This one shouts "food poisoning." Too quick and too universal for SARS. Teenagers on a field trip - naw,
I was never a garbage gut...heh heh...
The most common one with this incubation period is staph food poisoning, followed by strep and enteropathogenic E. coli. Pretty miserable stuff, but not fatal to the young and healthy.
Boy, when *I* had food poisoning from bad fish, I thought I was gonna die and afraid I wouldn't!! Nasty nasty stuff.