August 10, 2005
Wednesday

ANCHORAGE, Alaska - Deadly avian influenza has been found among migrating geese in Asia.

Once associated only with domesticated fowl, a virus thought to have the potential to trigger a pandemic among humans may now be leapfrogging across the globe in wild flocks.

The first major outbreak reported in wild birds killed thousands of waterfowl at Qinghai Lake in western China, according to reports published last month in Science and Nature. Russian health officials confirmed last week that the disease appeared in poultry in western Siberia near Novosibirsk, possibly carried from Southeast Asia by other migrating birds.

Scientists fear that the H5N1 virus will now spread along the world's flyways to Europe, India and other population centers.

Alaska is the first stop on the avian route from Asia to North America.

Are we next?

To answer that question, dozens of biologists had already launched an ambitious project this summer testing thousands of wild geese, ducks and other migrating birds across the state for the presence of avian influenza.

Think of it as a viral missile defense system, using sterile swabs instead of radar to catch the flu bugs carried by birds.

Most alarming on the list of possible discoveries is the deadly H5N1, a strain of avian flu that has infected at least 109 people in four countries, killing half of them, since it erupted among Southeast Asian poultry flocks in 2003, according to the World Health Organization.

"Alaska is the one place in the world where migratory birds (from both hemispheres) come together," said Jonathan Runstadler, a veterinarian and assistant professor of molecular biology at the University of Alaska Fairbanks Institute of Arctic Biology. "We potentially could have overlap of viral strains from the Americas and Asia. . . . It could be sort of a keystone for the virus's ecology."

Both domesticated and wild birds carry all kinds of flu, most posing no threat to people. But scientists have linked several of the most deadly human epidemics to strains originating in poultry or livestock.

As a result, tracking the evolution of the H5N1 bird flu has become one of the most critical tasks facing world health officials over the past two years.

In its present form, the H5N1 virus doesn't easily infect people - almost all victims caught the virus directly from infected domestic fowl.

But if the virus were to mutate into a form that could pass easily from person to person, it could trigger a pandemic on the scale of the 1918 flu epidemic, which killed 50 million people worldwide and thousands in Alaska.

Researchers who have been scrambling for a human vaccine against the virus reported promising results last week from early tests, and federal officials said Sunday they will stockpile millions of doses. But so far, the vaccine has been tested on only 450 people and there are questions about whether manufacturers can fill the demand if the disease starts to move rapidly through large human populations.

In a sense, Runstadler and other biologists are monitoring Alaska's avian tourists, screening the state's migrating and resident birds.

The project is called the University of Alaska Program on the Biology and Epidemiology of Avian Influenza in Alaska, and is funded by one of the university's biomedical research programs.

Pinning down basics - where the different strains of flu virus live, how they spread, how they change, how they interact with the birds - is a necessary first step.

"One of the reasons we don't understand the ecology of the virus is that we don't know what happens to the virus in its natural ecosystem," Runstadler said in a written statement explaining the program. "We need to understand how the biology of birds impacts disease transmission."

So far, the project has marshaled 30 to 40 field biologists. They and their associates will swab the intestinal openings of 5,000 birds temporarily captured for banding or other studies. By the end of the season, they hope to sample 25 species from all regions of the state.

The intestinal samples will be checked in a lab for avian influenza virus. Positive hits will get their genetic secrets cracked and then catalogued in a public database of DNA maintained by the National Institutes of Health.

Finally, a team of Alaska scientists will create a geographic database showing types of flu, species of birds, where and when they surfaced.

The H5N1 flu reportedly killing wild birds in western China and Russia is not identical to the H5N1 flu that killed people in Southeast Asia, Runstadler said.

But any H5N1 in migratory birds could evolve into something far more threatening to humans as the virus mixes and interacts with other strains in other birds, livestock and even people.

With birds from across the globe mingling each summer, Alaska could become an especially potent zone for viral mutation, Runstadler said.

"Can geese or ducks or other migratory birds bring a potentially harmful agent to Alaska and then to other areas as well? Yes, that's a possibility."

No evidence exists that Alaskans have ever caught flu directly from wild birds in the state, he said. And no one has found the deadly H5N1 strain in Alaska's migrating birds.

But scientists need more data.

"Right now if this H5N1 strain in Asia and Russia erupted into a pandemic strain," which could easily spread person to person, "we really don't have any basis for understanding what to do about that."

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