What if Google knew before anyone else that a fast-spreading flu outbreak was putting you at heightened risk of getting sick? And what if it could alert you, your doctor and your local public health officials before the muscle aches and chills kicked in?
That, in essence, is the promise of Google Flu Trends, a new Web tool that Google.org, the company's philanthropic unit, unveiled Tuesday, right at the start of flu season in the U.S.
Google Flu Trends is based on the idea that people who are feeling sick will probably turn to the Web for information, typing things like “flu symptoms” or “muscle aches” into Google. The service tracks such queries and charts their ebb and flow, broken down by regions and states.
Early tests suggest that the service may be able to detect regional outbreaks of the flu a week to 10 days before they are reported by the Centers for Disease Control and Prevention. Some public health experts say that could help accelerate the response of doctors, hospitals and public health officials to a nasty flu season, reducing the spread of the disease and, potentially, saving lives.
It could also offer a dose of comfort to stricken individuals in knowing that a bug is going around.
“This could conceivably provide as early a warning of an outbreak as any system,” said Lyn Finelli, lead for surveillance at the influenza division of the CDC. She noted that people often search the Internet for medical information before they call their doctor.
“The earlier the warning, the earlier prevention and control measures can be put in place, and this could prevent cases of influenza,” Finelli said. Between 5 percent and 20 percent of the nation's population contracts the flu each year, she said, leading to an average of roughly 36,000 deaths.
Google Flu Trends is the latest indication that the words typed into search engines can be used to track the collective interests and concerns of millions of people, and even to forecast the future.
“This is an example where Google can use the incredible systems that we have to come up with an interesting, predictive result,” said Eric Schmidt, Google's chief executive. “From a technological perspective, it is the beginning.”
For now the service covers only the U.S., but Google is hoping to eventually use the same technique to help track influenza and other diseases worldwide.
The premise behind Google Flu Trends has been validated by an unrelated study indicating that the data collected by Yahoo, Google's main rival in Internet search, can also help with early detection of the flu.
“In theory, we could use this stream of information to learn about other disease trends as well,” said Philip Polgreen, assistant professor of medicine and epidemiology at the University of Iowa and a co-author of the study based on Yahoo's data.