In September 2012 Minnesota Department of Health staff investigated an outbreak of norovirus among co-workers who ate food provided by a restaurant located in Brooklyn Park, Minnesota. The meal date was September 18. No other foods were provided by at the meeting and no other foods were shared at the office in the 2 days before or after the meeting.

Twenty two meeting attendees were interviewed and 13 met the case definition. The median incubation period for cases was 33 hours (range, 15 to 56 hours). Stool samples from 3 ill attendees tested positive for norovirus GII at the MDH Public Health Laboratory. Consuming shredded cheese was significantly associated with illness.

City of Brooklyn Park Environmental Health (CBPEH) staff interviewed 23 restaurant employees. Three reported recent gastrointestinal illness. These employees reported becoming ill on September 9, 16, and 20, respectively. The restaurant reported that block cheese was shredded each morning but could not identify the employee responsible for shredding cheese on September 18. Public health staff concluded that the source of contamination was likely an infected food worker.