Cholera
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
- Death
- Arrhythmia from electrolyte imbalance
- Brain damage from prolonged hypoglycemia and failure of gluconeogenesis
- Aspiration pneumonia
- Paralytic ileus
Differential Diagnosis
Acute diarrhea
Infectious
- Viral (e.g. rotavirus)
- Bacterial
- Campylobacter
- Shigella
- Salmonella (non-typhi)
- Escherichia coli
- E. coli 0157:H7
- Yersinia enterocolitica
- Vibrio cholerae
- Clostridium difficile
- Parasitic
- Toxin
Noninfectious
- GI Bleed
- Appendicitis
- Mesenteric Ischemia
- Diverticulitis
- Adrenal Crisis
- Thyroid Storm
- Toxicologic exposures
- Antibiotic or drug-associated
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
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:
- hyponatremia
- hypokalemia
- hypoglycemia
- hemoconcentration (increased hematocrit & plasma protein concentration) from water depletion)
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]
- Use local susceptibility to choose if available
- Option 1: doxycycline 300mg x 1 PO[7]
- Option 2: azithromycin 1 gm (20mg/kg) x 1 PO [7]^
- Option 3: erythromycin 500 QID x 3 days[7]^@
- Option 4: ciprofloxacin 1g x 1 PO
- Option 5: TMP-SMX DS BID s 3 days
- Give children Zinc and Vitamin A supplementation
- ^Pregnant
- @Children
Disposition
- Admit if hypotensive or hemodynamically unstable, severe electrolyte abnormalities
See Also
External Links
References
- ↑ 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.
- ↑ Sack DA, et al. Cholera. Lancet 2004; 363:223.
- ↑ Neilson AA, Mayer CA. Cholera - recommendations for prevention in travelers. Aust Fam Physician. 2010 Apr;39(4):220-6
- ↑ 7.0 7.1 7.2 Stanford Guide to Antimicrobial Therapy 2014.