People who attended events related to a wedding held on May 19, 2017 became ill with vomiting and/or diarrhea. Three possible meals were investigated as a source of illness. These included a groom's dinner held on a boat on May 18, catered sandwiches served to members of the wedding party, and a reception following the wedding ceremony held at an event center.

Minnesota Department of Health epidemiologists conducted a case control study using a guest list provided by the bride. A total of 72 wedding attendees were interviewed. Thirteen people met the definition for an outbreak case. Eleven of 13 attended all three events. The median incubation period from the groom's lunch was 50 hours (33 to 65 hours). Eleven of 13 cases had the wedding day sandwiches. The median incubation period from the lunch was 32 hours (range, 15 to 47 hours). All thirteen cases attended the reception. The median incubation was 25.5 hours (range, 8.5 to 44.5 hours). No one was hospitalized and no one died.

Wedding attendees were asked which events they had attended along with foods and beverages consumed at each event. Attending the groom's dinner and eating sandwiches served at lunch on the wedding day were both associated with illness. Among those who attended the groom's dinner, only consumption of sandwiches on the wedding day was associated with illness (11 of 11 cases vs. 7 of 12 controls, OR undefined; p=0.04). No food item served at the reception was associated with illness, and no food served at the groom's dinner was associated with illness among those who attended the event.

Investigators received conflicting information about the source of the sandwiches. Reported sources were either a grocery store or a restaurant. Hennepin County Health Department sanitarians assessed both places. No ill employees were noted and neither place had received any customer complaints. Eventually the bride confirmed that the sandwiches were prepared at the restaurant.