Cholera

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Cholera bacteria under an electron microscope

Cholera is an infectious disease caused by the bacterium Vibrio cholerae.[1] It infects the small intestine.

There are many types (strains) of the Vibrio cholera bacteria. Some of them cause more serious illnesses than others. Because of this, some people who get cholera have no symptoms; others have symptoms that are not very bad, and others have very bad symptoms.[2]

The most common symptom is large amounts of watery diarrhea.[3] In the worst cases, diarrhea can be so bad that people can die in a few hours from dehydration.[4]

Cholera is a very old disease. Writings about cholera (written in Sanskrit) have been found from the 5th century BC.[5] Throughout history, there have been many outbreaks and epidemics of cholera.

Cholera still affects many people throughout the world. Estimates from 2010 say that between 3 million and 5 million people get cholera every year, and 58,000–130,000 people die from the disease every year.[3][6] Today, cholera is called a pandemic.[3][7] However, it is most common in developing countries,[8] especially in children.[3]

Cause[change | change source]

People usually get cholera by eating food or drinking water that is unclean. When people have cholera, they have a lot of diarrhea, and the cholera bacteria stays alive in their feces. In developing countries, often there is not good sanitation. Cholera can spread if this diarrhea gets into water that other people use.[9] For example, if sewage (human waste) gets into a river that many people use, people can get cholera if they:

  • Drink the water from the river.[9]
  • Eat food that they have washed in the river.[9]
  • Eat fish that live in the river,[10] if they are not cooked well enough to kill the cholera bacteria.[11]
    • This is the most common cause of cholera in developed countries.[12] People eat seafood like oysters that were taken from waters with the cholera bacteria in them and sent to stores in developed countries.

Cholera is very rarely spread directly from person to person.[12]

Signs and symptoms[change | change source]

Cholera's main symptoms are very bad diarrhea and vomiting clear fluid.[12] These symptoms usually start suddenly. They start half a day to five days after the person gets infected. (This is called cholera's "incubation period".)[13]

If they do not get treatment, about half of people with very bad cholera die.[12] People with very bad cholera can have so much diarrhea that they do not have enough water and electrolytes (salts) left in their bodies to survive.[12] Cholera has been nicknamed the "blue death" because a person dying of cholera may lose so many body fluids that their skin turns bluish-gray.[14]

Other symptoms may include:[12]

A person with severe dehydration from cholera. He has sunken eyes and saggy skin from dehydration.

Prognosis[change | change source]

If people with cholera get good, quick medical treatment, less than 1% die from the disease. However, if cholera is not treated, at least half of people with the disease (50% to 60%) die.[12][15]

Some strains of the Vibrio cholera bacteria have different genes than others, which make them more dangerous. These more dangerous strains of cholera bacteria caused the 2010 epidemic in Haiti and the 2004 outbreak in India. With these strains of cholera, a person can die within two hours of getting sick.[4]

Treatment[change | change source]

Nurses treat a cholera patient in 1992

There is no cure for cholera. However, there are different treatments that can help. For example:

  • Giving fluids to treat dehydration, either by mouth or through a needle placed into a vein (intravenously).[5]
  • Giving important electrolytes like potassium and sodium chloride (salt)[16]
  • Giving antibiotics (sometimes). These will make symptoms go away faster and not be as bad. However, people will recover without them if they are not too dehydrated. Because of this, antibiotics are suggested for people who have very bad cholera and are very dehydrated.[17]
  • Patients should keep eating; this helps their intestines return to normal.[18][19]

Prevention[change | change source]

Individuals[change | change source]

There is a cholera vaccine that can be taken by mouth. It provides some protection from cholera for about six months.[3]

People can also do some other things to prevent cholera. For example:[19][20]

Governments[change | change source]

Cholera hospital in Dhaka, showing typical "cholera beds," which are easy to disinfect

It is possible for governments to stop outbreaks or epidemics from happening. For example, cholera is very uncommon in developed countries because they have good sanitation and because they add chemicals to their water to kill germs. Even after people start to get cholera, it is possible for governments to stop the disease from spreading, through:[16]

  • Sterilization: Any material that touched a cholera patient should be cleaned with disinfectant and washed in hot water, using chlorine bleach if possible. Hands that touched cholera patients or their things, like clothing or blankets, should be carefullly cleaned and disinfected with water that has chlorine in it, or with other effective antimicrobial agents (chemicals that will kill bacteria).
  • Sewage: Sewage can be treated with antibacterial chemicals like chlorine or ozone, which can kill the cholera bacteria.
  • Sources: Warnings about possible cholera in the water should be posted around contaminated water sources, with directions on how to kill the bacteria in the water through things like boiling or adding chlorine for possible use.

