We've been here from Nov 16 to 30 at POP; Nov 30 to Dec 7 at POR; and currently we're at CBR until Sunday.
We've been in all the parks, eaten at a lot of buffets, and only eaten on site (parks, resort TSs and food courts).
We haven't been sick....nor have we talked to anyone that said they'd been ill.
Remember that there are several THOUSAND rooms amongst all the resorts, and therefore thousands of people as well. While I feel sorry for those that got sick while on vacation, even the DISer group is relatively small percentage of the overall population at the resorts.
Follow common sense procedures to help prevent catching anything....wash your hands with hot water and soap often......try to keep your hands away from your mouth, nose and eyes in case they have germs on them....wash your hands before eating.....and try to convince your kids (and maybe yourself) that the handrails are really NOT a good place for your hands, because of the thousands of other hands that were there before you. Just following these religiously will likely stop half of the illness that would typically be around a place where lots of people tend to hang out.
Stay healthy everyone!