Elizabeth Doughman, editor, WATTPoultry USA and Poultry Future: Hello, I’m Liz Doughman, the editor of WATT PoultryUSA and Poultry Future.
In today’s episode, my guest is Kay Russo, DVM, partner at RSM Consulting.
As I’m sure many listeners are aware, the current HPAI outbreak has devastated the U.S. poultry industry, with the largest impact felt in turkeys and layers. Avian influenza has also been detected in dairy cattle and people associated with poultry and dairy farms.
Thanks for joining me to talk about avian influenza, Kay.
How did you discover that avian influenza was infecting dairy cows?
Kay Russo, DVM, partner, RSM Consulting: It started back in March for me, ultimately. There was a sort of mystery disease circulating in dairy cattle in Texas and it started in the January/February timeframe. I got pulled into it in March.
I was a clinical dairy veterinarian for several years, and later in life, I went back and pursued training and a board certification in poultry medicine. One would say that never really seemed relevant until this whole debacle.
Anyways, I got a call one day: ‘Hey, Kay, will you call Dr. Barb Peterson in the panhandle?’ – She’s one of the clinical veterinarians down there. – ‘and see if you can offer any assistance?’ I called her and we texted back and forth and we talked, and the symptoms weren't like anything we'd really ever seen clinically. All the the usual tests were coming up negative so I got to wondering with the symptoms as they were. We had digestive symptoms, respiratory symptoms, we had mastitis. I got to thinking we've had influenza jump into a number of different species, particularly H5N1 in the last two years. And I suggested to Barb that maybe this is something that we ought to look for.
Serendipitously, later that day, I got a call from another individual I used to work with when I was in practice, and he says, ‘Hey, will you talk to Dr. Nick Schneider,’ who's another veterinarian down in the panhandle. And so I said, ‘okay, But Aaron, I think I think this might be flu. I think we should look into this.’
Immediately, Dr. Schneider called me. He said, ‘you think this could be flu?’ And I said, ‘Yeah. What are the birds doing on the farm?’ And he said, ‘you know, I've noticed a lot of them are dead.’ I said, ‘what?’ He said, ‘well, I figured they were poisoned.’ And so immediately we all sort of started texting, and I suggested that they pick up some of those birds and test them for H5N1. Dr. Barb submitted some birds, and they came back positive for H5N1.
At that point, I started to run around like kind of a frazzled Paul Revere, and I was emailing vets and regulatory bodies like the National Veterinary Services Library (NVSL) and the Centers for Disease Control (CDC) because at the same time, we were seeing humans that were demonstrating symptoms. Everything I was reading in the literature was 50 percent mortality rate in human cases worldwide.
I'm thinking, oh my gosh, if this is truly H5 in cattle, and we're seeing it in humans, what are we dealing with here? And then we started to see cats on the farms that were neurologic. And so after the birds tested positive, Dr. Barb got one of her buddies at Iowa State to run flu tests on the milk and some cats. And that was our first positive.
Truly, it was a scary time. I mean, these vets had sick people, they had cows, birds, cats that were neurologic on the farms. And there were really only a handful of us that knew that this could be H5. We really didn't know what the regulatory agencies were going to do. This announcement came out on a Monday after the test was confirmed by the national labs and we're all bracing, but the agencies really didn't do anything.
That's when it really sort of took off. We started mobilizing as a small group and submitting samples for testing to various researchers to sort of start to piece this puzzle together, in the absence of any guidance, which was really the first data that was generated on flu and cattle.
I know I’m running on a bit, but it's really kind of an interesting story. Maybe, maybe there will be a movie about it someday. Who knows?
Doughman: Now I have to ask who would play you in a movie?
Russo: We thought about this jokingly in the beginning, Have you ever seen Home Alone 2 in New York? You know that crazy pigeon lady? I want her to play me if she’s still alive.
Doughman: Are there any differences between how avian influenza presents in poultry and cows?
Russo: Both species – as we've seen in the last 10 months or so – have an appreciable morbidity rate. That means a lot of the population that gets infected gets sick. However, in poultry, there's also this high mortality rate, meaning a lot of them die.
On the dairy side, the herds that are infected over time will return to normal production relatively speaking, however, they're often, on average, a couple of pounds, if not more, below where they were before or where they should be. And if we look of cull rates, so sending cows to slaughter due to lack of production, those are variable after, during and after infection. That has to do, in part, to management, conditions, weather and other factors that can exacerbate the disease state.
