In December 2012, Minnesota Department of Health (MDH) and Hennepin County Human Services and Public Health Department (HSPHD) staff investigated an outbreak of norovirus that occurred among members of different meal parties occurring over several dates. Sixty-two restaurant patrons were interviewed. Nineteen patrons met the case definition. Most cases (18) dined at the restaurant on December 22. One person ate on December 23. Stool specimens collected from five cases tested positive for norovirus GTII.

Cases and controls both reported eating a wide variety of foods. Eating the bread and butter basket placed on each table was significantly associated with illness (17 of 19 cases vs. 19 of 38 controls; odds ratio, 8.5; 95% confidence interval, 1.7 to 42.0; p=0.004).

Minneapolis Division of Environmental Health (MDEH) sanitarians visited the restaurant on December 26 and 27 and did not note any critical violations. However, some issues were observed including bare-hand contact while cutting bread and preparing produce, one hand sink was missing a nailbrush, and a designated hand sink was needed in the dishwashing area. No employees reported gastrointestinal illness prior to or on the implicated meal dates.

Investigators concluded that while the source of contamination was not identified, the most plausible scenario is that the bread baskets were contaminated by an unidentified ill or recently ill food worker.