An outbreak of E. coli linked to Chipotle restaurants in the Pacific Northwest has now spread to a total of six states, including Minnesota, the Centers for Disease Control and Prevention (CDC) reports.
The first cases were confined to Washington and Oregon late last month, and the restaurant chain temporarily closed dozens of locations in those states in response to the outbreak.
Now, the same strain of E. coli has been reported in California (two cases), Minnesota (two cases), New York (one case) and Ohio (one case).
In Minnesota, one person became ill after eating at a Chipotle in Burnsville between Oct. 19 and Nov. 8, according to the state Department of Health.
The other person also came down with the same strain of E. coli, but did not eat at a Chipotle before getting sick, the St. Paul Pioneer Press reports.
"The epidemiologic evidence available at this time suggests that a common meal item or ingredient served at Chipotle Mexican Grill restaurants in several states is a likely source of this outbreak," the CDC said in its statement, noting that 43 of the 45 people who became ill had eaten at a Chipotle prior to getting sick.
Six of them needed to be hospitalized, but there have been no deaths, according to the CDC.
Health officials are still trying to determine what specific food is linked to the illness. But given the illness only seemed to affect people within a three-week time period, experts speculate it was a fresh produce item that was contaminated, according to Reuters.
High heat kills the E. coli bacteria, and it's not likely that all of the affected restaurants would have served undercooked meat.
The price of Chipotle's stock dropped 12 percent on Friday after the E. coli update was released, Reuters reports.
Chipotle, based in Denver, has about 1,900 restaurants across the country, and touts its food as fresh and healthy. But this is the third food safety lapse this year for the company, which has hurt its reputation, Reuters notes.
In January hundreds of Chipotle restaurants, including several in Minnesota, temporarily took pork items off their menus because the company discovered one of its pork suppliers was not meeting its strict standards for animal treatment.
In September, more than 40 people who ate at Minnesota Chipotles became sick with salmonella from eating tainted tomatoes.