Ultimately, there's been this narrative that sort of started in the beginning of all this, that this is a virus that only infects lactating cows, and it's only confined to the utter of those cows. And I don't think that narrative is aging. We're finding this virus in multiple organ tissues of these animals. We've seen seroconversions, so antibodies in nonlactating animals.
If we look at the disease in the two different populations, where it really gets interesting is looking at it from a regulatory standpoint. Now in poultry, this virus is a foreign animal disease, and it requires depopulation to slow the regional spread of the virus.
This is the same virus in dairy cattle, but ultimately, it's not been managed that way. What we've seen is this sort of ballooning regional spread of the virus because we're not controlling it. That's been exemplified in areas like California in the last couple months.
It's remarkable that the same virus in two different animal agriculture classes has such a different regulatory playbook.
Doughman: In a perfect world, what would the poultry and dairy industries do to slow the spread of avian influenza?
Russo: That's a big question. I think the answer to this lies in this three-legged stool analogy, if you will.
The first leg is keeping the outside out, and that's basically biosecurity. The second leg is keeping the inside in. In infected herds or flocks, it’s quarantining. In the case of poultry, it’s quarantining and stamping it out. Then the third leg of that stool is improving the protection of the host, the animal that could get infected.
If we look at biosecurity, which is where a lot of the emphasis has been, we have conceptual biosecurity, structural biosecurity and procedural biosecurity. These all mean different things.
We do need to stay on top of biosecurity, because there can be procedural drift over time with any group of workers. If you do things day in and day out, ultimately the procedure ends up drifting. So, we do need to stay on top of that.
But the inherent problem in my mind here is that we can't really expect poultry farms or dairies to be biosecurity level three facilities. There's theory, and then there's reality. If we look at some of the recent data that I've seen, at least both in the dairy and poultry outbreaks, some of these farms are getting infected, for instance, after high wind events.
Everyone sort of tiptoes around this scenario, because it's hard to control the wind, right? We can't control the weather. But I do think we have to consider things like this, because we don't filter the air entering into most poultry facilities, like we do in swine, for instance. This is an access point for the virus, even in the face of good biosecurity. And so that's the first leg.
The second leg is quarantine. Don't move animals during quarantine. Shut it down. In the last 10 months, we've had dairies that are quote-unquote quarantined, but that continue to move animals to slaughter and move young stock on and off the operation. So, so really isn't quarantine, right?
This is a poultry podcast, but if you have any knowledge of dairy, you'll know that dairies replace 30 percent of their herd every year. It's not done all at once, so it's done on a rolling basis. And what does this do with an infected situation? It's constantly adding naive animals into this population, which allows that virus to sustain itself.
Is it possible for modern dairy to shut down movement at this point? I don't think so from a welfare standpoint, it's come at a huge cost to neighboring facilities. I mean, we've seen spillover to poultry. We've seen spillover to other dairies, in part, because of this.
Finally, on this three-legged stool, we've got this immune status in the animals. Part of that's good management of air quality. Then this billion dollar topic of vaccination, and it's kind of a contentious issue, but I believe vaccination of poultry and other at risk species really needs to be considered now and in the immediate future.
Doughman: What are your thoughts on the recent updates to the U.S. Department of Agriculture (USDA) poultry indemnity program?
Russo: That's another great question. The USDA, I think, is placing all of their eggs into this biosecurity basket. No pun intended for the poultry podcast. Don't get me wrong, I think biosecurity is essential, but it's really only one leg of that three-legged stool.
We saw positive shifts between the 2015 outbreak and the current outbreak in the sense that heightening biosecurity and rapidly stamping out flocks that were infected did, in fact, reduce lateral spread of the flu between poultry farms.
Now, at least up into the point where cattle were infected with this virus, most of the infections are attributed to sort of these point source introductions from waterfowl. That's until cattle came on the scene. That changed the game because they aren't held to the same standards as poultry. We're again seeing a lot of lateral spread coming from them, spilling into the poultry. We've got poultry facilities at this point that are damn well biosecure and they're still getting hit.
I think focusing on biosecurity alone is really an oversimplification of the H5 problem. For the USDA to sort of bear down on that for poultry given the recent biosecurity audit announcement, it just seems a bit off to me. At times like this, it feels like they're trying to mop the seashore, right?
