How Maps Help Us Address and Prevent Epidemics

Cholera Outbreak of 1854

Why Maps are Important?

Maps are often used to represent an area of land or natural feature, but one use of maps that is frequently overlooked, is the way that they can be used to learn about and prevent epidemics.

Mapping epidemics is important because it can help to effectively respond to the situation and detect where the most help is needed. With maps, people can easily tell where the worst of the disease is, which can effect decisions like travel.

In this picture, you can see a map of the spread of COVID-19, the ongoing pandemic.

The Cholera Outbreak of 1854

About Cholera

Cholera is a waterborne disease that kills swiftly and effectively. It causes stomach pains, throwing up and diarrhea. But what makes Cholera so fatal is the way it dehydrates blood. So much that the skin begins to sag as the organs shut down. All of this can happen in the span of 24 hours. Up until 1885, it was incurable. Thus, the only way to save people from this deadly disease, was to prevent it from happening in the first place.

For more information on Cholera, click the link below.

John Snow

John Snow

John Snow was born in 1813 and was a well educated child. By the time he was 14, he was an apprentice for a Newcastle surgeon. When Snow was 18, he was sent into the coal mines to help miners who had fallen sick sue to Cholera. While there was no cure at the time and patient after patient died, John Snow kept journals of the outbreak and recorded his findings. The outbreak of 1831 was devastating and spread across several countries including India and Russia. At the time though, there was nothing that doctors could do and so, John Snow moved on and about 20 years later, he has a licensed doctor and member of the Royal College of Surgeons.

Miasmists, Contagists or Neither?

A common misconception, regarding the spread of Cholera, at the time was that it was spread through 'bad air' or miasma. Another smaller group of people, believed that it was spread like the common flu, from person to person. John Snow, however, was skeptical. He was suspicious because the first signs of Cholera were stomach pains and if the disease was contracted due to bad air, he believed the first signs would occur in the throat. While this reasoning was definitely flawed, it set him on the path to discovering the true cause, infected water.

The 2nd Outbreak

Although John Snow had moved on with his career, he never forgot Cholera and when a second outbreak occurred, he was ready. While there was still no cure, he wanted to take this opportunity to learn about the disease. The year was 1854, the first case of Cholera was reported. A six-moth-old child, living on Broad Street, London, had contracted the disease.

Within a few hours Cholera was already spreading through Soho, a hot, humid and overpopulated neighborhood in London. Upon arrival, John Snow began to knock on people's doors trying to find a pattern. From a previous experiment, John Snow already had the theory that Cholera was spread through ingestion, most often water. Knocking on doors and speaking to the residents of Soho lead him to the Board Street Pump, the culprit of the whole ordeal and Snow was going to prove it.

One of the Most Iconic Epidemic Maps Ever

As John Snow took to the streets collecting data, he recorded where the sick or infected lived. He started to connect them to the Broad Street Pump. Snow made a map that showed the cases of the disease being within walking distance of the pump and with this map ha was able to prove that the cause of the outbreak was the water form the Broad Street Pump.

This was the original map that John Snow made to show that the cases of Cholera revolved around the Broad Street Pump.

Loose Ends

While the map had a majority of sick residents within walking distance of the Broad Street Pump, there were some exceptions. For example, a woman living quite far from the pump died of Cholera. This was explained by the fact that she had water from the Pump carted all the way to her house. Another exception was a workhouse close to the pump, there were extremely few cases of Cholera which was unusual because of the 500 or more workers living there. John Snow discovered that the workhouse had its own well of healthy water.

This is a modified map that shows walking distances from the pumps. The center circle with the pumps and the various dots represents the Broad Street Pump.

John Snow had discovered that the Broad Street Pump was infecting the Soho neighborhood but he still didn't know what had contaminated the pump. In order to figure it out, he went back to the very beginning. Snow visited the family of the six-month-old infant that had been the first to be infected. As if turns out, the mother of the child had thrown the child's soiled diapers into a cesspit outside her home. Said cesspit incidentally had cracks in it, leading straight into the well water of the Broad Street Pump.

How Maps Help us Address and Prevent Epidemics

    Maps are important tools. John Snow's Cholera map lead to the end of the 1854 outbreak. Because of his map, he was able to prove that the Broad Street Pump was the source of the disaster. Thus, when the pump handle was removed, the outbreak came to an end. John Snow's map was innovative and revolutionary and has paved the way of epidemic maps. They can help us understand where epidemics come from, where they might spread next etc. In the 21st century, you can look up COVID-19 on any internet platform and maps, information, data, news and more will appear in seconds.

The spread of COVID-19, showing the origin of the virus and the first countries it was spread to.

For more information on the current COVID-19 virus, read through the link below.

Maps aren't the only thing that save lives in an epidemic. What may seem like small actions, make an enormous difference. For example, right now. Staying inside, wearing masks when you leave, ordering things online, staying six feet form others and washing your hands. All of these things not only keep you safe, but keep others safe as well. Do your part. Stay safe and save lives.

Thank you to our COVID-19 doctors.