The Agenda with Steve Paikin (Audio) - What Ontarians Need to Know About Bird Flu

Episode Date: March 6, 2025

Most people don't even want to think about the prospect of another pandemic. But experts are warning that it's important to track and contain H5N1, more commonly known as bird flu, which has been detected in Ontario. Recently, it's forced poultry farms into quarantine and turned up in Canada geese. Last November, it caused the hospitalization of a British Columbia teen. So, what do we know about avian influenza - and how concerned should we be? Joining us now on that, in Guelph, Ontario: Dr. Shayan Sharif, professor of immunology at the Ontario Veterinary College; And here in our studio: Dr. Samira Mubareka, infectious-diseases physician, medical microbiologist, and scientist at the Sunnybrook Research Institute. See omnystudio.com/listener for privacy information.

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Last November it caused the hospitalization of a British Columbia teen. So what do we know about avian influenza and how concerned should we be? Joining us now on that in Guelph, Ontario, Dr. Shayan Sharif, professor of immunology at the Ontario Veterinary College. And here in our studio, Dr. Samira Mubarakka, infectious diseases physician, medical microbiologist and scientist at the Sunnybrook Research Institute. Great to have you both on our program again for sadly what is a rather timely topic again. Dr. Mubarakka, let me just start with you. H5N1, what does that code refer to?

So that refers to the subtype of the virus. There are many different types of influenza virus, and what we're talking about today is influenza virus A. So both influenza virus A and B can infect humans. Influenza virus A also infects a wide range of other animals. And the subtypes refer to the proteins on the surface of the virus.

So hemagglutinin is the H, and neuraminidase is the N. And the H5N1 subtype is the avian influenza subtype that we're concerned about, because it's highly pathogenic in chickens. Excellent, okay. Dr. Shreef, the bird flu detected in Ontario. When did that first happen? It actually happened almost to the day three years ago

in 2022, not that far away from the place that I'm speaking to you from in city of Guelph. It happened very close to us. It was first detected in Ahoke and that was not quite surprising, but has actually transpired over the last three years or so has been somewhat surprising and I can

go into details in the future. Well okay maybe as you take us on that path you can let us know it started in that one instance but how prevalent is it now? It is actually quite prevalent, especially I would say across Canada it was quite prevalent in BC, in Alberta, and also in Ontario, Quebec, Saskatchewan. So all provinces have actually had major cases of outbreaks of avian influenza over the last three years or so. I would say BC has really taken the brunt of those outbreaks in Canada. It has suffered the most, specifically in Fraser Valley of British Columbia, but other provinces have also suffered immensely. And Dr. Mubarka, how widespread has it become in other animals now? Well, I think that's been a major red flag.

We've seen spillover of this virus into many other mammals. No doubt people have heard about what happened in the US also approximately a year ago with spillover into dairy cattle. And we've also seen intermittent spillover into other mammals, some of them wild, but also some domestic animals. So here in Ontario, we've had spillover into at least one dog, and there have been spillover

into cats in various jurisdictions. So it's really been a major concern. And then, of course, there's been spillover into humans as well. And into poultry farms. How does it get into poultry farms and therefore send the price of eggs and chicken and everything else way up?

Well, there are a number of different mechanisms. But predominantly, it's spillover from wild birds. So wild birds are the reservoir for the virus. And we know that wild birds migrate. There are four migratory flyways here in North America and spillover from these birds into poultry farms is something that is a major driver of those outbreaks. But I'll hand it over to Dr. Sharif who's an expert in poultry biology and disease. Sure, pick up the story please. All right,

thank you very much Dr. Mubarak. As Dr. Mubarak mentioned there are many different ways of transmission of the virus. First and foremost in this particular case for this particular strain of virus we do know that micro-herb birds play a very key role. However, there are also many other ways for transmission of virus. For example, the virus might be aerosolized and it might travel from one place to another place, depending on humidity, depending on temperature of the environment, depending on many of the environmental conditions. So that's one way of transmission of the virus. The other transmission route for the virus is via what we call fomites.

