The 2013 flu season in the United States is forecasted to be a particularly harsh one due to the aggressive flu strain designated as H3N2 that is sweeping the nation and causing many to become hospitalized due to the symptoms, an epidemic status has been declared by the CDC.

A virus reaches epidemic status when there is a rapid increase in infection in a localised area. However the CDC can only base its information on the patients that present to their doctors and hospitals with symptoms. CDC data does not necessarily capture the full picture of those that may have the virus but are not seeking medical treatment. Every week, millions of users around the world search for health information online. 

Google has 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. When compared with traditional flu surveillance systems Google found that many search queries tend to be popular exactly when flu season is happening. By counting how often these search queries are seen, it can be estimated how much flu is circulating in different countries and regions around the world.

Below is the current google map for the United States, click on the graph to view further detail on the Google website.

 

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