The New York Times created an interactive map that shows where the outbreaks of the Swine Flue are located.  

These types of epidemiological maps have been around for a while.  In fact, they were the very first examples of geographic representations of data.  Probably the most famous example is John Snow’s map of the 1854 Cholera outbreak in London. 

Snow plotted the cholera cases on a map of Soho in London and he marked the water pumps with a cross.  This showed that there was a high concentration of cholera cases around a water pump on Broad Street. 

Click on the map to download high resolution maps

This evidence prompted the local authorities to investigate the pump.  They found that it was contaminated and they replaced its handle.  This is a great example of the power of data visualization.  Finding the cause of the local epidemic could have been achieved through statistical analysis but here a visual representation of the data on a map was far more efficient. 

John Snow was thanked for his contribution to the fight against cholera with a commemorative pump on the exact location of the old contaminated one.  The pub on the corner was also named after him.  John Snow however was a teetotaler – he only drank boiled water … .