Gatwick Airport is on alert to guard against a killer flu outbreak.

While health authorities monitor the spread of Severe Acute Respiratory Syndrome (Sars), a virus which has affected at least 15 countries, staff at the airport are ready to act if any passenger shows suspect symptoms.

The airport does not receive flights from Hong Kong, where Sars was first detected, but the risk of an infected passenger arriving at Gatwick has prompted concern.

Terminal manager Andy Rozumski said any precautions or response to an outbreak of Sars would be dictated by Gatwick Health Control and the airport was always in a state of readiness for any travellers suffering from contagious diseases.

He said: "Port health staff are monitoring the situation. If they feel anything could spark off a particular crisis, they would implement their contingency plans which we would support.

"We are on alert. We have procedures in place for all sorts of diseases around the world."

There have been more than 2,000 reported cases of Sars, dubbed Asian Flu Virus, and 78 deaths. Tests were underway today to establish whether a man in the east of England is the fifth person in the UK to come down with the virus.

Gatwick Health Control manager Sheri Goddard said: "An outbreak would be treated in the same way as a normal sick passenger.

"We would attend the aircraft and isolate those who had any suspect symptoms.

"But we do not have any flights coming from Singapore, China or Hong Kong at the present time, so we cannot take any more action and cannot be more proactive.

"We have given advice to Gatwick Airport to check out the Department of Health web site, which has a run down of procedures to take, and have advised senior managers on what to look for and to contact us about any airline passengers who show presenting symptoms."

A Virgin Airlines spokesman said the company had received calls from a number of anxious customers asking about flights to the Far East and the risks of infection but enquiries fell off when government information about the outbreak became more readily available.