Mark Honigsbaum and David Adam 

Facing up to the virus that could kill thousands

· Officials prepare for a national emergency · But experts say pandemic remains unlikely
  
  


In July, almost unnoticed by the national press, a deadly bird virus arrived on a pheasant farm in Surrey. Experts from the Department for the Environment, Food and Rural Affairs (Defra) identified Newcastle disease, a virus usually mortal to turkeys and geese but not humans, in a flock of 9,000 pheasant chicks imported from France ahead of the shooting season.

Within hours of the diagnosis, veterinary experts had swung into action, throwing up a 3km exclusion zone around the farm near Cobham and culling 10,000 birds. The carcasses were burned and premises cleaned to stop the virus escaping. It was four weeks before Defra's Veterinary Exotic Diseases Division felt it was safe for poultry movements in the area to resume. This weekend, with the news that H5N1, a far more deadly bird virus, has reached Turkey, similar emergency plans are being readied by officials from Defra and other agencies. The scenario they are preparing for is that the H5N1 virus, which so far has led to the culling of billions of chickens in south-east Asia and 60 human deaths, will soon arrive on these shores.

What happens next depends on where the outbreak occurs, whether it can be contained and - most important of all - whether it mutates to become infectious between people. So far, only poultry workers or those directly exposed to chicken faeces or blood are thought to be at risk, though direct human-to-human transmission cannot be ruled out.

"Every time a new person gets infected with the virus there is a small chance that person will trigger a pandemic," said Neil Ferguson, a scientist at Imperial College, who has been running simulations on what might happen were H5N1 to reach Britain. "It's a very small chance, probably 1 in a 1000, 1 in 10,000 or less."

Should diseased birds reach Britain, the first step for veterinary officials would be to contain the outbreak as they did with Newcastle disease. An amber alert would be sounded and samples sent to the Veterinary Laboratory Agency (VLA) in Weybridge, Surrey. If Ian Brown, the head of avian virology there, confirms the cause of death as H5N1, the alert level will be raised to red and a whole series of emergency procedures, from quarantine, restriction of poultry movements to culling, will swing into action. Other agencies, such as the Department of Health, the Health Protection Agency and the Ministry of Defence, would be brought into the loop. In the event that the outbreak cannot be contained, Defra may have to consider mass culling programmes and - as in the foot and mouth outbreak - the possibility of vaccination.

At this point, with the risk of the virus spreading to human populations, the Department of Health would appoint a UK national influenza pandemic committee to coordinate the response of hospital trusts and local authorities. The Civil Contingency Secretariat (CCS) of the Cabinet will also be alerted and Cobra, the emergency committee which coordinates Whitehall's response to terrorism, readied for a possible breakdown in civil order.

The Department of Health's pandemic preparedness plan published in March envisages as many as 54,000 Britons dying in the first few months of a flu pandemic. But in June, CCS officials warned that that could be an underestimate. The more likely figure, they said, was 700,000 - a projection the Department of Health is expected to take on board when it updates its pandemic plan later this month.

In the most serious case, officials estimate there would be as many deaths in the 12 weeks of an epidemic as there usually are in a year. At the peak of the pandemic, 19,000 people would require hospital beds, prompting councils to requisition schools to accommodate the sick.

To treat the dying, the government would begin drawing down its stockpiles of oseltamivir (Tamiflu), an anti-viral drug that treats flu. But with only 14m courses, enough for a quarter of the population, likely to be available, sooner or later rationing would have to be imposed, with health professionals and essential civil servants the first in line. The government would also come under pressure to release stores of its precious flu vaccine. At present there are contingency plans for just two to three million doses.But there is no guarantee that vaccines which protect against annual human flu strains will also work against H5N1.

The consequences hardly bear thinking about. Earlier this year, in a dress rehearsal in the East Midlands codenamed Operation Arctic Circle, officials quickly concluded that mass mortuaries would be needed to bury the dead. But no one knows whether, in the event of a pandemic, any of these measures will prove effective. John Avizienius, senior scientific officer at the RSPCA and a member of Defra's avian influenza stakeholder group, said: "All you can do is plan for the worst case scenario."

Next week, in committee rooms across Europe, officials will be doing just that. The first item on their agenda will be the results of VLA tests being conducted this weekend on dead ducks and chickens recovered from a farm in Romania's Danube delta. If the Romanian birds are found to have the virus, as in the case of the turkeys from a farm in the Asian region of Turkey which the VLA last week said had died from H5N1, the European Union may have no choice but to close its borders.

With the news that several poultry workers in Turkey may have contracted the disease, the EU may soon be faced with having to take more drastic measures - such as restricting the movement of people too.

But will it do any good? Last week, wildfowl experts and amateur bird watchers were urged to fan out across the Thames Estuary, Morecambe Bay and the Ribble, looking for tell-tale deaths among migratory birds arriving from Russia.

The fear is that wild geese moving from western China to Siberia may have spread the virus to several species of ducks and gulls that briefly visit British shores on their annual migration north. These ducks, many of which may not show signs of illness, may be passing on the virus to poultry on British farms.

In the hope that they are not, Defra and the Wildfowl and Wetland announced last week that they would be conducting tests on 11,000 wild birds - three times the normal level. "The risk of avian influenza spreading from eastern Russia to the UK via migrating birds is still low," said Defra's chief vet, Debby Reynolds. "However, we have said all along that we must remain on the look out."

FAQ: Precautions

What could I do to protect myself and my children?
If you are fit and healthy, not a lot. There is no vaccine that can protect against the H5N1 avian flu virus because scientists do not yet know what we will be up against.

Isn't there a vaccine in development?
Some manufacturers are working on general H5N1 vaccines which they hope would provide some protection in the event of a pandemic.

Is there any treatment?
Two antiviral drugs, Tamiflu and Relenza, reduce the severity of a flu bout and shorten it, which could save people's lives and reduce the period during which they are infectious to others. The government has ordered 14m doses of Tamiflu.

Can children take it?
It is only licensed for those over 13, but experts believe it is safe at lower doses for those much younger.

 

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