|Mystery viral pneumonia outbreak affects 59 people, China rules out SARS or MERS|
|Vietnam closely monitors severe pneumonia outbreak in central China|
|Vietnam records no Ebola virus infection|
|The outbreak of pneumonia comes just a few weeks before China's busiest travel season of the year. (Photo: AFP/PETER PARKS)|
While the United Nations health agency said it needed more comprehensive information to confirm precisely the type of pathogen causing the infections, it said a new coronavirus was a possibility.
But on Thursday, Chinese state television was more conclusive, citing pathogen test results from a preliminary assessment expert group.
"As of Jan 7, the laboratory detected a new type of coronavirus," China Central Television (CCTV) said in a report. "The new coronavirus that caused this epidemic situation is different from previously discovered human coronaviruses, and further understanding of the virus requires more scientific research."
Coronaviruses are a large family of viruses that can cause infections ranging from the common cold to SARS. Some of the virus types cause less severe disease, while some - like the one that causes MERS - are far more severe.
"The initial information about the cases of pneumonia in Wuhan ... pointed to a coronavirus as a possible pathogen causing this cluster," the WHO said in a statement.
It added that since Chinese authorities have conducted laboratory tests and eliminated the SARS coronavirus and the MERS one as possible causes, as well as flu, bird flu, adenovirus and other common respiratory pathogens, "therefore, a novel coronavirus could not be ruled out".
The pneumonia outbreak started last month, and 59 cases had been reported by Chinese authorities by Sunday.
The WHO noted that coronaviruses emerge periodically - including in 2002 to cause SARS and in 2012 to cause MERS.
It said that according to Chinese authorities, the virus behind the Wuhan cases can cause severe illness in some patients and does not appear to pass easily from person to person.
"More comprehensive information is required to confirm the pathogen, as well as to better understand the epidemiology of the outbreak, the clinical picture, the investigations to determine the source, modes of transmission, extent of infection, and the countermeasures implemented," the WHO said.
SARS killed 349 people in mainland China and another 299 in Hong Kong in 2003.
According to WHO, the virus, which infected more than 8,000 people around the world, is believed to have originated in the southern Chinese province of Guangdong.
WHO announced that China was free of SARS in May 2004./.