At a poultry farm in central Bohemia, 40 kilometers (25 miles) from Prague, 4,000 cages fill a building half the length of a football field, and red-feathered hens stick their necks out to pluck seed that passes along a network of conveyer belts.

The sound of beaks hitting belts is like a chorus of drums, a din echoed in three other similar buildings on the farm during feeding time. In all, some 80,000 hens are housed here, indoors, away from the chance encounters with wild, migratory birds that could make the farm's population susceptible to a deadly strain of the bird influenza virus currently stoking fear across Europe.

Avian flu, carried by wild birds, has now turned up on poultry farms in Greece, eastern Romania and rural Turkey. Since health officials confirmed those cases, the response around Europe has focused on minimizing the chance of a flu outbreak that could rival or exceed the flu pandemic of 1918, which killed as many as 50 million people. For that to happen, the flu strain would have to mutate from the strain confirmed in Turkey and Romania, known as H5N1 — which can infect people who spend extended amounts of time in close contact with birds — to a form that can be transmitted from human to human.

For the moment, it's unclear how much of the debate is science and how much of it is the scare factor, but one thing is clear: Czechs are worried.

They are looking for vaccines in record numbers. The mere mention of avian flu to poultry farmers, who will be the focus of heightened government monitoring, creates uneasiness. (Workers at the farm visited by The Prague Post declined to comment, as did the company that owns it.)

"We have noticed that fears of the disease are increasing among the population," says Josef Duben, spokesman for the State Veterinary Administration of the Czech Republic.

At issue is the risk of contagion, a source of major concern with the H5N1 strain of avian bird flu as it can be transmitted from domestic poultry to migratory birds, which allows it to spread over great distances quickly.

This virus is responsible for the deaths of 60 people and millions of poultry in Asia, where it originated in 2003. It's believed to threaten only people who come into direct, prolonged contact with infected birds. But scientists warn that unlike other bird flu viruses, H5N1 could mutate into a contagious form easily passed from human to human, like the common cold — and could result in a pandemic.

To add to fears, scientists say the H5N1 strain is already showing similarities to past flu viruses that have devastated populations. The Spanish flu of 1918, for example, originated from bird-to-human transmission, according to research published this month in the United States.

Mobilizing

As Turkey, Romania and Greece continue with tests and containment, the rest of Europe is scrambling for preventive measures.

Czech health authorities are stepping up inspections of poultry farms, monitoring wild bird populations, and say they will increase supplies of anti-flu drugs.

The State Veterinary Administration says that from now until next March it plans to carry out "detailed monitoring" of many of the country's 700 commercial poultry farms. It is also drafting plans to monitor individual breeders, who number in the thousands.

The country breeds some 40 million farm birds in total.

"In case the bird flu gets to the Czech Republic, it would pose a bigger problem to those keeping their chickens in a backyard," says Karel Bublák, a south Moravian poultry farmer.

The agency says it is increasingly on the lookout for sick or dead birds in Nové Mlýny, an area of artificial lakes in south Moravia where many migratory flocks stop.

Michael Vít, the Czech Republic's chief public health officer, says his office plans to boost anti-flu drug supplies in order to cover 20 percent of the country's population, enough to protect the elderly, the young, the feeble and the sick, he says.

Across Europe, governments are bracing for the worst-case scenario of a catastrophic pandemic.

Public health officials in France are stockpiling 200 million face masks to ward off germs. In Germany, scientists plan to begin spraying migrating birds on an island in the Baltic Sea with a vaccine that would kill the flu virus before it is transmitted.

Swiss pharmaceutical company Roche says it is donating thousands of doses of its flu drug Tamiflu to Romania, Turkey and the World Health Organization.

In a series of emergency meetings recently, EU health officials agreed on tough new regulations aimed at containing an outbreak of H5N1 bird flu, including a ban on poultry imports from Greece, Romania and Turkey. They also called on countries to keep poultry indoors on farms.

No cause for panic

But health officials in the Czech Republic are calling for calm and say the media is unnecessarily hyping a disease that right now is only a potential threat to domestic poultry.

"The situation right now is not critical or crucial at all," says Duben. "Hopefully it will stay like that. The bird flu so far has not appeared here."

Prime Minister Jiří Paroubek said Oct. 15 that there was little need to force farmers to move their poultry populations indoors. "The panic is not grounded," he told reporters.

Officials are blaming a run on vaccines that have left the shelves at clinics and doctors offices bare on what they call "negative reports" in the media.

"The supplies of flu vaccinations in the Czech Republic are not nearly sold out, they are completely sold out," says Josef Kredba, the business director at one vaccine supplier, Alliance UniChem.

Czechs have long lagged behind their EU counterparts in getting regular flu shots; the EU average is 22 percent, and traditionally only about 7 percent of Czechs get annual shots.

That has changed in recent weeks.

More vaccines will hit shelves in the next two weeks, health officials say. But Kredba thinks that might not be enough. "We see that even persons who never in their life went for an anti-flu shot are now interested in getting one."

Although standard flu shots and drugs might have little effect on a pandemic caused by a new bird flu mutation, experts say they do increase immune response in general.

Meanwhile, the government has come under some criticism for lacking adequate supplies of anti-flu drug Tamiflu.

Public health officer Vít agrees. He says that right now the country's 600,000 doses of Tamiflu would only cover a third of those most at risk. But another 125,000 doses arrived from the EU this week, and Vít says he is asking for even more.

Better prepared?

Amid all the panic and planning are the voices of a group of scientists and experts that say it is irresponsible to draw direct comparisons between H5N1 and past flu pandemics like the one in 1918. They also say it is not inevitable that a flu pandemic would exact the same death toll today because of better research on how flu spreads and more coordinated response measures.

People are also generally more fit and healthy, they say. Many more receive annual flu shots than did 75 years ago and vaccines are generally effective.

And, they say, Europe has already confronted a less serious strain of bird flu, in the Netherlands in 2003, which devastated that country's poultry farms and caused countries to form broad 'pandemic plans.'

"The threat to public health will probably be manageable, largely due to the lessons we learned ... in the Netherlands," says Dr. Albert Osterhaus, head of a group of scientists studying flu in Europe.