Millions Of Iowa Chickens Infected With Deadly Strain Of Bird Flu

6:03 minutes

rows and rows of dozens of chickens. the camera is closeup to one row bringing five chickens in stark focus with a blurry background
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state of science iconThis article is part of The State of Science, a series featuring science stories from public radio stations across the United States. This story, by Katie Peikes, was originally published on Iowa Public Radio.

Iowa and federal agriculture officials have confirmed a deadly strain of bird flu in a large commercial flock of egg-laying hens in northwest Iowa’s Buena Vista County. It’s the fourth case of bird flu in the state and the largest flock to date to be infected by this year’s outbreak.

Chloe Carson, a spokesperson for the Iowa Department of Agriculture and Land Stewardship, said Friday that initial reports indicate there are approximately 5.3 million birds in the flock.

Carson said the department won’t have exact numbers for a few days. The numbers will be released by the U.S. Department of Agriculture once all the birds have been destroyed to prevent the disease from spreading.

It’s the second confirmed case of bird flu in Buena Vista County this year. The virus was confirmed in a commercial flock of nearly 50,000 turkeys in the county on March 6.

The deadly strain was also confirmed in a flock of more than 915,000 commercial egg-laying hens in southwest Iowa’s Taylor County on March 10 and a backyard flock of nearly 50 chickens and ducks in Pottawattamie County on March 1.

Agriculture officials have cautioned producers and backyard flock owners to keep their birds away from wild birds that are migrating. They can carry the virus in their saliva or feces and show no signs of infection.

Bird flu has been found in commercial and backyard flocks in 17 states, according to the U.S. Department of Agriculture.

Iowa has about 56 million egg-laying chickens and is the top egg-producing state in the country. In the 2014-2015 bird flu outbreak, Iowa and Minnesota were hit the hardest. More than 50 million birds were killed in that outbreak, including nearly 33 million in Iowa.

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Segment Guests

Katie Peikes

Katie Peikes is agriculture reporter for Iowa Public Radio & Harvest Public Media in Ames, Iowa.

Segment Transcript

IRA FLATOW: And now it’s time to check in on the state of science.

SPEAKER 1: This is–


SPEAKER 2: –Iowa Public Radio News.

IRA FLATOW: Local science stories of national significance. Bird flu is spreading in the Midwest. Millions of birds have had to be culled in this spring’s outbreak. The last bad year of bird flu was in 2015. So how worried should we be about this year? Joining me now to talk about it is my guest. Katie Peikes is agriculture reporter for Iowa Public Radio and Harvest Public Media. She’s based in Ames, Iowa. Welcome to Science Friday, Katie.


IRA FLATOW: So when did this year’s bout of bird flu start ramping up?

KATIE PEIKES: Yeah, so the very first confirmation of this bout of bird flu was in a commercial flock of 29,000 turkeys in Indiana. And that was in early February. And we really saw it start to ramp up in the later part of that month to now.

IRA FLATOW: How exactly does bird flu spread?

KATIE PEIKES: Yeah, so wild birds like ducks and geese can carry the virus and shed it through their excrement or saliva, and not show any signs of illness. And it’s a virus, so once it gets into a flock and a bird starts coughing, for example, bird flu can rapidly spread through those droplets and infect other birds. And I talked with Iowa State University poultry veterinarian Yuko Sato about how it spreads. So let’s listen.

YUKO SATO: So it kind of depends on what signs they manifest in. So for example, if they have respiratory infection, it’s going to spread through– if they’re coughing or sneezing, they’ll have droplets that aerosolize. And they’re spreading it that way. If it manifested into diarrhea, then it’ll spread through feces. And then that could also be aerosolized and spread through that. It can also do direct contact. So if there’s sick birds and they’re contacting each other, it’s kind of like contact to contact there.

KATIE PEIKES: So that’s bird to bird spread. But also, a person could step in goose excrement and then walk into a barn, and it could spread that way. And Yuko Sato said bird flu can also come in through contaminated farming equipment, transportation vehicles that are contaminated with the virus. But these possibilities are what she calls weak links. She said that there isn’t a concluded study on how exactly bird flu gets into barns. And these possibilities are also why poultry producers are told to practice good sanitation. And that’s the things that they can do to keep germs and diseases off of their farms.

IRA FLATOW: And cases of bird flu have been found in Iowa on both commercial and in backyard farms?

KATIE PEIKES: Yeah, so we’ve had a handful of confirmations of bird flu in both commercial and backyard flocks. And that includes a couple of large commercial flocks. In one case, bird flu was confirmed in a commercial flock of more than 915,000 egg-laying hens. And in another case, bird flu reached a commercial flock of 5.3 million egg-laying hens.

IRA FLATOW: Wow, so those are enormous flocks. What exactly happens in flocks like these when bird flu is detected?

KATIE PEIKES: Yeah, so those are enormous flocks. And once bird flu is detected in a flock, state and federal agriculture officials will quarantine the property that’s infected. They’ll establish what they call a control zone, where they’ll alert flock owners within a six-mile radius of the case. And then they have to cull the infected flock. All the birds in that flock have to be culled to prevent bird flu from spreading.

So then officials will dispose of the carcasses. The carcasses are usually composted inside of barns or outside on a producer’s property, but they can also be buried or even brought to a landfill, if the landfill will accept it. And it’s a really heartbreaking process for the producers whose flocks are impacted. I mean, these animals are their livelihood.

IRA FLATOW: We mentioned that 2015 was the worst year in recent memory for the bird flu. More than 50 million birds in 15 states had to be culled, and 33 million in Iowa alone. Any idea, Katie, about how this year’s outbreak could compare to that terrible year?

KATIE PEIKES: It’s still too early to tell. Migratory birds are on the move, and their migration is picking up, so we could see more cases of bird flu happen. But producers and agriculture officials emphasize that they’ve dealt with this before and they know more now than they did in 2015, and that they’re more prepared to deal with this.

IRA FLATOW: Is there an expectation that this will impact consumers?

KATIE PEIKES: So in 2015, egg prices soared, but it’s still too early to tell how this bird flu outbreak could impact consumers. Chicken prices are already up because of inflation. Egg prices have been consistently higher this year. And here in Iowa, you know, bird flu reached a flock of 5.3 million egg-laying hens. And that’s a lot of hens. But an economist told me that that’s only about 11% of all of the egg-laying hens in Iowa alone. And it’s a very, very small portion of all of the chickens and turkeys nationally.

IRA FLATOW: Because of COVID, of course, I think we’re all pretty spooked by the idea of animal to human transmission of viruses. Can that happen at all with bird flu?

KATIE PEIKES: So agriculture officials are saying that this is not an immediate health concern for people. And they also emphasize that it’s still safe to eat poultry products. The Centers for Disease Control and Prevention also believes that the risk to human health is low, but they are keeping a close eye on possible human infections.

IRA FLATOW: Katie Peikes is agriculture reporter for Iowa Public Radio and Harvest Public Media, based in Ames, Iowa. Katie, thanks so much for joining us. I really appreciate it.

KATIE PEIKES: Thanks, John.

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