An E. coli outbreak linked to Chipotle Mexican Grill Inc. has spread to a total of six states, including California and New York, according to the Centers for Disease Control and Prevention.
The evidence suggests that an ingredient or "common meal item" served by Chipotle in several states was the source of the outbreak, the agency said in a statement on Friday.
The company's shares tumbled as much as 9.7 percent to $552 after the CDC published the report, marking the worst intraday drop in almost three years.
The E. coli investigation had previously focused on Oregon and Washington State, where dozens of people got sick after eating at Chipotle restaurants.