Chipotle Mexican Grill in Simi Valley, Calif.
An E. coli O26 outbreak linked to Chipotle restaurants sickened 60 people and resulted in 22 hospitalizations.

ATLANTA – Two outbreaks of E. coli O26 (STEC 26) linked to Chipotle Mexican Grill restaurants appear to be over, the Centers for Disease Control and Prevention (CDC) reported.

An initial, larger outbreak sickened 55 individuals across 11 states, while a second, smaller outbreak sickened five people in three states. The outbreaks resulted in a total of 22 hospitalizations. CDC noted there were no reports of deaths or hemolytic uremic syndrome, a type of kidney failure.

An epidemiological investigation seemed to suggest a common meal item or ingredient was the source of the illnesses. Investigators tested multiple food items from Chipotle restaurant locations; and whole genome sequencing, an advanced laboratory technique, was used to get more detailed information about the DNA fingerprints of the STEC O26 bacteria that caused illness. Ultimately, the investigation did not identify a specific food or ingredient as the source of the illness outbreaks, CDC said.

“When a restaurant serves foods with several ingredients that are mixed or cooked together and then used in multiple menu items, it can be more difficult for epidemiologic studies to identity the specific ingredient that is contaminated,” CDC said in its report.

Additionally, reviews of Chipotle’s distribution records were unable to identify a single food item or ingredient that could explain either outbreak.

Chipotle said it lost many of its customers after the E. coli outbreaks and a norovirus outbreak in Boston. The company’s stock has fallen nearly 30 percent since the end of October following reports of the first outbreak. Since then, Chipotle’s executives have pledged to improve food safety and regain consumer trust. To lure customers back to its restaurants, Chipotle implemented new food safety procedures with its restaurants, suppliers and central kitchens. Additionally, the company plans a marketing campaign set to begin this month.