No deaths have been reported.
A specific food has not been confirmed as the source of the outbreak, according to the CDC, but 22 of 26 sick people reported eating sandwiches at Wendy’s restaurants in Michigan, Ohio and Pennsylvania before getting sick.
As a precaution, Wendy’s is removing the romaine lettuce being used in sandwiches from restaurants in that region, since most sick people reported eating sandwiches with romaine lettuce, according to the agency.
The CDC said it is not advising that people avoid eating at Wendy’s restaurants or that people stop eating romaine lettuce.
The agency is investigating to confirm whether romaine lettuce is the source of the outbreak, and whether the lettuce used at the Wendy’s stores was served or sold at other businesses.
Nineteen infections have been reported in Ohio, 15 in Michigan and two in Pennsylvania. An additional case has been reported in Indiana. Three of the cases in Michigan involve people who have a type of kidney failure called hemolytic uremic syndrome, the CDC said.