Unless you know that people who didn't eat didn't get sick (at Harmony), I wouldn't be too quick to blame it on the food. Many, if not most bacteria pass from hand to hand to mouth and nose to hand and so on, and with so many ill at once it sounds to me like bacteria, as opposed to a virus, which usually incubates for a few days.

I'm not a doctor, but I've worked for years in settings where preventing the spread of just such mini-epidemics was important, and watched for all the time.

And it's really true, soap and water are your friends. Someone mentioned no hot water, but cold water and a good ten second soap lathering will do the trick.

Okay, sanitation lecture mode off. Sorry, reflexive response.