Several guests at a Manhattan catering hall report sudden vomiting and diarrhea about 24 to 36 hours after a banquet. The most common cause of such outbreaks, often spread by an ill server handling ready-to-eat food, is:

Explanation

Norovirus is the leading cause of foodborne illness outbreaks and spreads easily from an infected worker to ready-to-eat foods; it causes sudden vomiting and diarrhea 12 to 48 hours after exposure and is highly contagious. Workers with vomiting or diarrhea must be excluded. Perfringens is tied to time-abused stews, Trichinella to undercooked pork or game, and ciguatoxin to certain reef fish.