What it means is that things such as, for example, equipment, machinery, things of that nature that can be moved from one farm to another farm could carry with them the virus and those could potentially cause transmission of the virus from one place to another place. Human beings can also act as a method for transmission of the virus and what I mean by that is that when we go to a farm and our shoes, our boots are contaminated, potentially when those boots and shoes go to another farm potentially they can carry the virus mechanically and cause transmission from one farm to another farm. But as Dr. Mubarak mentioned correctly, for this particular strain

of virus the main mode is via migratory periods. If this thing can literally fly across the country, Dr. Mubarka, how exactly do we stop it? Well, I think one of the key things is to know where the virus is and what it's doing. So surveillance is one major component of the response because mitigation really depends on knowing those two things. We also know the virus is re-assorting.

So, you know, re-assorting. So the virus has, it's comprised of genetic segments that can be switched between low pathogenic avian influenza viruses, highly pathogenic avian influenza viruses, and it can also mutate and acquire adaptation. So being aware of all of these factors and knowing what the risks are associated with any of these changes is really key. And then of course there are some of the things that are really important, biosecurity on farms

in terms of preventing spread between farms and within farms obviously and also between species, you know, poultry and humans, poultry and any other animals. And then of course there are some other key things that can be done. So vaccination can always play a role and you know that's a much more complex discussion than you know simply saying oh well why don't we just vaccinate all poultry or all humans. There's so many different considerations that have to go into that. I would assume that's impossible to do. Well vaccinating poultry as opposed to wild

birds would be more feasible but there are implications for trade and again Dr. Sharif would know a lot about that. Vaccination for humans we know you know now that Canada has procured vaccine stockpile that's being manufactured here in Canada you know the provinces will consider how to roll that out but I think that that's going to be a major activity or preventative measure that can be done to try and mitigate spillover into humans who are at high risk. Okay, vaccinating humans, Dr. Sharif, we all get, we've been through COVID, but I would assume vaccinating animals is just a non-starter.

I mean, how do you do that? Well, as a matter of fact, Steve, you would be surprised to know that every chicken in Ontario that is hatched and raised in this province receives at least a few doses of vaccines, a variety of different kinds of vaccines. But up to this point, we don't really have a vaccination strategy and roll out for avian influenza vaccination. However, if you look at other jurisdictions, such as, for example, China, Mexico, parts of South America,

they've been continuously and consistently using vaccines for protection against avian influenza and also some other jurisdictions, for example, in the European Union, the French authorities, almost a year and a half ago or so, they gave the go-ahead to the industry to start vaccinating their poultry. Not every species within the poultry industry, they only focused on ducks. So geese, turkeys, and chickens were not vaccinated. However, that's also a possibility,

and I understand that some other European countries are also looking at vaccination as a potential method for mitigating the risk of transmission. But I should just mention that vaccination is just one tool in the toolbox. There are many other tools in the toolbox that one needs to use, such as, and I would say first and foremost, biosecurity.

And what I mean by biosecurity is the measures that you put in place to ensure that there is no farm to farm transmission. We cannot really prevent migratory birds from migrating. There may be some drastic measures that one can use in order to prevent migration of birds, but I think this is going to be a catastrophic event for our ecosystem.

So as a result of that, we only have a certain number of elements at our disposal that we can use in order to be able to control the virus from spreading from one farm to another farm. And I call those biosecurity measures that farmers can put in place. And they have already done that. So it's not as if this is something brand new for the industry. They've already done it. But it seems that this virus, similar to COVID-19, Steve, as you pointed out, it seems to be actually finding those vulnerable spots and it starts penetrating through those spots. And that's why I think you know we need something above and beyond

by security. Well you used the word catastrophic there so let me ask about cats. If you've got Dr. Mubarakkha, a cat is now a good time to make sure it does not go outside. That's correct. And it's interesting because cats have not only exhibited severe disease and, you know, actually succumbed to infection through what's called necrotizing encephalitis. So, you know, it's a very neuroinvasive disease in cats and can be fatal. But they've also acquired the virus through a number of different routes. So one could be through predation, so birds, obviously, sick birds.

But also, it sounds like from what's going on in the United States, in terms of dairy cattle, cats have also picked up the virus in barns, probably from drinking raw milk. And then also, there's the whole raw pet food recall that's been an issue. So again, mostly in the US where cats have, we think are probably infected from consuming raw pet food.

