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 agricultural production.

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.