Coronavirus confirmed on cruise ship with stranded Australians on board

Japanese authorities have confirmed a further 10 cases of coronavirus on a quarantined cruise ship with 226 Australians stuck on board.

The Diamond Princess, currently docked in the Japanese port of Yokohama near Tokyo, is one of two cruise ships currently in quarantine with confirmation passengers and crew have been inadvertently exposed to the virus.

At least 100 people are showing symptoms.

Brisbane couple Carole and John Welch are among the 226 Australians trapped on board the Diamond Princess, which is believed to be carrying 3700 people.

The couple said they've been in contact with other Australians on board and are unsure why no one has heard from the government about the outbreak or their potential quarantine on board.

"I wish they would get on to the job. They need to get us off this ship," she said.

"It would just be nice to know someone cares."

"It's interesting that you've been able to contact us but nothing from the government.. it didn't seem too hard for you to do it Karl, so why would it be hard for them?" Ms Welch added.

Ms Welch said they've been unable to leave their cabins.

"So far so good, but I don't know how it is going to be in a few days after being stuck in a small cabin with no fresh air, no windows," Ms Welch told Today.

"We can't see anything, we can't talk to anyone. We are just getting food delivered and that's about it."

Ms Welch said there was a lot of confusion around the coronavirus on the ship.

"It's hard to know what the real truth is. I guess in many cases, more people die from the flu. I don't want to make light of the situation. I don't know the full facts about the virus itself," she said.

A second ship, the World Dream, is docked at Hong Kong's Kai Tak Cruise Terminal with 1,800 people on board, the city's Department of Health said.

Cairns retirees Paul and Jacqueline Fidrmuc are also on the Diamond Princess waiting for updates on the virus.

"We are just kind of sitting tight really," Ms Fidrmuc said.

"It's a little bit daunting. But look, we can't do anything ... We are good strong healthy people and we've got good immune systems and fingers crossed that ... we can fight it off."

Everyone on board the Diamond Princess face two weeks of quarantine and isolation.

Japan health officials have confirmed 10 passengers, including two Australians, have so far tested positive for the virus.

The infected patients were transferred by Japan's coast guard to hospitals on the mainland while the remainder of the passengers and crew were placed in quarantine.

It's believed the virus was brought onboard by an infected 80-year-old Hong Kong man, who joined part of the 14-day cruise, and tested positive for the virus after disembarking on January 25

Ships are considered particularly at risk from outbreaks, due to the close-living quarters of passengers and crew. Researchers are still unsure exactly how the coronavirus spreads and how infectious it is.

Chinese officials had previously said that patients can be infectious even if they are not presenting symptoms.

An early study on asymptomatic transmission of the virus published last week in the prestigious New England Journal of Medicine appeared to confirm Chinese health officials' assessment.

But public health officials now say the report may be flawed. Interviews with the Chinese patient at the center of the study revealed she may have actually had mild, nonspecific symptoms.

An important factor yet to be determined is whether the Wuhan coronavirus spreads via the fecal-oral route, like norovirus and severe acute respiratory syndrome (SARS), according to Dr. John Nicholls, a clinical professor in pathology at the University of Hong Kong.

Norovirus is a contagious stomach bug that causes vomiting and diarrhea that is notorious for infecting cruise passengers.

Viruses like norovirus spread so quickly on cruises because "you've got so many people in a crowded area and people are sharing areas, touching places," Nicholls said.

Cruise companies worldwide have vowed to enact extra measures to protect their customers from infection, with several barring passengers who have been to mainland China in the past 14 days.

Royal Caribbean has canceled eight cruises out of China through early March and will "deny boarding to any individual who has traveled from, to or through mainland China or Hong Kong in the past 15 days".

It will offer those people full refunds, the company said in a statement.

It will also conduct health screenings for all China or Hong Kong passport holders as well as on guests who report feeling unwell or demonstrate any flu-like symptoms.

The virus has infected more than 20,000 people in mainland China and nearly 200 worldwide across 25 countries and territories. It has claimed 492 lives worldwide, all but two in mainland China.

CNN contributed to this report