The rehearsal before the nightmare

Centre for Emergency Preparedness and Response of the Health Protection Agency (HPA) The value of Simulation Exercises 

From a bland, open-plan office in the Wiltshire countryside, distinguished only by a large plasma television screen and a "bat phone" prominently displayed on a table, officials gather regularly to handle the most horrific disasters. This week, their eyes were on the European early warning and response system displayed on the screen, while their ears listened out for the phone, which is linked to a protected government communications network.

They have been coping with the challenge of a flu pandemic that threatens to kill millions of people and cause billions of pounds of economic damage and disruption.

Last month, from the same heavily guarded operations room - dubbed "the blue lagoon" by staff after the shade of its government-issue carpets - they were dealing with the unintended release by terrorists of a biological weapon. Early next year, they will be preparing for the aftermath of extreme weather and flooding.

None of these events has so far come to pass but the staff at the Centre for Emergency Preparedness and Response of the Health Protection Agency (HPA) believe the experience they have accumulated in recent years will prove invaluable when the next public health emergency strikes.

The crisis erupting this week in Harbin, the Chinese city threatened by a toxic slick, is a reminder of the unrest that can result from such catastrophes.

For John Simpson, who heads the centre, the most recent proof of its effectiveness was the response to the suicide bombings on London's public transport system this summer, which his team helped co-ordinate. "For me, it was just like another simulation," he recalls. "Everything worked incredibly well. Staff said that because of the exercises, they knew who to phone."

The UK has a long history of emergency planning, rooted in bitter experience that includes IRA terrorist attacks and a series of train crashes that gave the health and emergency services a strong reputation for disaster response.

During the 1990s, and inspired by some of the events of the period, emergency planning was focused on large-scale simulations with the police and hospitals, using scenarios such as the deliberate release of anthrax or sarin. But a very different type of threat triggered broader interest: that of recalcitrant software engineers. It was concern about the impact of how computer programmes with internal calendars would cope with the year 2000 that sparked action.

"Y2K did a lot," says Mr Simpson. "There were questions about hospital power supplies and data collection. In the event, I only remember one generator that went down. But it increased the culture of planning and raised the profile withhealth authorities' chief executives." The new terrorist threats after September 11 2001 provided additional impetus, and in April 2003 the HPA decided to create a unit focused around the response to chemical, biological, radiological and nuclear events. They simulated the release of nerve agents; the effects of an industrial chemical spill; and outbreaks of smallpox and West Nile virus.

Then a new subject came up. "We started to say that you can talk about all these theoretical events but the one thing you can predict will happen one day is a flu pandemic," he says. So as international attention be-gan to turn to the risk of avian flu spreading "efficiently" to humans, he planned a response. In contrast with most previous one-off, dramatic "big bang" events, flu is particularly difficult to manage because of its timescale. It may come in waves and last for six months around the world, so the planners call it a "rising tide" event.

Preparation for the first such pandemic simulation - dubbed "Icarus" - began in February last year. It culminated in London 10 months later with a "desk top" exercise in which officials planned a response rather than trial runs on the ground by emergency services. It has been followed by a series of others. The centre drafts a scenario, supplemented by computer simulations and mock media bulletins and questions from ministers to add to the uncertainty. "We never successfully recreate the media and always underestimate the time it takes. We learnt the importance of getting relevant messages out, notably about self-treatment rather than going to hospital."

Mr Simpson concedes that there is an element of artificiality and a risk that participants may "game" the simulation rather than behaving as they would in reality. But he argues that the exercises provide important lessons. "Getting all the major players together in a building for a day provides large intangible benefits," he says. "If something happens, people have met and can talk. Simply getting to know opposite numbers is useful, and clarifying roles and responsibilities. It gives us the ability to look at plans, see how they interact and suggest improvements." For the first time with Icarus, the HPA included a broader range of participants, including businesses. It invited along utility companies and supermarkets in an effort to understand how infrastructure and daily life would be affected. "Flu has such a lot of business continuity issues," says Mr Simpson. "A lot of large companies have got to get more signed up."

One participant was O2, the telecoms provider. "I tended to look at vertical sectors, such as how our engineers would respond to a pandemic," says one employee who took part. Icarus probed sensitive issues such as whether to close schools. This is something Mr Simpson argues should only happen if children turn out to be a predominant way to transmit a pandemic virus, given that parents - including many who work in the health service - would then have to stay at home to look after them. The pace of flu simulations has since intensified. "We've got them by the skip-load," he says, estimating about two-fifths of his centre's work is now geared to flu, including providing back-up for regional equivalents around the country. "Not a week goes by without somewhere in the UK having some form of exercise." "Arctic Sea" took place in the East Midlands. "Aurora" was run from Bradford. Each of the HPA's nine regions will do one or more in the months ahead.

The agency is preparing an "off the shelf" package so local authorities can run their own versions and is increasingly moving to computer simulations that diverge from prepared scenarios and allow participants' decisions to determine the outcome.

The latest exercise - called "Common Ground" - runs for two days, from 6am till 9pm. It brings a new international dimension and marks foreign recognition of the HPA's expertise in the area. While France, Germany, the Netherlands, Australia and Canada are among a number of other countries to hold pandemic simulations, the European Commission awarded the HPA the $900,000 (£615,000) contract for the flu exercise and last month's bio-terror contract after a competitive tender.

"Common Ground" is designed to test how countries across Europe, as well as international organisations, vaccine and drug manufacturers would cope with a pandemic, probing their interactions and testing the outcomes of different national approaches and how they would cope with likely undersupplies of medicines.

"Most exercises are not looking for marks out of 10," says Mr Simpson. "They are about posing questions, seeing how people deal with them, and testing plans to see if they are fit for the purpose. This loop is happening, lessons are being learnt and amendments made." If the result is to reduce the impact of a future pandemic, simulations may be an under-appreciated investment that is worth the cost.

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