Inspiration at Infogram: Life-Saving Data Visualizations in the Time of Cholera

The history of data visualization contains some exciting and inspiring stories. This is one example of a map that saved lives. 

In 1854, a cholera epidemic spread quickly through Soho in London. The Broad Street area had seen over 600 dead, and the remaining residents and business owners had largely fled the terrible disease. Cholera was terrifying, especially since people weren’t sure how it spread. In the mid-19th century it was still widely believed that the disease spread via “miasma”, the unpleasant smell and vapor in the air.

Physician John Snow disagreed with the miasma theory. Prior to 1854, he had theorized that cholera spread through contaminated food and water. But, without evidence, his work was mostly rejected.

When cholera hit London again in 1854, Snow set to work. Visiting the houses and hospitals, he plotted the locations of cholera deaths on a map. The surviving maps of his work show a method of tallying the death counts, drawn as lines parallel to the street, at the appropriate addresses. Snow’s research revealed a pattern, and he saw a clear concentration around the water pump on Broad Street. This had to be the focus of the infection.

With this evidence he was able to convince the local authorities to remove the handle from the water pump, rendering it useless. This was a paradigm shift: when the received wisdom was that infection followed a bad smell, convincing people that clear, odorless water from a well could lead to sickness was unheard of. The epidemic subsided rapidly.

Collaborating with Henry Whitehead, a local cleric, Snow discovered that the diapers of a baby sick with cholera had been washed into a cesspit within an arm’s length of the water pump. The causation was now clear, and Snow’s work showed the path towards the modern era of epidemiology.

Dr John Snow. Photo credit: Centre for Sexual & Reproductive Health

At Infogram, we find this especially inspiring because this is also a story of how Snow’s data collection and visualization saved lives. Maps are data visualizations within the context of geography, and like other data visualizations they can be used to communicate abstract, even ground-breaking ideas.

The charts, graphs, infographics and maps you create with Infogram are all examples of data visualization. Used well, they have the power to persuade, convince, enlighten and educate. Infogram grew out of the realization that data visualization is crucial to understanding and communicating complex ideas.

Data visualization is a key part of data literacy. Just like conventional literacy that involves both reading and writing, data literacy involves both reading and creating data visualizations. We believe that higher data literacy leads to better decisions, be it within organizations or among the wider public. That’s what inspires us at Infogram to create products that make it easy to communicate effectively with data.

John Snow’s map of cholera outbreaks changed how we saw a disease and gave data journalists a model of how to work today. Feeling inspired? Subscribe to our newsletter and create your own data visualizations with Infogram.