USDA, Anitox poultry experts offer insights into the current wave of highly pathogenic avian influenza (HPAI) and how to mitigate its effects
Across the United States and Canada, commercial poultry operations are being affected by highly pathogenic avian influenza (HPAI) outbreaks.
Dr. David Swayne, laboratory director of the USDA’s Southeast Poultry Research Laboratory (SEPRL), and Dr. Enrique Montiel, Anitox’s global director of nutrition and live production, join the Chat to discuss how the HPAI virus arrived stateside and what can be done to prevent further outbreaks.
Transcription of Feed Strategy Chat with Dr. David Swayne, laboratory director, USDA’s Southeast Poultry Research Laboratory, and Dr. Enrique Montiel, Anitox’s global director of nutrition and live production
Jackie Roembke, editor in chief, WATT Feed Brands/Feed Strategy: Hi, everyone. Welcome to Feed Strategy Chat. I’m your host, Jackie Roembke, editor in chief of WATT Feed Brands and Feed Strategy magazine.
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Today we are joined on Zoom by Dr. David Swayne, laboratory director of the USDA’s Southeast Poultry Research Laboratory (SEPRL), and Dr. Enrique Montiel, Anitox’s global director of nutrition and live production. They are here to discuss the evolution of the highly pathogenic avian influenza (HPAI) outbreak in the United States and how its effects might be minimized.
Hello, gentlemen, how are you today?
Dr. David Swayne, SEPRL laboratory director: Excellent. Thank you for the invitation to speak with you.
Dr. Enrique Montiel, Anitox global director of nutrition and live production: Very well. Thank you for having us today.
Roembke: Excellent. Thank you very much for being here. Well, let’s get right into it. Dr. Swayne, how do AI virus strains cross continental borders and enter countries like the United States?
Swayne: Well, thank you for that question. It’s a very complex answer. But I want to try to simplify it and just talk about what we have here in North America today.
We have an outbreak of a highly pathogenic avian influenza (HPAI) virus — and this is very impressive. It has only happened twice in the last 50 years. How that virus came into the United States? It was transmitted by migratory waterfowl and their normal migratory process. It occurred in 2014 and the end of 2021. So twice in 50 years, it’s not a very common occurrence.
Generally, HPAI outbreaks occur in local areas, and they’re eradicated immediately and they don’t spread across continents. The current virus, which has been around since 1996, has been spreading throughout Europe and Asia and then it crossed into North America twice through those migratory birds.
Roembke: Very good. Dr. Montiel, since the virus is mainly in migratory waterfowl, how does it make its way into poultry production operations?
Montiel: Well, that’s another very complex question. I’ll try to give a short answer. There’s always ways in their path, through any territory, the migratory birds can come in contact directly or indirectly with poultry operations.
One is that when [migratory birds] come close, if there are large bodies of water, for example, close to the poultry operation that will facilitate for them to approach the poultry operation.
The other one is that when the birds come in — and this is something that’s been speculated as well — some of the local birds can come in contact with these birds, the migratory birds, and don’t get in touch directly with commercial poultry. [Local birds] can act as vehicles or vectors to transport the virus from the migratory birds into poultry operations.
The other one is a matter of biosecurity. How some of the migratory birds come closer to inhabited areas and people can inadvertently, for example, walk over droppings or drive over droppings and then come back in contact with poultry operations.
There’s many ways unfortunately that this can happen. I tried to mention some of the main things that happen. There’s many ways how it can happen.
Roembke: The next question is for both of you: Are there any particular considerations that need to be taken into account regarding the types of poultry productions — so the differences between broilers, layers and, of course, turkeys?
Swayne: This is an area where specific research studies can give us some answers, some insights, into why some birds and not other terrestrial poultry species.
Here at USDA, the Southeast Poultry Research Lab, we have a laboratory where we can safely work and do experimental studies with these highly pathogenic influenza viruses. And from what we’ve determined over many years of research, including the most recent viruses, is that turkeys tend to have a greater susceptibility to HPAI viruses. The viruses tend to be transmitted turkey to turkey more easily in direct contact, for example, the current HPAI outbreak, which is an H5F1 virus. This virus, in our new studies here at Southeast Poultry shows it transmits and infects turkeys very easily. Whereas in chickens, it can cause infections, but it does not transmit bird to bird very well.
This can be borne out by looking in the field where it seems that turkeys as far as the number of premises affected is much greater than the number of chicken facilities, either layer or broilers, that are affected. And this biological difference seems to be at least one factor that could explain that.
Roembke: Dr. Montiel, do you have anything to add to that?
Montiel: I think that’s the basis of it. There’s always a concern that turkeys are more susceptible. They’re most susceptible to the initial infection and they can act as a source to propagate the outbreak in the rest of the poultry. But I think that’s probably the main thing. They are probably a smaller consideration that is important, but besides susceptibility is the type of operation some biosecurity is better in some types of poultry than in others. So is the small vulnerability in farms, for example, to have open houses versus like bird control in place and access and all that.
So the susceptibility will be the absolute No. 1, and that type of operation will be also something to think about.
Roembke: Dr. Swayne, are there any specific factors that contributed to the current outbreak?
Swayne: That’s an excellent question and one that science is looking at in detail.
There are probably multiple factors that could account for a change and we know from looking back historically at other HPAI outbreaks, this is only the second time where we’ve had a HPAI virus move from another continent into North America. In this case, moving Eurasia into North America.
The previous time was in 2014-2015, we had an outbreak of a similar type of virus, actually, it’s a predecessor virus. But why did it happen just two times in the last 50 years? We don’t really know.
And there are scientists who are looking at multiple questions, including: Have there been changes in migratory bird patterns that could be explained either by local changes in climate or could it be a part of a bigger climate change? Or is it completely by random chance that this occurred?
But scientists around the globe are trying to answer some of these questions and look at factors that might have impacted the change.
Roembke: Dr. Montiel, any advice to minimize the effects of the current outbreak and, of course, to prevent future outbreaks?
Montiel: I think everybody has always looked at the U.S. as an example of how the avian influenza outbreaks are handled. I think the No. 1 thing is always biosecurity.
The approach is always to control the outbreak and eliminate the positive birds and prevent the outbreak from spreading. This is one way to handle it; it’s not the only way. Other countries have decided, for example, to vaccinate and prevent the disease, but not the infection.
Roembke: Dr. Swayne, do you have anything you’d like to add?
Swayne: Yes, Dr. Montiel is correct, biosecurity practices at the highest level are the best way we can assure our farmers to keep this HPAI virus out of their their houses.
I think the other thing is in a more long-term approach. We have to look at, are there ways in the farm environment where we can discourage these migratory waterfowl from coming in close to the poultry barns, for example. We need to be looking at ways to discourage having large ponds or other water areas close to poultry barns. They should be quite a bit away from them so that you won’t have a close interaction between those poultry barns and potential sites where wild waterfowl would come in.
Also need to make sure you maintain spill-free feed areas around those barns around the silos and things that will not attract in these migratory wild birds and keep them separated. So that is also sort of a secondary issue, in addition to biosecurity, but try to plan to keep the wild birds away.
Roembke: Thank you so much, gentlemen. And if you would like ongoing coverage of the HPAI outbreak in the United States, visit Feed Strategy’s sister site, www.WATTPoultry.com. Thanks again, and thanks to you for tuning in.