Microbiology · Year 2 · from Microbiology
Case 2: Disseminated Gonococcal Infection
Presentation
A 24-year-old woman presents to her primary care physician with a 5-day history of fever, migratory joint pain affecting her wrists, hands, and knees, and a skin rash. She initially thought she had "the flu" but became concerned when she noticed painful bumps on her hands and ankles.
She reports being sexually active with multiple partners and inconsistent condom use. Her last menstrual period was 1 week ago.
Physical examination reveals temperature 38.4°C. Multiple joints have signs of tenosynovitis with tenderness along tendon sheaths at the dorsum of both wrists and the right ankle. She has 5-6 papulopustular lesions with an erythematous base scattered on her distal extremities, including between the fingers. The right knee has a small effusion but is not severely inflamed.
Clinical Image
Laboratory identification of Neisseria gonorrhoeae - including culture characteristics and biochemical testing.
Image Source: Lecture image - gonococcal identification
Questions
- What is the most likely diagnosis? What spectrum of disease can this infection cause?
- What is the mechanism by which this patient developed systemic disease from a likely genital infection?
- Why might this patient's menstrual period be relevant to her clinical presentation?
- How should this patient be evaluated and treated?
Answers
- Diagnosis and disease spectrum:
Diagnosis: Disseminated gonococcal infection (DGI) caused by Neisseria gonorrhoeae.
The classic triad present in this patient:
- Tenosynovitis: Inflammation of tendon sheaths (wrists, hands, ankles)
- Dermatitis: Papulopustular lesions on erythematous base, typically few in number, on distal extremities
- Polyarthralgia/polyarthritis: Migratory joint pain affecting multiple joints
Full spectrum of gonococcal disease:
| Localized Disease | Complicated Local Disease | Disseminated Disease | |-------------------|---------------------------|---------------------| | Urethritis | Pelvic inflammatory disease (PID) | Tenosynovitis-dermatitis syndrome | | Cervicitis | Epididymitis | Purulent gonococcal arthritis | | Proctitis | Tubo-ovarian abscess | Endocarditis (rare) | | Pharyngitis | Fitz-Hugh-Curtis syndrome | Meningitis (rare) | | | Perihepatitis | |
DGI represents hematogenous spread and occurs in 0.5-3% of gonococcal infections.
- Mechanism of dissemination:
From mucosal infection to bloodstream:
- Gonococcal infection begins at mucosal surface (cervix in women, urethra in men, pharynx, rectum)
- Many genital infections in women are asymptomatic (up to 50%), allowing untreated persistence
- N. gonorrhoeae can invade through mucosal epithelium
- Bacteria enter the bloodstream → bacteremia → seeding of joints, skin, other sites
Bacterial factors favoring dissemination:
- Certain strains with specific Por protein types disseminate more readily
- Strains causing DGI are often serum-resistant (resist complement killing)
- Interestingly, DGI strains often cause milder local symptoms (asymptomatic genital infection)
Host factors favoring dissemination:
- Complement deficiency (C5-C9): Terminal complement required for bactericidal activity against Neisseria - deficient patients have markedly increased risk of both gonococcal and meningococcal disseminated disease
- Female sex: Women have 4x higher risk of DGI than men
- Recent menstruation (see below)
- Pregnancy
- Relevance of menstrual period:
Menstruation is a significant risk factor for DGI:
Mechanisms:
- Increased gonococcal proliferation: Changes in cervical mucus and vaginal pH during menstruation favor bacterial growth
- Endometrial shedding: Provides access for bacteria to submucosal blood vessels
- Iron availability: Menstrual blood provides iron, a critical growth factor for N. gonorrhoeae (the organism has sophisticated iron acquisition systems)
- Retrograde flow: May facilitate ascending infection
Clinical correlation:
- DGI symptoms often begin during or shortly after menstruation
- This patient's presentation 1 week after her last menstrual period fits this pattern
- PID is also more common immediately after menstruation
- Evaluation and treatment:
Diagnostic evaluation:
- NAAT testing: Cervical, pharyngeal, and rectal swabs (cervical alone may miss up to 20% of infections)
- Blood cultures: Often negative in DGI (may be positive early in course)
- Joint aspiration: If significant effusion - send for Gram stain, culture, NAAT, cell count
- Skin lesion culture: Low yield but can be attempted
- Screen for other STIs: HIV, syphilis, chlamydia (coinfection rate with chlamydia is 20-40%)
- Pregnancy test: Affects treatment choices
Treatment of DGI:
- Ceftriaxone 1 g IV or IM every 24 hours until clinical improvement (usually 24-48 hours)
- Then transition to oral therapy to complete at least 7 days total
- Add doxycycline 100 mg PO BID x 7 days if chlamydial infection not excluded
For purulent gonococcal arthritis:
- Same antibiotic regimen
- Joint drainage (repeated aspiration or arthroscopy) essential
Partner management:
- All sexual partners from past 60 days should be evaluated and treated
- Expedited partner therapy (providing prescription for partner) is an option
- Patient should abstain from intercourse until treatment complete and partners treated