People infected with cholera suffer acute diarrhea. This highly liquid diarrhea, colloquially referred to as "rice-water stool," is loaded with bacteria that can infect water used by other people. Cholera is transmitted from person to person through ingestion of water contaminated with the cholera bacterium, usually from faeces or other effluent. 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 supplies. Any infected water and any foods washed in the water, as well as shellfish living in the affected waterway, can cause an infection. Cholera is rarely spread directly from person to person. ''V. cholerae'' harbors naturally in the zooplankton of fresh, brackish, and salt water, attached primarily to their chitinous exoskeleton. Both toxic and non-toxic strains exist. Non-toxic strains can acquire toxicity through a lysogenic bacteriophage. Coastal cholera outbreaks typically follow zooplankton blooms, thus making cholera a zoonotic disease.
Potential human contribution to transmissibility
Cholera bacteria grown ''in vitro'' encounter difficulty subsequently growing in humans without additional stomach acid buffering. In a 2002 study at Tufts University School of Medicine, it was found that stomach acidity is a principal factor that contributes to epidemic spread. In their findings, the researchers found that human colonization creates a hyperinfectious bacterial state that is maintained after dissemination and that may contribute to epidemic spread of the disease. When these hyperinfectious bacteria underwent transcription profiles, they were found to possess a unique physiological and behavioral state, characterized by high expression levels of genes required for nutrient acquisition and motility, and low expression levels of genes required for bacterial chemotaxis. Thus, the spread of cholera can be expedited by host physiology.
Further Reading
This article is licensed under the Creative Commons Attribution-ShareAlike License.
It uses material from the Wikipedia article on
"Cholera"
All material adapted used from Wikipedia is available under the terms of the
Creative Commons Attribution-ShareAlike License.
Wikipedia® itself is a registered trademark of the Wikimedia Foundation, Inc.