In October 2011, Minnesota Department of Health (MDH) staff investigated an outbreak of norovirus involving two individuals from separate households. The two had eaten take-out food from a restaurant in Waseca, Minnesota on October 28. MDH obtained patron names from credit card and check transactions from the restaurant. A total of 38 patron interviews were completed. Only the two individuals from the original complaint met the case definition.

The incubation period for both cases was 17 hours. Both reported diarrhea and abdominal cramps. Neither case visited a healthcare provider. Both recovered. Both cases submitted a stool sample collected 4 days after illness onset to the MDH Public Health Laboratory. One was positive for GI.6A.

Waseca County Public Health Services Environmental Health specialists and MDH interviewed 15 of 16 restaurant employees. A manager/supervisor who worked during October 26-28 reported that a household member had been ill with vomiting on October 24 or 25 for 24 hours or less. The employee did not report any symptoms and refused to submit a stool sample. Investigators suspect this asymptomatic employee who prepared various menu items was the source of contamination.