Bird flu: Why weren't we warned? How did it get here? How scared should you be?

It started with the death of a young girl in Thailand a year ago. The virus has now reached Europe and many fear it is only a matter of time before it arrives in Britain. Geoffrey Lean and Severin Carrell report

During the previous week the chickens had fallen sick and died of what was then the little-known bird flu, which yesterday turned up in Romania, raising fears that it would shortly arrive in Britain. Sakuntala had helped destroy the dead birds.

Over the next days her condition rapidly worsened. She became increasingly short of breath as the virus invaded her respiratory tract and started to eat away at the tissue of her lungs. Five days later, as she struggled to breathe and writhed in pain, she was admitted to the local hospital.

Her mother, Pranee Thongchan, who was living in Bangkok, 250 miles away, travelled up country that day to nurse her. But the little girl died the next day, and her mother went back to the capital. Three days later, Pranee developed bird flu and died in agony. It seems certain she caught it from Sakuntala.

If, as the World Health Organisation (WHO) now believes is inevitable, bird flu turns into a human pandemic, killing many millions, the tragic tale of Sakuntala and her mother - officially reported earlier this year in The New England Journal of Medicine - will go down as the moment that one of the greatest catastrophes to hit the world began.

The Journal called the story an "unprecedented warning", and said that "all prerequisites for the start of a pandemic have been met save one" - the virus acquiring the ability to spread rapidly from person to person. Professor John Oxford, of Queen Mary, University of London, says: "It sends a shiver down my spine."

Pandemics are quantum leaps in the development of flu. Normally an existing flu virus, which has been around for decades, undergoes a slight shift, enabling it to infect some people who have built up immunity from previous bouts of the disease.

But every so often, about three or four times a century, an entirely new one arrives. No one has any natural protection against it, and so - once it has developed the ability to spread between people - it is free to commit mass slaughter. So far as we know, the virus always originates in wild birds, and has come out of Asia.

Experts believe this is about to happen again. They cannot say when the bird flu virus will adapt to become extremely infectious to humans, but they say it will do so. The WHO warns that "the world is now in the gravest possible danger of a pandemic".

The latest potential outbreak goes back to 1997, when the virus first appeared in Hong Kong, infecting 18 people. The authorities reacted with admirable vigour, slaughtering all the area's 1.5 million poultry in just three days, and it seemed to disappear. But nearly two years ago it reappeared in South Korea, and by early this year had spread to eight eastern Asian countries. Slaughtering 150 million birds throughout the region has failed to halt the disease, and so far about 120 people are known to have caught it. Half of them have died - an extraordinarily high mortality rate.

Shigeru Omi, the WHO's director in the area, says: "All attempts to bring it under control in South-east Asia have failed."

Now it is spreading around the world. On Thursday, scientists at the Veterinary Laboratories Agency in Weybridge, Surrey, confirmed that tests showed poultry in Anatolia, in Turkey, had the disease. And yesterday, the Romanian government announced that it had been found in its country too.

The crucial event in this spread took place at the massive Qinghai Lake, high in the mountains of north-western China, which is a summer hub for migrating birds from all over Asia. Thousands of wild birds died from the virus there this summer, and in August infected survivors began fanning out towards their winter quarters.

A trail of infected poultry farms followed their migration route across Siberia, and has now reached Europe. It is still largely a bird disease, with only rare cases of humans catching it. But experts warn that it is only a matter of time before the critical mutation that would spark a devastating human pandemic takes place. This month, Sir Liam Donaldson, the Government's Chief Medical Officer, warned that it was a "biological inevitability" it would seriously affect the health of people in Britain. Unofficially, the Government is preparing for up to 750,000 deaths.

How could it come to Britain? The good news is that the virus's appearance in Europe does not mean the threat of it arriving in Britain this winter has increased. The flocks of ducks, geese and waders suspected of carrying it to Turkey and Romania from the parts of Siberia so far known to be infected rarely fly to Britain. They go south via the Mediterranean, to winter in eastern Africa.

On Thursday, officials at Margaret Beckett's Department for Environment, Food and Rural Affairs held an emergency telephone conference with experts from the Royal Society for the Protection of Birds, the British Trust for Ornithology and the Wildfowl and Wetlands Trust to reassess the threat. A note of the meeting, passed to The Independent on Sunday, concludes: "The consensus was that the risk of movements of waterbirds from Turkey or Romania direct to NW Europe this coming winter is low."

