Digital epidemiology: tracking diseases in the mobile age

Being stuck in bed, waiting for the flu to run its course, is pretty unpleasant. And it’s also really boring. What else is there to do but search for symptoms online, and read entries about the flu on Wikipedia or WebMD or post messages on Facebook and Twitter about how sick you are? A lot of people get the flu every year and many of them do exactly that: they search for relevant information, and share their misery with the rest of us. The consequence is remarkable: a description of their symptoms, time-stamped and perhaps even geo-tagged, is online. Which means that the internet has a rather detailed picture of the health of the population, coming from digital sources, through all of our connected devices, including smartphones. This is digital epidemiology: the idea that the health of a population can be assessed through digital traces, in real time. It has the potential...