Health officials reported an outbreak of the norovirus in Boston.
More than 120 students of Boston College were reported getting sick after eating at Chipotle restaurant.
A similar outbreak of E. coli linked to Chipotle restaurants in nine different states was earlier reported. Health authorities are now testing students for possible E. coli infection.
"While the tests for E. coli have not yet been returned, Boston College is focusing its attention on the norovirus outbreak," the Boston College spokesman said in a report by The Wall Street Journal.
In Chapman University in Orange, a norovirus outbreak may have affected as many as 50 students.
"This can be difficult to eradicate," Mary Platt, university spokesman, said in a report by LA Times.
The school's cafeteria was closed and disinfected as well as bathrooms and common areas.
"It could be food-borne," Platt said. "We just don't know. This type of thing could have come from anywhere."
Highly contagious, norovirus can be spread by contaminated food, poor hygiene and touching contaminated areas. Symptoms include diarrhea, nausea and vomiting.
In August, a norovirus outbreak affected 93 people, 80 customers and 13 employees, at a Southern California Chipotle.
"This is the height of norovirus season. It does well in the winter. Between now and March, we'll probably see an outbreak per week linked to a restaurant, a college or a hospital," Benjamin Chapman, an associate professor at North Carolina State University, said. Chapman specializes in restaurant food safety.
"It's important to note that we have been in business for 22 years and served millions of people in that time without seeing incidents like we have seen this year... That said, even one illness connected to our restaurants is too many, so we have set a goal to be an industry leader in food safety," Chris Arnold, Chipotle spokesman, said. The restaurant already announced its plans to strengthen its food-safety measures.
In the U.S., norovirus is the number one cause of outbreaks from contaminated food and the leading cause of gastroenteritis affecting an estimate of 20 million Americans every year according to ABC News.
