Tokyo 2020 Olympics organisers say "countermeasures against infectious diseases" are in place, amid fears over the spread of the deadly coronavirus.

The disease has killed 17 people and infected almost 600 after originating in the city of Wuhan in China.

What is a coronavirus? The World Health Organisation (WHO) describes coronaviruses as a large family of viruses ranging from the common cold to more severe diseases such as Severe Acute Respiratory Syndrome (SARS), which killed nearly 800 people globally during a 2002/03 outbreak that also started in China

Japan has seen just once case of the outbreak so far, but there are fears of a wider spread with million of visitors expected at the Games this summer.

"Countermeasures against infectious diseases constitute an important part of our plans to host a safe and secure games," Tokyo 2020 said in a statement.

Kazuhiro Tateda, president of the Japanese Association for Infectious Diseases, said on Wednesday: "We have to be very careful about what kind of infectious diseases will appear at the Tokyo Olympics.

"At these kinds of mass gatherings, the risks increase that infectious diseases and resistant bacteria can be carried in."

In the months leading up to the 2016 Olympics in Brazil, there were concerns over the outbreak of the Zika virus, but all events went ahead as scheduled.