A collaboration between Google and the U.S. Centers for Disease Control and Prevention in Atlanta has yielded an online tool that may help people know about flu outbreaks even more quickly than existing surveillance methods.
The new tool, called Google Flu Trends, will monitor search trends to see abnormally large numbers of searches for the flu and related terms. It will then publish a map of affected areas in its new service.
Google says its new system will be able to detect influenza outbreaks up to two weeks faster than the traditional surveillance systems in use.
"As with any communicable disease, early detection is key for health professionals to react quickly," said Jeremy Ginsberg, the lead engineer who developed the new site.
"With online search queries, what we see is millions of people who are interested in searching online for information about health. And with winter approaching, more people will be curious about flu, because we are entering the flu season."
A paper accompanying the launch of the site was accepted by the journal Nature, with the editor in chief, Philip Campbell, praising the "exceptional public health implications of this paper."
The journal is allowing the paper to be discussed with the public before it is published.
But while researchers in the field call the new system interesting and novel, they are not ready to get behind the new site yet.
"I think the way to tell, obviously, is to compare it with actual surveillance data, which they should be able to pick up locally," said Stephen Morse, an epidemiologist at Columbia University's Mailman School of Public Health. "Whether searching for the flu is meaningful or not can only be compared with another gold standard method."
Morse said the system is open to a few problems.
"I think the approach sounds like a reasonable one, but I can think of several reasons why people might want to search for information on the flu," he said.
For example, Morse noted, as a flu researcher, he searches for flu information constantly, despite not being ill. More prevalent problems could accompany an increase in flu-related search terms because of a media report about the flu or, at this point, the threat of avian influenza.
Others have similar concerns.
"It's certainly intriguing and outside-of-the-box," said Dr. Lisa Jackson, an infectious disease specialist with the Group Health Center for Health Studies in Seattle. "The difficulty is that the term, flu, is not just used for influenza. A lot of people think of flu as a gastrointestinal issue."
She cited the rhinovirus, which causes stomach flu, along with the norovirus and rhinovirus, which cause the common cold -- which many mistake for flu -- as possible confounders of Google's new system.
"I think a big problem is that the term, flu, is used for lots of different things, so right away you have an issue with that," Jackson said. "I'm not sure how well [Google Flu Trends] will translate into helping us identify areas of influenza activity."
In response to concerns like this, Ginsberg said that in researching the new site, the data that is gathered from search engine queries is compared against past search trends and physician data. In the past, the trends in searching for flu have lined up well with actual outbreaks.