Norovirus/Norwalk virus

Norovirus/Norwalk virus

Updated: 01/29/2024

© Jun Wang, MD, PhD

 

General features

  • Most common cause of epidemic nonbacterial gastroenteritis
  • Norovirus 
    • Single-stranded RNA and hexagonal capsid
    • 5 genogroups, I, II and IV are human pathogens
    • Highly contagious, Fecal-oral transmission
  • Usually not severely ill
  • Lasting 24-72 hours, usually self-limited
  • Associated with shellfish, prepared foods, etc
  • Diarrhea due to transient malabsorption of D-xylose and fat and inhibition of brush-border enzymes including alkaline phosphatase and trehalase

Key clinical features

  • Usually not severely ill
  • Nausea, vomiting, moderate watery diarrhea (4-8 stools/day)
  • Signs of volume depletion: tachycardia, hypotension, ONLY in severe cases
  • Stools usually do NOT contain mucous or leukocytes

Diagnosis

  • Usually clinical diagnose
  • Confirmation needed for immunocompromised patients with severe or persistent symptoms
  • Multi-pathogen molecular tests to confirm
  • Other pathogens need to be ruled out in patients with atypical presentations

Treatment

  • Fluid and electrolytes replacement
  • Symptom relief

 

 

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