WELLFLEET, Mass. — State health officials have closed shellfish beds in the Cape Cod town of Wellfleet after dozens of people who ate raw shellfish became sick.

The public health advisory issued on Thursday closes four shellfish harvesting areas immediately and orders local businesses to recall any affected shellfish that was harvested on or after Sept. 26.

Officials said they had received reports of approximately 75 people with suspected norovirus illness in the past two days, mostly associated with eating raw shellfish at weddings or at restaurants in the outer Cape Cod area.

The closings come days before the 16th annual Wellfleet OysterFest scheduled for Saturday and Sunday. Organizers say the festival will go on as scheduled, but no raw shellfish will be served and oysters from outside Wellfleet will be used in a shucking contest.