Cunard's Queen Mary II cruise ship hit by norovirus 28 December 2012 Last updated at 12:12 A cruise ship due to arrive in Hampshire is undergoing extra cleaning following an outbreak of the norovirus winter vomiting bug. Cunard's Queen Mary II currently has 19 confirmed cases of the illness on board, the company has said. The liner is due back in Southampton on 10 January. It comes after hundreds of passengers contracted the bug on P&O's Oriana during a Baltic cruise which arrived in Southampton on 14 December. Enhanced sanitation The affected passengers on Queen Mary II, which is currently cruising the Carribean, have been confined to their cabins and "enhanced sanitation protocols" are being carried out, Cunard has said. "The safety and comfort of passengers and crew is always our number one priority," a spokesperson for the company added. The ship departed New York on Saturday and there are 2,613 passengers on board. It will begin a 72-day world voyage to Australia from Southampton on 10 January. P&O Cruises apologised to 417 passengers on Oriana who suffered diarrhoea and vomiting during a 10-day Baltic cruise earlier in the month. It was the second bout of the diarrhoea and vomiting bug in successive voyages on the ship, which carries up to 1,843 passengers. Ten cases were also confirmed on P&O's Azura which arrived in Southampton on 15 December following an 11-night tour of Iberia.