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Targeting Avian Influenza

Researchers and extension educators in the college take aim at the latest outbreak.

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It’s coming. A plague that has already claimed nearly 50 million birds in the United States since last winter is expected to strike Pennsylvania this fall or next spring. An army of researchers and extension educators in the College of Agricultural Sciences is on high alert, ready to deploy every tool in its arsenal to fight the infection.

"If we have a really severe avian flu outbreak, it’s estimated that there could be losses of more than 50,000 jobs and billions of dollars."

The disease, caused by three related strains of highly pathogenic H5NX avian influenza, otherwise known as bird flu, affects chickens, turkeys, guinea fowl, and perhaps even in some instances hawks, eagles, and other raptors. It first entered the United States in December 2014 from waterfowl migrating south from Canada. So far, the flu has been detected in wild birds in 21 western and midwestern states. Fifteen states have experienced deaths among poultry, with egg-laying chickens and turkeys in Iowa and Minnesota among the hardest hit.  “It seems inevitable that the flu will get introduced to Pennsylvania,” says Rick Roush, dean of the college. “We want to make sure it doesn’t cause huge losses in the poultry industry.”

According to Roush, Pennsylvania’s $1.4 billion egg industry is the fourth largest in the country. “If we have a really severe avian flu outbreak, it’s estimated that there could be losses of more than 50,000 jobs and billions of dollars,” he says.

To prepare for an outbreak, the College of Agricultural Sciences is working with several agencies, including USDA and the Pennsylvania Department of Agriculture. All entities are pitching in funds and staff members to help tackle the problem. The Pennsylvania state legislature has supported allocating $2 million to the college to strengthen its capacity with new faculty members and extension staff members—which is pending a budget agreement with the governor—and the college and University administration are allocating up to $1.6 million to ensure that their facilities, supplies, and current staff members are ready, including tripling the number of birds per day that can be tested for infection.

“The United States is experiencing the worst and largest animal disease event in its history with the highly pathogenic avian influenza outbreaks in poultry,” said John Clifford, chief veterinary officer at USDA, recently at the USA Poultry and Egg Export Council meeting. “We have a very short window of time to prepare and be ready by the fall before the wild bird migration starts.”

Gregory Martin, Penn State Extension educator, serves alongside representatives from USDA and the Pennsylvania Department of Agriculture on the state’s avian influenza task force. “We have a plan of attack in place for when highly pathogenic avian influenza strikes the state,” he says. “It involves a series of events that will take place to help fight the spread of the disease from the location where it is first found.”

The Target

What is the highly pathogenic avian influenza H5NX that is now in North America? Well, what it’s not is something that will harm humans. “The Centers for Disease Control and Prevention have determined that this is a low risk to humans,” says Martin. “And it’s also not in the food supply, so any poultry, meat, and eggs will be fine. With all the responders dealing with this in the Midwest, we haven’t heard of anybody getting sick.” In the past, some strains of highly pathogenic avian influenza, such as H5N1, have affected humans, but the viruses that are moving through the United States today are different.

The viruses are transmitted to gallinaceous birds—think chickens, turkeys, guinea hens, pheasants, and grouse—from wild waterfowl—primarily ducks and geese. Waterfowl are not clinically affected by the viruses; they show no symptoms, yet they freely pass them among themselves through their feces. Unfortunately, when the viruses pass to gallinaceous birds, the effect is almost always lethal.

The problem occurs when waterfowl migrate. “There are four major flyways across North America,” says Roush. “So far, the three western ones have been associated with avian flu outbreaks. The assumption is that birds are all mixing up in Canada. In other words, they take various pathways to get to the same resort, they mix around there for a while, then they go home. So we’re expecting some avian flu to pass through our state when the birds fly south this fall.”

Along their route, waterfowl stop to rest and feed in lakes, ponds, and wetlands. And that’s when they can spread the viruses to gallinaceous birds. This could occur when a farmer steps on duck poop and then tracks it into his or her poultry house. The viruses can also come in on farm equipment. “The viruses are so small they can even enter a poultry house on dust,” says Martin.

