ID
Vibrio Cholera
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Vibrio Cholera
, Cholera, Vibrio Cholerae
See Also
Diarrhea
Infectious Diarrhea
History
Famous role in public health history
Yemen as of 2016-2017 has the largest Cholera outbreak in history
London Physician John Snow (1813-1858)
Linked Cholera outbreak to Broad Street Pump in 1854
Proved Cholera to be a
Waterborne Illness
Snow was also a proponent of
Anesthesia
in childbirth
Knighted by Queen Victoria on birth of seventh child
Pathophysiology
Incubation: 4 hours to 5 days (average 1-2 days)
Causes Toxigenic,
Secretory Diarrhea
Enterotoxin adheres to intestinal epithelial cell
Fluid loss occurs in
Small Bowel
Large Intestine
is overwhelmed by large fluid volume
Unable to reabsorb majority of fluid losses
Organism survival
Not viable in pure water (stable in salt water)
Survives up to 24 hours in sewerage
Survives in impure water with organics for 6 weeks
Withstands freezing for 3-4 days
Readily killed by drying, heat, or disinfectants
Transmission
Large infectious dose needed to cause disease
Fecal contamination of food or water
Waterborne Illness
Foodborne Illness
Heavily soiled hands or utensils
Biological Weapon
Infective aerosol dose: 10-500 organisms
Symptoms
Asymptomatic to severe sudden onset
Only 1 symptomatic patient for every 400 infected
Vomiting
Headache
Intestinal cramping
Low grade fever or afebrile
Painless voluminous
Diarrhea
Rice water stools
Fluid losses: 5-10 liters per day (up to 15 liters per day)
Signs
Dehydration
Hypovolemia
to shock
Course
Usual duration: 1 week
Death may occur due to severe
Dehydration
if untreated
Mortality rates approach 50% from
Dehydration
without aggressive
Fluid Replacement
Mortality 0.2% with aggressive rehydration (see below)
Labs
Stool
microscopy
No or minimal
Fecal Occult Blood
No or minimal
Fecal Leukocytes
Darting, motile short curved
Gram Negative Rod
s
Darkfield microscopy
Phase contrast microscopy
Management
Fluid and
Electrolyte
replacement
See
Oral Rehydration Therapy
Aggressive fluid and
Electrolyte
replacement is the key to effective management (drops mortality from 50% to 0.2%)
Lactated Ringers
is preferred crystalloid if IV hydration is required
Replace
Electrolyte
s (e.g.
Potassium
)
Management
Antibiotic
s
Indication: Moderate to severe disease
May shorten the duration of
Diarrhea
Reduces
Bacteria
l shedding
Adult Preparations
Tetracycline
500 mg four times daily for 3 days
Doxycycline
300 mg x1 dose or 100 mg bid for 3 days
Azithromycin
500 mg orally daily for 3 days (or 1 g for 1 dose)
Erythromycin
250 mg orally three times daily for 3 days
Ciprofloxacin
1 g orally for 1 dose
Child Preparations
Azithromycin
10 mg/kg/day orally daily for 3 days
Erythromycin
30 mg/kg/day orally divided three times daily for 3 days
References
Gilbert (2016) Sanford Guide, accessed 9/12/2016
Prevention
Water Disinfection
Dry heat at 117 degrees C (steam or boiling)
Short exposure to disinfectants
Water chlorination
Good Hygiene
Frequent
Hand Washing
Exclusive use of safe water and food
Lice
nsed killed
Cholera Vaccine
Indicated during epidemics
Efficacy: 50-86% protection lasts only 6 months
Vaccine
schedule
Initial Doses: 0 and 4 weeks
Booster Doses: every 6 months
References
Luquero (2014) N Engl J Med 370(22): 2111-20 +PMID: 24869721 [PubMed]
Prognosis
Indicators of severe disease and worse outcomes
Difficult access to medical services
Blood Type
O (45% of U.S. persons)
Low gastric acidity
Antacid
therapy
Partial gastrectomy
Resources
CDC Cholera
http://www.cdc.gov/cholera/index.html
WHO Cholera
http://www.who.int/cholera/en/
References
Harris (2012) Lancet 379(9835): 2466-76 +PMID:22748592 [PubMed]
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