Google helps trace the spread of flu

San Francisco: Not satisfied with reinventing the internet, Google's boffins have now come up with a system to track the spread of flu across the United States by referencing the terms used in Google searches.

The system, called Google Flu Trends, plots the location of searches for flu-related terms, to come up with a flu map. The early-warning data is then passed on to the US Centres for Disease Control and Prevention (CDC) based in Atlanta, Georgia, which can choose to take preventive action such as distributing more flu vaccines in the affected areas.

The scheme avoids privacy issues by relying only on aggregated data that cannot be traced to individual searchers.

Timely data

The flu records provide timely data that could be two weeks ahead of government figures. "The data is really, really timely," said Dr Lyn Finelli, chief of influenza surveillance at the CDC.

"They were able to tell us on a day-to-day basis the relative direction of flu activity for a given area. They were about a week ahead of us. They could be used [as] an early warning signal for flu activity."

Between five and 20 per cent of the US population contracts the flu each year, Finelli told the New York Times on Wednesday, leading to roughly 36,000 deaths on average.

Google developed the model by comparing hundreds of billions of Google searches with CDC data on outbreaks.

"This seems like a really clever way of using data that is created unintentionally by the users of Google to see patterns in the world that would otherwise be invisible," said Thomas W. Malone, a professor at the MIT Sloan School of Management in Cambridge, Massachusetts.

They were able to tell us on a day-to-day basis the relative direction of flu activity for a given area ... They could be used [as] an early warning signal."