Virus ravages US cruise ships

On Thursday, another Miami-based cruise operator cancelled a scheduled trip to the Caribbean after more than 500 passengers contracted the virus over the course of four voyages.

Since the latest passengers disembarked at Fort Lauderdale, 573 staff have been scrubbing remote controls, clock radios and even Bibles at the beginning of a 10-day deep clean of the ship, the Amsterdam.

Holland America Line had frantically tried to avoid cancelling Amsterdam voyages over the past month, instructing its staff to clean round the clock, but watched helplessly as 454 passengers and 70 crew members fell ill.

"They were cleaning all the time," Lori Druckeroff, a retired passenger, told news agency Associated Press.

"You'd see people and then they would not be there for dinner, so you knew they got sick."

The virus, which is spread through food and water and contact with infected people or their possessions, causes diarrhoea, vomiting and stomach cramps - all symptoms associated with the Norwalk virus.

Holland America, which is owned by Carnival Corp., is now working with the Centers for Disease Control and Prevention.

Every surface of the Amsterdam will now be dry-cleaned, steam-cleaned and disinfected by 573 crew members, and 2,500 pillows will be replaced.

Disney, meanwhile, pledged that its cruise liner Magic would continue with its voyage despite passengers starting to get ill on Wednesday.

The ship left Port Canaveral in Florida with 3,200 people on board last Sunday and is due to return on Saturday.

Magic will be disinfected while at sea, a Disney spokesman said, and passengers who fall ill will be offered compensation.