News: Over 645 get sick on Royal Caribbean Cruise Ship due to Norovirus

Cruise ships just got a little more shady. At least 600 people have fallen sick due to an outbreak on a Royal Caribbean cruise ship. The U.S. Centers for Disease Control and Prevention reported the outbreak when it was discovered that many people were quarantined during the ship’s tour. Passengers complained of diarrhea and vomiting. It isn’t clear what caused the illness, but the Center for Disease Control will board the ship on Monday to find out.

Norovirus outbreaks are notoriously difficult to control. The virus is easily passed from person to person, spreads through food and ice, and also can survive on inanimate objects for days.

Even with scrupulous cleaning, the virus can still remain intact, according to Dr. Richard Besser, ABC’s chief medical correspondent.

“The virus is not killed by alcohol sanitizers. It survives and can be infectious on surfaces,” he said. "People who are infected will shed the virus for days after their symptoms resolve. This is a real problem for food workers on cruise ships. Lastly, if you go into a bathroom that has been used by someone who has the norovirus, you can get sick.”