Cholera causes


 * Associate Editors-In-Chief: Priyamvada Singh, MBBS [mailto:psingh@perfuse.org]

Overview
Cholera is a severe diarrheal disease caused by the bacterium Vibrio cholerae. . Persons infected with cholera have massive diarrhea. This highly liquid diarrhea, which is often compared to "rice water," is loaded with bacteria that can spread under unsanitary conditions to infect water used by other people.

Causes

 * Cholera (or Asiatic cholera or epidemic cholera) is a severe diarrheal disease caused by the bacterium Vibrio cholerae.
 * Transmission to humans is by ingesting contaminated water or food. The major reservoir for cholera was long assumed to be humans, but some evidence suggests that it is the aquatic environment.
 * V. cholerae is a Gram-negative bacteria which produces cholera toxin, an enterotoxin, whose action on the mucosal epithelium lining of the small intestine is responsible for the characteristic massive diarrhea of the disease.

Transmission

 * Cholera is transmitted from person to person through ingestion of feces contaminated water loaded with the cholera bacterium.
 * The source of the contamination is typically other cholera patients when their untreated diarrhea discharge is allowed to get into waterways or into groundwater or drinking water supply.
 * Any infected water and any foods washed in the water, and shellfish living in the affected waterway can cause an infection.
 * Cholera is rarely spread directly from person to person.
 * V. cholerae occurs naturally in the plankton of fresh, brackish, and salt water, attached primarily to copepods in the zooplankton. Both toxic and non-toxic strains exist. Non-toxic strains can acquire toxicity through a lysogenic bacteriophage. Coastal cholera outbreaks typically follow zooplankton blooms. This makes cholera a zoonosis.