We've seen a lot of spillovers, not only from cattle to poultry, but also in the peridomestic species. What I mean by that is rodents, cats, birds and we've seen it in domestic pigs in Oregon. We've seen it in humans. What is the role that these spillovers play in this regional viral ecology? It's still yet unclear.
The risk factors associated with other production animal species like beef cattle and swine up until this point have been largely ignored. So clearly, our tactics aren't keeping up, necessarily, with the viruses’ new tricks.
The last thing I want to say on this is that the American Association of Avian Pathologists (AAAP) assembled an H5 task force that really focuses on driving solutions to address this issue. They really nailed it when they called for better and more transparent regional surveillance tools for all species that includes poultry, cows, pigs, horses, domestic animals and waterfowl. They asked for a more consistent risk based national response, more investment in understanding this complex viral ecology I've been talking about and finally, investment and a real intention to actually employ vaccines for all at risk species and populations. You can go online and look up that statement that was drafted by AAAP, but it really summarizes this nicely and where I think the USDA does need to head.
Doughman: Should we be concerned about avian influenza jumping to people outside the dairy and poultry industries?
Russo: That's another looming question that's being asked frequently in the news. The short answer, I think, to that is we do need to stay vigilant.
The individuals that are being most at risk are those with direct contact with infected birds and mammals, so dairy and poultry farm workers, backyard bird owners and those with regular contact with migratory waterfowl, for instance. But, with these spillover events that we're seeing into other species, this virus is kind of casting its net quite a bit wider, and so this may have more impact on the population at large.
The CDC says the risk to the general population is still considered low because we haven't seen clinically any human-to-human spread. I've heard of anecdotal spread, but it's not been documented clinically by the CDC.
Ultimately, we need to be alert however, because a few minor changes in the genetic sequence of this virus or a more significant change – like a reassortment event between an individual that's infected with a human flu strain and H5 that they picked up from a dairy cow that could result in a rapid change in the properties of the virus and the risk to the population.
The CDC says for workers that are at risk, get your seasonal flu shot. This helps to avoid one of those major reassortment risks. If we look at the populations that are currently most impacted, they're rural populations. At the start of this, it was damn hard to get a rural health system to even consider the possibility of H5 infections in humans. I spent one afternoon on the phone trying to find a clinic in rural Texas that would test workers with even a rapid influenza A test last March, and it came up short. As we look at this and we monitor this over time, these point of care tests at the at the local level are going to be crucial to identifying cases early and identifying cases before we see a major shift in in human infections.
So again, we need to stay vigilant and hold our state and national public health systems accountable for rapidly sharing info so that these local health departments can assess this risk.
Between you and me and everyone else listening in the wake of COVID, it's kind of shocking how sluggish the response to this threat has been, at least as it trickles down to the local level. If there's one thing I can say, for animal agriculture and those folks listening in, I think we need to make certain we continue to stay on top of food safety in the face of this outbreak to avoid products entering the marketplace with live H5 virus. Just in the last few weeks, we've seen raw milk that is infecting cats in California that was sold from stores. Most recently, we're seeing a raw pet food recall that contain infected turkey. We need to keep up with this situation and stay vigilant.
I know that was a long answer, but it's kind of a complex problem at this point.
Doughman: There are a lot of misconceptions about food production. How should agriculture be communicating with the general public about avian influenza?
Russo: I'm probably not the best person to ask that question. I am a brutally honest person, and I expect the same from those with whom I communicate.
I personally believe it's important to give the public, or at least the scientific community, the facts in such a way that they can understand them. The caveat is that this is a rapidly evolving situation, and what we know today may change tomorrow, but I feel like if we leave voids in what we share, the general public will start to fill in those gaps with speculation which could ultimately cause more harm than good.
I've seen this some with the regulatory agencies, where there is quite a lot of information that isn't shared even with the scientific community. This ends up resulting in a lot of hand waving to fill in those gaps and I think that does more harm than good.
At the end of the day, I believe over-communication and honesty is the best policy, because people can deal with what they know. It's sort of this unknown that ends up breeding misinformation, speculation and ultimately distrust.
Doughman: Thanks again, Kay, and thanks to you for tuning in. For more episodes of the Future of Poultry podcasts, please like and subscribe on WATTPoultry.com or wherever you access podcasts.
