Google Follows the Flu

Track the flu with Google (NASDAQ:GOOG) this winterThe service, called Flu Trends, uses computers to crunch millions of Internet searches people make for keywords that might be related to the flu -- for instance "cough," or "fever." It displays the results on a map of the U.S. and shows a chart of changes in flu activity around the country. The data is meaningful because the Google arm that created Flu Trends found a strong correlation between the number of Internet searches related to the flu and the number of people reporting flu symptoms.

Google built the service with the guidance of the Centers for Disease Control and Prevention, the U.S. government's public-health watchdog that runs a range of flu-surveillance systems. Flu Trends can be a complement to those tools, health officials say.

Flu Trends "maps very closely to the influenza-like trends that we see in the U.S.," says Lyn Finelli, lead of the influenza surveillance team at CDC's headquarters in Atlanta.