Louisiana health officials say they closed a harvesting area and ordered a recall of oysters taken from there since April 26 after 14 people became ill with norovirus.
The closure started Tuesday and was expected to last at least three weeks.
The recall includes shucked, frozen, breaded and processed oysters and those for the half-shell market taken from Area 23 in Terrebonne Parish southwest of New Orleans. Some of the oysters were shipped to Maryland, Texas and Georgia.
Health officials said people became ill after eating oysters from that area at one New Orleans-area restaurant.
State health officer Dr. Jimmy Guidry says the oysters were likely contaminated by sewage dumped from a boat in the harvesting area.
Norovirus causes vomiting or diarrhea. Health officials say no one was hospitalized.