Cholera is a waterborne disease caused by the bacterium Vibrio cholera. The main symptom is severe diarrhea, which results in the loss of large quantities of water and salts; if left untreated, this severe dehydration can lead to death within four to six hours. Cholera is spread through the fecal-oral route, in which human feces containing the bacterium contaminate drinking water. Keeping water clean and free of human waste is the best way to prevent cholera.
The best way to treat cholera is through oral rehydration therapy, in which patients drink water mixed with sugar and salts to replace the lost bodily fluids. This is an affordable and effective treatment that works well enough for most cases of cholera. For more serious cases, intravenous therapy (injecting the sugar-salt solution directly into the veins) is preferable. Although antibiotics are not necessary to treat cholera, they may be used to shorten the period of diarrhea and thus reduce the amount of fluid that needs to be replaced.
While in the 19th century cholera killed thousands of people in European cities, improved sanitation has now all but eradicated the disease in the industrialized world. Today it is still endemic (that is, regularly found) in poorer regions of the world like sub-Saharan Africa, India, and Bangladesh. By some estimates, cholera causes up to 100,000 deaths annually, the vast majority of which occur in the developing world.
Cholera is believed to have originated in India in the Ganges River Delta thousands of years ago. The modern history of cholera begins in 1817 when it spread outside India for the first time in recorded history. The rest of the 19th century saw waves of successive cholera pandemics (worldwide epidemics) in which hundreds of thousands of people died. Since 1817, there have been seven worldwide cholera pandemics.
The city of London underwent rapid industrialization in the 19th century, and the unsanitary conditions in which the poor lived greatly facilitated the spread of cholera. In particular, widespread water pollution caused by dumping sewage directly into the River Thames contributed to the severity of cholera outbreaks. (The Thames was also used as a source of drinking water.) There were four main outbreaks of cholera in London in the 19th century: 1831-1832, 1848-1849, 1854, and 1866.
Cholera, and the need to understand how to prevent and treat it, played an important role in the founding of epidemiology, the study of disease in large populations. During the 1854 cholera outbreak, the physician John Snow used statistical analysis to demonstrate that cholera was waterborne rather than airborne.
Cholera was also instrumental in the development of public health, which is defined by the World Health Organization (WHO) as “all organized measures (whether public or private) to prevent disease, promote health, and prolong life among the population as a whole.”
“150 Years of Cholera Epidemiology.” The Lancet 366, no. 9490 (2005): 957.
Claisam, Mariam, and Ronald Waldman. “Cholera.” In Encyclopaedia Britannica.
Howard-Jones, Norman. “Robert Koch and the Cholera vibrio: A Centenary.” British Medical Journal (Clinical Research Edition) 288, no. 6414 (1984), 379-381.
Kavic, Stephen M., and Eric J. Frehm, and Alan S. Segal. “Case Studies in Cholera: Lessons in Medical History and Science.” Yale Journal of Biology and Medicine 72, no. 6 (1999): 393-408.
Speck, Reinhard S. “Cholera.” In The Cambridge World History of Human Disease, edited by Kenneth F. Kiple, 642-649. London: Cambridge University Press, 1993.
Written By Ben Stampfl
Table of Contents
- Outbreak of 1831-1832
- Outbreak of 1848
- Outbreak of 1853-1854
- Outbreak of 1866
- John Snow
- Joseph Bazalgette and the sewer system
- Robert Koch