"Flu is underreported. People don't tend to go to hospitals or physicians unless they think they are very sick. What you're seeing, usually, when you actually get reports of flu outbreak, is those who are sick enough."
Morse said novel methods that observe human behavior to make predictions about disease outbreaks greatly aid the fight against influenza.
"I think we need a lot of ideas like this," he said.
Dan Childs contributed to this report.