By Barth Anderson

(Editor's note: Barth submitted this piece one day before the NY Times came out with the same information!)

We've all heard about it by now. A deadly avian flu virus known ominously as H5N1 is killing wild birds in droves, leading scientists to conclude that migratory waterfowl must be spreading the virus globally. Fearing the virus's effects on domestic poultry, the World Health Organization and other public health groups recommend housing chickens in huge "biosecurity barns," in order to limit domestic contact with wild birds.

Logical, perhaps, but hard data doesn't support the "migratory-bird-as-culprit" theory.

In fact, mounting evidence shows the opposite, that the H5N1 infection stream may be flowing the other way - from large, commercial poultry operations into the wild.

Avian Flu 101

First, let's talk about avian flu - not as it pertains to humans, but as it pertains to its namesake: birds.

There are three main types of avian flu, classified H9, H7, and H5. Each is lethal to birds, and like all influenzas, each can mutate rapidly making them very difficult to prevent or stop.

While most Americans have only paid attention to avian flu very recently, in the form of headline-grabbing H5N1, U.S. chicken farmers know avian flu in all its horrid variety. That's because, USDA officials estimate, between eighteen and twenty outbreaks of avian flu occur each year in U.S. poultry flocks. For example, due to outbreaks in 2003 and 2004, 400,000 birds were infected by avian flu or "depopulated" to prevent further infection in the U.S. And a huge outbreak of the H7 avian flu virus in 2004 didn't stop until a million and a half birds had been infected or depopulated in Canada.

So avian flu is nothing new. As a matter of fact, it has a roaring, super highway already established in the U.S., driving straight through the factory-style, commercial chicken industry.

The West African Hop

Perhaps the only good thing about a killer virus like H5N1 is that, because of its deadliness, it invites intense, scientific scrutiny, allowing us to learn a great deal about how it spreads.

But strongly held, preconceived ideas about a virus can cause blind spots, even in the most serious scientists. Take for example the case of Nigeria's February 2006 outbreak of H5N1, when the feared virus emerged in four giant poultry farms that straddle two states in the West African nation. Reading the time line of events, the virus seemed to spread westward into Africa after swirling throughout Indonesia, China, and Vietnam for months. Then it emerged in Turkey and Iraq in January, followed by Nigeria in February.

But as William B. Karesh, a veterinarian with the Wildlife Conservation Society in New York, asked in The Washington Post, "How did [H5N1] skip the whole Nile Delta [which is abundant with waterfowl species] and get to Nigeria? That kind of bothers me. Common sense would dictate that it should be all over Egypt by now."

Even more curious, according to The Washington Post, is that the Nigerian farms where H5N1 emerged "are not near wetlands where migratory birds spend the winter."

So if not by migratory birds, how did H5N1 hop from infected countries east of Africa to West Africa, without first infecting the rest of the continent?

"I would never rule out wild birds," Karesh said. "But I think we have to look at the most probable routes, and the most probable route would be poultry."

The Fox is already in the Hen House

A recent study from the international agricultural policy group, GRAIN, draws an identical conclusion to Karesh's.

Collating studies conducted by WHO, the UN's Food and Agriculture Organization, the World Organization for Animal Health and experts on migratory birds, the GRAIN report, Fowl Play: The Poultry Industry's Central Role in the Bird Flu Crisis, questions the conventional wisdom that migratory birds are mainly responsible for spreading avian flu. From the report:

"The main weakness in the migratory bird theory is that the geographical spread of the disease does not match with migratory routes and seasons. 'No species migrates from Qinghai, China [where the Chinese H5N1 outbreaks have centered] west to Eastern Europe,' says BirdLife's Dr. Richard Thomas. 'When plotted, the pattern of outbreaks follows major road and rail routes, not [migratory bird] flyways. And the absence of outbreaks in Africa, South Asia, Southeast Asia and Australia this autumn is hard to explain, if wild birds are the primary carriers.'"

But the most damning evidence in the GRAIN report comes after examining a serious lack of evidence. The report cites Proceedings of the National Academy of Sciences, in which scientists tested wild birds in one of China's persistent H5N1 hot zones. If migratory birds were to blame for the intense infection, one would expect to find ample evidence of wild bird infections. But of 13,000 tested, only six infected birds were found.

The study's conclusion about H5N1's spread - migratory birds were not responsible for continually causing the virus to emerge in this hot zone. "Transmission within poultry is the major mechanism for sustaining H5N1 virus... in this region," the study determined.

Outbreaks in the U.S. seem to follow commercial poultry traffic as well. A 2004 Northeast Texas outbreak was tied to a Houston live poultry market. A Delaware outbreak of H7 in 2004 started with a backyard farm - but the virus was believed to have been carried to the farm after infected chickens were purchased from a live poultry market in New Jersey. Says Ron DeHaven of USDA's National Veterinary Services Laboratory, this was "the same virus that we have been finding in the live bird market system for a number of years."

The poultry industry needn't break out the birding glasses and binoculars to spot who's responsible for hatching widespread avian flu. A mirror will do.

Hunt and Peck

Meanwhile, Organic Valley, one of America's largest producers of organic eggs, seems to provide living proof that migratory birds aren't to blame for avian flu outbreaks.

"[Our birds] are not more at risk just because they have outdoor access," says David Bruce, a farmer coordinator for Organic Valley, referring to the organic practice of free-ranging poultry. "We've had flocks outdoors for 12 years, right in the Mississippi flyway," he says of Organic Valley's primarily Wisconsin-based flock. "We've never had an outbreak."

How could that possibly be? The Mississippi flyway is one of the major pathways for migratory birds in North America, after all.

If you hold to the theory that migratory birds are to blame, you could say they've gotten very lucky, but regardless of how avian flu bugs spread, Bruce credits organic poultry practices for strengthening Organic Valley flocks.

"Caged birds are generally more stressed, which impairs immunity, and [the commercial poultry] use of preventative antibiotics impairs immunity overall," according to Bruce. Organic livestock practices forbid the use of antibiotics, after all (but not vaccines).

Free-range organic chickens are healthier, Bruce claims, because they forage outdoors, not in spite of it. Healthier birds fight off infection more easily, and a constant, low-level exposure to the elements bolsters their immunity.

In other words, organic birds are actually strengthened through contact with birds in the wild, not weakened by it.

The best offense is a strong defense

Organic practices are founded on the good health of animals, their feed and the soil it's grown in. That's not just hippie-dippy grooviness: Twelve years of poultry farming in a migration flyway without an avian flu outbreak is hard to argue with.

So focusing solely on migratory birds seems misguided when the domestic poultry industry is especially vulnerable to outbreaks of avian flu. An audit of industry practices seems urgently necessary. In the Canadian avian flu outbreak of 2004, for example, 42 commercial operations suffered flu infections while a mere 11 backyard flocks were hit.

This may be because "biosecure" barns prevent contact between domestic and wild birds, but they don't improve the health of the animals within. Indeed, the space within these barns is hopelessly overcrowded, and the air is choked with ammonia from chicken feces (the primary source of avian flu infection). Commercial chickens often have their beaks and talons clipped to prevent them from damaging one another, and they fatten so quickly that they suffer health problems as a result. In short, these barns are stuffed with immune-deficient birds.

And all it takes is importing one sick bird from outside to wipe out a 9,000-bird flock. Forget about the barns, when a healthy flock within could stop a virus cold.