II. Epidemiology

  1. Epidemic outbreaks of Acute Diarrheal illness
  2. Most common cause of Viral Gastroenteritis in the world
    1. Causes 90% of non-Bacterial Gastroenteritis (and 18% of all Gastroenteritis)

III. Pathophysiology

  1. Taxonomy
    1. Family: Caliciviridae
    2. Genus: Norovirus
    3. Species: Norwalk Virus
  2. Transmission
    1. Fecal-oral route (Foodborne Illness or Waterborne Illness)
    2. Fomites and surfaces
  3. Precautions
    1. Highly contagious
    2. Bleach is effective at killing virus on surfaces (but many other disinfectants are not)

IV. Causes: Sources

  1. Contaminated drinking water
  2. Contaminated raw produce or uncooked food
  3. Shellfish from contaminated water
  4. Food contaminated by infected food handler

V. Symptoms

  1. Onset: 12 to 48 hours after exposure
  2. Duration: 12 to 60 hours
    1. Illness may be prolonged for months in Immunocompromised patients
  3. Systemic symptoms
    1. Low grade fever (variably present)
    2. Lethargy
    3. Weakness
    4. Myalgias
    5. Malaise
    6. Headache
  4. Gastrointestinal symptoms
    1. Nausea
    2. Projectile Vomiting (esp. children)
    3. Watery Diarrhea
    4. Abdominal Pain

VI. Prevention

  1. Antibody to Norwalk is not protective

VII. Resources

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