Understanding Timings Can Help Poultry Growers Prepare For ‘Host-Adapted’ Avian Influenza

MARY HIGHTOWER

FAYETTEVILLE, ARKANSAS

 Understanding the timing of outbreaks of highly pathogenic avian influenza, or HPAI, can help poultry farms prepare and protect their flocks, according to economists.

Between February 2022 and April 2026, HPAI has affected 212 million birds, with more than 1,000 commercial flocks affected, according to the Animal and Plant Health Inspection Service, part of the U.S. Department of Agriculture.

Jada Thompson, associate professor of agricultural economics for the University of Arkansas Division of Agriculture who specializes in poultry, has done extensive research on the effects of HPAI.

“When the United States poultry industry encountered the H5N2 strain of HPAI in 2014, it was mostly spread house-to-house through contaminated materials, trucks and laborers,” she said.

“This prompted sweeping changes in biosecurity culture that still exist today,” Thompson said. “These changes, along with a hot summer, helped to end the outbreak by June 2015.

“However, since the 2022 introduction of a host-adapted H5N1 virus, poultry growers in the Mississippi Flyway have faced increased disease risk, despite the wide adoption of these enhanced biosecurity measures,” she said. “This most recent outbreak has spread instead by external introduction, rather than house-to-house as in 2014.”

“‘Host-adapted’ refers to the virus’s ability to persist in wild bird populations. Where previous HPAI events ravaged both poultry and wild birds, the current H5N1 2.3.4.4b classification is less likely to kill some wild bird species,” Thompson said. “This means that waterfowl can become infected and still survive migration, spreading the disease across the flyway.”

“Examining the geographic distribution of HPAI detections over time reveals a clear seasonal pattern that mirrors waterfowl migration,” said Matthew Marchant, whose findings are contained in the paper “Bird Flu on the Move,” published in Southern Ag Today earlier this year.

Marchant is a Ph.D. student in environmental dynamics at the University of Arkansas, working with Thompson in the department of agricultural economics and agribusiness. Thompson is a faculty member with UADA’s research arm, the Arkansas Agricultural Experiment Station, and the Dale Bumpers College of Agricultural, Food and Life Sciences at the University of Arkansas.

“During the summer months, detections are sparse and concentrated in the northern reaches of the flyway, where birds spend the breeding season,” he said. “As fall migration begins, HPAI’s geographic footprint expands southward, spanning nearly the entire flyway from October through May.”

“Understanding seasonality affords producers a predictable window each year to prepare before peak exposure periods arrive,” Marchant said.

“A host-adapted virus in a migratory population means recurring seasonal risk for the foreseeable future,” he said. “However, that seasonality also gives producers, researchers, and communities time to plan ahead.

“Understanding when and where the disease is likely to appear turns an unpredictable force into a manageable calendar of preparation and vigilance,” Marchant said. “Community preparedness, which begins at the farm level, remains the most effective tool available against this disease.”

According to APHIS, current cases are concentrated in the northern Plains states.

Find UADA biosecurity resources online.

Listen to Marchant discuss this research on a podcast by the Fryar Price Risk Management Center of Excellence.   ∆

MARY HIGHTOWER

UNIVERSITY OF ARKANSAS