|Screen Cap from healthmap.org/en/|
You can see all kinds of outbreaks, or just track one specific virus, such as Avian or Swine Flu.
But it's not limited to flu strains. I'm looking at Pennsylvania now and I can see reported the incidents of a bunch of people who got sick from drinking contaminated raw milk.
The app is free from http://healthmap.org/outbreaksnearme/ and comes in either iPhone or Android flavor.