Follow Flu Trends around the World in Real-Time

Google found that certain search terms are good indicators of flu activity. Google Flu Trends uses aggregated Google search data to estimate current flu activity around the world in near real-time.

Google found a close relationship between how many people search for flu-related topics and how many people actually have flu symptoms. Of course, not every person who searches for "flu" is actually sick, but a pattern emerges when all the flu-related search queries are added together. Google compared its query counts with traditional flu surveillance systems and found that many search queries tend to be popular exactly when flu season is happening. By counting how often they see these search queries, they can estimate how much flu is circulating in different countries and regions around the world. Google's results have been published in the journal Nature.