TWO Japanese citizens evacuated from the epicentre of the 2019 novel coronavirus outbreak have been diagnosed with the infection after initially testing negative, said the Health Ministry today.

One of the two, a man in his 50s who returned from the Chinese city of Wuhan on the first Japanese evacuation flight on January 29, previously tested negative for the virus twice.

However, a third test 12 days later found that the man – who has been isolated in his hotel room since his return – was, in fact, infected.

According to the World Health Organisation, the coronavirus incubation period “could be up to 14 days”.

The second evacuee, a man in his 40s, returned from Wuhan on January 30 and initially tested negative for the virus, but was diagnosed after a second test on Monday.

The new cases bring the number of infections in Japan to 28, excluding dozens diagnosed aboard a cruise ship moored off the coast.

So far, 135 people on board Diamond Princess have tested positive for the virus since the vessel arrived off Japan last week.

Authorities are removing from the ship the most recently diagnosed 65 crewmen and passengers.

Diamond Princess was carrying 3,711 people when it arrived off Japan on the evening of February 3, and was officially placed into quarantine two days later.

Only those diagnosed with the virus or suffering other serious health conditions have been allowed to disembark the ship, which is expected to remain in quarantine until at least February 19.

People on board today tweeted that medicines are being delivered to passengers, and that the captain announced the vessel will head out to sea overnight to produce fresh water and carry out other operations.

Japan has evacuated hundreds of its citizens from Wuhan since the outbreak began. They have been asked to self-quarantine, with most staying in government-appointed hotels for a period of 14 days.

Evacuees from the first flight are expected to be released from self-quarantine this week after undergoing an additional test for the virus, said officials.

Japan is planning to send a fifth evacuation flight to Wuhan later this week. – AFP, February 11, 2020.