Gastro bugs are dogging the US cruise industry in 2010, with seven substantial outbreaks on US-based cruise ships. So far, testing has confirmed at least three were caused by the highly contagious norovirus.
Cruise passengers are advised to wash their hands thoroughly using warm water and soap before and after eating, after using the toilet, after visiting common areas, or touching doorknobs or guard rails.
More Details http://www.usatoday.com/travel/cruises/item.aspx?type=blog&ak=81743.blog