Now, scientists have discovered a new Sydney strain of Norovirus was to blame for the outbreak. The Sydney strain, which emerged within about the last two years, is not considered unusually dangerous.
However, it has quickly become a common cause of vomiting and diarrhea, with symptoms lasting several days.
The highly contagious stomach bug, once known as Norwalk virus, can be picked up from an infected person, contaminated food or water or by touching contaminated surfaces. It can also be airborne.