P&O: norovirus was introduced by passengers
P&O has sent passengers who travelled on board the Oriana a letter advising them to take "extra precautions" to prevent the spread of the norovirus.
The letter says that the company suspected that the illness was "inadvertently introduced on board by embarking passengers" because of "currently elevated Norovirus activity throughout the United Kingdom".
It advised passengers that "the case numbers decreased rapidly during the cruise" and that "the ship has undergone an additional and extensive disinfection".