History[change | change source]

Drawing of Death bringing cholera (from Le Petit Journal, 1912)

Cholera probably started in the Indian subcontinent. As early as the 5th century BC, people in the Ganges River delta area wrote about cholera.[12] The disease first spread to Russia in 1817 by trade routes (over both land and sea). Later, cholera spread to the rest of Europe, and from Europe to North America and the rest of the world.[12]

Seven cholera pandemics have happened in the past 200 years. The latest started in Indonesia in 1961.[21] There have also been many serious outbreaks. The worst outbreak in recent history happened in Haiti after the earthquake there in 2010. Between October 2010 and August 2015, more than 700,000 Haitians got cholera, and over 9,000 died.[22] The outbreak was caused by a United Nations base where Nepalese soldiers were living.[23] The soldiers would dump human waste into the Artibonite River, which many Haitians used for drinking, cooking, and bathing.[24][23]

Since cholera became common in the 19th century, it has killed tens of millions of people.[25] Just in Russia, between 1847 and 1851, more than one million people died of cholera.[26] During the second pandemic, which lasted from 1827-1835, the disease killed 150,000 Americans.[27] Between 1900 and 1920, in India, up to eight million people died of cholera.[28]

in 1854, an English doctor named John Snow was the first person to realize that contaminated water caused cholera. Today, countries in Europe and North America filter and add chlorine to their water supplies. This has made cholera very uncommon in these countries.[12]


Other websites[change | change source]

References[change | change source]

