The cabbage was likely contaminated at some point prior to distribution to restaurants.
Routine monitoring by the Minnesota Department of Health (MDH) identified the 15 cases of illness associated with Shiga toxin-producing E. coli O111. Bacterial isolates from all of the cases had the same DNA fingerprint. This genetic strain of E. coli O111 had not been seen in the United States previously.
MDH investigators were able to interview 14 of the cases: 13 of them ate at 9 different Applebee’s restaurants in Minnesota, and one ate at Yard House.
Many cases had reported eating the Oriental Chicken Salad at Applebee’s, leading Applebee’s to voluntarily and out of an abundance of caution pull the menu item and specific ingredients from the salad from their menu for a time. It was returned to the menu after Applebee’s obtained different sources for the ingredients.
The common food item across all foods consumed by cases was green whole head cabbage.
Minnesota officials traced the cabbage to a common supplier outside of Minnesota and continue to work with the United States Food and Drug Administration (FDA) to investigate its source. The FDA examination of the potentially involved farms is still ongoing.
Single cases of illness that match the outbreak strain have occurred in three other states.
The illnesses occurred between June 25 and July 3. Four of the people who became ill were hospitalized and all have recovered. No new cases connected with this outbreak have been identified in Minnesota since July 10.
Symptoms of illness caused by E. coli O111 typically include stomach cramps and diarrhea, often with bloody stools, but only a low-grade or no fever. People usually become ill two to five days after exposure, but this time period can range from one to at least eight days. Most people recover in five to 10 days. Complications from infection are more common among those with weaker immune systems, including young children and the elderly. As with E. coli O157:H7, infection with E. coli O111 should not be treated with antibiotics, as this practice might promote further complications.