Big data: How cellphones help track diseases

"Big data" has become quite the buzzword this year. But the possibilities for these massive data sets carry far beyond the hunt for terrorists. Public health officials use the same kind of data for a similar goal: saving lives.

Researchers can now pull together huge amounts of information – think Google Trends, Twitter messages about flu symptoms, or frequency of visits to WebMD – with the aim of tracking diseases. Officials have sought after such information for decades, but the increasing availability of big data makes the hunt faster and more accurate than ever before.