Photograph of Chipotle restaurant exterior
Chipotle has been under scrutiny after two major illness outbreaks.

BOSTON – Chipotle Mexican Grill Inc. reopened the Boston restaurant at the center of a norovirus outbreak that sickened more than 130 individuals earlier this month. The company closed the Cleveland Circle restaurant for about three weeks.

Many of the customers sickened were students at Boston College. Norovirus is a very contagious virus that can be spread by contaminated food or water, or by touching contaminated surfaces. Symptoms of infection include stomach pain, nausea, diarrhea and vomiting.

The norovirus outbreak came soon after public health officials linked Chipotle restaurants to an outbreak of E. coli O26 in the Pacific Northwest. The company temporarily closed several restaurants. Chipotle responded to the problem by implementing an enhanced food safety program.

The company’s shares closed down (493.52) on the New York Stock Exchange on Dec. 28.