Cholera: Difference between revisions
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* Endemic to Asia, Africa, and Central and South America <ref>http://www.who.int/cholera/en/</ref> | * Endemic to Asia, Africa, and Central and South America <ref>http://www.who.int/cholera/en/</ref> | ||
* Occasionally seen on the Gulf Coast of US, due to inadequately cooked seafood. | * Occasionally seen on the Gulf Coast of US, due to inadequately cooked seafood. | ||
==Pathophysiology== | |||
===Pathophysiology=== | |||
* Usually Vibrio cholera, which produces an enterotoxin which causes a secretory diarrhea<ref>LaRocque R and Pietroni M. “Approach to the Adult with Acute Diarrhea in Developing Countries”. UpToDate.com</ref> | * Usually Vibrio cholera, which produces an enterotoxin which causes a secretory diarrhea<ref>LaRocque R and Pietroni M. “Approach to the Adult with Acute Diarrhea in Developing Countries”. UpToDate.com</ref> | ||
==Natural History== | |||
===Natural History=== | |||
* Transmission via ingestion of contaminated food or water, usually undercooked seafood | * 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)<ref>Mobula LM. Community health facility preparedness for a cholera surge in Haiti. Am J Disaster Med. 2013 Autumn;8(4):235-41</ref> | * Incubation period between hours to 5 days, depending on size of inoculum (usually 1-2 days)<ref>Mobula LM. Community health facility preparedness for a cholera surge in Haiti. Am J Disaster Med. 2013 Autumn;8(4):235-41</ref> | ||
* Most people are asymptomatic, and simply have bacteria in their feces for 7-14 days | * 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 | * Diarrhea is most severe in days 1-2, usually resolves in 7 days | ||
==Clinical Features== | ==Clinical Features== | ||
* Classic “rice water” diarrhea with fishy odor; usually painless | * Classic “rice water” diarrhea with fishy odor; usually painless | ||
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* 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”) | * 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”) | ||
* Acidosis from loss of bicarbonate; muscle cramps from loss of K, Ca | * Acidosis from loss of bicarbonate; muscle cramps from loss of K, Ca | ||
==Differential Diagnosis of Watery Diarrhea== | ==Differential Diagnosis of Watery Diarrhea== | ||
* Enterotoxigenic E. coli (most common cause of watery diarrhea)<ref>Marx et al. “Cholera and Gastroenteritis caused by Noncholera Vibrio Species”. Rosen’s Emergency Medicine 8th edition vol 1 pg 1245-1246.</ref> | * Enterotoxigenic E. coli (most common cause of watery diarrhea)<ref>Marx et al. “Cholera and Gastroenteritis caused by Noncholera Vibrio Species”. Rosen’s Emergency Medicine 8th edition vol 1 pg 1245-1246.</ref> | ||
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* Enteroaggregative E. coli (EAEC) | * Enteroaggregative E. coli (EAEC) | ||
* Enterotoxigenic Bacteroides fragilis | * Enterotoxigenic Bacteroides fragilis | ||
==Workup== | ==Workup== | ||
* Diagnosis largely clinical presentation + epidemiological risk factors | * Diagnosis largely 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 (tell the lab cholera is suspected, so appropriate medium is used) | * Diagnosis can be confirmed by stool cultures on TCBS medium (tell the lab cholera is suspected, so appropriate medium is used) | ||
==Management== | ==Management== | ||
* Aggressive volume repletion. Usually can be given orally if mild/moderate volume depletion; give rehydration solution to replete electrolyte loss. </ref>* Sack DA, et al. Cholera. Lancet 2004; 363:223.</ref> | * Aggressive volume repletion. Usually can be given orally if mild/moderate volume depletion; give rehydration solution to replete electrolyte loss. </ref>* Sack DA, et al. Cholera. Lancet 2004; 363:223.</ref> | ||
Revision as of 00:35, 2 October 2014
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, which produces an enterotoxin which causes a secretory diarrhea[2]
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
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 depletion. However, most cases are mild.
- Occasionally seen: sudden watery vomiting, borborygmi, abdominal cramping.
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”)
- Acidosis from loss of bicarbonate; muscle cramps from loss of K, Ca
Differential Diagnosis of Watery Diarrhea
- Enterotoxigenic E. coli (most common cause of watery diarrhea)[4]
- Norovirus (often has prominent vomiting)
- Campylobacter
- Non-typhoidal Salmonella
- Enteroaggregative E. coli (EAEC)
- Enterotoxigenic Bacteroides fragilis
Workup
- Diagnosis largely clinical presentation + epidemiological risk factors
- Fecal smears will NOT show leukocytes or erythrocytes.
- Diagnosis can be confirmed by stool cultures on TCBS medium (tell the lab cholera is suspected, so appropriate medium is used)
Management
- Aggressive volume repletion. Usually can be given orally if mild/moderate volume depletion; give rehydration solution to replete electrolyte loss. </ref>* Sack DA, et al. Cholera. Lancet 2004; 363:223.</ref>
- Oral rehydration solution includes in 1L of water: 2.6g NaCl, 2.9g Trisodium citrate, 1.5 g KCl, and 13.5 g glucose.
- If severe dehydration, bolus with 100 ml/kg over 3 hrs. LR is solution of choice. May require more than 350 ml/kg in first 24 hours.
- Antibiotic treatment decreases severity and duration of disease. Antibiotic resistance patterns are changing constantly. Most recommended currently is azithromycin 20mg/kg single dose.
- Alternatives: ciprofloxacin 1g single dose; doxycycline 300mg single dose; TMP-SMX double strength BID for 3 days; erythromycin 500 QID for 3 days. [5]
- Give children Zinc and Vitamin A.
Sources
- ↑ http://www.who.int/cholera/en/
- ↑ LaRocque R and Pietroni M. “Approach to the Adult with Acute Diarrhea in Developing Countries”. UpToDate.com
- ↑ Mobula LM. Community health facility preparedness for a cholera surge in Haiti. Am J Disaster Med. 2013 Autumn;8(4):235-41
- ↑ Marx et al. “Cholera and Gastroenteritis caused by Noncholera Vibrio Species”. Rosen’s Emergency Medicine 8th edition vol 1 pg 1245-1246.
- ↑ Neilson AA, Mayer CA. Cholera - recommendations for prevention in travelers. Aust Fam Physician. 2010 Apr;39(4):220-6