At least 83 people have been taken ill with a contagious norovirus on board a ship sailing to ports in California.
Princess Cruises spokeswoman Karen Candy said on Wednesday that 66 passengers and 17 crew members were sick and had to be isolated in their cabins on the Crown Princess.
The ship docked in San Francisco on Monday, when around 37 passengers were reported to be ill, meaning the number had almost doubled by mid-week, reports the Wall Street Journal.
The Crown Princess is currently on a seven-day cruise that includes stops at San Diego and Santa Barbara before finishing in LA on Saturday.
According to the Consumerist, Ms Candy said staff have enhanced the sanitation of surfaces like railings, door handles and lift buttons.
She added: "We believe the cause to be the common virus called Norovirus, which is extremely contagious and easily transmitted from person-to-person.
"At the first sign of an increase in the numbers of passengers reporting to the medical centre with gastrointestinal illness, we immediately initiated additional enhanced sanitation procedures to interrupt the person-to-person spread of this virus."
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