McDonald's is pulling salads in 14 states after an illness was linked to greens sold in its restaurants in Iowa and Illinois.
Montana was included in the list of states, although no cases of the illness have yet been reported here.
McDonald's is removing the lettuce blend from identified restaurants and distribution centers. At least one of the affected restaurants is in each of the following states: Illinois, Iowa, Indiana, Wisconsin, Michigan, Ohio, Minnesota, Nebraska, North Dakota, South Dakota, Montana, Kentucky, West Virginia and Missouri.
The illness is caused by the foodborne parasite Cyclospora. More than 100 people have been affected in Illinois and Iowa since May.
The most common symptom is watery diarrhea. Other symptoms could include appetite loss, intestinal pain, nausea and fatigue.
"Out of an abundance of caution, we decided to voluntarily stop selling salads at impacted restaurants until we can switch to another lettuce blend supplier," McDonald's said in a statement. "We are in the process of removing existing lettuce blend from identified restaurants and distribution centers — which includes approximately 3,000 of our U.S. restaurants primarily located in the Midwest."