Avian Flu - Again
Poultry farmers across the Upper Midwest are bracing for a potentially deadly disease spread by wild birds. U of M experts are providing insight and guidance.
This spring, as Minnesotans anticipated a respite from Covid-19, another
epidemic crept into the state.
The disease, called highly pathogenic avian influenza, is a descendant of the
virus that infected poultry flocks in 2015 and
“devastated the Upper Midwest,” says Carol
Cardona, D.V.M., professor and Pomeroy
Endowed Chair in Avian Health in the U of
M’s College of Veterinary Medicine. The
2015 outbreak infected more than 200 com-
mercial flocks and caused the death of more
than 50 million birds from the Mississippi to
the West Coast.
Will 2022 be a repeat? Or will lessons
learned limit the damage? The stakes are
high—for individual farmers and the state’s
poultry industry as a whole. For turkeys
and chickens, especially, the virus is nearly
always fatal. Once infection is detected, the
flock is doomed.
This particular virus, classified as H5N1,
circulates among wild and domestic birds
primarily in Eurasia. Occasionally, it hitches a
ride on infected waterfowl to North America.
Sometime last year, it traversed the North
Atlantic to Canada. By December, the virus
was discovered in wild waterfowl in Newfoundland and Labrador. By mid-January,
it was detected in two ducks shot in South
Carolina. Minnesota confirmed its first case
in domestic poultry in late March, and as of
April 5, the virus had infected 13 commercial
flocks and two backyard flocks in the state.
By early May, the virus had been detected
in domestic poultry flocks in 19 Minnesota
counties and in wild birds in 29 counties.
“Now we’re seeing it move back up as
the migrations come north again in spring
migration,” Cardona says.
Infected wild birds visit backyard flocks,
perhaps sharing the same ponds and food.
They leave infected droppings around
commercial operations, which can be tracked
inside. Once established in commercial
barns, the virus is spread mostly by humans.
“People and equipment,” says Cardona. “So, food comes in. You have to have someone who checks the birds every day, who
checks to make sure the feed is flowing, to
make sure the water is working, that nothing is broken. And that person can easily
carry disease organisms on their feet.”
“If one bird tests positive in a flock, the
whole flock has to be euthanized,” says
Abby Schuft, assistant Extension professor
for the Center for Agriculture, Food and
Natural Resources. “Otherwise that virus
continues to live in that flock and keeps reinfecting any new animal that would appear.”
The ramifications for Minnesota’s farm
economy are huge. The state is the number
one turkey producer, raising about 49 million turkeys on 559 turkey farms. Minnesota
ranks in the top 10 or so in egg production
and top 15 in broiler chickens. It’s also the
top state in pheasant production. Poultry
accounts for 16 percent of the state’s livestock production and 5 percent of overall
Since the 2015 epidemic, “we’ve learned
how to stop this virus,” Cardona says.
“We’ve learned to take it seriously from the
get-go. We’ve learned how to communicate
about it. And we’ve implemented some new
strategies that we think are going to help.”
For one, researchers have discovered how
important it is to eradicate an infected flock
immediately. “We weren’t doing it as rapidly
as we needed to,” Cardona says about the
previous outbreak. “Within 24 hours of a
diagnosis, those birds are supposed to be
gone so the virus can’t replicate anymore.”
Another big improvement: Back in 2015,
farmers had to take samples from sick
birds to the University’s diagnostic lab in St.
Paul. A new lab has been built in Willmar,
far more convenient for much of the state.
“And that means response times can be
improved,” says Cardona.
Additional projects include a “secure
poultry supply plan,” which helps move
animals and products to markets from
disease-free farms in a way “to mitigate the
risks of disease exposure, optimize detection and overall work on emergency disease
preparedness,” says Cardona. University
researchers have also developed methods
that make it easier for farms to sample large
flocks for infections.
Another response to the 2015 epidemic
was the creation of Schuft’s job “to help
fill in some gaps that were identified in
outreach.” Since then, she has worked with
commercial and backyard flock owners to
improve protocols, ranging from developing a biosecurity plan audit every other
year to more obvious steps like limiting
unnecessary visitors and establishing a
“line of separation” to keep potentially
contaminated items on the one side of an
entry, and healthy birds on the other. “That
takes time, to make sure that you are clean
when you enter a facility—clothing, boots,
hats, hands,” Schuft says. “That takes effort
and it takes a lot of training to make sure
people are doing it properly.”
Those messages have sunk in. “We
learned a lot from 2015 and are more
prepared this time around,” says Britta
McGuire (B.S. ‘08), an owner of Sparboe
Farms, an egg producer in Litchfield. “Protecting our farms from HPAI takes a lot of
personal vigilance and absolute adherence
to our robust biosecurity plan by all of our
employees, customers, and vendors.”
Examples include monitoring and minimizing traffic in and out of farms, providing
continuous training and updates to all
employees, and conducting ongoing influenza surveillance testing, McGuire says. In
February, Sparboe took part in a voluntary
avian flu preparedness exercise conducted
by the University.
Cardona—among many others—hopes
the research, preparation, and outreach
will pay off and prevent a repeat of 2015.
“Frankly I’m betting our do-over in 2022 is
a lot less severe.”
Greg Breining is a freelance writer in the Twin Cities.