It says the main threat is indirect, and some way off - caused by birds from the area moving on to Africa and infecting others that spend their summers in Britain. "If wild birds can carry the virus, then mixing of populations in Africa or on the breeding grounds next summer might mean that the risk of them carrying it to north-west Europe would be greater next spring or autumn."

The Netherlands considers the danger great enough to have brought all its poultry indoors, and some experts say Britain should do the same. Ministers ruled this out in August, but are re-examining their position.

British ornithologists argue that more attention should be paid to the threats from smuggling of wild birds or legal poultry imports. An internal report for the Royal Society for the Prevention of Cruelty to Animals - written by Dennis Alexander, who recently retired from his post as one of the Government's most senior experts on avian flu - warns that illegal imports, such as of parrots and song birds, from East Asia, could pose a "high risk".

The EU has strict quarantine rules for imported wild birds but it has no way of enforcing these on exporting countries. Experts also say that controls on moving poultry from infected areas should be far stricter. Experts argue for restrictions to be imposed throughout regions at risk - even before the disease emerges.

In Britain, the Government's contingency plans only allow for movement controls to be imposed once infection is suspected on a farm, and then only within a 15-mile radius. Yet the birds are often infectious - and sometimes die - before they show symptoms of the disease. If Britain's poultry farms are infected, an industry worth about £2bn faces decimation. But this would pale in comparison with the devastation to human lives and the economy if the virus should become highly infectious to people.

The likeliest scenario is that the mutation will take place in China and South-east Asia, and be carried to Britain by a passenger on a commercial flight. Professor Oxford warns it could arrive here just a day after beginning to spread widely in Asia.

No fully effective vaccine will be ready in Britain in time for the first wave. Instead, the Government is relying on building up stocks of anti-virals, like Tamiflu, which may blunt its effects. But Britain dithered last March in ordering the drug, which means that it will not have enough if the pandemic arrives in the next year.

The Government will try to slow the pandemic's spread by closing schools and theatres and cancelling sporting events. But we are at the virus's mercy, waiting to see when it will make its first big move to infect humans since little Sakuntala's mother became infected at her dying daughter's bedside.

HOW THE IoS BROKE THE STORY

27 February 2005

The World Health Organisation warned of "the gravest possible danger of a pandemic", the US Centers for Disease Control said it was a "very ominous situation", and the Food and Agriculture Organisation described the threat as a "sword of Damocles" hanging over the world. But Britain had still failed to add to its stockpile of 100,000 courses of the only drug known to be effective. Experts warned the country would need 20 million.

13 March

The IoS revealed that one of the country's leading experts believed that two million Britons could die in a bird flu pandemic.

26 June

Bird flu is as much of a danger to Britain as terrorism, ministers had been told by the official Civil Contingencies Secretariat.

18 September

New research claimed that bird flu would slash at least £95bn from Britain's GDP and create a global depression to rival that of the 1930s.

HEALTH ADVICE

What to do if a pandemic strikes

If avian flu starts to pass rapidly from person to person, sparking a pandemic, protecting yourself and your family will be largely in your own hands. There will be little that the Government or doctors will be able to do to stop you catching it.

Existing flu jabs will be of no use. Anti-viral drugs, such as Tamiflu, can reduce the severity of the illness if taken within 48 hours of symptoms first appearing, and should save lives. But, in the short-term, supplies are scarce. The Government ordered 14.6m courses of the drug last spring, but was relatively late in doing so and we are some way back in the queue.

So what can you do in the meantime? First, don't panic. Try to minimise contact with other people: that will not just provide self-protection, but will help prevent the virus spreading.

Get in stocks of food and water and try, as far as possible, to sit out the pandemic. The authorities will almost certainly have closed schools and theatres, cancelled sporting fixtures and may restrict transport.

Otherwise, self-protection means reverting to what may seem old-fashioned rules of hygiene.

The virus can be breathed in, or taken in through the skin. So carry a handkerchief for when you need to blow your nose or sneeze. Cover your mouth when you cough. Remember the old rhyme "coughs and sneezes spread diseases".

Wash your hands frequently. Experts say you can catch the flu from handshakes or doorknobs. Avoid touching your eyes, nose or mouth. Never share mugs, glasses, cutlery, towels or toothbrushes. Use paper towels to clean surfaces regularly, then bin them. And if, despite all this, you do catch the virus, avoid passing it on.