“Cruise ships are a place were infections can spread quite quickly,” Professor Kelly said. “Anywhere where you have a large number of people in close quarters, mixing very closely, that does increase the chance of infection.”
The Diamond Princess and its 3700 passengers and crew were placed in a 14-day quarantine on January 25 after it emerged a Hong Kong man who later tested positive for the virus had spent several days aboard.
At least 273 passengers have been tested for coronavirus so far, and there are fears the quarantine period may restart every time a new case of the virus is diagnosed.
Those on board have been issued with thermometers and have been told to report themselves to crew if their temperature is higher than 37.5 degrees.
Home Affairs Minister Peter Dutton ruled out an evacuation mission for the stranded Australians.
“The Japanese authorities, they have an advanced health system and they are dealing with what’s a very difficult situation,” Mr Dutton said.
American author Gay Courter, who is on the Diamond Princess, said passengers were concerned the ship’s air conditioning may be spreading the disease.
“[R]emoving all passengers to a land-based quarantine where air is not recirculated is safer…. [N]o one can prove recirculated air is not the method of spreading to new individuals.”
Another cruise liner, the World Dream, has been quarantined in Hong Kong since Wednesday, with Australians numbering 16 out of the more than 3600 passengers and crew on board.
Officials quarantined the vessel after discovering eight former passengers, all from Wuhan, had tested positive for the disease after disembarking the vessel last week.
Over 40 passengers and crew later reported symptoms of upper respiratory infection, but all tests for coronavirus have so far come back negative.
A third cruise ship, the Westerdam, is at sea to the west of Japan, after being denied entry to harbours in the Philippines, Japan and Taiwan.
The vessel, operated by Holland American Line, has over 2000 people on board, including at least two Australians. There are so far no confirmed cases of coronavirus on board the ship
After leaving Hong Kong on February 1, the ship was scheduled to call into several Japanese ports. But on Friday, Japanese Prime Mininister Shinzo Abe announced the ship had been turned away due to fears there was coronavirus on board.
The cruise operator rejects those suggestions.
“The ship is not in quarantine and there are no known cases of coronavirus on board,” a spokesperson for the cruise line said.
Taiwan and the Philippines have also blocked the Westerdam from docking, and Guam reportedly will also deny the vessel a port.
Katharine Jones, who is travelling on the Diamond Prince with a friend, praised the efforts of the ship’s crew to keep passengers comfortable. Playing cards have been distributed and more TV channels have been added to the on board entertainment system. Smokers are even being offered nicotine gum.
“We both feel safe, we are comfortable, we have plenty of food. We are secure in knowing our health and safety is their highest priority,” Ms Jones said.
Ms Courter said crew members were also under threat from the virus.
“It’s important to remember that the crew, who have much tighter packed quarters, are also at risk.”
Janek Drevikovsky is a journalist at The Sydney Morning Herald.