Chipotle Stock Continues to Slide Amid E. Coli Scare

Chipotle shares extended their slide Monday after the company said an E. coli outbreak is expected to lead to its first sales decline since going public in 2006.

The stock fell further in after-hours trading after Boston College said it was working with local health officials to determine whether the outbreak was also responsible for sickening several of its students, including members of its men's basketball team.

Chipotle noted that none of the cases reported so far by the Centers for Disease Control and Prevention have been in Massachusetts. It said it closed its restaurant in Boston's Cleveland Circle anyway while health officials investigate.

Chipotle's stock fell 6 percent to $518 in after-hours trading, after closing down 1.7 percent Monday. The stock is down more than 20 percent since mid-October when reports of the E. coli outbreak began to surface.

In a filing with the Securities and Exchange Commission Friday, Chipotle said sales have been "extremely volatile" since early November as a result of the outbreak. Sales plummeted by as much as 22 percent as additional cases were reported, and were down 16 percent for all of November.

For the fourth quarter, the company expects sales to drop between 8 and 11 percent at established locations if current trends continue. The figure, a key measure of financial health because it strips out the volatility of newly opened and closed locations, has not declined since the chain went public.

The Centers for Disease Control and Prevention has said the outbreak has sickened 52 people in nine states. It has not yet identified the ingredient that made people sick.

The first cases were reported at the end of October, with the most recent illness starting on Nov. 13.

About 48 million people get sick from a foodborne illness each year, according to the CDC.

Chipotle Mexican Grill Inc., based in Denver, had said that whatever the likely ingredient was that made people sick is out of its restaurants and that it is adopting stricter food-safety standards.

The company said some of its local produce suppliers might not be able to meet the new standards. Locally sourced produce accounts for a "relatively small percentage" of the produce the chain uses, said Chris Arnold, a Chipotle spokesman.

Jeffrey Bernstein, a Barclays analyst, noted that fast-food chains have recovered from similar foodborne illnesses in the past. But he noted the E. coli cases are "all the more damaging" for Chipotle because of its "Food With Integrity" slogan.