LONDON, Sept 24, 2012 (AFP) - The World Health Organisation issued a global alert on Monday for a new SARS-like respiratory virus which left a man from Qatar critically ill in a London hospital and killed at least one more in Saudi Arabia.

The 49-year-old Qatari was admitted to an intensive care unit in Doha on September 7 suffering from acute respiratory infection and kidney failure before being transferred to Britain by air ambulance on September 11, the WHO said.

A Saudi Arabian national died earlier this year from a virtually identical virus, the WHO said, while Saudi medical authorities said they were investigating other possible cases of the disease.

The WHO confirmed the illness was in the coronavirus family but was not SARS, or Severe Acute Respiratory Syndrome, which swept out of China in 2003, killing more than 800 people worldwide.

“This is a new virus,” WHO spokesman Gregory Hartl told AFP.

Britain's Health Protection Agency confirmed the presence of the new corona virus and then found that it was a 99.5 percent match with a virus obtained from the lung tissue of a 60-year-old Saudi man who died earlier this year.

Coronaviruses are causes of the common cold but can also include more severe illnesses including SARS.

The announcement comes ahead of next month's annual Muslim hajj pilgrimage to Saudi Arabia's holy city of Mecca which will attract nearly three million believers, although the WHO said it did not recommend any travel restrictions.

In Britain, the HPA, an organisation set up by the government to manage infectious diseases, meanwhile, stressed no-one else in Britain, including those who had come into contact with the man, were reporting symptoms.

The HPA said the new virus was “different from any that have previously been identified in humans.”It said there were encouraging signs that it was not as infectious as SARS as there had been no evidence of illness in people who had been in contact with the Qatari or the Saudi, including in health workers.

The World Health Organization on Wednesday urged health workers around the world to report any patient with acute respiratory infection who may have travelled to Saudi Arabia or Qatar and been exposed to a new SARS-like virus confirmed in two people so far.

The United Nations agency put out a global alert on Sunday saying a new virus had infected a 49-year-old Qatari who had recently travelled to Saudi Arabia - where another man with an almost identical virus had died.

The Qatari remained critically ill in hospital in Britain, according to the WHO's latest information as of Tuesday.

The WHO said on Wednesday no new case of acute respiratory syndrome with renal failure due to the new virus had been reported but its investigations continued.

“We've got things in place should things change, should the behaviour of the virus change,” spokesman Gregory Hartl said.

The WHO said it was working closely with Saudi authorities regarding health measures for the haj pilgrimage to Mecca next month when millions of Muslims travel to the kingdom and then return to their home countries.

CLINICAL DEFINITION

Its clinical guidance to 194 member states said health care workers should be alert to anyone with acute respiratory syndrome that may include fever (above 38C or 100.4F) and cough, requiring hospitalisation, who had been in the area where the virus was found or in contact with a suspect or confirmed case within the previous 10 days.

The virus, known as a coronavirus also related to the common cold, comes from the same family as SARS (Severe Acute Respiratory Syndrome) which emerged in China in 2002. SARS infected 8,000 people worldwide and killed 800 of them before being brought under control.

The WHO said it was identifying a network of laboratories that could provide expertise on coronaviruses to countries.

“Though it is a very different virus from SARS, given the severity of the two confirmed cases so far, WHO is engaged in further characterizing the novel coronavirus,” it said, referring to genetic sequencing.

Hartl, speaking to reporters on Tuesday, said: “This is not SARS, it will not become SARS, it is not SARS-like.”

It was not established whether the virus spread by human to human contact or just how it was transmitted, he said.

“We don't know if all cases of infections are as severe as the two cases we have currently or in fact whether there have been 2 million cases of this virus and only 2 severe cases.”