Two people have been killed by a deadly new pneumonia virus strain linked to killer SARS as authorities warn it has spread to other countries.
Wuhan pneumonia is the name for a new coronavirus which has struck down 41 people since breaking out in the Chinese city of Wuhan.
Japan has now confirmed its first case of infection, while the World Health Organisation said a case was reported in Thailand.
China has sought to play down speculation that it could be a reappearance of the SARS epidemic, which killed hundreds in 2002 and 2003.
Speculation is rife online however that China is playing down the extent of the outbreak.
The US State Department has issued a travel alert.
Officials in Wuhan said last weekend that 41 people had pneumonia caused by the new coronavirus and a 61-year-old man had become the first person known to have died. Today, reports are emerging that a second person has died.
The patient who died is a 69-year-old man, who saw the onset of illness on December 31, according to Chinese media. He died on January 15.
Meanwhile Japan's government has confirmed that a man treated for pneumonia after returning from China has tested positive for the new coronavirus identified as a possible cause of an outbreak in the Chinese city of Wuhan.
The man developed a fever and cough on January 3 while in Wuhan, the sprawling capital of Central China’s Hubei province.
He returned to Japan on January 6 and was taken to hospital four days later as the symptoms persisted. His X-ray image showed signs of pneumonia, officials said.
The man has since been released from hospital as his condition improved. He was only identified as a man in his thirties in the Kanagawa prefecture, west of Tokyo, and Kyodo News agency said he is Chinese.
The World Health Organisation said it was consulting with Thai and Chinese health authorities after a case was reported in Thailand.
The US State Department issued a health alert update today about travel to the Wuhan region. It referred to a Watch Level 1 Alert by the US Centers for Disease Control and Prevention urging citizens travelling in the region to avoid contact with animals, animal markets or animal products, among other precautions.
Thai health authorities said today they were stepping up monitoring of passengers arriving at airports ahead of the Lunar New Year holiday, when 800,000 Chinese tourists are expected to visit Thailand.
Coronaviruses are a large family of viruses that can cause infections ranging from the common cold to Severe Acute Respiratory Syndrome (SARS). Some of the virus types cause less serious disease, while some - such as the one behind Middle East Respiratory Syndrome (MERS) - are far more severe.
Common symptoms include a runny nose, headache, cough and fever. Shortness of breath, chills and body aches are associated with more dangerous kinds of coronaviruses, according to the US Centres for Disease Control and Prevention.
The World Health Organization (WHO) has said the new Wuhan virus could spread and has warned hospitals worldwide.
Jeremy Farrar, a British-based infectious disease specialist and director of the Wellcome Trust global health charity, said news of a case in Japan was "extremely concerning".
He warned it was possible that multiple cases with mild symptoms might be masking the true numbers of people infected, indicating that many cases may be going unreported.
"Wuhan is a major hub and with travel being a huge part of the fast-approaching Chinese New Year, the concern level must remain high," he said in a comment emailed to Reuters.
"It is probable that we are looking at patients being affected over a number of days from multiple animal sources and with some degree of human-to-human transmission."
A fish market in Wuhan has been linked to the outbreak.
Japanese official Eiji Hinoshita told reporters that the Japanese man who returned from China told officials he did not go to the fish market, but had "close contact" with at least one person with pneumonia symptoms at a place where he stayed during the visit.
Japan is urging those visiting or returning from Wuhan to wear masks and promptly go to medical institutions if they have a cough and fever.
Officials claim the virus is not considered highly contagious and just passing by or talking to patients would not be a concern.
