Most folks who wake up feeling crummy will sit down with a computer or smartphone before they sit down with a doctor.
They might search the Web for remedies or tweet about their symptoms. And that's why scientists who track disease are turning to the Internet for early warning signs of epidemics.
"Surveillance is one of the cornerstones of public health," says Philip Polgreen, an epidemiologist at the University of Iowa. "It all depends on having not only accurate data, but timely data."