  1. Finkelstein, Richard A. (1996). “Chapter 24: Cholera, Vibrio cholera O1 and O139, and Other Pathogenic Vibrios.” In Medical Microbiology (4th ed.). Galveston, Texas: University of Texas Medical Branch at Galveston. ISBN 0-9631172-1-1. http://www.ncbi.nlm.nih.gov/books/NBK8407/.
  2. "Cholera - Vibrio cholerae infection Information for Public Health & Medical Professionals". cdc.gov. United States Centers for Disease Control and Prevention. January 6, 2015. http://www.cdc.gov/cholera/healthprofessionals.html.
  3. 3.0 3.1 3.2 3.3 3.4 World Health Organization (March 26, 2010). "Cholera vaccines: WHO position paper". Weekly Epidemiological Report (World Health Organization) 13 (85): 117-128. ISSN 0049-8114. http://www.who.int/wer/2010/wer8513.pdf. Retrieved January 31, 2016.
  4. 4.0 4.1 NPR News. Presenter: Richard Knox. NPR. 2010-12-10.
  5. 5.0 5.1 Harris JB, LaRocque RC, et al. 2012. "Cholera". Lancet 379 (9835): 2466–76. doi:10.1016/s0140-6736(12)60436-x. PMID 22748592.
  6. Lozano R, Naghavi M, et al. 2012. "Global and regional mortality from 235 causes of death for 20 age groups in 1990 and 2010: A systematic analysis for the Global Burden of Disease Study 2010". Lancet 380 (9859): 2095–128. doi:10.1016/S0140-6736(12)61728-0. PMID 23245604.
  7. "Cholera - Vibrio cholerae infection". cdc.gov. United States Centers for Disease Control and Prevention. October 27, 2014. http://www.cdc.gov/cholera/index.html. Retrieved January 31, 2016.
  8. Reidl J and Klose KE 2002. "Vibrio cholerae and cholera: Out of the water and into the host". FEMS Microbiology Reviews 26 (2): 125–39. doi:10.1111/j.1574-6976.2002.tb00605.x. PMID 12069878.
  9. 9.0 9.1 9.2 Ryan KJ, Ray CG (editors) (2004). Sherris Medical Microbiology (4th ed.). McGraw Hill. pp. 376–7. ISBN 0-8385-8529-9.
  10. Colwell, Rita (March 6, 2013). "Oceans, Climate, and Health: Cholera as a Model of Infectious Diseases in a Changing Environment (Lecture)". Rice University: James A Baker III Institute for Public Policy. http://bakerinstitute.org/videos/civic-scientist-lecture-series-rita-colwell-oceans-climate-and-health-cholera-model-infectious-diseases-changing-environment/. Retrieved January 31, 2016.
  11. "Sources of Infection & Risk Factors". cdc.gov. United States Centers for Disease Control and Prevention. November 7, 2014. http://www.cdc.gov/cholera/infection-sources.html. Retrieved January 31, 2016.
  12. 12.0 12.1 12.2 12.3 12.4 12.5 12.6 12.7 12.8 12.9 Sack DA, Sack RB, et al. 2004. "Cholera". Lancet 363 (9404): 223–33. doi:10.1016/S0140-6736(03)15328-7. PMID 14738797.
  13. Azman AS, Rudolph KE, et al. 2012. "The incubation period of cholera: A systematic review". Journal of Infection 66 (5): 432–438. doi:10.1016/j.jinf.2012.11.013. PMC 3677557. PMID 23201968.
  14. McElroy, Ann; Townsend, Patricia K. (December 30, 2008). Medical Anthropology in Ecological Perspective (5th ed.). Boulder, Colorado: Westview Press. p. 375. ISBN 978-0813343846.
  15. Todar, PhD, Kenneth. "Vibrio cholerae and Asiatic Cholera". Todar's Online Textbook of Bacteriology. http://www.textbookofbacteriology.net/cholera.html. Retrieved January 31, 2016.
  16. 16.0 16.1 "First steps for managing an outbreak of acute diarrhea". World Health Organization Global Task Force on Cholera Control. http://www.who.int/topics/cholera/publications/en/first_steps.pdf.|accessdate=January 31, 2016
  17. "Cholera - Vibrio cholera infection". cdc.gov. United States Centers for Disease Control and Prevention. November 7, 2014. http://www.cdc.gov/cholera/index.html. Retrieved January 31, 2016.
  18. World Health Organization (2005) The Treatment of Diarrhoea: A Manual for physicians and other senior health workers . WHO Press, 14, 20-21. Report. Retrieved on January 31, 2016.
  19. 19.0 19.1 United States Centers for Disease Control and Prevention (November 17, 2010) Community Health Worker Training Materials for Cholera Prevention and Control . Centers for Disease Control, 7-8. Report. Retrieved on January 31, 2016.
  20. "Cholera and food safety". World Health Organization Regional Office for Africa. World Health Organization Regional Office for Africa - Division of Prevention and Control of Non-Communicable Diseases. http://www.afro.who.int/index.php?option=com_docman&task=doc_download&gid=1712. Retrieved January 31, 2016.
  21. "Cholera's seven pandemics". cbc.ca. CBC News. October 22, 2010. http://www.cbc.ca/news/technology/cholera-s-seven-pandemics-1.758504. Retrieved January 31, 2016.
  22. "UN must step up, apologize, and help drive cholera from Haiti". The Boston Globe. August 12, 2015. http://www.bostonglobe.com/opinion/editorials/2015/08/12/must-step-apologize-and-help-drive-cholera-from-haiti/ZZ2f9CGMl7kullUNz9bimM/story.html?event=event25. Retrieved January 31, 2016.
  23. 23.0 23.1 Cravioto A, Lanata CF, et al. Final Report of the Independent Panel of Experts on the Cholera Outbreak in Haiti . United Nations. Report. Retrieved on January 31, 2016.
  24. "Cholera cases found in Haiti capital". MSNBC. 23 October 2010. Archived from the original on 26 October 2010. http://www.msnbc.msn.com/id/39787756/ns/health-infectious_diseases/. Retrieved January 31, 2016.
  25. Lee, Kelley (2003). Health Impacts of Globalization: Towards Global Governance. Palgrave Macmillan. p. 131. ISBN 0-333-80254-3.
  26. Hosking, Geoffrey A. (2001). Russia and the Russians: A History. Harvard University Press. p. 9. ISBN 0-674-00473-6. https://books.google.com/books?id=oh-5AAmboMUC&pg=PA9&dq&hl=en#v=onepage&q=&f=false.
  27. Byrne, J.P. (2008). Encyclopedia of Pestilence, Pandemics, and Plagues: A-M. ABC-CLIO. p. 99. ISBN 0-313-34102-8. https://books.google.com/books?id=5Pvi-ksuKFIC&pg=PA99&dq#v=onepage&q=&f=false.
  28. Hays, Jo N. (2005). Epidemics and Pandemics: Their Impacts on Human History. ABC-CLIO. p. 347. ISBN 1-85109-658-2. https://books.google.com/books?id=GyE8Qt-kS1kC&pg=PA347&dq&hl=en#v=onepage&q=&f=false.