BEIJING, Sept. 25 (Xinhuanet) -- The World Health Organization said on Monday that it is too early to say whether there could be a SARS-like respiratory disease outbreak after a Qatari man was struck down with a related virus and is critically ill in hospital in Britain.
"It's still very early days," said Gregory Hartl, a WHO spokesman. "At the moment we have two sporadic cases and there are still a lot of holes to be filled in."
He added it is unclear how the virus spreads. Coronaviruses are typically spread in the air, but Hartl said scientists are considering the possibility that the patients were infected directly by animals. He said there is no evidence yet of any human-to-human transmission.
British officials alerted WHO on Saturday of the new virus in a man transferred from Qatar to Britain on Sept. 11 and is being treated in an intensive care unit at a London hospital for problems including kidney failure.
The 49-year-old man has recently traveled to Saudi Arabia, where another man with an almost identical virus had already died.
The virus, known as a coronavirus, comes from the same family as SARS which emerged in 2002 and killed 800 people.
Britain's Health Protection Agency (HPA) and respiratory disease experts said there is no immediate cause for concern, although authorities are watching out for any signs of the virus spreading.
"This new virus ... is different from any that have previously been identified in humans," the HPA said.
John Oxford, a professor of Virology at Queen Mary, University of London, said he was not too concerned as the new virus is "more likely to join numerous other members of the coronavirus family and behave like a nasty infection rather than join the exception group like SARS".
Other experts said it is unclear how dangerous the virus is.
"We don't know if this is going to turn into another SARS or if it will disappear into nothing," said Michael Osterholm, a flu expert at the University of Minnesota. He said it is crucial to determine the ratio of severe to mild cases.
The situation has raised concerns ahead of next month's annual Hajj pilgrimage, which brings millions of people to Saudi Arabia from around the world.
The WHO said it is in touch with health authorities in Britain, Qatar, Saudi Arabia and the Stockholm-based European Centre for Disease Prevention and Control (ECDC)
"We're asking for information from whoever might have seen such cases, but as of the moment we haven't had any more notifications of cases," said Hartl.