Difference between revisions of "Cholera"

(Pathophysiology)
 
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===Risk Factors===
 
===Risk Factors===
* Persons with blood group O are more likely to have severe disease  
+
*Persons with blood group O are more likely to have severe disease  
  
 
{{Vibrio species}}
 
{{Vibrio species}}
  
 
==Clinical Features==
 
==Clinical Features==
*Classic “rice water” diarrhea with fishy odor; usually painless
+
*Classic “rice water” [[diarrhea]] with fishy odor; usually painless
*Fluid losses can be significant, up to 1L/hr, leading to severe fluid and electrolyte depletion.  However, most cases are mild.
+
*Fluid losses can be significant, up to 1L/hr, leading to severe fluid and [[electrolyte abnormalities]].  However, most cases are mild.
*Occasionally seen: sudden watery vomiting, borborygmi, abdominal cramping.
+
*Occasionally seen: sudden watery [[vomiting]], borborygmi, abdominal cramping.
 
Later manifestations:
 
Later manifestations:
*Fluid loss may lead to → sunken eyes, dry mouth, cold clammy skin, decreased skin turgor, or wrinkled hands and feet (also known as “washer woman’s hands”)
+
*[[Dehydration]]] may lead to → sunken eyes, dry mouth, cold clammy skin, decreased skin turgor, or wrinkled hands and feet (also known as “washer woman’s hands”)
*Acidosis from loss of bicarbonate
+
*[[Acidosis]] from loss of bicarbonate
*Muscle cramps from loss of K, Ca
+
*Muscle cramps from [[hypokalemia]], [[hypocalcemia]]
 +
 
 +
===Complications===
 +
*Death
 +
*[[Arrhythmia]] from [[electrolyte imbalance]]
 +
*Brain damage from prolonged [[hypoglycemia]] and failure of gluconeogenesis
 +
*Aspiration [[pneumonia]]
 +
*Paralytic [[ileus]]
  
 
==Differential Diagnosis==
 
==Differential Diagnosis==
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==Evaluation==
 
==Evaluation==
===Work-up===
+
*Diagnosis largely based on clinical presentation + epidemiological risk factors
 
*Fecal smears will NOT show leukocytes or erythrocytes.   
 
*Fecal smears will NOT show leukocytes or erythrocytes.   
 
*Diagnosis can be confirmed by stool cultures on TCBS medium (must inform lab cholera is suspected so appropriate medium is used)
 
*Diagnosis can be confirmed by stool cultures on TCBS medium (must inform lab cholera is suspected so appropriate medium is used)
 
+
*Labs; non-specific abnormalities:
===Evaluation===
+
**[[hyponatremia]]
*Diagnosis largely based on clinical presentation + epidemiological risk factors
+
**[[hypokalemia]]
 +
**[[hypoglycemia]]
 +
**hemoconcentration (increased hematocrit & plasma protein concentration) from water depletion)
  
 
==Management==
 
==Management==
#Aggressive volume repletion (primary treatment)<ref>Sack DA, et al. Cholera. Lancet 2004; 363:223.</ref>
+
*Aggressive volume repletion (primary treatment)<ref>Sack DA, et al. Cholera. Lancet 2004; 363:223.</ref>
#*Mild/moderate dehydration: [[oral rehydration solution]]  
+
**Mild/moderate dehydration: [[oral rehydration solution]]  
#*Severe dehydration: [[IV fluids]]
+
**Severe dehydration: [[IV fluids]] - bolus lactated ringers 100ml/kg over 3 hrs
#**Bolus 100ml/kg LR over 3 hrs
+
**May require more than 350ml/kg in first 24 hours
#**May require more than 350ml/kg in first 24 hours
+
*Antibiotics (decreases severity and duration of disease)<ref>Neilson AA, Mayer CA. Cholera - recommendations for prevention in travelers. Aust Fam Physician. 2010 Apr;39(4):220-6</ref>
#Antibiotics (decreases severity and duration of disease)<ref>Neilson AA, Mayer CA. Cholera - recommendations for prevention in travelers. Aust Fam Physician. 2010 Apr;39(4):220-6</ref>
+
**Use local susceptibility to choose if available
#*Use local susceptibility to choose if available
+
**Option 1: [[doxycycline]] 300mg x 1 PO<ref name="Stanford">Stanford Guide to Antimicrobial Therapy 2014.</ref>
#**Option 1: [[doxycycline]] 300mg x 1 PO<ref>Stanford Guide to Antimicrobial Therapy 2014.</ref>
+
**Option 2: [[azithromycin]] 1 gm (20mg/kg) x 1 PO <ref name="Stanford" />^
#**Option 2: [[azithromycin]] 1 gm (20mg/kg) x 1 PO <ref>Stanford Guide to Antimicrobial Therapy 2014.</ref>^
+
**Option 3: [[erythromycin]] 500 QID x 3 days<ref name="Stanford" />^@
#**Option 3: [[erythromycin]] 500 QID x 3 days<ref>Stanford Guide to Antimicrobial Therapy 2014.</ref>^@
+
**Option 4: [[ciprofloxacin]] 1g x 1 PO
#**Option 4: [[ciprofloxacin]] 1g x 1 PO
+
**Option 5: [[TMP-SMX]] DS BID s 3 days
#**Option 5: [[TMP-SMX]] DS BID s 3 days
+
*Give children Zinc and Vitamin A supplementation
#Give children Zinc and Vitamin A supplementation
 
