Gonorrhoea

Related Subjects: |Treponema |Bejel (Endemic syphilis) |Pinta |Yaws (Frambesia) |Syphilis |Non gonococcal urethritis |Gonococcal urethritis |Lymphogranuloma Venereum (LGV) |Chancroid |Donovanosis |Haemophilus ducreyi |Trichomoniasis Vaginalis |Gardnerella vaginalis

💡 Uncomplicated gonorrhoea is most common in 15–24-year-olds. Complications include epididymo-orchitis, prostatitis, urethral stricture, pelvic inflammatory disease (PID), tubal infertility, ectopic pregnancy, and chronic pelvic pain.

📖 About

• Neisseria gonorrhoeae is a Gram-negative diplococcus causing urethritis, cervicitis, PID, arthritis, and sepsis.
• Higher risk in patients with complement C8/C9 deficiency.
• ⚠️ Reinfection is common due to antigenic variation of pili and outer membrane proteins → no lasting immunity.

🔬 Microbiology

• Gram-negative, kidney-shaped diplococcus.
• Oxidase-positive, but unlike meningococcus does not ferment maltose.
• No capsule; outer membrane lipooligosaccharide (LOS) triggers strong cytokine response.
• Optimal growth: 37 °C on chocolate/Thayer-Martin agar in 5% CO₂.

🧬 Virulence Factors

• Type IV pili → adherence, invasion, and gene conversion (antigenic variation).
• IgA protease → evades mucosal immunity.
• LOS endotoxin → intense inflammatory response.
• Iron-binding proteins → survival in host.

🏠 Transmission & Reservoir

• Primarily a sexually transmitted infection (STI) 💋.
• Reservoirs: urethra, cervix, rectum, pharynx.
• Asymptomatic carriage is common in women → silent spread.
• Vertical transmission: neonatal conjunctivitis (ophthalmia neonatorum) 👶.

🩺 Pathogenesis & Complications

• Genitourinary: Urethritis, cervicitis, epididymitis, prostatitis, salpingitis, Bartholin’s abscess.
• Rectal: Proctitis with pain, discharge, bleeding.
• Pharyngeal: Often asymptomatic; sore throat occasionally.
• Fitz-Hugh–Curtis syndrome: Perihepatic adhesions (“violin-string” 🎻 pain).
• Ophthalmia neonatorum 👁: Purulent conjunctivitis within days of birth; untreated → corneal scarring & blindness.
• Disseminated infection 🦵: Migratory polyarthritis, tenosynovitis, pustular rash. Higher risk in women (postpartum, menstruation) & complement deficiency.

🔎 Clinical Features

• Men: Purulent urethral discharge 💧, dysuria, epididymal pain.
• Women: Vaginal discharge, dysuria, pelvic pain, intermenstrual bleeding.
• Exam: Mucopurulent endocervical discharge, friable cervix.
• Complications: PID, infertility, ectopic pregnancy, stricture, systemic spread.

🧾 Investigations

• NAAT (urine or swabs): First-line, high sensitivity.
• Microscopy: Intracellular Gram-negative diplococci in PMNs (especially in men).
• Culture: Thayer-Martin agar – needed for sensitivity testing.
• Always test for co-infections: Chlamydia, HIV, syphilis, hepatitis.

💊 Antimicrobial Resistance

• Penicillin & fluoroquinolones ❌ not reliable.
• Macrolide resistance (azithromycin) rising.
• Cephalosporins (ceftriaxone) remain first-line, but reduced sensitivity reported globally.

🩺 Management (UK – BASHH Guidelines)

• First-line: Ceftriaxone 1 g IM single dose 💉.
• Dual therapy: Azithromycin 1 g oral single dose sometimes co-prescribed (covers chlamydia + slows resistance).
• Partner notification & testing via sexual health clinic.
• Test of cure: NAAT at 2 weeks after treatment.
• Screen for other STIs: syphilis, HIV, chlamydia, HBV, HCV.
• Neonates: Ophthalmia neonatorum → immediate systemic ceftriaxone/cefotaxime.

🧾 Case Vignette

A 20-year-old man presents with profuse purulent urethral discharge and dysuria. Microscopy shows Gram-negative diplococci inside neutrophils. He has multiple sexual partners.

🔑 Teaching pearl: Classic gonorrhoea. First-line = ceftriaxone IM single dose. Always test for other STIs and arrange partner notification.

💡 Exam tip: “Gram-negative diplococci + purulent urethritis in young adult” → think N. gonorrhoeae. UK treatment = ceftriaxone IM, with test-of-cure and partner tracing ✅.