An Enigmatic Virus Takes its Toll

From Minnesota Alumni Magazine Fall 2015

The U is at the forefront of understanding the deadliest, costliest avian flu epidemic ever—and preventing another.

By Greg Breining

Earlier this year a killer invaded more than 108 farms in Minnesota. A new form of avian flu caused the deaths of more than 9 million turkeys and chickens in 23 counties west and southwest of the Twin Cities. Many birds died outright from the virus, and farmers were forced to euthanize the rest of their flocks to prevent the virus’s spread. The effect on the poultry industry in Minnesota and other Midwestern states was devastating.

Though avian flu is common, such a lethal strain is unprecedented. “We’ve never seen this kind of widespread farm-to-farm transmission,” says renowned epidemiologist Michael Osterholm (M.S. ’78, M.P.H. ’80, Ph.D. ’80), director of the University of Minnesota’s Center for Infectious Disease Research and Policy. “This is such an aberration.”

The U played a key role in the state’s effort to control the outbreak and assist farmers, and, in the aftermath of the virus’s rampage, is at the forefront of figuring out how to prevent a repeat. Brigid Tuck, senior economic impact analyst for the University Extension Service, put the cost of lost poultry and egg production at $647.2 million, including $171.7 million in lost wages and benefits. In all, some 2,500 jobs have been affected. Damage has rippled into industries including processing and trucking. In May, for example, Willmar-based Jennie-O Turkey Store laid off 233 employees. “Just the other day I saw a truck outfitted to haul poultry, and it was empty,” Tuck said. “It made me realize how significant that is for that particular industry.”

Classified as H5N2, a subtype of the influenza virus, this particular bird flu probably originated in Asia and hitched a ride to North America aboard wild migratory ducks and geese that began to appear in the Pacific Northwest last December. University of Minnesota faculty who had been monitoring infected wild birds warned the state Board of Animal Health, the Minnesota Department of Agriculture, and the poultry industry about the threat to Minnesota. In early March, the virus was detected at a Minnesota turkey farm, the first in many Midwestern states.

Through late spring and summer, University researchers sifted through the wreckage of the state’s poultry industry. Like investigators of a serial murderer, they used their specialized knowledge of virus transmission and high-tech laboratories to learn more about this particular killer, its victims, and its movements from scene to scene. They want to understand what enables the disease to spread so that the next time—and there will very likely be a next time—they can stop the contagion early.

“It does not fit within an established pattern,” says Jeff Bender (D.V.M. ’89, M.S. ’95), professor of veterinary public health. “I think that is what was so dramatic about this and why it is earth-shattering for the producers. They have not seen anything like this.”

Bender has been conducting an epidemiological investigation of the flu’s spread. The U.S. Department of Agriculture sent 81 questionnaires to farms in Minnesota and four other affected states. Some farms were infected; others escaped unharmed. Bender and colleagues are analyzing the responses to try to determine what might have made the difference. They’re also interviewing farm managers and supervisors to better understand who might have visited the farms before the outbreak and what biosecurity measures were followed—or ignored.

“It’s a chance to sit down and meet with them and really talk about what happened. That’s actually one of the reasons we’re doing this study—to try to examine if there are biosecurity mechanisms that work, could work, or should be enhanced,” Bender says. Much remains to be learned, and investigators are still reviewing data. The U’s Veterinary Diagnostic Lab has been testing thousands of samples from domestic birds seven days a week. And investigators are also looking into the possibility that wind may have carried the virus, which is shed in birds’ feces. Associate Professor of Veterinary Medicine Montserrat Torremorrell tested facilities at six infected farms in three states and concluded that it’s possible the virus could become airborne—though it’s far from definite.

At the state level, Minnesota is gearing up to battle future outbreaks. This spring the Legislature provided funding for a new veterinary isolation lab on the St. Paul campus and for improvements to the veterinary diagnostic lab in Willmar. But the most pressing task remains learning how the virus so easily evaded the measures poultry farmers take to protect their flocks.


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