As executives with Chipotle Mexican Grill prepare a new advertising campaign — sans food safety references — federal officials say nothing has been ruled out as the root cause of E. coli outbreaks among the chain’s customers. However, Chipotle officials suggested they have information about the cause of some of their customers’ illnesses in a Jan. 19 news release about an upcoming meeting with Chipotle employees.

The two E. coli outbreaks linked to Chipotle restaurants had sickened at least 58 people across 12 states as of the most recent update from the Centers for Disease Control and Prevention. That update was posted Dec. 21. Three weeks later, Chipotle founder Steve Ells told attendees at a financial conference he expected the government to “soon” declare the outbreaks over. That announcement has not yet been made. The CDC’s outbreak response team leader said Jan. 21 that the investigation continues. “CDC met with Chipotle executives on Jan. 5 at CDC in Atlanta,” said CDC doctoral epidemiologist Matthew Wise. “This is an ongoing investigation and we regularly share relevant investigation updates with Chipotle. It is not done on a scheduled basis.” Investigators at the Food and Drug Administration also continue to search for the cause of the E. coli outbreaks, which began in October and November. “Nothing has been ruled out as a root cause,” said FDA’s health communications specialist David Steigman. “We continue discussions with Chipotle officials. They are sharing with us how they plan to address food safety in their restaurants.” Those food safety plans are the topic of the meeting with the chain’s 60,000 employees scheduled for Feb. 8. All Chipotle restaurants will close for four hours that day so Ells and other executives can thank them for their “extraordinary work implementing Chipotle’s comprehensive new food safety programs,” according to a Jan. 19 news release. “The company will also share information as to what may have caused some customers to become ill in 2015.” Hundreds of Chipotle’s customers were victims of six confirmed foodborne illness outbreaks in the second half of 2015:

• Seattle — E. coli O157:H7, July 2015, five sick people, source unknown;
• Simi Valley, Calif. — Norovirus, August 2015, 234 sick people, source was sick employee;
• Minnesota — Salmonella Newport, August and September 2015, 64 sick people, source was tomatoes but it is not known at what point in the field-to-fork chain the pathogen was introduced;
• Nine states — E. coli O26, began October 2015 and not yet declared over, 53 sick people, source unknown. States involved are California, Illinois, Maryland, Minnesota, New York, Ohio, Oregon, Pennsylvania and Washington;
• Boston — Norovirus, December 2015, 151 sick people, source was sick employee; and
• Three states — E. coli O26, began December 2015 and not yet declared over, five sick people, source unknown. States involved are Kansas, Oklahoma and Nebraska, but the sick Nebraska residents ate at a Chipotle location in Kansas.

Ells and other top Chipotle executives said Jan. 13 that the outbreaks will not be referenced in their new consumer advertising campaign, which is set to launch in mid-February. Instead, the consumer campaign will feature the same kinds of ads Chipotle has previously used in broadcast and outdoor advertising. In a separate effort, Ells and the other executives will do interviews with news media with two main talking points — “we believe this is over” and “we have implemented changes” — the founder told attendees at the annual ICR Conference on Jan. 13.   (To sign up for a free subscription to Food Safety News, click here.)