"neither has the cruise industry seen anything as widespread as this"
You can not make a statement like that without backing it up.
Here is the Cruise Industry news. I encourage you to read all the news and official releases. RED is the important items.
The Norwalk virus has plagued cruise lines for years, particularly during summers in the Alaska/Northwest Canada region. It is very contagious and is spread through contact with surfaces touched by the infected -- anything from a stair rail to a casino chip. Symptoms include nausea, diarrhea and vomiting and it generally lasts about two days.
Typically, when cruise ships report a significant affected percentage (about 3 percent or more), they undergo an intense super-sanitation process, swabbing down surfaces with extra-strong cleaning products. But, despite efforts of Disney Magic's "cast members," not to mention intensified preventive measures taken by Holland America's Amsterdam, the illness continues to spread.
While cruise lines, particularly Holland America over the Amsterdam outbreaks, are taking a lot of heat from media and travelers over handling of information (and sensitivity towards passengers) about Norwalk Virus, the air-borne strain, highly contagious, is not limited to floating pleasure palaces. Norwalk and look-alike viruses have caused similar outbreaks in other places, from a school near Houston to a hospital in London. The virus flourishes from well populated and enclosed areas.