In eighteen fifty-four nobody could see a cholera bacterium, and the respectable explanation was : bad air rising from filth. John Snow, better known as an anesthetist, backed the unpopular alternative that cholera travels in water. When an epidemic broke out in London on the thirty-first of August, he suspected one particular pump on Broad Street. How could he test that?
With death records and doorsteps. Snow reviewed the death records of area residents who had died of cholera and interviewed their households, documenting that most of the dead had lived near the and had drunk its water. He took the finding to community leaders. The pump handle came off on the eighth of September, and no further cholera deaths followed.
John Snow is a legendary figure in epidemiology and was best known in his own lifetime for his work in anesthesiology. His interest in cholera led him to support an unpopular theory: that the disease was transmitted by water rather than through miasma, the bad air that most authorities blamed.
On the thirty-first of August in eighteen fifty-four, London experienced a recurrent epidemic of cholera. Snow suspected the water from the Broad Street pump as the source, which was a specific enough claim to be wrong in a checkable way.
To test it he reviewed the death records of area residents who had died from cholera and interviewed their household members. The pattern he documented was that most of the deceased had lived near the pump and had drunk water from it. He presented his findings to community leaders, and the pump handle was removed on the eighth of September.
Removing the handle prevented additional cholera deaths, which supported his claim that cholera was a waterborne, contagious disease. The cause nonetheless remained a matter of debate until was isolated in eighteen eighty-three. The CDC treats the investigation and the removal of the handle as the model for modern , which is why the anniversary was marked at all.
wat. He never saw the thing that was killing them. He only worked out where they had all been drinking.
wat wat
He identified a risk, recommended an action and watched the deaths stop, all without knowing what the agent was, which is the shape every outbreak investigation has taken since.
How do we know?
The Centers for Disease Control and Prevention marked the one hundred and fiftieth anniversary of the episode in its Morbidity and Mortality Weekly Report, setting out what Snow did and what followed.
What is still unknown
The CDC describes death records and household interviews, not the dot map Snow is remembered for. It also notes that the cause of cholera stayed under debate until the organism was isolated in eighteen eighty-three.
Learn something?
Where to next
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