What Is Cholera?

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Cholera epidemics arise in a long cycle superimposed on existing endemic disease. This pattern relates to declining population level immunity from a previous outbreak.

Environmental factors are also important in the epidemiology of Cholera. Due to changes in the surface water temperature and terrestrial nutrient discharge, there occurs proliferation of phytoplankton and zooplankton and a consequent increase in Vibrio cholerae.

[Harris, J. B., LaRocque, R. C., Qadri, F., Ryan, E. T., & Calderwood, S. B. (2012). Cholera. The Lancet, 379(9835), 2466–2476. doi:10.1016/s0140-6736(12)60436-x]

- Why are the population affected by the Cholera?

A bacterium called Vibrio cholerae causes cholera infection. After ingestion of the Vibrio cholera, most of the bacteria are killed by gastric acid. Surviving organisms colonize the small intestine and elaborate cholera toxin (CTX), the major virulence factor for pathogenic strain. CTX binds to the intestinal walls, where it interferes with the normal flow of sodium and chloride. This causes the body to secrete enormous amounts of water, leading to diarrhea and a rapid loss of fluids and salts (electrolytes).

Contaminated water supplies are the main source of cholera infection, although raw shellfish, uncooked fruits and vegetables, and other foods also can harbor V. cholerae.

People get infected due to consumption of such contaminated foods.

[Harris, J. B., LaRocque, R. C., Qadri, F., Ryan, E. T., & Calderwood, S. B. (2012). Cholera. The Lancet, 379(9835), 2466–2476. doi:10.1016/s0140-6736(12)60436-x]

References:

- Cholera - Vibrio cholerae infection (2014, November 6). Retrieved September 13, 2016, from http://www.cdc.gov/cholera/general/index.html

- Sack, D. A., Sack, R. B., & Chaignat, C. (2006). Getting Serious about Cholera. New England Journal of Medicine. 355(7), 649-651. doi:10.1056/nejmp068144

- Ali, M., Lopez, A. L., You, Y. A., Kim, Y. E., Sah, B., Maskery, B., & Clemens, J. (2012). The global burden of cholera. Bulletin of the World Health Organization. 90(3), 209-218. doi:10.2471/blt.11.093427

- Ferri, F. F. (2014). Ferri's clinical advisor 2014: 5 books in 1. Philadelphia, PA: Elsevier/Mosby.

- The Weekly Epidemiological Record (WER). (2015, October 2). Retrieved September 13, 2016, from http://www.who.int/wer/en/

- Harris, J. B., LaRocque, R. C., Qadri, F., Ryan, E. T., & Calderwood, S. B. (2012). Cholera. The Lancet, 379(9835), 2466–2476. doi:10.1016/s0140-6736(12)60436-x

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