The Boston Globe reported today on a large norovirus outbreak at the Harvard Faculty Club.  The Club is currently closed for deep-cleaning after 100-200 people fell ill shortly after Easter brunches held this past Sunday and Tuesday.   Notably, this was the Club’s second closure in a week due to norovirus concerns.

It appears, however, that more than just the unlucky souls at Harvard have been affected by norovirus recently.  The Globe also reports that "The norovirus outbreak at the club is not the only one in recent weeks. A norovirus may have caused more than 70 students to become ill at Emerson College in Boston since the middle of last month."

Norovirus outbreaks are frequently quite large, and can be difficult to contain.  The virus is shed in large numbers in the vomit and stool of infected individuals, most commonly while they are ill. Some individuals may, however, continue to shed norovirus long after they have recovered from the illness.  Aerosolized vomit has also been implicated as a mode of norovirus transmission.

The CDC states that “noroviruses can cause extended outbreaks because of their high infectivity, persistence in the environment, resistance to common disinfectants, and difficulty in controlling their transmission through routine sanitary measures” (MMWR, 2001, June 1).

Because of the ease with which norovirus is transmitted, places with large groups of people are particularly susceptible to outbreaks.  Cruise Ships are a common site of norovirus outbreaks.  According to the CDC, this is because (1) health officials in government and the industry do a good job of tracking illness on cruise ships; therefore, outbreaks are found and reported more quickly on a cruise ship than on land.  (2) Close living quarters in cruise ships increases the amount of group, and person to person, contact.  And (3) frequent new passenger arrivals means increased chances of bringing the virus aboard ship and introducing it to passengers and crew alike.