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Gonorrhoea and chlamydia
Gonorrhoea (Neisseria gonorrhoeae) and chlamydia (Chlamydia trachomatis) are the main causes of urethritis and cervicitis; they often occur together and without symptoms, so diagnosis is by NAAT, partners are treated and other infections are tested.
Why it matters in the exam
The exam shows a young man with purulent urethral discharge and dysuria, a woman with discharge and post-coital bleeding, or a patient with arthritis, pustules on the limbs and tenosynovitis (disseminated gonorrhoea). The question tests current CDC treatment: ceftriaxone 500 mg intramuscularly as a single dose for gonorrhoea, and doxycycline 100 mg twice daily for 7 days for chlamydia (in pregnancy — azithromycin 1 g). Also asked are the complications — PID, ectopic pregnancy and infertility, epididymitis, Fitz-Hugh-Curtis syndrome, reactive arthritis and neonatal conjunctivitis — and partner treatment, retesting after 3 months, and HIV and syphilis testing. Remember the new recommendation of doxycycline 200 mg as post-exposure prophylaxis (doxy-PEP) for men who have sex with men and transgender women with a previous bacterial infection, and the rise in gonococcal antibiotic resistance, which is why quinolones are not used. In LGV, caused by invasive chlamydia strains, treatment is longer — 21 days.
Key points
- Gonorrhoea and chlamydia are the main causes of urethritis and cervicitis, and often occur together and without symptoms.
- Diagnosis is by NAAT from every exposed site, together with HIV and syphilis tests.
- Gonorrhoea is treated with ceftriaxone 500 mg intramuscularly, and chlamydia with doxycycline 100 mg twice daily for 7 days.
- Complications include PID, ectopic pregnancy, infertility, epididymitis and disseminated gonorrhoea with arthritis and pustules.
- Partners must be treated and retesting done after 3 months; doxy-PEP suits high-risk groups.
Summary table
| Aspect | Gonorrhoea | Chlamydia | Note |
|---|---|---|---|
| Picture in men | Profuse purulent discharge, dysuria, incubation of days | Scant discharge or no symptoms | Both cause epididymitis and proctitis |
| Picture in women | Usually no symptoms; cervicitis | Usually no symptoms; post-coital bleeding | PID, ectopic pregnancy, infertility |
| Diagnosis | NAAT from urine, vagina, pharynx and rectum; culture for susceptibility | NAAT | Test every exposed site |
| Treatment (CDC 2021) | Ceftriaxone 500 mg intramuscularly, single dose | Doxycycline 100 mg twice daily for 7 days; in pregnancy azithromycin 1 g | If chlamydia is not excluded in gonorrhoea — add doxycycline |
| Disseminated and complications | Disseminated gonorrhoea: pustules, tenosynovitis, arthritis | LGV, reactive arthritis, neonatal conjunctivitis and pneumonia | Disseminated gonorrhoea: ceftriaxone 1 g daily intravenously |
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Sources
- CDC Sexually Transmitted Infections Treatment Guidelines, 2021 — Chlamydial infections; Gonococcal infections
- CDC clinical guidelines on doxycycline post-exposure prophylaxis for bacterial STI prevention, 2024 — Recommendations
- European guideline on the management of gonorrhoea in adults (IUSTI), 2020 — Treatment
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.