What are the recommended screening guidelines for Chlamydia trachomatis in sexually active individuals under 25 years old?

Guideline-aligned answer with reasoning, red flags and references. Clinically reviewed by Dr Kola Tytler MBBS CertHE MBA MRCGP.

Posted: 16 August 2025Updated: 16 August 2025 Guideline-Aligned (High Confidence) Clinically Reviewed
Dr Kola Tytler MBBS CertHE MBA MRCGPClinical Lead • iatroX

Recommended screening guidelines for Chlamydia trachomatis infection in sexually active individuals under 25 years of age:

  • Screening is recommended from age 13 years onwards for sexually active individuals, with particular emphasis on those under 25 years of age as a high-risk group.
  • All people under 25 years diagnosed with chlamydia should be offered repeat testing 3–6 months after treatment to check for re-infection.
  • Screening should be part of a broader sexual health assessment, including testing for other STIs such as gonorrhoea, hepatitis B, HIV, and syphilis.
  • Testing can be done in genito-urinary medicine (GUM) clinics or in primary care if the patient declines or cannot attend GUM.
  • Self-sampling options should be offered to improve uptake and accessibility of testing.
  • Partner notification and treatment are essential to reduce re-infection and onward transmission.
  • Patients should be provided with written information about chlamydia, including transmission, treatment, and prevention of further STIs.

These recommendations are based on the British Association for Sexual Health and HIV (BASHH) UK national guideline for chlamydia management and NICE clinical knowledge summaries and guidelines on reducing sexually transmitted infections ,.

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