DOCTORS were today waiting for the results of tests on a man who may be the first in the UK to be suffering from a potentially fatal mystery pneumonia bug.

The man is being treated in isolation at a specialist infectious diseases unit at North Manchester General Hospital.

It was confirmed yesterday that it was the first "probable case" of Severe Acute Respiratory Syndrome (SARS) in England.

The bug, which experts say cannot be treated with standard drugs, has already claimed nine lives and has been branded "a worldwide health threat".

Passengers who flew in from Hong Kong on the same plane as the man, who is in his 60s and lives in Manchester, were urged to watch out for symptoms of the illness.

The man involved travelled from Hong Kong to Amsterdam on KLM flight number KL 0888 and then from Amsterdam to Manchester on flight number KL 2037 on Saturday, March 15.

Chief Medical Officer Professor Sir Liam Donaldson said: "At the moment we treating it as a possible link to the outbreak in the Far East."

The Department of Health said evidence suggested infection was mainly passed on through close contact, such as family members and healthcare workers.

And the World Health Organisation (WHO) said almost all reported cases to date had occurred in health workers who cared for a person with SARS or in family members.

"There is no evidence to date that the disease spreads through casual contact," it said.

But the DoH issued advice for passengers on the same flights as the man and said it had notified the airline involved.

It said if people who were on the flights developed high fever and chest symptoms, such as a cough or breathing problems, they should contact a doctor and explain their travel history.

The man is classed as a "probable case" which means, as well as having symptoms, chest X-rays have shown evidence of pneumonia or adult respiratory distress syndrome.

The Greater Manchester Strategic Health Authority said the patient, who has not been named, went to A&E where doctors believed he may have been suffering from SARS.

He was then admitted for assessment to the specialist Infectious Diseases Unit at North Manchester General Hospital.

Stephen Farey, divisional director of medicine at the hospital, said: "He is stable and is being nursed in an isolation cubicle.

"Various tests have been carried out and the results are awaited."

At the weekend the WHO declared the bug "a worldwide health threat" and said cases had been reported on three continents.

The first cases of the acute respiratory illness were reported in south China and Vietnam but outbreaks have since been reported across south east Asia and even in Canada.

Anyone who has recently been to the Far East and develops symptoms should see a doctor.

The Government said travellers to south east Asia should be aware of the outbreaks and take them into account in their travel plans.

However the WHO said there was no current justification for any restriction in travel or trade.