Ireland will be one of 28 countries participating in an international exercise aimed at testing the ability of health and emergency services to cope with a human influenza pandemic.
Informed sources said last night that senior officials from the Health Service Executive and the Department of Health would take part in the "table-top" simulated pandemic to be held before the end of the year.
Officials of the Department of Agriculture may also be involved in the exercise.
It is understood that the exact dates of the two-day exercise are being kept secret to make it as realistic as possible.
One highly-placed source said last night that the exercise would assess the measures in place to contain such an outbreak and examine the liaison arrangements between the health services in various countries
It is understood that the international exercise will be co-ordinated from a central control room in Britain.
Dr John Simpson, deputy director of emergency preparedness at Britain's Health Protection Agency, said the event had been planned since January - long before the H5N1 avian virus spread from southeast Asia to birds in Turkey, Romania and Croatia, heightening fears of a global pandemic.
"It's a command post exercise. All the countries and organisations have teams playing, and it is co-ordinated from a central operations room in the UK," he said.
The agency has led similar exercises in recent years, with scenarios including a bioterrorism attack.
The H5N1 virus has killed more than 60 people in Asia, but so far it has not shown it can spread easily from person to person.
In order to do that, the virus would have to mutate on its own or mix its DNA with a human influenza virus.
In the European exercise, hundreds of officials at health departments across the Continent, as well as experts in other areas, will help assess how well countries are prepared and identify what gaps need to be filled if a pandemic emerged.
Dr Simpson said groups involved would be given prompts from a pre-written script to kick off the mock exercise.
Although he could not reveal details, he said the scenario would probably be a pandemic strain emerging in southeast Asia and spreading to Europe.
"The likelihood of it happening [ in Europe] is vanishingly small, because they have always developed in southeast Asia previously - where the conditions for reassortment are so much better," Dr Simpson said.
A deadly outbreak is more likely to begin in Asia because of the closer proximity between humans and animals.
Dr Simpson said that in the event of an outbreak emerging in Asia, Europe would have about two weeks to prepare.
The European exercise will also examine the role of countermeasures, including antiviral drugs and any vaccine.
It will also assess containment measures and examine the role of the European Commission during a pandemic.
"We know at some point there will be a pandemic, so it is an important thing to have preparedness for," Dr Simpson said.