Operation Poultry Protection

large-4i3a1575.jpgPatty Dunn and Eva Wallner-Pendleton are veterans in the never-ending fight to keep Pennsylvania poultry flocks free of serious diseases. As avian pathologists in the college, their task requires constant vigilance under any circumstances. But Dunn, Wallner-Pendleton, and their colleagues in the Penn State Animal Diagnostic Laboratory are now in a heightened state of alert. Photo credit: Michael Houtz

It all starts with a sick or dead bird—that’s when the plan goes into effect. A farmer or poultry-house operator will send the bird to the Animal Diagnostic Lab at Penn State. There, veterinarians Patricia Dunn and Eva Wallner-Pendleton will examine the bird. “The Penn State lab along with two sister labs within the state are the front line for the diagnosis of avian influenza in Pennsylvania,” says Dunn.

The team will use a polymerase chain reaction test to detect genetic material in the viruses contained within the bird to determine if it is a highly pathogenic avian influenza virus. “It’s a test that you can get an answer for the same day, which is extremely important,” says Dunn.

The next step in the plan, once the virus or viruses have been confirmed, is to impose a quarantine around the infected birds. The quarantined birds will then be depopulated, or put down. “It may seem extreme, but these birds are going to die from the bird flu anyway,” says Dunn. Typically, when a poultry house gets infected, some 90 to 95 percent of the flock dies within several days.

Meanwhile, Dunn, Wallner-Pendleton, and Huaguang Lu, clinical professor of veterinary and biomedical science, will be busy testing the samples from the birds from neighboring farms within a several-kilometer radius around the affected farm to ensure that it hasn’t spread. “It can really snowball to a lot of samples depending on how many birds are in the monitored zone around the infected premise,” says Dunn. The college is now prepared to test several hundred birds per day.

The last step in the plan is disposal. “Currently, in the Midwest, they’re composting the birds; they’re putting them into a mulch or vegetation strata that helps digest the birds down to their nutrients,” says Martin. “The heating process is high enough to where it kills all the pathogens, so it’s safe to use out on the field as a fertilizer. The goal is to save as much as possible.”

Composting dead chickens is an interesting thought when you imagine a chicken house with 400,000 laying hens, a typical size for the large farms in Pennsylvania, and a 90 percent death rate. “That’s a lot of dead chickens,” says Martin. Researchers in the college, including Martin and Paul Patterson, professor of poultry science, are investigating alternative ways to euthanize the birds as well as improved methods for recovering the meat for other purposes.

Strategic Advantage

Recovering some monetary value from the dead birds is important for the people who own them. So far, Iowa and Minnesota have suffered tremendous losses, especially among their egg-laying chickens and turkeys. “We already have seen the prices of eggs go up,” says Martin. “And we’re probably going to see it this fall with fresh turkey prices. So our Thanksgiving and Christmas turkeys will be a little bit more expensive than last year.”

But Pennsylvania’s poultry likely won’t be as hard hit. “Pennsylvania has the longest-running monitoring program for avian influenza of any state, mainly because we had an influenza outbreak that was centered here in the 1980s,” says Dunn. “There were about 17 million birds affected. Up until now, that was the most well-known and biggest highly pathogenic avian influenza outbreak in the country. As a result of that, a lot of monitoring was begun in our state.” According to Dunn, farmers are so used to participating in that monitoring program that they will be well prepared when the next outbreak occurs.

Farmers also have a lot of knowledge about the current outbreak. “We’ve done education here at the Animal Diagnostic Lab for producers, company managers, flock owners, just about any segment you could think of, to try to get the word out about the potential introduction of this strain,” says Dunn. “We tell them what to look for, who to call, what to do.”

The team even has created posters and banners to display at Pennsylvania’s county fairs. “The Secretary of Agriculture has made the decision not to allow poultry shows at the county fairs this year to make sure they are not places where avian influenza could enter or spread,” says Dunn.

So far, keeping a flock healthy does not include giving birds flu vaccines. “We do have some vaccines out there, but USDA has determined at this time that they are not very effective, so there’s still research being done on finding a vaccine that will work for this particular strain of avian influenza,” says Martin.

In the meantime, the college is in a high state of readiness and will help to lead the resistance against the virus when it arrives in Pennsylvania.

“We have several people in the college who are experts on avian flu, and we are currently trying to make sure that everybody else in the college who can contribute in one way or another is lined up and ready to go when we see flu in the state,” says Roush. “We’re a land-grant university with an extensive network of educators across the state. We use this network to make sure we make really good contact with everybody out there who might find infected birds, so they know how they can get in touch with the experts.”