  
 
:^Pregnant
 
:^Pregnant
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==Disposition==
 
==Disposition==
*Admit if hypotensive or hemodynamically unstable, severe electrolyte abnormalities
+
*Admit if [[hypotensive]] or hemodynamically unstable, severe [[electrolyte abnormalities]]
 +
 
  
 
==See Also==
 
==See Also==
 
*[[Diarrhea]]
 
*[[Diarrhea]]
*[[Travel Medicine]]
+
*[[Travel medicine]]
  
 
==References==
 
==References==

Latest revision as of 17:13, 28 August 2019

Background

  • Endemic to Asia, Africa, and Central and South America [1]
  • Occasionally seen on the Gulf Coast of US, due to inadequately cooked seafood.

Pathophysiology

  • Usually Vibrio cholera (gram negative), which produces an enterotoxin which causes a secretory diarrhea[2]
    • Toxin causes increase in cell cAMP leading to secretion of water and electrolytes into the gut lumen

Natural History

  • Transmission via ingestion of contaminated food or water, usually undercooked seafood
  • Incubation period between hours to 5 days, depending on size of inoculum (usually 1-2 days)[3]
  • Most people are asymptomatic, and simply have bacteria in their feces for 7-14 days
  • Diarrhea is most severe in days 1-2, usually resolves in 7 days

Risk Factors

  • Persons with blood group O are more likely to have severe disease

Vibrio species

Clinical Features

  • Classic “rice water” diarrhea with fishy odor; usually painless
  • Fluid losses can be significant, up to 1L/hr, leading to severe fluid and electrolyte abnormalities. However, most cases are mild.
  • Occasionally seen: sudden watery vomiting, borborygmi, abdominal cramping.

Later manifestations:

  • Dehydration] may lead to → sunken eyes, dry mouth, cold clammy skin, decreased skin turgor, or wrinkled hands and feet (also known as “washer woman’s hands”)
  • Acidosis from loss of bicarbonate
  • Muscle cramps from hypokalemia, hypocalcemia

Complications

Differential Diagnosis

Acute diarrhea

Infectious

Noninfectious

Watery Diarrhea

Traveler's Diarrhea

Evaluation

  • Diagnosis largely based on clinical presentation + epidemiological risk factors
  • Fecal smears will NOT show leukocytes or erythrocytes.
  • Diagnosis can be confirmed by stool cultures on TCBS medium (must inform lab cholera is suspected so appropriate medium is used)
  • Labs; non-specific abnormalities:

Management

  • Aggressive volume repletion (primary treatment)[5]
    • Mild/moderate dehydration: oral rehydration solution
    • Severe dehydration: IV fluids - bolus lactated ringers 100ml/kg over 3 hrs
    • May require more than 350ml/kg in first 24 hours
  • Antibiotics (decreases severity and duration of disease)[6]
  • Give children Zinc and Vitamin A supplementation
^Pregnant
@Children

Disposition


See Also

References

  1. http://www.who.int/cholera/en/
  2. LaRocque R and Pietroni M. “Approach to the Adult with Acute Diarrhea in Developing Countries”. UpToDate.com
  3. Mobula LM. Community health facility preparedness for a cholera surge in Haiti. Am J Disaster Med. 2013 Autumn;8(4):235-41
  4. Marx et al. “Cholera and Gastroenteritis caused by Noncholera Vibrio Species”. Rosen’s Emergency Medicine 8th edition vol 1 pg 1245-1246.
  5. Sack DA, et al. Cholera. Lancet 2004; 363:223.
  6. Neilson AA, Mayer CA. Cholera - recommendations for prevention in travelers. Aust Fam Physician. 2010 Apr;39(4):220-6
  7. 7.0 7.1 7.2 Stanford Guide to Antimicrobial Therapy 2014.