A senior Olympic official in Japan has warned that the coronavirus outbreak could “throw cold water” on preparations for Tokyo 2020, although organisers insist that there are no plans to cancel the Games.

Toshiro Muto, the chief executive of the Tokyo Olympic organising committee, said he was concerned about the impact the spread of the virus was having in the run-up to the Olympics, which are due to open in 170 days.

“I am seriously worried that the spread of the infectious disease could throw cold water on the momentum toward the Games,” Muto said during a meeting in Tokyo with officials from the International Paralympic Committee. “I hope that it will be stamped out as soon as possible.”

Muto’s concerns were echoed by Saburo Kawabuchi, the mayor of the athletes’ village, where 11,000 competitors will stay during the Games.

“I truly hope that the infectious disease will die down somehow so that we will be able to operate the Paralympics and Olympics smoothly,” he said. “In the worst case we will do our utmost for the athletes so that they will be able to concentrate on performing their best.”

The coronavirus outbreak, which has killed 490 people in mainland China and infected more than 23,000, has disrupted several qualifying events that were due to be held in the country, including those for women’s football and basketball, boxing and badminton.

Quick Guide What are coronavirus symptoms and should I go to a doctor? Show 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.

There have been no deaths from the virus in Japan, but it has the largest number of infections – 33 – outside China. On Wednesday, 10 passengers onboard a luxury cruise liner off the Japanese port of Yokohama tested positive for the illness, forcing health authorities to place all 3,700 passengers and crew in quarantine for 14 days.

Craig Spence, a spokesman for the Paralympic committee, said: “We have full confidence that the relevant authorities, in particular here in Japan and the World Health Organization, will take all the necessary measures to address the situation.”

But Tokyo’s governor, Yuriko Koike, has suggested that failure to contain the outbreak could affect the Games. “We must firmly tackle the new coronavirus to contain it, or we are going to regret it,” she said last week.

Demand for the 7.8m Olympics tickets is high, with applications exceeding supply by at least 10 times. About 4.5m tickets have been distributed domestically via a lottery.