How is spatial analysis related to diseases? The story of John Snow
Over the past few weeks the news has been filled with awful stories of the Ebola outbreak in West Africa. I came across this excellent map of the spatial patterns of the outbreak.
It reminded me of just how closely linked place and health are, the discovery of which is one of the first stories we were told in our demographic theory classes at university. It is the story of John Snow – the physician, not the Game of Thrones heartthrob.
In 1854 there was a cholera outbreak in the Soho area of London. Medical theory at the time believed that disease was caused by breathing in foul smelling air. Yet that theory could not explain why cholera was not affecting all of London. In investigating the outbreak, John Snow discovered that all the victims were located in a small area, and all had drunk water from the same street pump. Once the authorities removed the handle of the pump, the cases of cholera rapidly declined. Below is the map that John Snow produced, with dots showing the homes of victims.
For this discovery, John Snow is regarded as the founding father of epidemiology, the scientific study of spatial patterns, disease and population.