Australian authorities have asked a cruise liner to cancel a planned port call after three crew members tested positive for the H1N1 flu virus, which is commonly known as swine flu. Two thousand passengers are on board the Pacific Dawn, which is on a cruise around the Great Barrier Reef.
The request for the Pacific Dawn to stay away from the Australian mainland comes at federal officials confirm that more than 100 Australians are now infected with the H1N1 virus - up from 59 on Wednesday.
The cruise liner, which is carrying about 2,000 passengers, was to dock in the tropical city of Port Douglas in Queensland early Friday.
Crew members test positive
But after three crew members tested positive for swine flu, it canceled that stop and others. Instead, it is expected to sail to Brisbane, a major city that can safely handle a large number of people who may have been exposed to the virus. All those on board will be treated with anti-viral drugs on arrival.
As the ship's owners voluntarily agreed to the request to stay at sea, the authorities have not issued a formal quarantine order.
Nicola Roxon, the federal health minister, says she would force the Pacific Dawn into isolation if such a drastic step were necessary.
"Certainly there will be no hesitation from our government or from the states and territories to take the advice of the health officials if they thought that was necessary," she said. "Remember we're talking about a disease which will spread within the community. We haven't made decisions and have not received advice that we should restrict internal travel within Australia."
Most Australian cases mild
Roxon says most Australian cases of H1N1 had been mild but four people have been hospitalized.
Some infectious disease experts warn that up to a fifth of Australia's 21 million people could be infected by the H1N1 virus in the months ahead. They have called for major sporting events and concerts to be abandoned for the sake of public health.
Other scientists, though, think the public is being unduly alarmed and say the virus so far is no worse than other strains of influenza that affect Australia each winter.
The number of dead globally from swine flu has exceeded 100, most of them in Mexico and the United States. More than 13,000 people have been infected around the world.