Related Subjects:
|Treponema
|Bejel (Endemic syphilis)
|Pinta
|Yaws (Frambesia)
|Syphilis
|Non gonococcal urethritis
|Gonococcal urethritis
|Lymphogranuloma Venereum (LGV)
|Chancroid
|Donovanosis
|Haemophilus ducreyi
📖 About
- Haemophilus ducreyi is the causative agent of chancroid – a sexually transmitted infection (STI) characterised by painful genital ulcers and inguinal lymphadenopathy.
- Important globally as chancroid lesions increase the risk of HIV transmission.
🔬 Characteristics
- Gram-negative, pleomorphic rods.
- Fastidious organism → requires heme (Factor X) for growth.
- Non-motile, non-spore forming.
- Difficult to culture in standard labs → diagnosis often clinical.
🌍 Source & Epidemiology
- Endemic in tropical & subtropical regions with limited STI control programs.
- Transmitted through sexual contact.
- Commoner in populations with high HIV prevalence (open ulcers aid transmission).
🦠 Pathogenicity & Clinical Features
- Genital ulcers: soft, painful, non-indurated, with ragged edges and friable base (contrast with syphilis = painless, indurated).
- Lesions may be multiple and coalesce.
- ~50% develop inguinal lymphadenopathy → tender, may suppurate into buboes needing drainage.
- Healing is slow if untreated; chronic ulcers worsen HIV risk.
⚠️ Resistance
- Many strains produce beta-lactamase → resistant to penicillins.
- Resistance varies geographically → local sensitivity patterns matter.
💊 Management
- Antibiotics: effective regimens include:
- Azithromycin: 1 g PO single dose ✅ (preferred for compliance).
- Ceftriaxone: 250 mg IM single dose.
- Erythromycin: 500 mg PO QDS for 7 days.
- Ciprofloxacin: 500 mg PO BD for 3 days (avoid if high resistance).
- Supportive: incision & drainage of buboes if fluctuant.
- Partner notification & treatment: essential for public health control.
- Follow-up to ensure lesion resolution and prevent reinfection.
