Cholera

Cholera is a bacterial infection causing profuse watery diarrhea and rapid dehydration. It is endemic in much of Africa and South & Southeast Asia.

CASES/YEAR
420 (US); 4,000,000 (Global)
AGENT TYPE
Bacteria
OTHER NAMES
Vibrio cholerae; Enterotoxigenic strains of E. coli (Related Infection)
ACUITY
Acute-Severe
INCUBATION
Few hours to 5 days (usually 2-3 days); [CCDM]
INITIAL SYMPTOMS
Profuse watery diarrhea with vomiting early and then rapid dehydration; Most cases are mild or asymptomatic. [CCDM, p. 102] Rice water stools and severe dehydration in a few hours--only cholera causes this syndrome; [Cecil, p. 1918]
PRECAUTIONS
"Use Contact Precautions for diapered or incontinent persons for the duration of illness or to control institutional outbreaks." [CDC 2007 Guideline for Isolation Precautions] Transmitted by asymptomatic persons with infection; Communicable usually for only a few days after recovery, but occasionally, carrier state persists for several months. "However, safe water and adequate sanitation limit the potential for outbreaks, and secondary transmission in developed countries is exceedingly rare." [CCDM, p. 104-5]
COMMENTS
FINDINGS:
Vibrio cholerae bacteria produce a toxin that causes profuse watery diarrhea. Mild cases resemble gastroenteritis caused by rotavirus or ETEC. In severe cases, infection can produce profound dehydration in just a few hours. Diarrhea is painless, but patients may have oliguria and muscle cramps with weakness. Prolonged volume depletion may cause acute renal failure and death. [Merck Manual, p. 1582] Patients with cholera are afebrile and may be hypothermic. [PPID, p. 2638] In children, coma and convulsions are complications of severe hypoglycemia. Cramps in abdominal and skeletal muscles may occur. [Guerrant, p. 153] Leukocytosis is associated with severe cholera. A rare type is cholera "sicca" in which patients have ileus and distention instead of diarrhea. [Cecil, p. 1919] Cases with cholera sicca (abdominal swelling and shock) may be misdiagnosed as "acute abdomen" requiring surgery. [ID, p. 665]

EPIDEMIOLOGY:
A single-dose vaccine is licensed in the U.S. "Direct transmission from person to person, even to health care workers during epidemics, has been reported but is infrequent." [CDC Travel, p. 188-9] The organism appears to persist in coastal salt waters (brackish water or estuaries). Transmission takes place by the fecal-oral route. "Man-made or natural disasters (e.g., floods) resulting in population movements and overcrowded refugee camps are potentially fertile ground for explosive outbreaks with high case fatality rates." Outbreaks have occurred from eating undercooked or raw seafood. [CCDM, p. 104] Death from dehydration can occur within 6 to 12 hours. Cholera is difficult to eradicate because it has an environmental reservoir, but it was eliminated from the US and Northern Europe by safe water and sanitation. Worldwide, two billion people currently lack adequate sanitation. Vaccines play an important role in integrated programs to control and prevent cholera in endemic areas. [PPID, p. 2643-4]

RELATED INFECTION:
The gastroenteritis caused by enterotoxigenic strains of E. coli (ETEC) is similar to cholera. Children in developing countries become immune to ETEC, but travelers to these countries become ill after consuming contaminated food or water. [CCDM, p. 163-5] "ETEC requires special laboratory techniques for identification." [Foodborne Illnesses. MMWR. 4/16/04]
DIAGNOSTIC
Culture; Fecal smear: motile vibrio on darkfield or phase contrast microscopy; Dipsticks for O1 and O139 serotypes are available; [CCDM, p. 103] Stool cx with biochemical ID of isolate; PCR available; Crystal VC dipstick limited usefulness; [ABX Guide]
SCOPE
Endemic in much of Africa and South & Southeast Asia; Endemic in Hispaniola since 2010;; From 2010-2016, 107 confirmed cases of cholera in the United States were acquired abroad.; [CDC Travel]
SIGNS & SYMPTOMS
  • >myalgia
  • G abdominal pain
  • G diarrhea
  • G nausea, vomiting
  • H leukocytosis
  • N lethargy
  • N muscle weakness
  • N seizure
  • *acute renal failure
  • *bowel obstruction
  • *myocarditis
  • *pneumonia
  • *shock
  • *stupor, coma
  • *weight loss
ANTIMICROBIC

Yes

VACCINE

Yes

ENTRY
Ingestion
SOURCE
Person-to-Person, Human Fecal-Oral, Eating Contaminated Food, Eating Infected or Toxin-Containing Fish, Eating Contaminated Mollusks or Crustacean, Eating Contaminated Produce, Waterborne (Ingesting, Inhaling, or Swimming)
RESERVOIR
Fish and Shellfish, Human
RISK FACTORS
  • Eat undercooked meat or fish
  • Ingest infectious agents in food/water
  • Travel to endemic area
  • Victim--water/food release
TREATMENT
Greater than 50% mortality may occur in severe cases, but is less than 1% with rehydration (oral for mild cases and IV for severe cases). [CCDM]
REFERENCES FOR CASES/YEAR
1. (US) Published in MMWR 2011; Use correction factor of 10 for reported diseases: 42 X 10 = 420;
2. (Global) 3-5 million cases (100-120 thousand deaths); [Fact sheets from WHO] Averaged to 4 million;