ISLE OF RIEMS, Germany—No one is worried about the traditional Christmas goose in Europe this year, but health officials are scrambling to prepare for what some believe is the certain arrival this spring of a deadly strain of bird flu in migrating wild birds.
Europe first saw the deadly H5N1 bird flu strain this autumn, with cases discovered among dead wildfowl or small flocks of domestic birds in Croatia, Romania, Russia, Turkey and Ukraine. Experts are convinced that those cases are only a warning of what's to come.
Thomas Mettenleiter, the president of Germany's leading animal disease center, the Friedrich Loeffler Institute, said millions of wild birds left Europe flu-free this autumn to winter in Africa. There they'll mix with migrating birds from Southeast Asia, where the lethal strain of the virus is far more common.
Of the ways the disease could arrive in Europe—through infected meat, live poultry or pets—migration is the most troubling. Government has no control over how many birds will arrive and where they'll land.
"March and April are going to be high alert times here," said Mettenleiter. "We've got a lot of work to do before then."
The European Union issued a directive Tuesday urging nations to deal aggressively with low-threat strains of the virus. Investigations should be launched whenever a suspicion of infection arises, it said.
Philip Tod, a spokesman for the EU Health and Consumer Protection Commission, said bird breeders should enclose their pens to limit contact with wild fowl and that signs of the flu should trigger mass culling in infected areas.
Reinhard Burger, the vice president of Germany's infectious disease center, the Robert Koch Institute, said that in the past Europeans could cull infected birds. "But we've never seen numbers approaching what we're expecting to see—hundreds of millions of infected birds will likely be returning to Europe with the spring weather.
"We're walking on a narrow ledge in high mountains this winter. We're very worried," he said.
The bird flu virus started killing birds in Southeast Asia in 2003. Farms with 10,000 birds were wiped out in 48 hours. Millions of birds died or were culled. Since then, the lethal virus has jumped to humans in 141 cases, resulting in 73 deaths, according to the World Health Organization on Friday.
As Mettenleiter explains: "We don't know if H5 strains can sustain a human pandemic, but if they can, the results are potentially catastrophic."
Humans have no immunity to new strains, and some experts estimate that a pandemic could kill more than 100 million people worldwide.
Currently, the flu passes from infected birds into humans through extended contact. But the virus is constantly mutating. A pandemic could start if it mutates into a form that easily transmits from human to human.
Most troubling is the possibility that humans who already have a human strain of flu will be infected. Flu has the ability to "gene-swap," or essentially trade genetic coding. So the H5N1 strain could turn a nonlethal strain that spreads easily among humans into a lethal one.
A vaccine would greatly decrease the number of deaths from bird flu, but a human vaccine isn't possible until the precise mutation that's passing among humans is known, and that hasn't developed yet.
There is a vaccine for birds. But it only would make them more resistant to flu, not stop them from spreading the disease, Mettenleiter said. "If the strain can jump to humans, that's the last thing we want. For now, at least, chickens are our sentinels."
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(c) 2005, Knight Ridder/Tribune Information Services.
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