Armed with knowledge and expertise, and the ability to communicate rapidly with large numbers of people, the College of Agricultural Sciences and its partners are prepared to take on the viruses. Says Roush, “We’re as ready as we’ll ever be.”

—Sara LaJeunesse

Flyways: Avenues for the Spread of Disease

Avian influenza likely always will exist because migrating waterfowl and shorebirds the world over provide a reservoir for the disease.

The flu is most often spread by dabbling ducks that breed in the prairie pothole region of southern Canada and the U.S. upper Midwest. Those ducks are expected to carry the new, highly pathogenic H5NX farther east this fall in their southern migration. There are four waterfowl migration routes in the United States, and all but the Eastern Flyway have seen outbreaks of the highly pathogenic bird flu among wild and domestic birds in the last two years.

The Eastern Flyway takes migrating waterfowl over New York, Pennsylvania, Maryland, Virginia, the Carolinas, and Georgia to Florida’s Gulf coast and beyond. When they stop to rest and feed along the way, infected birds may shed the pathogens in their droppings and secretions.

North America Migration Flyways

H5NX by the Numbers
StateInfected PoultryFlyway
Arkansas 40,020 C
California 247,300 P
Idaho 30 P
Indiana Unreported M
Iowa 31,723,300 C, M
Kansas 10 M
Minnesota 8,987,050 C, M
Missouri 53,100 M
Montana 40 M
Nebraska 3,794,100 M
North Dakota 111,500 C, M
Oregon 200 M
South Dakota 1,168,200 C, M
Washington 6,710 P, M
Wisconsin 1,950,733 M
Grand Total 48,082,293

Poultry farms in 15 western and midwestern states have been affected by H5NX since December 2014.

“H5NX usually doesn’t make waterfowl sick, and it doesn’t affect people or other mammals,” said Margaret Brittingham, professor of wildlife resources. “But it does sicken and kill other birds, namely domesticated chickens and turkeys.”

Two years ago, explained Brittingham—a wildlife specialist with Penn State Extension— migrating waterfowl carried a novel strain of avian flu out of Asia to breeding grounds in the Bering Sea region of northern Russia, and from there ducks are believed to have conveyed it to Alaska, where south-migrating birds brought it to the Pacific Northwest.

The disease has spread east from there. Historically, the Eastern Flyway has not been spared by avian flu outbreaks, and there is no reason to expect that the disease won’t show up here this time.

Brittingham suggested that it is not only dabbling ducks that pose a risk for spreading avian flu to the east. “Even tundra swans that breed in the Arctic migrate through Wisconsin, which already has this disease, and then they turn eastward and go straight across Pennsylvania. We have about 90 percent of the population of tundra swans migrating through Pennsylvania on their way to the Chesapeake Bay, which is a big wintering area.”

Although avian flu poses a risk to wild turkeys, raptors, and upland birds, such as grouse and pheasants, ironically their populations are probably protected by their high susceptibility to the disease, according to Justin Brown, wildlife veterinarian for the Pennsylvania Game Commission and adjunct clinical associate professor at Penn State, headquartered at the University’s Animal Diagnostic Laboratory.

Because wild turkeys, birds of prey, and upland birds seem to be so vulnerable to avian flu—it kills them quickly—they are not effective carriers, he explained, and they are spread out, making a large-scale mortality event unlikely.

“If they are exposed, there will be some mortality, but I’m not expecting that we’ll see severe, widespread infection or population-scale impacts.”

Brown is concerned about the potential effect of avian flu on the Game Commission’s four pheasant-producing facilities—which turn out upward of 200,000 ringnecks annually—as well as private gamebird propagation farms and backyard poultry enterprises. Maintaining any kind of biosecurity is extremely challenging when birds, especially gallinaceous birds, are being raised outdoors.

The Game Commission has educated its personnel about influenza ecology and impacts on captive birds, and is stressing biosecurity precautions.

“But there’s only so much we can do with our captive farms because they’re open facilities,” Brown said. “In the unlikely event a dabbling duck flies over and defecates into a pen or enclosure, we may have a problem.”

—Jeff Mulhollem

For more information

Penn State Extension Avian Influenza Resources