control efforts in England.

The statistics are always published as soon as possible, allowing for the collection of data submissions, production and quality assurance. The final CTAD and GUMCAD deadlines for submission of all data (January to December) to UKHSA is mid-February each year after which they undergo extensive validation by members of the national and regional teams.

These official statistics are pre-announced at least 28 days in advance, in line with the Code of Practice for Statistics. The provisional publication date for the official statistics is pre-announced online in December and can be found on the UKHSA release calendar.

Accessibility and clarity

Accessibility is the ease with which users can access the data, also reflecting the format in which the data is available and the availability of supporting information. Clarity refers to the quality and sufficiency of the metadata, illustrations and accompanying advice.

We publish a number of different statistics products as part of the release, as stated in the relevance section. this means that users can access the statistics in a format and style that best suits their needs.

The official statistics are made available in a range of media (such as HTML and ODS) which optimise accessibility across different devices (such as desk top computers and smart phones) and different operating systems (such as Microsoft and Apple). The content has also been designed to be accessible for users with visual impairments. For example, the data and data notes are presented in a way that is compatible with a data reader, and graphics are designed in a way that is accessible to people who are colour-blind (such as using sufficient contrast between colour gradients).

The accessibility statement for www.gov.uk explains some of the accessibility features for GOV.UK HTML pages.

Coherence and comparability

Coherence is the degree to which data that is derived from different sources or methods, but refers to the same topic, is similar. Comparability is the degree to which data can be compared over time and domain.

Data included in these and other STI reports published on GOV.UK has been collected in a consistent manner over time using surveillance data sets with approved Information Standards Notices from NHS England (formerly NHS Digital). GUMCAD data has been reported since 2008, and CTAD data has been reported since 2012. Figures reported in 2020 and 2021 are notably lower than previous years due to the disruption to SHSs during the national response to the COVID-19 pandemic.

Trade-off between timeliness and completeness

There is a trade-off between timeliness and completeness for the statistics. Given the high-profile nature of these statistics, we may allow additional time for reporters to submit data after the deadline or to resubmit corrected data following queries raised as part of data validation and quality assurance. We also ensure there is sufficient time for validation of all outputs.

Uses and users

Users of statistics and data should be at the centre of statistical production, and statistics should meet user needs.

This section explains how the statistics are used, and how we understand user needs.

Appropriate use of the statistics

These data are reported as diagnosis numbers and rates because they are restricted to data on STIs diagnosed at SHSs, while the NCSP data is based on data from all local authority commissioned settings providing chlamydia testing. Users therefore should not use these statistics as a direct measure of STI incidence in the general population for the following reasons:

• many people with STIs do not experience any symptoms and may not seek testing (opportunistic asymptomatic screening is only provided for chlamydia through the NCSP which, to reduce reproductive harm, is targeted to young women only)
• some people with STI related symptoms may find it difficult to access STI testing
• while most STI testing is provided at SHS, some testing occurs in other settings such as GPs (chlamydia testing from GPs is captured via CTAD, but that is not the case for other STIs such as gonorrhoea) or via private providers

There are several important factors to consider when comparing STI trends over time. These include:

• the recommendation for asymptomatic screening of gay, bisexual and other men who have sex with men at multiple anatomical sites (genital, rectal and pharyngeal) led to an increase in detection of STIs in this population in the early 2010s; there was also more testing for STIs using more sensitive diagnostic tests at this time, which also contributed to an increase in diagnoses, but it is unlikely that these factors would have been the main drivers for increasing trends in STIs since the mid to late 2010s
• several factors have contributed to the rise in STIs in the period covered by these official statistics; these include behavioural factors such as less condom use as well as structural factors such as increased demand for sexual health services
• disruption to service delivery during the first year of the COVID-19 pandemic led to reduced testing and fewer STI diagnoses
• the scale up of online postal self-sampling services to test for STIs increased during 2020 and 2021; this has led to an increase in testing but there is evidence of inequalities in the use of online services by residential area-level deprivation

Known uses

We are aware that the statistics are used in several different ways, including:

• monitoring STI trends and inequalities in STIs
• joint strategic needs assessments for local authorities
• commissioning of sexual health services and chlamydia screening
• health promotion
• research
• teaching

Known users of the statistics are primarily in local authorities, providers of sexual healthcare, charities, academia and research.

User engagement

We undertake a broad range of different user engagement activities to ensure we fully understand our users and their needs. These include, but are not limited to:

• regular meetings with key stakeholders including local authority commissioners
• regular meetings with the English Sexual Health and HIV Commissioners’ Group
• regular meetings with the British Association for Sexual Health and HIV (BASHH)
• regular care pathway workshops with local providers and their commissioners
• hosting an annual meeting with clinical stakeholders to discuss the epidemiology of gonorrhoea and gonococcal antimicrobial resistance
• regular contact with various sexual health charities
• teaching at undergraduate and postgraduate level
• developing e-courses with BASHH
• providing statistics for individual clinics
• completing data requests from academic researchers as well as internal and external stakeholders, including the president of BASHH
• contributing to Parliamentary Questions and Chief Medical Officer briefings
• producing publicly available slide sets for educational use
• giving presentations at conferences such as the annual BASHH and UKHSA conferences

We have worked with stakeholders to develop and improve our outputs based on user feedback. For example, responding to greater interest in inequalities by publishing a breakdown of the data by ethnic group. We have continued to innovate and improve on this offering, by working with data from the 2021 census.

Related statistics

Further STI data is available on the UKHSA STI annual data tables web page in the form of tables, and a slide set.

Further data on chlamydia tests and diagnoses in adults aged 15 to 24 years are available on the UKHSA NCSP annual data tables web page.

Interactive tables, charts, and maps showing local area STI data is available on the Sexual and Reproductive Health Profiles.

Further information on the GUMCAD and CTAD Surveillance Systems.

Further information on the Gonococcal Resistance to Antimicrobials Surveillance Programme (GRASP).

Further information on trends in mpox.

Further information on trends in HIV diagnoses in the UK.

For the latest LGV surveillance data for the UK.

For the latest guidance and data on Shigella spp.

STIs in other countries

Most health protection functions in the UK are devolved to the other UK nations’ public health agencies. Public Health Scotland publishes STI reports such as this report on gonorrhoea, while Public Health Wales publishes annual data as does the Public Health Agency of Northern Ireland.

The European Centre for Disease Prevention and Control publishes annual STI reports with data from counties in the European Union and European Economic Area (EU and EEA). Many European countries also publish annual STI reports, such as this report from the Netherlands. As was the case for many countries of the EU and EEA, there was a sharp rise in many STIs between 2021 and 2022 in England; this was particular pronounced for gonorrhoea with the largest proportional rise (by age group) among young people.

The US Centers for Disease Control and Prevention also publishes annual STI reports, and the World Health Organization publishes estimates of global and regional STI trends.

Comparisons of STI trends between countries must be made with caution because the level of sexual health provision and STI testing, as well as the comprehensiveness of surveillance systems, vary between countries. For instance, the number of gonorrhoea diagnoses made in England in 2022 exceeded the total reported across the EU and EEA that year, but this is because there is more comprehensive ascertainment of STIs in England. This more comprehensive ascertainment is a result of the fact that England has dedicated sexual health services which provide open access STI testing and treatment, all of which report GUMCAD data to UKHSA.