A "norovirus outbreak" refers to a situation where a lot of people in a particular place or area become sick with the norovirus at the same time. Full definition
From these results it is clear that asymptomatic individuals are infected with norovirus at a high rate, and these healthy individuals are an important source of norovirus outbreaks in Indonesia. (sciencedaily.com)
On cruise ships, staff sometimes recommend eating mushy white rice with the cooking water to passengers when norovirus outbreaks occur. (thehealthyhomeeconomist.com)
Days before the opening ceremony of the Pyeongchang Winter Olympics, 1,200 security staff have been sequestered after a suspected norovirus outbreak. (fortune.com)