As the Northern Hemisphere gears up for flu season amid the H1N1 pandemic, companies are analyzing Web activity to create early warning systems, reports The Washington Post [1].

The practice of analyzing information to spot disease has been dubbed "infodemiology", and one of biggest Internet companies is all over it.

Google's public Flu Trends [2] system, for example, is designed to pick up early clues by tracking and analyzing Internet searches for flu information. "We keep track of what queries have been asked, and how often," said Roni Zeiger, the Flu Trends product manager. Because people often search for information on the Web before going to a doctor, the system can provide an early warning of trouble, he said.

During the 2007-08 flu season Google used an early version of the system that consistently detected flu rates one to two weeks ahead of official reports, the company said in a paper published in February.

Such information-based analytics may not only provide early warnings to public health officials but to the ordinary mom with a cellphone.

Other companies and programs scan live Web chatter for mentions of, or reports about, the flu.

Boston-based HealthMap's automated system sends out an hourly Web "crawler" that hunts for flu information in seven languages.

Its creators on Tuesday launched a cellphone application called "Outbreaks Near Me" that can alert users to illnesses nearby. "If you move into a zone where there's an outbreak, your phone would actually alert you," said John Brownstein, assistant professor of pediatrics at Children's Hospital in Boston, where HealthMap [3] is based. The application also allows users to send back to HealthMap their own flu alerts.

The Post, however, notes that such technologically novel tools cannot replace the doctor-driven disease surveillance systems created by the Centers for Disease Control and Prevention [4].

Nevertheless, Ashley Fowlkes, an epidemiologist with the CDC, seems cautiously optimistic about Web-based surveillance. "It'll always be a nice adjunct to current surveillance systems and . . . may serve as an early warning system," she told the Post.

♦ Screenshot of Google Flu Trends [2]

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