The Salt Lake County Health Department said tests pointed to bacteria commonly found on skin that can be introduced to food when prepared with bare hands and not heated or cooled properly.
Nicholas Rupp, a spokesman for the health department, had no details about the meals served or those who fell ill last Sunday night or how it was prepared.
Emergency crews were called to the shelter Sunday night after receiving reports of vomiting at the Road Home shelter. More than 50 people were hospitalized and all were released by Monday night.
The shelter did not serve any meals over the weekend, but many people who stay overnight eat at the same nearby kitchens and dining halls, including St. Vincent de Paul Dining Hall.
Rupp said the health department is not taking any disciplinary action against the dining hall at this time. But it may step up its random inspections from the two visits per year to ensure that proper protocols are being followed.
The dining hall has cooperated with the investigation and the suspected food poisoning appears to have been an isolated incident, the department said.
Health department inspectors visited the dining hall Monday morning and reported only one violation — that water in a sink used for hand washing did not reach 100 degrees Fahrenheit within 30 seconds.
