Guarding the Henhouse

By Christine Gorman

Joe Chisholm, 62, has taken every precaution that he and the poultry industry can think of to protect his chicken farm in Pocomoke City, Md., from avian flu. After he gets up every morning at 5:30, he reads the paper, drinks a cup of coffee and heads out the door for the first of four inspections of his chicken houses about 30 yards away, keeping an eye open for sickly-looking birds. He also sprays his shoes with disinfectant when he goes to an area where other chicken farmers may be, washes down all trucks before they roll onto the farm and stays informed through e-mail messages from poultry veterinarians. "I take a lot of pride in keeping everything neat and clean," Chisholm says. "I just don't want to take a chance."

Lately, Chisholm has been paying a lot more attention to the news from overseas. Since the highly pathogenic H5N1 virus was first reported in Turkey last fall, avian flu has spread swiftly, landing in France, Germany, Iraq, India, Nigeria, Niger, Poland and many other countries. So far this year, three dozen human cases have been confirmed in China, Turkey, Iraq and Indonesia.

Even if H5N1 remains a problem mostly among birds, however, the virus could have a devastating economic impact on Chisholm and many other farmers and the businesses that depend on them. Poultry sales have already plummeted across Asia and Europe. Overall, U.S. exports of broiler chickens were down 30% in December 2005 compared with the prior year. The greatest danger, however, may be in Africa, where the income, not to mention the food, that chickens provide can mean the difference between life and death.

Most experts think it's just a matter of time before avian flu finds its way to the Americas. Dr. David Nabarro, U.N. coordinator for avian and human influenza, told reporters last week he believed that H5N1 would jump to the New World "within the next six to 12 months." The U.S. government appears to agree. "Be prepared for H5N1 being identified in the U.S.," Agriculture Secretary Mike Johanns said earlier this month. "It would be almost biblical to think we would be protected."

Warnings like that are hard to ignore, and major U.S. poultry growers are paying close attention. In January the industry decided to step up its existing biosecurity measures by testing some birds in every flock for the most dangerous types of avian flu before they leave the chicken house to be slaughtered. All the birds in an infected flock would be put down immediately, and the surrounding area quarantined. "Our strategy is to keep sick birds on the farm," says Richard Lobb of the National Chicken Council. "Once the virus escapes into the environment, it's very hard to control."

U.S. poultry farmers have already learned that hard lesson, having faced outbreaks of other avian flus as recently as 2002 and 2004. H5N1 is only one of more than 100 subtypes of the influenza A virus. The majority of the subtypes are found in birds. A few, such as H3N2 and H1N1, have adapted to infect humans. The 2002 avian outbreak, which struck in Virginia, was the H7N2 subtype, and it illustrated the importance of early detection. "The outbreak was not contained in time and spread to 200 farms up and down the Shenandoah Valley," says Lobb.

By contrast, the 2004 outbreak--also a low-pathogenic strain of H7N2, which struck on the Delmarva Peninsula--was discovered right away, and both the states and the industry jumped into gear, euthanizing flocks, setting up quarantines and compensating farmers for their downed birds. "You had guys from Mountaire Farms and Perdue Farms working side by side," says Chisholm. "That's unusual because this is a competitive business." The quick response limited damage to just three farms.

Of course, before you can contain a sick farm, you have to know where it is. That's where the latest in geolocating devices comes in. Poultry veterinarians have been mapping U.S. commercial farms with handheld GPS tools (similar to the electronic navigational readers many people have in their cars) and entering the locations into large computerized databases for use in an emergency. They have even used the popular free software program Google Earth to fine-tune the positions of some chicken houses. That way, if the industry's testing program ever turns up evidence of H5N1 infection, officials will know exactly which flocks to sacrifice and where to draw the quarantine lines.

Vaccinating against avian flu could potentially avoid those problems since inoculated chickens don't get sick in the first place. But while some European farmers have begun doing just that, the idea seems impractical in the U.S. "If you have to put down a flock, you lose maybe 50,000 birds," notes Lobb. "That is much easier than trying to vaccinate 10 billion birds, which is about what we will produce this year."

Another way to protect flocks is to block the virus from ever alighting here. Whether that can be done depends on how the pathogen arrives. Everybody's favorite suspects these days seem to be migrating birds. If you check a map of migration flyways, it's pretty easy to trace a potential route for an infected bird from Europe to Canada and then on down through the U.S. But would that really happen?

"Even though the big flyway maps look like they overlap, the birds themselves don't," says Dr. William Karesh, director of the field veterinary program of the Wildlife Conservation Society. Gene studies of avian-flu strains from the past 30 years seem to confirm that, with no evident commingling among the viruses. "The birds of the New World and the birds of the Old World don't share their viruses," Karesh says. "That doesn't mean it's impossible. That would be irresponsible. But it doesn't happen normally."

In any event, most commercial chicken houses (where the birds spend their entire lives indoors) have no contact with migratory birds. Even free-range chickens are generally not clucking all over hither and yon and so can easily be brought indoors if need be. That still leaves the exotic-pet market (legal and illegal) and the illegal importation of poultry products. Connecticut recently confiscated a load of imported chicken feed labeled JELLYFISH.

Whatever measures the government imposes, commercial poultry farmers are about as prepared as they can be. "You can't stop bringing feed to the farm," says Doug Green, 53, who has four chicken houses in Princess Ann, Md. "You can't stop bringing fuel. There's a certain amount of interaction that has to go on." Controlling that amount is where the difference between sick flocks and healthy ones will lie

With reporting by Reported by Melissa August / Washington, David Bjerkie / New York