CTAD Chlamydia Surveillance System
Information about the collection and reporting of CTAD, the surveillance system for chlamydia in England.
Applies to England
About
The CTAD Chlamydia Surveillance System is the mandatory surveillance system for chlamydia and collects data on all publicly commissioned chlamydia testing from laboratories in England. CTAD is an electronic, pseudonymised and depersonalised data set.
The UK Health Security Agency (UKHSA) uses chlamydia data from CTAD and the GUMCAD STI Surveillance System to report chlamydia testing activity and to monitor the National Chlamydia Screening Programme (NCSP).
How to submit CTAD data
Technical guidance and data set specifications are available at:
CTAD specification and technical guidance
Guidance on data submission requirements for services providing self-sampling tests for sexually transmitted infections (STIs) can be found at:
GUMCAD and CTAD data submission for STI self-sampling services
When to submit CTAD data
| Submission period | Reporting deadline |
|---|---|
| January to March 2026 | Friday 8 May 2026 |
| April to June 2026 | Friday 7 August 2026 |
| July to September 2026 | Friday 13 November 2026 |
| October to December 2026 | Friday 12 February 2027 |
Where to access chlamydia surveillance data
Chlamydia surveillance data is subject to strict data sharing and publication rules (particularly regarding small numbers) outlined in the UKHSA HIV and STI data publication guidelines.
Information on chlamydia tests and diagnoses in England is available in a variety of outputs.
National Chlamydia Screening Programme annual data tables
These official statistics present information on chlamydia testing and diagnoses in people aged 15 to 24 years in England by demographic characteristics and geographical region.
Sexual and Reproductive Health Profiles
These provide local authority area data on STI and HIV diagnoses and services through interactive maps and charts.
These are restricted-access reports for monitoring local, regional and national chlamydia screening trends. They are accessible to registered NHS and local authority users only.
Sexual health, reproductive health and HIV in England
This guide is to help local government, service providers and commissioners understand the sexual and reproductive health data available across England and how the data can be accessed.
CTAD data requests
Aggregate CTAD data can be requested by completing the CTAD data request form and sending this to ctad@ukhsa.gov.uk
Data requests may take 20 working days to complete (they may take longer during busy periods).
UKHSA sexual health and HIV privacy information
UKHSA’s sexual health and HIV privacy information explains the de-personalised data we collect, how we use it and how we protect this information.
Contact information
For further information or to request access to the HIV and STI Web Portal, please contact the CTAD team at ctad@ukhsa.gov.uk
Updates to this page
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Updated data submission and reporting deadlines.
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Updated data submission and reporting deadlines.
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Updated 'Resources', 'Submission and reporting deadlines', 'Accessing CTAD data' sections and added 'UKHSA sexual health and HIV privacy information'.
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Updated data submission and reporting deadlines.
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Updated data submission and reporting deadlines.
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Updated data submission and reporting deadlines.
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Updated data submission and reporting deadlines.
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Updated the submission and reporting deadlines.
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First published.