Cunard, which owns the Queen Mary 2, said there are 19 passengers with "active symptoms" as of Friday. The Centers for Disease Control web site states 194 passengers and 11 crew reported being ill during the voyage. The web site lists the causing agent of the illness as "unknown."
In a statement to ABC News, the cruise line said, "There has been an incidence of a mild gastrointestinal illness among the passengers on Queen Mary 2. This illness is suspected to be Norovirus, which is highly contagious and typically transmitted from person to person."