Cholera

Alternative names

V. cholerae; Vibrio

Definition

Cholera is an infection of the small intestine caused by the bacterium Vibrio cholerae. It results in profuse, watery diarrhea.

Causes, incidence, and risk factors

Cholera is an acute illness characterized by watery diarrhea. The toxin released by the bacteria causes increased secretion of water and chloride ions in the intestine, which can produce massive diarrhea. Death can result from the severe dehydration brought on by the diarrhea.

Cholera occurs in epidemics when conditions of poor sanitation, crowding, war, and famine are present. Endemic areas include India, Asia, Africa, the Mediterranean, and more recently, South and Central America, and Mexico. The infection is acquired by ingesting contaminated food or water.

A type of Vibrio bacteria also has been associated with shellfish, especially raw oysters. Risk factors include residence or travel in endemic areas and exposure to contaminated or untreated drinking water.

Symptoms

• sudden onset of watery diarrhea, up to 1 liter (quart) per hour
  o diarrhea has a "rice water" appearance, where the stool looks like water with flecks of rice in it
  o diarrhea has a "fishy" odor
  
• dehydration can occur rapidly
  o rapid pulse (heart rate)
  o dry skin
  o dry mucus membranes or dry mouth
  o thirst, excessive
  o "glassy" eyes or sunken eyes
  o no tears
  o lethargy
  o unusual sleepiness or tiredness
  o low urine output
  o sunken "soft spots" (fontanelles) in infants
  
• abdominal cramps
  
• nausea
  
• vomiting
  

Note: Symptoms can vary from mild to severe.

Signs and tests

• Gram stain and stool culture show cholera
  
• blood culture may show cholera
  

Treatment

The objective of treatment is to replace fluid and electrolytes lost through diarrhea. Depending on the condition of the person, oral or intravenous fluid will be given. Tetracycline and other antibiotics may shorten the duration of the symptoms.

Note: Tetracycline is usually not prescribed for children until after all the permanent teeth have come in, because it can permanently discolor teeth that are still forming.