Pretty sure that my son had it, but it is so prevelent around here that his Dr. isn't even testing for it anymore if you are an otherwise healthy person. Confirmed cases of kids having it in each of my kids classrooms , husbands secretary had it - and I just drove my neighbors child home from school with a suspected case of it (her best friend has a confirmed case) (I'm their emergency contact.)
So yeah, in MD at least, there is alot of it.