Google Search to Improve Pandemic Response

By Greg McNevin

November 13, 2008: The power of Google search has been demonstrated in a new and interesting way this week, with the company showing how its Trends tool, or in this case, Flu Trends, can uncover flu outbreaks a fortnight earlier than traditional methods.

Flu Trends uses search data to estimate flu activity down to the state level as users search for online health information.

“As you might expect, there are more flu-related searches during flu season, more allergy-related searches during allergy season, and more sunburn-related searches during the summer,” writes Google on the Flu Trends home page. “We have found a close relationship between how many people search for flu-related topics and how many people actually have flu symptoms.”

Naturally, not everyone who searches for "flu" is sick, but Google says that a pattern emerges when all the flu-related search queries from each state and region are added together.

“We compared our query counts with data from a surveillance system managed by the U.S. Centers for Disease Control and Prevention (CDC) and discovered that some search queries tend to be popular exactly when flu season is happening,” says Google. “By counting how often we see these search queries, we can estimate how much flu is circulating in various regions of the United States.”

Traditionally, flu surveillance systems can take up to two weeks to collect and release surveillance data. Google search queries, however, can be analysed rapidly enabling flu estimates to be released daily.

Google says that because of this rapid reaction, Flu Trends may provide an early-warning system for outbreaks of influenza. A very welcome capability with the threat of Avian Flu lingering.

Early detection of a disease outbreak can reduce the number of people affected. If a new strain of influenza emerges under certain conditions and a pandemic looms, Google says that up-to-date influenza estimates may enable public health officials and health professionals better respond to an outbreak.

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