The Norovirus outbreak at the Cleveland Circle Chipotle in Boston now includes 141 Boston College students, according to the college. All but 12 of those sickened ate at the restaurant prior to developing symptoms. The 12 who did not eat at Chipotle before becoming ill, had contact with someone who was ill or something that an ill person handled.
Norovirus is highly contagious. Symptoms, which include diarrhea, vomiting, nausea and abdominal cramps, usually develop within 12 to 48 hours of exposure and last up to three days.
As the leading cause of food poisoning outbreaks in the U.S., Norovirus sickens about 20 million Americans every year. About 65 percent of Norovirus outbreaks happen at restaurants and originate from an infected food worker.
The virus is transmitted when a food handler who has been sick has microscopic amounts of vomit or stool on his or her hands and touches food that is eaten by someone else or contaminates a food preparation area by touching it.
It takes just a a small amount of Norovirus to make someone sick. The amount of Norovirus that fits on the head of a pin is enough to make 1,000 people sick.
People who are sick with Norovirus are most contagious while they are experiencing symptoms but may also infect others before symptoms start and for about two days after symptoms resolve. That’s why it’s especially importnat to stay home when you are sick.
The Massachusetts Health Department has not found any other pathogens during its test of those sickened in Boston. The Norovirus outbreak took place at the same time Chipotle has been linked to a nine-state E. coli outbreak that has sickened 52 people. The E.coli outbreak includes cases in California (3), Illinois (1), Maryland (1), Minnesota (2), New York (1), Ohio (3), Oregon (13), Pennsylvania (1), and Washington (27). Health officials have not yet determined the food source of that outbreak.