The number of people who have become ill in a multi-state E. coli outbreak linked to Wendy’s continues to grow.

The number of people who have reported becoming ill in an E. coli outbreak that has been linked to romaine lettuce in Wendy’s sandwiches has grown to 84.

The Centers for Disease Control and Prevention updated its investigation status on the E. coli outbreak on Thursday, saying that while it has not identified a specific food as the source of the outbreak, many of the people who have become ill reported eating Wendy’s sandwiches with romaine lettuce on them.

According to the CDC‘s report, four states are included in the outbreak – Michigan, Ohio, Indiana, and Pennsylvania. Out of the 84 people who have become ill with E. coli, 38 have been hospitalized for their symptoms. No deaths have been reported.

In Michigan, where the majority of cases have been reported, eight people have developed a type of kidney failure called hemolytic uremic syndrome from E. coli infections. A total of 53 people have become sick with E. coli infections in the state.

As many as 23 people have become ill as part of the E. coli outbreak in Ohio, with six people confirmed to have infections in Indiana and two reports of illnesses in Pennsylvania.

Since the E. coli outbreak was first reported on Aug. 17, Wendy’s restaurants in the region have stopped selling sandwiches with romaine lettuce. The chain said that it uses a different type of romaine lettuce for its salads.

The CDC said in its report that there is no evidence that romaine lettuce sold in grocery stores or served at other restaurants is linked to this E. coli outbreak.

E. coli infections can include symptoms such as fever, diarrhea (often bloody), vomiting, and stomach cramps. Most people recover in five to seven days, but some people can develop kidney failure.

The CDC advises anyone who has symptoms of an E. coli infection should seek immediate medical attention.