Google warns the US of flu outbreaks

(AP) - Internet giant Google has launched an early-warning system for influenza outbreaks in the US. By tracking the popularity of certain Google search queries, its engineers "can accurately estimate the level of flu in each state, in near real time," a Google spokesman said.

Google Flu Trends currently only covers the US, but the technology giant is hoping to eventually use the same technique to help track influenza and other diseases worldwide. The system, which keeps track of searches such as "flu symptoms," enables the early-warning data to be available each day, much quicker than traditional flu-tracking systems which can take one to two weeks.

"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," a Google spokesman said. "We have 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 from each state and region are added together. During the last flu season, we shared our preliminary results with the Epidemiology and Prevention Branch of the Influenza Division at CDC. Together we saw that our search-based flu estimates had a consistently strong correlation with real CDC flu data."

A paper on the methodology behind Google Flu Trends is expected to be published in the journal Nature. The spokesman added: "For epidemiologists, this is an exciting development, because early detection of a disease outbreak can reduce the number of people affected."