Gonorrhoea
Overview
•Neisseria gonorrhoeae - gram-negative diplococcus; kidney-shaped cocci in pairs
•On microscopy: intracellular gram-negative diplococci within neutrophils (polymorphonuclear leucocytes) - classic finding in urethral discharge
Investigations
🥇 First-line
•NAAT - high sensitivity/specificity; urine, self-taken vulvovaginal swab, or clinician swab
•Essential alongside NAAT: Culture swab from affected sites - allows antibiotic sensitivity testing; mandatory due to resistance
•Gram stain of urethral discharge - gram-negative intracellular diplococci in neutrophils; sensitivity ~90% in symptomatic men, ~50% in women
•If DGI suspected: Joint aspiration and synovial fluid culture - gram-negative diplococci on microscopy
🏆 Gold standard
•Culture with sensitivity testing - guides targeted therapy given high resistance rates
Management
🥇 First-line
•ceftriaxone 1g IM single dose - uncomplicated urogenital, rectal, and pharyngeal gonorrhoea (BASHH); always required for pharyngeal infection
•Second-line (non-pharyngeal only): cefixime 400mg oral single dose - if IM injection not possible
•Cephalosporin allergy: gentamicin 240mg IM + azithromycin 2g oral - specialist advice required
•Sensitivity-guided: oral ciprofloxacin 500mg single dose - only if confirmed susceptibility
•Pregnancy: ceftriaxone 1g IM remains treatment of choice
•Test of cure (TOC): mandatory for all patients - NAAT at 2 weeks post-treatment; unlike chlamydia where TOC is not routinely recommended
•Partner notification: all contacts within previous 3 months must be tested and treated; abstain from sex until treatment complete
Disseminated Gonococcal Infection (DGI)
•Occurs in ~1-3% of untreated cases; more common in women (higher rates of asymptomatic local infection)
•Classic triad:
•Dermatitis - pustular or haemorrhagic skin lesions on the extremities
•Tenosynovitis - tendon sheath inflammation, especially fingers, wrists, ankles (painful 'trigger finger' pattern)
•Septic arthritis - mono- or pauciarticular; N. gonorrhoeae is the most common cause of septic arthritis in young sexually active adults