There are about 2,500 reported norovirus outbreaks in the U.S. each year. Norovirus, which is sometimes called the "cruise ship virus," causes more than 90% of diarrheal disease outbreaks on cruise ships, according to the CDC. However, norovirus outbreaks on cruise ships account for only a small percentage of all reported norovirus outbreaks.

Oysters linked to a norovirus outbreak that were shipped to retailers and distributors in New Jersey and other states have been recalled, according to the U.S. Food and Drug Administration. An event celebrating the top restaurants in Los Angeles that left at least 80 people sickened with norovirus was linked to the oysters, ABC6 reported.