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.