About 90 percent of the 184 inmates at the Cass County Jail in North Dakota became ill Sunday night and early Monday morning with a potential foodborne illness, Sheriff Paul Laney said.

None of the inmates had to be taken to a hospital for medical treatment, though nurses from Fargo Cass Public Health did treat those whose symptoms were most severe, the jail’s Chief Nurse Heidi McLean said.

Doug Jensen, a registered sanitarian with Fargo Cass Public Health said all aspects of food supply, storage and preparation will be examined to determine where the illness came from.

There have been no reports of illnesses among staff, Laney said, though many of those who had been on duty overnight were at home.

Inmates were served a chili macaroni casserole, corn and cornbread for supper Sunday, Laney said.

The jail has contracted its food services for nearly five years with CBM Food Service of Sioux Falls, S.D., Laney said.

There’s been a spate of health inspector scams preying on restaurants throughout the U.S. in the past five years. From handwashing signs for cash to extorting fake inspection fees, the fake inspector business has been booming.

WHO-TV reports a man calling a Des Moines restaurant pretending to be a state health inspector was interrupted when a real inspector got on the phone.

Emily Wegner says she was at the restaurant Wednesday when she heard a server yell into the kitchen that the state health department was on the phone. Wegner, whose job it is to inspect restaurants, says she got on the phone and told the caller that he was not an inspector and that she was.

The fake inspector wanted to schedule an appointment but asked for a deposit for the visit.

Wegner says the state does not charge for inspections.

Wegner says she got the caller's information and reported the scam to police.