In December 2012, the Minnesota Department of Health (MDH) investigated an outbreak of norovirus associated with a restaurant located in Mankato, Minnesota. Initial reports of illness came from three of four meal companions from separate households who ate lunch at the restaurant on December 14. The lunch meal was the only common exposure among the ill persons. The median incubation was 27.5 hours (range, 27.5 to 31 hours). The median duration of illness was 37 hours (range, 21.5 to 66.5 hours). No one was hospitalized and no one died. One patron stool sample was tested at the MDH Public Health Laboratory (PHL). The specimen tested positive for GII.

All three cases reported consuming a pasta dish served with parmesan chicken. The patron who was not ill reported consuming a pasta dish without chicken and a Rice Krispie bar. Meaningful statistical analysis of food items could not be performed because additional controls could not be recruited.

Interviews were completed for 27 of 28 food workers. Eight food workers reported recent illness. Employee illness onset dates ranged from November 28 to December 14. Stool samples were submitted by three recently ill food workers to the MDH PHL. All three tested positive for norovirus GII. Nucleic acid sequencing was conducted on norovirus positive samples from patrons and food workers. The nucleic sequences were identical.