A Royal Caribbean cruise was just hit with a major norovirus outbreak. Why cruise ships are a breeding ground for the disease.

Dozens of people traveling on a Royal Caribbean cruise have been sickened due to a norovirus outbreak, the Centers for Disease Control and Prevention reported on Sept. 29. At least 71 people have come down with the gastrointestinal illness aboard the Serenade of the Seas voyage from San Diego to Miami. The cruise set sail on Sept. 19 and is due to ...