Read a great article at abc.com which gave lots of good info on the Norovirus
and how to avoid it.
-See how your specific ship rates at the CDC
(If you cannot find your ship under individual ship names, search by cruiseline, and it should be listed there)
-The Norovirus is so potent, because, "Additionally, the infection dose of norovirus is very low. It takes only 10 particles of the virus to make you sick, as opposed to the 100,000 particles of salmonella you would have to be exposed to in order to get sick. "
-Ways to avoid the virus include, Wash your hands well with soap and water. Use an alcohol-based hand gel, and bring disposable disinfecting wipes to wipe down doorknobs, phones and other surfaces in your cabin. (thought this probably was a great idea since rooms may not get disinfected with the same attention to detail as frequently used public and food areas). Also, be very careful when caring for someone who is ill with norovirus since it is so highly contagious. Bodily fluids can transmit the infection.
-The virus spreads through food, water, contaminated surfaces and person-to-person contact. The reason it could be so hard to get rid of on a cruise ship is because people can also bring it on board and it can live on surfaces for more than a week. Cruise ships often visit places that have poor sanitation, so passengers can easily catch it from a restaurant they visited at a port. (so take that hand sanitizer with you when you visit ports areas!)