Passengers stuck on a cruise ship in Japan where more than 500 people were infected with coronavirus have been allowed to start leaving the vessel. 

The Diamond Princess was quarantined in the port of Yokohama for two weeks after a man who left the ship in Hong Kong was later diagnosed with the virus. 

More than 540 people have tested positive for Covid-19 on the cruise, which originally carried 3,700 passengers and crew, with those infected transferred to hospitals in Japan. 

The country – which ranks second in the world after China in the number of confirmed coronavirus cases because of infections on the ship – has come under fire for its handling of the cruise quarantine. 

Around 500 people were expected to leave the ship on Wednesday, a Japanese health ministry official said, with the operation completed by Friday. 

However, the quarantine is not over for all passengers – those who shared a room with passengers who tested positive for the infection will have to stay on the ship for another 2 weeks from the time the infected roommate left. 

Meanwhile, crew members – who have been sharing rooms – will be moved to separate cabins and will undergo health checks, officials said.

One passenger, who had been tweeting about their experience on the ship, wrote: “Day:15: Everyone here, thanks for your support over the last two weeks. If you ever find yourself quarantined in a windowless room but with access to WIFI, note you can count on people around the world to help.”

Australian Prime Minister Scott Morrison said on Tuesday there were 220 Australians on board and that a total of 169 would be evacuated. Those evacuated will be flown to Darwin, where they will be quarantined for 14 days.

It comes after the US evacuated more than 300 nationals on Monday. Meanwhile, a captain’s announcement on the cruise said that Hong Kong passengers would be evacuated over the next day and a Canadian charter flight would arrive on Friday. 

Britain – along with Italy, Israel and Taiwan – is also reportedly preparing to evacuate citizens. 

Among those on board the ship are Brits David and Sally Abel. However, in a Facebook post he said it was unlikely they would be on a planned evacuation flight to the UK after they both tested positive for coronavirus. 

“We are going to a hostel because there isn’t a hospital bed anywhere around,” he said. “So, we’re going to a hostel and in four or five days we’ll be removed from the hostel and put into a hospital, where we will receive treatment.

“So I can’t see that there’s going to be any way we’re on that flight to the UK.”

In mainland China, where Covid-19 is understood to have originated, almost 75,000 cases have been reported, while more than 2,000 people have died. 

However, a new study has suggested that the epidemic may be slowing in China, with the number of new infections falling since early February. 

The Chinese Centre for Disease Control and Prevention examined 44,672 cases of the disease which were confirmed in the mainland as of February 11 and found that more than 80% of cases were mild. 

Meanwhile, severe symptoms such as pneumonia occurred in 14% of cases and critical illness in 5%. The fatality rate was 2.3%-2.8% for males compared with 1.7% for females.

The death rate is lower than for Sars and Mers, diseases caused by coronaviruses related to the one that causes Covid-19. But the new virus could ultimately prove more deadly if it spreads to far more people than the others did.

The study also warned that while cases seem to be declining, that could change as people return to work and school after the Lunar New Year holidays, typically the busiest period for Chinese travellers.