Vibrio parahaemolyticus

Microbiology

• Halophilic (salt-loving) marine pleomorphic Gram-negative rod that causes foodborne diarrhea

Pathophysiology

• Has the capacity to produce an enterotoxin that causes small bowel inflammation
  • Two hemolysins, thermostable direct hemolysin (TDH) and TGH-related hemolysin (TRH)
• Strains without TDH or TRH are usually mild
• Likely has a different mechanism of action thatn *V. cholera* for causing diarrhea

Epidemiology

• Major cause of acute diarrhea in Japan, but also found in east Asia and southern US
• Ubiquitous in coastal waters, especially in warmer seasons
• Generally acquired by consumption of raw or undercooked seafood, especially raw oysters
• Serotype O3:K6 is an important cause of outbreaks, and is the current pandemic strain

Clinical Presentation

• Causes acute diarrhea, ranging from mild watery diarrhea to dysentery
• Usually, cramping and abdominal pain with low-grade fever and headache
• Rarely can cause soft tissue infections and bacteremia

Management

• Usually self-limited
• Can use doxycycline or fluoroquinolone to shorten the duration of diarrhea