Bird flu isn’t as bad this year because of Iowa’s response, ag officials say
Iowa is particularly susceptible to the deadly bird flu because of its large chicken flocks. (Photo by Stephen Ausmus/Animal Research Services, USDA)
The current outbreak of highly contagious and deadly avian influenza has affected far more flocks and states this year than the last outbreak seven years ago, but the number of birds that have been culled this year is fewer. Why?
In the 2014-2015 outbreak, Iowa accounted for about two-thirds of the more than 50 million birds that were destroyed after being infected by the virus. This year, Iowa accounts for about a third of the 37.5 million that have been culled, according to U.S. Department of Agriculture data.
“We are extremely pleased with our ability to respond quickly to control and eradicate the disease,” said Chloe Carson, a spokesperson for the Iowa Department of Agriculture and Land Stewardship.
Iowa is particularly susceptible to the deadly bird flu because it is the nation’s leading egg producer. Those egg-laying flocks often number in the millions and contribute mightily to the overall avian death toll.
Even though just 19 of the 285 infected nationwide flocks have been in Iowa — that’s about 7% — the state still has by far the most affected birds of any other state.
For comparison, Minnesota has 69 confirmed outbreaks but only 2.9 million affected birds compared with Iowa’s 13.4 million.
And the infections appear the be waning. There have been two confirmed outbreaks in Iowa in the past two weeks, and both of them were backyard flocks of chickens, ducks and geese. The affected flocks were six birds in Kossuth County on April 22 and 46 birds in Bremer County on May 2.
“We are hopeful that things are winding down and we’ll see an end to the spread very soon, but too early to tell at this point,” Carson said. “Birds are still migrating.”
Wild, infected birds are the likely sources of infection. They can be asymptomatic, whereas the virus is most often deadly to domesticated birds.
IDALS has asked residents to report clusters of dead birds to help monitor the virus, but none have been reported in Iowa since late March, according to the USDA.
Carson attributes Iowa’s relative success with the virus this year to heightened vigilance in protecting flocks from infection. There have been no flock-to-flock transmissions, which was a key driver of infections in 2015. This year, all commercially raised birds of infected flocks have been disposed of near their facilities, Carson said.
The state attempts to cull infected flocks within 24 hours of detection to stem the spread of the virus. The meat and eggs of infected birds are destroyed.
Nationwide, the month of April was worse in terms of overall flock infections — nearly double — compared with March, but April had fewer birds affected. There were 87 virus detections in March for a total of about 20.9 million birds, according to USDA data. In April, there were 166 detections for a total of 14.7 million birds.
That’s mostly due to fewer egg-laying operations being infected in April. A total of nine of those sites with 10.6 million birds were affected.
In March, 11 egg-laying facilities were infected with a total of 17.7 million birds.
The total infected flocks across the country this year has exceeded those of the 2014-2015 outbreak — 285 to 232. The number of affected states is also larger — 33 to 21. Yet the total number of birds affected is smaller, in part because backyard infections account for a larger percentage.
Backyard flocks, which are considerably smaller than commercial flocks, account for about 39% of this year’s infections, whereas they accounted for about 9% of the 2014-2015 infections.
The infected flocks in Iowa this year include:
— March 6: A commercial flock of about 50,000 turkeys in Buena Vista County.
— March 10: A commercial flock of about 916,000 egg-laying chickens in Taylor County.
— March 17: A commercial flock of more than 5.3 million egg-laying chickens in Buena Vista County.
— March 20: A backyard flock of 11 chickens and ducks in Warren County.
— March 23: A commercial flock of about 54,000 turkeys in Buena Vista County.
— March 25: A commercial flock of about 250,000 young hens in Franklin County.
— March 28: A commercial flock of about 28,000 turkeys in Hamilton County.
— March 28: A commercial flock of about 1.5 million egg-laying chickens in Guthrie County.
— March 29: A commercial flock of about 35,500 turkeys in Buena Vista County.
— March 31: A commercial flock of more than 5 million egg-laying chickens in Osceola County.
— March 31: A commercial flock of about 88,000 turkeys in Cherokee County.
— April 2: A commercial flock of about 37,000 turkeys in Sac County.
— April 2: A commercial flock of about 15,000 breeding chickens in Humboldt County.
— April 4: A commercial flock of about 8,000 turkeys in Hamilton County.
— April 5: A commercial flock of about 46,000 turkeys in Hardin County.
— April 20: A commercial flock of about 30,000 turkeys in Bremer County.
— April 22: A backyard flock of 6 birds in Kossuth County.
— May 2: A backyard flock of 46 birds in Bremer County.
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