After careful investigation, including plotting cases of cholera on a map of the area, Snow was able to identify a water pump in Broad (now Broadwick) Street as the source of the disease.
He had the handle of the pump removed, and cases of cholera immediately began to diminish.
Cholera is an acute diarrheal disease that in severe cases rapidly leads to dehydration and death if appropriate treatment is not provided immediately.
It is caused by infection of the intestine with the bacterium (toxigenic strains of O1 and O139 types).
However, Snow's 'germ' theory of disease was not widely accepted until the 1860s.
Snow was also a pioneer in the field of anaesthetics.He became a member of the Royal College of Surgeons in 1838, graduated from the University of London in 1844 and was admitted to the Royal College of Physicians in 1850.At the time, it was assumed that cholera was airborne.In 1854 two water companies, the Southwark and Vauxhall Waterworks Company and the Lambeth Waterworks Company, supplied water to South London.The intake of Southwark and Vauxhall was located next to Battersea Park.John Snow, along with his assistant Mr John Joseph Whiting, visited the dwellings of every person who died from cholera in South London during this period.With utmost attention to detail and at great risk to their own personal health, Snow and Whiting recorded important details surrounding the deaths of these individuals.To exploit the Grand Experiment, Snow and his assistant, Mr John Joseph Whiting, visited the addresses where each of the cholera deaths occurred and recorded the details surrounding each death.Snow placed Mr Whiting in charge of visiting the addresses that lay in districts where water was supplied only by the Southwark and Vauxhall Waterworks Company.To commemorate the 160th anniversary of the publication of Snow’s second edition of and to redress this epidemiological slight, we highlight John Snow’s important work in South London, unearth the original data that Snow collected at great risk to his own personal health and present a first-time mapping of these data in time and space.We trust that this piece will foster a deeper appreciation for John Snow’s contribution to epidemiology and increase respect for small yet valuable epidemiological data.