Ill workers were probably the cause of more than 80 people being sickened by a foodborne illness at the Edinburgh USA Golf Course clubhouse restaurant.

Minnesota Health Department spokesman Doug Schultz said the investigation is not final, but one or more foodworkers were either working while ill or working too soon after being ill.

A Dec. 8 banquet for Totino Grace High School football players sickened at least 77 people at the restaurant in Brooklyn Park. Complaints of illness came from three other banquets from Dec. 6 through 8. About 568 attended the four events. And four complaints came from restaurant patrons who ate there from Dec. 6 through 10 and also had diarrhea and vomiting.

The Health Department has not pinned down a specific contaminated food item, but it is likely there were multiple food dishes or items.

"We are entering the peak season for norovirus in Minnesota, so it is important that everyone wash their hands after going to the bathroom and before handling food. Stay home if you are ill," Schultz advised.