Fourteen Americans evacuated from the coronavirus-stricken Diamond Princess cruise ship in Japan tested positive for the illness but were allowed to board two chartered planes bound for quarantine on US military bases.

Their return almost doubles the number of confirmed cases, which had stood at 15, of the new coronavirus in the United States.

The 14 passengers tested positive for the virus after disembarking the cruise liner, which is moored off the Japanese port of Yokohama, but before boarding the planes. They were all asymptomatic so health authorities deemed them "fit to fly," the State Department and the Department of Health and Human Services said today.

They were cordoned off from the other passengers during the flight, they said.

Advertisement

"These individuals were moved in the most expeditious and safe manner to a specialised containment area on the evacuation aircraft to isolate them in accordance with standard protocols," the departments said.

A total of 328 Americans were evacuated on the two flights; all are due to go into quarantine for 14 days, the maximum incubation period for the virus, at Travis Air Force Base in Fairfield, California, or Lackland Air Force Base in San Antonio.

Flight data showed that one flight had landed at Travis and the other in San Antonio.

Another 44 Americans from the cruise ship had tested positive for coronavirus and had been taken to hospitals in Japan.

The quarantined cruise ship the Diamond Princess at Yokohama port, near Tokyo, Japan.
The quarantined cruise ship the Diamond Princess at Yokohama port, near Tokyo, Japan.

The World Health Organisation said new data has yielded better understanding of how the virus circulates and shows a decline in new cases, WHO Director General Tedros Adhanom Ghebreyesus said in a news conference. But he cautioned against that as a sign the virus has reached its apex.

"Trends can change as new populations are affected. It's too early to tell if this reported decline will continue," he said. "Every scenario is still on the table."

There are still puzzling unknowns, such as why children make up relatively few cases, though researchers are confident that coronavirus is less deadly than SARS and MERS viruses.

Japan's Health Ministry reported 99 new cases of coronavirus among the passengers and crew of the Diamond Princess, increasing the total number of infections from the ship to 454. Of those, 18 are in serious condition, the Yomiuri newspaper reported.

Advertisement

Yosuke Kita, a senior official in the Japanese Health Ministry, said the government will have finished testing everyone on board the Diamond Princess today.

The number of confirmed infections in China now exceeds 70,000, with the death toll rising to 1770, the overwhelming majority of both in Hubei province. But China's National Health Commission has stressed that the number of new cases outside Hubei province has been declining, as authorities impose draconian restrictions on people's movements in an attempt to stop transmission.

Another cruise liner, the Westerdam, owned by Holland America Line, is at the centre of a coronavirus-related investigation.

Hundreds of passengers have flown home, mostly through Thailand or Malaysia, after the ship docked in the Cambodian port of Sihanoukville and Cambodian health authorities deemed it coronavirus-free.

But an American woman has since tested positive for the virus, setting off a scramble to trace the infection.

Holland America Line said that it was working closely with government and health officials in Malaysia and Cambodia, as well as experts from the US Centres for Disease Control and Prevention and the World Health Organisation, to try to trace people who may have been exposed to the virus.

An 83-year-old American woman who disembarked from the ship at Sihanoukville on Friday took a charter flight to Kuala Lumpur, the capital of Malaysia, along with 145 other passengers. They had all passed health checks by Cambodian authorities and cleared to leave the ship and travel onward.

When the woman arrived in Kuala Lumpur, she reported not feeling well and tested positive for the virus. Malaysian authorities say she is in stable condition.

Her travelling companion tested negative and none of the other passengers or crew members reported symptoms, the company said.

The Westerdam remained in Sihanoukville, where it had docked last week after spending two weeks at sea. Authorities in Japan, Taiwan, Guam, the Philippines and Thailand had turned it away after seeing what had happened with the Diamond Princess, where the number of infections had grown rapidly even while the vessel and its passengers were supposed to be quarantined.