Vibrio vulnificus
🦠 Vibrio vulnificus is the leading cause of death from seafood consumption in the US.
⚠️ Around 25% of infections occur from direct inoculation of an open wound exposed to warm seawater containing the organism.
ℹ️ About
- 🌊 Marine-borne, motile, curved rod-shaped Gram-negative bacillus
- 🧑⚕️ Causes fulminant sepsis in immunocompromised hosts, especially those with liver disease or cirrhosis
- 🍤 Acquired via ingestion of raw/undercooked seafood (esp. oysters) or direct wound exposure to contaminated seawater
- 🧬 Closely related to Vibrio cholerae
🧬 Aetiology
- 🌍 Found in estuaries, brackish ponds, and coastal waters, especially in warm climates
- 🍽️ ~75% via ingestion of infected seafood (esp. raw oysters in the US)
- 🩸 ~25% via direct wound contact with contaminated seawater
🩺 Clinical Features
- 💩 Gastrointestinal: watery diarrhoea, cramping, nausea, vomiting, fever
- 🌡️ Septicaemia: fever, chills, hypotension, rapidly progressive shock
- 🩹 Skin/soft tissue: painful haemorrhagic bullae, blistering lesions, ecchymoses, deep cellulitis
- ⚠️ Necrotising fasciitis and purpura fulminans may develop within hours
- 🚨 Mortality is very high (>50%) even with prompt antibiotics
🔎 Investigations
- 🧪 Bloods: FBC, U&E, LFTs, CRP
- 🧫 Blood cultures and wound cultures for organism identification
- ⚡ Early recognition is key → do not delay treatment while awaiting cultures
💊 Management
- 💉 Immediate empiric antibiotics: Doxycycline (or Vibramycin) + Ceftazidime is recommended
- 🩹 Aggressive wound care and supportive therapy
- 🔪 Surgical debridement required for necrotising infection; limb amputation may be lifesaving
- 🚨 Patients with painful, rapidly progressive haemorrhagic bullae should receive urgent surgical review
- 📉 Mortality >50% despite early antibiotics; higher in patients with cirrhosis, immunosuppression, or delayed treatment
📌 Exam Pearl:
– Think of Vibrio vulnificus in any patient with rapidly progressive haemorrhagic bullae after raw seafood ingestion or seawater exposure, especially if cirrhotic.
– This is one of the few infections where doxycycline is first-line for severe Gram-negative sepsis.
📚 References
