A sexually transmitted infection caused by Chlamydia trachomatis. It is the most common bacterial STI in the UK, often asymptomatic but associated with complications such as pelvic inflammatory disease (PID), infertility, and epididymitis if untreated.
Vaginal, anal, or oral sexual contact
Vertical transmission during birth → neonatal conjunctivitis or pneumonia
Highest prevalence in 15–24 year olds
Up to 70% of women and 50% of men may be asymptomatic
UK screening programme targets sexually active people aged 15–24
Urethral discharge (often clear/mucoid)
Dysuria
Testicular pain (epididymitis)
Rectal symptoms in MSM
Vaginal discharge
Intermenstrual or postcoital bleeding
Pelvic pain and dyspareunia
Cervicitis
Conjunctivitis in the first 2 weeks of life
Pneumonia in the first few months
🚨 Many carriers are asymptomatic, meaning infection can spread and cause long-term damage unnoticed.
| Women | Men | Both |
|---|---|---|
| PID | Epididymitis | Infertility |
| Tubal infertility | Prostatitis | Chronic pelvic pain |
| Ectopic pregnancy | Reactive arthritis | Proctitis (especially MSM) |
Nucleic acid amplification test (NAAT): first-catch urine in men; self-taken vaginal swab in women
Rectal or pharyngeal swabs if exposure relevant
Full STI screen offered alongside
💡 Routine screening is recommended for high-risk groups and young people (15–24).
Most uncomplicated infections respond to a short antibiotic course
Abstain from sexual activity until treatment completed and partners treated
Partner notification is essential
✨ The full textbook version includes: detailed pathophysiology, exact drug regimens with doses, pregnancy-specific management, test-of-cure criteria, long-term follow-up, and Fries Tips tailored for exams and clinical practice.
