Gastroenterology Book

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Vibrio CholeraAka: Cholera

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  1. See Also
    1. Diarrhea
    2. Infectious Diarrhea
  2. History
    1. Famous role in public health history
    2. London Physician John Snow (1813-1858)
      1. Linked Cholera outbreak to Broad Street Pump in 1854
      2. Proved Cholera to be a Waterborne Illness
      3. Snow was also a proponent of anesthesia in childbirth
      4. Knighted by Queen Victoria on birth of seventh child
  3. Pathophysiology
    1. Incubation: 4 hours to 5 days (average 2-3 days)
    2. Causes Toxigenic, Secretory Diarrhea
      1. Enterotoxin adheres to intestinal epithelial cell
      2. Fluid loss occurs in small bowel
      3. Large intestine is overwhelmed by large fluid volume
      4. Unable to reabsorb majority of fluid losses
    3. Organism survival
      1. Not viable in pure water (stable in salt water)
      2. Survives up to 24 hours in sewerage
      3. Survives in impure water with organics for 6 weeks
      4. Withstands freezing for 3-4 days
      5. Readily killed by drying, heat, or disinfectants
  4. Transmission
    1. Fecal contamination of food or water
      1. Waterborne Illness
      2. Foodborne Illness
    2. Heavily soiled hands or utensils
    3. Biological Weapon
      1. Infective aerosol dose: 10-500 organisms
  5. Symptoms
    1. Asymptomatic to severe sudden onset
      1. Only 1 symptomatic patient for every 400 infected
    2. Vomiting
    3. Headache
    4. Intestinal cramping
    5. Low grade fever or afebrile
    6. Painless voluminous Diarrhea
      1. Rice water stools
    7. Fluid losses: 5-10 liters per day
  6. Signs
    1. Dehydration
    2. Hypovolemia to shock
  7. Course
    1. Death may occur due to severe dehydration if untreated
    2. Usual duration: 1 week
  8. Labs
    1. Stool microscopy
      1. No or minimal Fecal Occult Blood
      2. No or minimal Fecal Leukocytes
      3. Darting, motile short curved Gram Negative Rods
    2. Darkfield microscopy
    3. Phase contrast microscopy
  9. Management: Fluid and electrolyte replacement
    1. See Oral Rehydration Therapy
  10. Management: Antibiotics
    1. Indication
      1. May shorten the duration of Diarrhea
      2. Reduces bacterial shedding
    2. Adult Preparations
      1. Tetracycline 500 mg q6h for 3 days
      2. Doxycycline 300 mg x1 dose OR 100 mg bid for 3 days
      3. Ciprofloxacin 500 mg bid for 3 days
      4. Erythromycin 500 mg q6h for 3 days
    3. Child Preparations
      1. Erythromycin 40 mg/kg/day divided qid for 3 days
      2. Trimethoprim/Sulfamethoxazole (Bactrim or Septra)
        1. Dose: 40 mg/kg/day (sulfa) divided bid for 3 days
      3. Furazolidone
        1. Three day regimen: 5 mg/kg/day divided qid
        2. One dose regimen: 7 mg/kg
  11. Prevention
    1. Water Disinfection
      1. Dry heat at 117 degrees C (steam or boiling)
      2. Short exposure to disinfectants
      3. Water chlorination
    2. Good Hygiene
    3. Licensed killed Cholera Vaccine
      1. Efficacy: 50% protection lasts only 6 months
      2. Vaccine schedule
        1. Initial Doses: 0 and 4 weeks
        2. Booster Doses: every 6 months

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