Students that were ill used their phone less, making fewer calls late at night and early in the morning. They also had a tendency to move around less than students who were feeling well. By monitoring these variables, it is believed that outbreaks of the flu can be caught earlier than the old way of looking for it. That consisted of collecting information from Doctors, many who write with third grade penmanship. By the time the information could lead to any type of pattern, it often was too late.
With 5.6 billion mobile phones in use globally, tracking human behavior has become easier. And that is especially true when you consider that there are certain traits that people have called Eigen behaviors. These include things like going out on the town, sleeping in late or working at home. There are only six of these behaviors and certain combinations of them tend to predict the behavior of a person with 90% accuracy. Combine that with a powerful tracking tool like a mobile phone, and you can understand how the phone will be used more and more to predict when and where certain diseases and illnesses will strike.
source: EnterpriseVodafone via Textually.Org