Boston College students treated after eating at Chipotle

MA was not among the nine states where health officials identified occurrences of E.coli, which started from October 19 through November 13.

The company, which is grappling with a states-wide E. coli outbreak linked to its restaurants, said the Boston incident appeared to be isolated to one location and that it would not shutter any other outlets in the city. But he added that Chipotle has no evidence to suggest they are related to the previous cases.

Investors concerned about the incident drove the fast-casual food chain’s stock (CMG) down as much as 5% in early trading Tuesday on news of the new incident – but the stock regained some ground after the company indicated that it was likely norovirus and not another E.coli incident.

On Monday, the school had said 30 students, including members of its men’s basketball team, had been sickened.

They are working closely with the Boston Public Health Commissioner and have ordered a temporary closure of the restaurant until they complete the investigation.

The chain known for touting its quality ingredients said Friday that it expects sales to drop between 8 percent and 11 percent at established locations for the fourth quarter if current trends continue.

The states with reported cases are Illinois, Maryland, Pennsylvania, California, Minnesota, New York, Ohio, Oregon and Washington.

Inspection Commissioner William “Buddy” Christopher Jr. told reporters his staff found critical violations at the Mexican restaurant – including hot food not kept warm enough and a sick employee who worked a shift last Thursday.

Shares of Chipotle declined $34.24, or 6.2 per cent, to $517.51 about 90 minutes before the market open. The company also hired food safety consulting firms to improve its already high standards for food safety.

The time between ingesting E. coli bacteria and feeling sick is usually three to four days, but may be as short as one day or as long as 10 days, according to the U.S. Centers for Disease Control and Prevention.