Researchers, Educators at Summit Share Efforts to Corral Highly Pathogenic Avian Influenza
βWe can make a global impact on avian influenza,β organizer Guillermo Tellez-Isaias, a research professor at the Center of Excellence for Poultry Science, said on Monday. βYour contributions will mean a more resilient future.β
By Mary Hightower β Oct. 18, 2023
FAYETTEVILLE, Ark. β At a two-day summit hosted in one of the nationβs top poultry states, researchers and educators from across the Americas discussed efforts to find ways to manage the spread of highly pathogenic avian influenza, a disease that has cost the poultry industry millions of birds across five continents.
The International Avian Influenza Summit was hosted Monday and Tuesday by the Center of Excellence for Poultry Science and the Arkansas Agricultural Experiment Station, part of the University of Arkansas System Division of Agriculture. The summit drew 1,842 registrations from 81 countries. The wide-ranging agenda featured presenters from Mexico, Chile, Scotland, the United States and other countries.
Since 2021, a very deadly strain of avian influenza called H5N1, has been circulating and affecting millions of birds and mammals around the world.
βWe are experiencing one of the most deadly bird flu outbreaks ever,β said Deacue Fields, head of the Division of Agriculture. βThis outbreak has cost U.S. poultry producers nearly 59 million birds across 47 states. There was a tremendous economic impact from this outbreak. We saw extremely high egg prices and also turkey prices.
βItβs important to come together now and be proactive in discussing the strategies that we can look to, to mitigate further spread of this terrible disease.β
βWe can make a global impact on avian influenza,β organizer Guillermo Tellez-Isaias, a research professor at the Center of Excellence for Poultry Science, said on Monday. βYour contributions will mean a more resilient future.β
Sampling to monitor spread
Among the first dayβs presenters was Julianna Lenoch, national coordinator wildlife services for National Wildlife Disease Program at APHIS β the Animal & Plant Health Inspection Service. Lenoch described efforts to monitor movement of the disease through migratory birds and other means.
The APHIS surveillance team restarted its efforts in May after a pause during the breeding period of the sampled birds.
βWe’re about four months into the surveillance right now. Our team, as of last week, had already collected about 13,000 samples,β she said. βOur target this year will be to get to almost 42,000 samples.β
She said that in the birds sampled in spring of 2022, βaround 7 percent of them were coming positive. We were running just shy of 1.9 percent in the winter of 2023 so a pretty dramatic drop in the apparent prevalence.
She said that samples collected from May-August of 2022 showed a 3 percent prevalence of avian influenza. During the same period in 2023, she said there was a βmuch lower prevalenceβ despite getting more than 7,000 samples.
βWe only found H5N1 in a total of 10 birds during that period,β Lenoch said. βSo, either we were sampling in different regions, or thereβs simply not as much avian influenza circulating, or we may be looking at a little bit of a tipping point where some of our wild bird species β at least the dabbling ducks βΒ may be developing some immunity.β
βUnfortunately, we are starting to see pickup both in our surveillance samples and our domestic side,β Lenoch said. βSo avian influenza is starting to trickle in again here in the United States.β
Highly pathogenic avian influenza has been confirmed this year in commercial and/or small flocks inΒ Oklahoma, Colorado, Montana, Utah, Idaho, South Dakota, North Dakota, and Minnesota.
AI in mammals
The sampling has found avian influenza in mammals as well, despite the U.S. lacking a national surveillance system for mammals. Currently, mammalian samples are βopportunistic,β coming from wildlife rehabilitation centers or state wildlife and natural resource agencies.
βMany of these animals have been neurologically affected, and a good portion of them are juveniles or young of the year,β Lenoch. βIn the US we’re approaching almost 200 individual detections and mammals we have had a wide breadth of species affected.
These include coyotes, foxes, skunks and raccoons. Avian influenza has also appeared in marine mammals such as seals and a bottlenose dolphin.
βThe leading theory is that likely many of these terrestrial mammals are likely eating sick or dead birds in the environment,β she said.
Vaccinating poultry for HPAI
Some countries, such as France, have begun vaccinating poultry against HPAI. On Sept. 29, APHIS placed restrictions on importation of poultry from France including ducks, duck eggs and other duck products.
βThe restrictions are based on the World Organisation for Animal HealthβsΒ definition of poultryΒ and are the result of Franceβs decision to vaccinate commercial meat ducks against HPAI,β APHIS said. βFranceβs decision to vaccinate presents a risk of introducing HPAI into the United States.β
However, Brian Umberson of the microbial security company Ancera, said attitudes about HPAI vaccination may be changing.
βWe’re starting to see the development of a positive view of using vaccinations because of the size of these outbreaks and the shock to the food supply,β he said.
Risk factors for HPAI on the farm
On Day 2, Alice Green, veterinary epidemiology officer for USDA, discussed a study that identified factors that increased the risk of infection on turkey farms.
Other factors βassociated with increased odds of H5N1 HPI infection included having both brooder and grower turkey production on the farm,β Green said. Having tom turkeys on the farm and βseeing wild waterfowl or shorebirds in the closest field was also associated with increased odds
βProximity to water and wild bird habitat, as well as presence of high densities of migratory wild waterfowl, have been identified as risk factors in previous outbreaks concentrations of domestic poultry in combination with high densities of wild birds provides a potential interface for viral transmission and spillover events,β Green said.
There are human factors as well. The study found that having a restroom β even a portable one and having access to a shower β were found to be protective factors.
Surveillance as an early warning system
Pedro Jimenez-Bluhm, assistant professor, Pontificia Universidad CatΓ³lica de Chile, discussed wild bird sampling efforts in Chile, at the southern end of the Pacific Flyway.
Starting in August 2022, βwe discovered some low-pathogenic viruses, but then we had this huge peak at the end of the year,β he said. βThatβs where we started seeing H5N1-positive samples.
βThrough this environmental sampling, in this case, we were actually able to get the positive (confirmation) one week before people were announcing mortalities,β Jimenez-Bluhm said, adding that this makes a lot of sense because βthere needs to be a certain viral load in the environment for animals to actually efficiently transmit this virus. So, this is a very sensitive way to actually detect the pathogen in the environment.β
Closing out the second day were presentations on strategies for developing vaccines for this virus strain, genome editing to examine avian influenza resistance in chickens and a presentation from Tellez-Isaias on βCRISPR and Quorum Sensing as strategic control measurements for Avian Influenza Virus.β
βTo learn more about Division of Agriculture research, visit the Arkansas Agricultural Experiment Station website: https://aaes.uada.edu. Follow us on π at @ArkAgResearch and Instagram atΒ @ArkAgResearch.
To learn about Extension Programs in Arkansas, contact your local Cooperative Extension Service agent or visitΒ https://uaex.uada.edu/. Follow us on π at @AR_Extension.
To learn more about the Division of Agriculture, visitΒ https://uada.edu/. Follow us on π atΒ @AgInArk.
About the Division of Agriculture
The University of Arkansas System Division of Agricultureβs mission is to strengthen agriculture, communities, and families by connecting trusted research to the adoption of best practices. Through the Agricultural Experiment Station and the Cooperative Extension Service, the Division of Agriculture conducts research and extension work within the nationβs historic land grant education system.
The Division of Agriculture is one of 20 entities within the University of Arkansas System. It has offices in all 75 counties in Arkansas and faculty on five system campuses.
The University of Arkansas System Division of Agriculture offers all its Extension and Research programs and services without regard to race, color, sex, gender identity, sexual orientation, national origin, religion, age, disability, marital or veteran status, genetic information, or any other legally protected status, and is an Affirmative Action/Equal Opportunity Employer.