Two charter flights carrying cruise ship passengers from Japan have landed at military bases in California and Texas, with passengers facing a quarantine period to ensure they do not have the Covid-19 virus that has been spreading thoughout Asia.

A plane carrying American passengers touched down at Travis air force base in northern California shortly before 11.30pm local time (0730 GMT) on Sunday. A second flight arrived at Lackland air force base in Texas about two and a half hours later.

Japan’s defence minister, Tarō Konō, had tweeted earlier that Japanese troops helped transport 340 US passengers on 14 buses from Yokohama port to Tokyo’s Haneda airport. About 380 Americans were on the Diamond Princess cruise ship.

The US said it arranged the evacuation because people on the ship were at a high risk of exposure to the virus. For the departing Americans, the evacuation cuts short a 14-day quarantine that began onboard the ship on 5 February.

Quick guide What are coronavirus symptoms and should I go to a doctor? Show Hide What is Covid-19? Covid-19 is caused by a member of the coronavirus family that has never been encountered before. Like other coronaviruses, it has come from animals. The World Health Organization (WHO) has declared it a pandemic. What are the symptoms this coronavirus causes? According to the WHO, the most common symptoms of Covid-19 are fever, tiredness and a dry cough. Some patients may also have a runny nose, sore throat, nasal congestion and aches and pains or diarrhoea. Some people report losing their sense of taste and/or smell. About 80% of people who get Covid-19 experience a mild case – about as serious as a regular cold – and recover without needing any special treatment. About one in six people, the WHO says, become seriously ill. The elderly and people with underlying medical problems like high blood pressure, heart problems or diabetes, or chronic respiratory conditions, are at a greater risk of serious illness from Covid-19. In the UK, the National health Service (NHS) has identified the specific symptoms to look for as experiencing either: a high temperature - you feel hot to touch on your chest or back

a new continuous cough - this means you’ve started coughing repeatedly As this is viral pneumonia, antibiotics are of no use. The antiviral drugs we have against flu will not work, and there is currently no vaccine. Recovery depends on the strength of the immune system. Should I go to the doctor if I have a cough? Medical advice varies around the world - with many countries imposing travel bans and lockdowns to try and prevent the spread of the virus. In many place people are being told to stay at home rather than visit a doctor of hospital in person. Check with your local authorities. In the UK, NHS advice is that anyone with symptoms should stay at home for at least 7 days. If you live with other people, they should stay at home for at least 14 days, to avoid spreading the infection outside the home.

The state department announced later that 14 of the evacuees confirmed they had the virus but were allowed to board the flight because they did not have symptoms. They were being isolated from other passengers on the flight, the state department and the Department of Health and Human Services said in a joint statement.

Dr Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases at the US National Institutes of Health, said on Sunday that an infected person who showed minimal symptoms could still pass the virus to someone else.

After arriving in the US, all of the passengers must go through a further 14 days of quarantine at the military facilities – meaning they will have been under quarantine for nearly four weeks.

Facebook Twitter Pinterest A plane carrying some of the American passengers arrives at Travis air force base in California. Photograph: Brittany Hosea-Small/AFP via Getty Images

Australia, Canada, Hong Kong and Italy were planning similar passenger evacuations. Other governments, including Canada and Hong Kong, will also require the passengers to undergo a second 14-day quarantine.

Japan on Monday announced a further 99 infections on the Diamond Princess, raising the ship’s total number of cases to 454. Overall, Japan has 419 confirmed cases of the virus, including one death. The US has confirmed 15 cases within the country. Separately, one US citizen died in China.

Cheryl and Paul Molesky, a couple from Syracuse in New York, opted to trade one coronavirus quarantine for another, leaving the cruise ship to fly back to the US. Mrs Molesky said the rising number of patients on the ship influenced the decision.

“We are glad to be going home,” she told NHK TV in Japan. “It’s just a little bit disappointing that we’ll have to go through quarantine again, and we will probably not be as comfortable as the Diamond Princess, possibly.”

She sent Associated Press a video of her and her husband boarding the plane with other Americans. “Well, we’re exhausted, but we’re on the plane and that’s a good feeling. Pretty miserable wearing these masks though, and everybody had to go to the bathroom on the bus,” she said.

Some American passengers said they would pass up the opportunity to fly to the US because of the additional quarantine. They were also concerned about being on a long flight with other passengers who may be infected or in an incubation period.

One of the Americans, Matthew Smith, tweeted that he saw a passenger with no face mask talking at close quarters with another passenger.

“If there are secondary infections onboard, this is why,” he said. “And you wanted me to get on a bus with her?”

He said the American health officials who visited their room were apparently surprised that the couple had decided to stay, and wished them luck. “Thanks, but we’re fine,” Smith said he told them.