Creeepy. As much as I like demographics, this still creeps me out: Google is using web searches to track the spread of the flu. In other words, spying. On people, who use Google, for web searches. And then making it into a huge spreadsheet, in a way.

Turns out a lot of ailing Americans enter phrases like “flu symptoms” into Google and other search engines before they call their doctors.

That simple act, multiplied across millions of keyboards in homes around the country, has given rise to a new early warning system for fast-spreading flu outbreaks, called Google Flu Trends.

Tests of the new Web tool from Google.org, the company’s philanthropic unit, suggest that it 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.

In early February, for example, the C.D.C. reported that the flu cases had recently spiked in the mid-Atlantic states. But Google says its search data show a spike in queries about flu symptoms two weeks before that report was released. Its new service at google.org/flutrends analyzes those searches as they come in, creating graphs and maps of the country that, ideally, will show where the flu is spreading.

The C.D.C. reports are slower because they rely on data collected and compiled from thousands of health care providers, labs and other sources. Some public health experts say the Google data 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.

But does this leave room for error? I mean, what if Americans watched a television show about the flu? And then they went on the Internet and searched for more information. It’s very easy to make an assumption that people have the flu. Who can tell?

I don’t like the unreliability of these things. There are too many variables and there’s too much to lose (like freedom, if there is a quarantine) if things go wrong, which they usually do.

Still, some public health officials note that many health departments already use other approaches, like gathering data from visits to emergency rooms, to keeping daily tabs on disease trends in their communities.

“We don’t have any evidence that this is more timely than our emergency room data,” said Dr. Farzad Mostashari, assistant commissioner of the Department of Health and Mental Hygiene in New York City.

Hmmm.

Tags: Big Brother, demographics, Google