Tests Show Norovirus to Blame for Illnesses Linked to Boston Chipotle [Updated]

Chipotle's latest public health disaster might not be caused by E. coli, but it still isn't good. Eighty students have been sickened after eating at one of the chain's locations near the campus of Boston College, reports the Associated Press. However, spokesperson Chris Arnold tells Eater the company thinks norovirus is behind the rash of foodborne illness.

"We believe it's most likely a norovirus (the health department in Boston seems to have the same theory) given the pattern and symptoms of illness," Arnold said in an email Tuesday afternoon. "It is important to note that noroviruses are very common, in part because they are so easily transmitted (they can spread through person-to-person contact, on surface areas, or through food or drink). According to CDC, there are approximately 20 million cases a year, making them the leading cause of gastroenteritis in the US."

Update: December 9, 10 a.m. Boston Public Health Commission director of communications Ché Knight says initial tests confirm the illnesses were caused by norovirus. There have been 65 known case reports that include Boston College residents, students, and non-BC patrons.

"After receiving a report of multiple cases of gastrointestinal illness among patrons who ate at the Chipotle Mexican Grill in Cleveland Circle, the Boston Public Health Commission, the City of Boston Inspectional Services Department, and the Massachusetts Department of Public Health launched an investigation to determine the cause and the nature of the illness," reads a statement provided to Eater. "Initial testing conducted by the State Public Health Laboratory has shown the presence of norovirus."

Reports of the foodborne illness first began to surface Monday afternoon. Boston College's administration sent an email to students warning against eating at the restaurant, which has been temporarily shuttered. Several players on the school's basketball team became sick, and a coach told SB Nation's BC Interruption they were "confirmed to have E. coli." It appears that initial "confirmation" may have been jumping the gun.

The news put a dent in Chipotle stock on Wall Street. Shares closed Monday's trading at 551.75 and opened Tuesday down 3.5 percent at 532.00. That number dipped to a session low of 527.95 at 10 a.m., but the stock rallied a bit after word began to surface that norovirus, not E. coli, may be responsible for the Boston illnesses. Chipotle ended the day down 1.72 percent at 542.24.

The company's stock has been hammered since Chipotle was connected to the nationwide E. coli outbreak in late October. After closing near an all-time high at 750.52 on October 13, the burrito giant has lost 28 percent of its value over the last seven weeks.

No matter the cause of the Boston College illnesses, they continue a recent trend of public health crises tied to Chipotle. The company's E. coli outbreak has sickened 52 in nine states, according to the Centers for Disease Control's last report. The company dealt with a salmonella outbreak in Minnesota in September, and earlier that month, another norovirus outbreak sickened nearly 100 in California.

The variety of foodborne issues has led Chipotle to consider new testing procedures and dropping its longtime pledge to serve local ingredients in an attempt at better quality control.