Detecting flu infections with Google searches

Traditional measurements of the number of people who currently have the flu rely on flu patients visiting their doctor, and their doctor reporting flu cases to a central health authority, such as the Centers for Disease Control and Prevention (CDC) in the US. This data collection process can take a while, and as a result, there is usually a delay of one or two weeks in making the data available.

In a very well known study, Google collaborated with the CDC to investigate whether the number of flu infections could be estimated from data on how often Internet users had searched for flu-related keywords, such as flu symptoms. As we discussed in Week 2, data on how frequently Internet users are searching for keywords is available to Google with no delay, opening up an opportunity to get much quicker estimates of the number of people currently infected with the flu. After watching the video above you can see what went wrong in January 2013, and how appropriate analyses might allow flu scare problems to be avoided and valuable information to be extracted from Google data.