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The Contributions of John Snow



When people hear the name John Snow, they might think of Jon Snow from the Game of Thrones. However, John Snow is another person with the same name. He is considered the father of contemporary epidemiology and was born in Yorkshire, England on March 15th,1814. He was the firstborn of nine children and completed three medical apprenticeships at the age of 14. In 1836, he started his formal medical education by receiving a doctor of medicine degree from the University of London. In 1849, he became a licensed specialist at the Royal College of Physicians of London. He eventually settled in Soho, a neighborhood in London, researching and having a medical practice there.


London Broad Street Pump Case and Cholera

Snow is known mainly for his work investigating the cholera outbreak from London’s Broad Street pump in 1854. The first cholera outbreak happened in London between 1831 and 1832 while Snow was still training to be a physician. However, when the second outbreak happened between 1848 and 1849, Snow and other physicians created the London Epidemiological Society to provide the government with methods of reducing disease. He had an opposing theory at the time that cholera was spread through fecal contact and contaminated water through microbes, which was debated until Vibrio cholerae was discovered; the accepted theory was that cholera was spread through the air. His contributions to epidemiology happened during the third outbreak when there was an outbreak of cholera on Broad Street in the Soho neighborhood. He used graphs, reasoning, and maps to determine why so many people were dying in this particular neighborhood, coming to the conclusion that the pump had unsanitary water circulating to people and killing them.



The Great Experiment

In 1854, Snow also did the Great Experiment, a study comparing cholera cases with one place receiving sewage-contaminated water from water within London and the other receiving clean water from the upper River Thames. The region getting water from the Thames was located away from the city and did not have as much exposure to sewage as the water from within London. In this study, Snow demonstrated how water being contaminated could affect healthy populations and lead to illness and death if the water was unsanitary.


Anesthesiology Contributions

Another contribution to medicine that not many people know about is his contribution to anesthesiology. He learned about anesthesia and the use of ether, which was used very frequently during surgery for pain relief when he was in the United States. After becoming skilled at using ether and becoming an anesthesiologist at St. George in 1847, he began to work with chloroform. Chloroform was used in a handkerchief for patients into unconsciousness but was not as safe. He was able to make an apparatus that used chloroform as anesthesia, which was done in a safer and more effective way.


Snow was able to contribute to medicine and epidemiology, paving the way for how current epidemiologists should go about figuring out the mode of transmission in outbreaks and determining safer ways for anesthesia to be incorporated into surgeries.




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Thank you for reading

-Siri Nikku


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