Beginning in August 2011, staff at the Minnesota Department of Health (MDH), Minnesota Department of Corrections (DOC) and Washington County Department of Public Health (WCPHE) conducted an investigation of gastrointestinal illness among inmates at three correctional facilities. Cases were in multiple living units at each facility.

A total of 209 cases were identified in inmates - 54 from the facility located in Stillwater with illness onsets from July 23 to August 11, 30 cases from the facility in Lino Lakes with illness onsets from July 25 to August 1, and 125 cases from the facility located in Faribault with illness onsets from July 30 to August 25. No one was hospitalized and no one died.

Stool samples from 17 inmates were tested at the MDH Public Health Laboratory (PHL). Enterotoxigenic E. coli (ETEC) O6:NM was found in samples from 7 inmates. Six of the isolates had indistinguishable pulsed-field gel electrophoresis patterns (EVEX01.0005/EVEA26.0002). The seventh isolate was two bands different by first enzyme (EVEX01.0007/EVEA26.0002).

All Minnesota correctional facilities use the same commissary menu, and food items used to fulfill this menu are ordered and received from a distributor in Wisconsin. The food service director at each facility orders food independently for his/her facility based on the menu guidelines and need. Each facility routinely freezes and store a representative tray of food from each meal served at the facility. Seven leftover trays were collected, and foods were tested at the MDH PHL. No ETEC was found.

Inability to obtain food histories from inmates created a challenge in identifying the outbreak vehicle and the source was not identified. Investigators theorized the likely vehicle was a food item received from the common distributor and served at the three facilities at slightly different times.