Ag Policy Blog

Expert: Current Highly Pathogenic Bird Flu Shifts From Outbreak to 'New Reality'

Chris Clayton
By  Chris Clayton , DTN Ag Policy Editor
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Snow geese migrating through the Mississippi flyway in 2022. Migratory waterfowl have been hit harder with highly pathogenic avian influenza with USDA finding more than 6,000 positive cases over the past year compared to less than 100 infected wild birds found through testing in 2015. Those wild birds are spreading HPAI wider this time, hitting farms in 47 states compared to just 15 states in the last outbreak. (DTN file photo by Elaine Shein)

ARLINGTON, Va. (DTN) -- Experts on highly pathogenic avian influenza (HPAI) don't see immediate relief from the year-long deadly bird flu, as the outbreak has become the deadliest animal disease in U.S. history.

"I've stopped thinking about this as an outbreak, but as a new reality," said Carol Cardona, chair of avian health at the University of Minnesota.

Cardona and others updated some of the challenges of the current bird flu outbreak last week at the USDA Outlook Forum.

The 2022-23 outbreak has hit 317 commercial farms and has hit domestic birds in 47 states. So far, more than 58.5 million birds have been infected or culled over the past 10 months. At least 15 states have reported cases over the last month.

The 2015 outbreak hit 211 farms in 15 states, infecting or forcing more than 50.4 million domestic birds to be culled. That outbreak also lasted about six months before cases subsided.

The big difference between now and the 2015 bird flu outbreak is the impact this current strain of HPAI is having on wild birds. USDA's wild bird surveillance has found more than 6,000 infected wild bird cases involving 100 species of birds over the past year. In 2015, USDA's wild bird surveillance detected HPAI in less than 100 wild birds. Ducks, geese and swans are being infected at a high rate, as are birds such as raptors and vultures, said Sarah Bevins, a research biologist at the National Wildlife Research Center in Fort Collins, Colorado.

A strain considered far more infectious to migratory birds can spread easier to farms around the country. Domestic birds as a group really don't have resistance to HPAI, Cardona said. There simply isn't much advantage to be gained in terms of genetic resistance. Domestic poultry are raised in such large groups that once the virus gets over the hurdle of making it into a barn, "It creates, you know, sort of a ping-pong ball in a jar type of situation, because it can spread rapidly once it's inside."

There are more than 800 different bird species in the U.S. "That complicates what we know and how we deal with avian influenza," Cardona said. Making a comparison, she added, "Think about how complicated COVID has been" on people.

Highly pathogenic avian influenza is defined by being deadly to birds such as chickens and turkeys.

Of the domestic birds infected over the past year, 76% -- nearly 44.5 million birds -- have been in egg-laying operations. Turkeys account for about 9.8 million infected or culled birds. The impact on broiler operations has been less, involving a little more than 3 million birds. Other recent cases have involved commercial game birds or ducks.

Cases continue to show up despite heavy emphasis in the poultry industry to tighten biosecurity after 2015.

"You would have thought we would have done a lot better in 2022 than we really did," Cardona said.

While the number of HPAI cases in domestic birds is higher and continues to spread, it's happening in different ways. In 2015, too often, cases were spread from farmers, workers or feed delivery trucks moving from farm to farm and spreading the infections as they moved. This time round, Cardona said, farm-to-farm spread has been reduced from 70% down to about 15%. Cardona credited that decline in farm-to-farm cases to biosecurity measures in the National Poultry Improvement Plan. Companies that were hit hard in 2015 have seen fewer cases in 2022, she said.

"It wasn't enough to stop an HPAI outbreak, but it helped," Cardona said. She later added, "There was too much virus for the protection that was there."

Rethinking production strategies, Cardona said there is no "easy button" but, "One of the top things would be vaccinations for poultry," she said, adding there is a lot of work on vaccines right now.

Cardona said it's rare for HPAI to transmit from birds to mammals, though USDA has reported some cases involving foxes, coyotes, racoons and other mammals that likely contracted the virus by eating dead wild birds.

Jennifer Moffitt, undersecretary for marketing and regulatory programs at USDA, also said the Centers for Disease Control considers the risk of human infection with HPAI to be low, but added, "It is prudent for us to continue to monitor for mutations and viral changes in mammals and birds to coordinate with public agencies across the country."

Trade regulations demand that once an infection is found on a farm, the entire population is culled. Cardona suggested there should be some work to see if depopulation can be reduced, such as if one barn on a farm is infected but others are not.

"That's a potential opportunity for future exploration to see if we, you know, could be more precise in the depopulation that we do," she said.

Cardona said there are multiple differences in the 2015 HPAI strain and the current one. While the 2015 strain of HPAI came from Asia through the Pacific flyway, the 2022 virus came first from Europe and through multiple transmissions.

"The virus is evolving here," she added.

USDA continues testing the wild bird population to look for signs of change in the virus on migratory birds. USDA has a goal this year to test more than 33,000 samples from wild birds in 49 states.


Smaller outdoor flocks have been hit harder this time around as well. So far, more than 450 backyard flocks have been infected. In contrast, only 21 backyard flocks were infected nationally in the 2015 outbreak.

Cardona said a lot of activity leading to biosecurity breaches occurs at night. She said cameras have shown wild birds will often come in and look for food at night.

"So, one thing we tell, you know, all our producers or backyard folks is feed your poultry indoors. If possible, put netting over the areas where birds might come in," she said.


While the outbreak is more severe, the impact on trade has changed since 2015 as well. In 2015, the U.S. saw 18 countries issue national bans on poultry imports from the U.S. while another 26 countries banned imports from the 15 states that had outbreaks.

This past year, more countries have agreed to ban exports from the local counties or vicinity of the infected farms instead of opting for state or national import bans. That has reduced some of the impact on U.S. exports. China, for instance, banned imports from the U.S. in 2015, but this past year, China was a larger share of U.S. poultry exports.

Broiler exports in 2023 also are expected to increase fractionally to 7.32 billion pounds. There will be more supply, but some exports will continue to be constrained because of restrictions from countries concerned about HPAI, according to USDA's Outlook.

The biggest impact has been a decline in shell egg exports, which were down 47% in 2022, a decline of 120 million dozen eggs. Turkey exports were also down more than 25% in 2022.


HPAI has been a driving force for food inflation and affected the availability of eggs. Table egg prices moved from an average wholesale price in New York in January 2022 of $1.24 a dozen to a peak of $5.40 a dozen in mid-December. For 2023, USDA projects egg prices will come down to $2.07 a dozen.

USDA last week projected egg production in 2023 would increase 4% to 9.4 billion dozen eggs. Table egg production will reach 8.1 billion dozen, about 5% higher than 2022 but still below the record volume from 2019.

"While not quite there yet, a full recovery in the laying flock is expected in the coming year," USDA stated.

USDA also projects that broiler production in 2023 will bump up 1% to a record 46.7 billion pounds.

USDA cites more broiler-egg placements in the third quarter of 2022, driven partially by recovery efforts from avian influenza. So far, broiler placements in early 2023 are higher than the same period last year.

Chris Clayton can be reached at

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