The Blackford County Health Department got Subway to close this week after many people complained of flu-like symptoms that even hospitalized some. More than 90 people were affected, according to Linda Briles, the local environmental health officer.

The Muncie Free Press reports the confirmation of norovirus came after testing of stool samples and interviews with people who dined there. Both the Blackford County Board of Health and the Indiana Board of Health participated in the investigation.

Briles said the contamination was traced to a human, but she could not be more specific until the state offered its report. She re-inspected the restaurant and Subway reopened Friday. That was after a week of investigation.