john snow the father of epidemiology


This blog is about John Snow, not the one from the Game of thrones series, no, this was a British doctor who was born in March 1813 known as the father of current epidemiology, in this blog we will tell his story so that we can understand its importance.

Who was John Snow (JS)?

This John Snow (not the murderer of Daenerys Targaryen) was a British who lived in the 19th century. Apparently from a young age he was always interested in research which led him to study medicine with an uncle’s friend, William Hardcastle, where he first faced cholera in 1831, in this combat cholera won by KO ( JS 0 – C1) and John decided that he would avenge that defeat until the last day of his life. After this, he studied at the Hunterian School of Medicine where he graduated as a doctor and focused on the study of anesthetic gases with which he achieved fame, allowing him to work for Queen Victoria, whom he helped in her last two deliveries.

Preparing for the battle JS VS Cholera

It was during his college and subsequent work as an anesthesiologist that he began to prepare for the ultimate battle with the cholera. He began his preparation by discussing with his medical colleagues about the possibility that water was the transmitter of the disease but at the 19th century that was a crazy idea.

At 19th century, it was considered that infections were transmitted in two possible ways: the first, it was called miasma transmission, which basically implied that the infection was in the air and certain atmospheric changes caused it to spread like a cloud and the second, called the “contagionist” theory, it only considered that the transmission of the disease was through direct contact with the patient. So no one believed the poor John Snow and had not other choice but to accept the ridicule from their colleagues. During this period, the cholera accumulated two more victories due to epidemics in London, JS0-C3.

Start of the battle

However, in the summer of 1854 there was a new cholera epidemic which killed 500 people in a few days, in the Golden Square area. This time our hero, already prepared with his ideas ready to be tested, armed himself with patience, good shoes, pencil and paper for the battle, then decided to make a map of the area most affected by the cholera of London and going house to house marking deceased by deceased he make a map of the distribution of the disease.

Seeing the map and with the idea he had about the route of transmission of the disease, he indicated to the local health authority that the closest water pump in this case, the one on Broad Street, should be removed (because he suspected that it was the cause of the disease), believing in John Snow, they removed the pump lever causing the number of infected to decrease, with this the marker had remained JS1-C3.

Epidemiología espacial

John Snow Victory

Unfortunately for our hero, the story does not end here, because the local health authority considered that the theories of our John Snow made no sense because they did not were accord to the knowledge of the time, that and the pressure generated by the people of the sector who wanted again their source of “virus”, I say water, and they installed the lever of well. Agaein the coholera won JS1.-C4.

After this, unfortunately, our hero passed away, in 1858. Anyone would say that this history has a bad ending where evil triumphs, but it was not like that, because after a few years (to be more precise 8 years) medical knowledge changed (accepting John’s theory) and realized the mistake that had been made and it was at that point in history that the score was JS infinite – C4.


In conclusion we will say that our John Snow taught us that knowledge should be synonymous with change and flexibility. Another lesson is that success does not come overnight, John prepared for years for his battle and although he did not see what he did, he did change the world with a little observation and study. Who knows, maybe some of us will be a John Snow who changes the world but never knows.

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