And then lastly, I think last week or the week before, there was a possibility that a cat, an indoor cat may have acquired an infection from their human owner. So cats are companion animals animals but they can also be feral. So they're one of those animals that can be peridomestic, domestic, and obviously at fairly high risk. So I think we're going to have to really make sure that we do good surveillance in cats as well. If an animal gets H5N1, what does the virus actually do to the animal? It depends on the species and that's something we have been completely broadsided

by with the dairy cattle. So that clinical manifestation is quite subtle. It doesn't look like a clearly respiratory disease. The virus is passing through mammary glands, through milk. So the cows, apart from the change in their milk production, looked fairly asymptomatic and again I deferred to my colleague in the agricultural sector to expand on that but it really some animals seem to get quite sick and succumb to the virus others are relatively what we would call

posse or asymptomatic, few symptoms. I think in humans it's too early to say. We know historically this virus has come with a high mortality rate but those were more ancestral strains. More recently we're seeing people presenting with conjunctivitis and recovering. So but those are also people who are relatively you know healthy young adults so time will tell. So Dr. Sharif most of the time this is not a fatal disease is that right? this is not a fatal disease, is that right? It's not a fatal disease in humans,

at least as Dr. Mubarak mentioned, the ancestral virus, the virus that this particular strain at the moment was derived from, that one was quite fatal. This one doesn't seem to be fatal in humans. However, when we talk about highly pathogenic virus, it means that it causes severe disease in chickens. And this virus causes severe disease in chickens. It can cause up to 100% mortality in chickens. So it is indeed severe, but it depends on the species. And I specifically said chickens, turkeys are also quite susceptible. However,

when it comes down to waterfowl, like ducks and geese and so forth, some species are susceptible, some species susceptible in the sense that they can catch the virus, they can shed the virus, and also they can show clinical signs of disease and eventually die of disease. Whereas some species of waterfowl seem to be actually quite resilient or resistant, so they pick up the virus, but they don't necessarily show clinical signs of the virus. So there is quite a bit of, I would say, variation in terms of clinical signs. For this particular virus, we didn't really know to what extent birds of prey, like hawks and eagles and so forth, would have been susceptible.

But with this virus, we came to to realization that they are quite susceptible. But this is not a normal situation where you have resistance across the board for many avian species but some of them are susceptible. In this case it seems that hundreds of species of birds appear to be susceptible. And I'm not going to speak too much about mammalian species because that's also a very interesting observation that we've been making over the last two and a half, three years or so, is that many mammalian species also seem to be susceptible.

Let me ask you, would you eat eggs or dairy right now? Absolutely. You would. As long as they're pasteurized and cooked. Not an issue there. Correct. Because, you know, we have seen in the United States, obviously, that I think that 35 million birds commercial flocks had to be culled because of all of what's going on right now.

Have we had a situation in Ontario where we've had to cull a lot of poultry, chickens, whatever? Absolutely. And I would actually add outbreak control to one of the key ways of preventing spillover. And I have to say, our counterparts on the animal health side are really what's standing between us and a severe outbreak, or even pandemic, in humans.

It's that stamping out an unfortunate but necessary depopulation of birds. So in Ontario, it's been least a million across Canada, you know, somewhere in the range of 15 million. A million what, or 15 million what? Poultry. Poultry alone. Yes, yes.

So a million in Ontario since the beginning of, just over, yes. So we should presumably be looking at increased prices for these things as a result. Well, it's hard to know, but one would anticipate depending on the extent of the outbreaks and control of possibility. I don't know if Dr. Sharif has some thoughts on that as someone who works in... Well, I want to know if you... Would you eat dairy and poultry right now? 110 percent. So here's the thing, Steve. I do as long as my my dairy and as long as my eggs are cooked.

If we were eating, let's say, raw chicken as part of our sushi meal, then I would have said maybe this is not the best time, you know, to eat sushi made out of raw poultry. But we don't. So as a result of that I would say fully cooked chicken meat, fully cooked eggs, and fully cooked, fully pasteurized dairy should be fine to consume. Raw milk, raw poultry, raw eggs, that's a totally different story. And Dr. Mubarak correctly pointed out that there has been some recalls for pet foods made out of raw materials.

And that was probably the source for contamination and infection contamination with H5N1 and potentially transmission of H5N1 to cats. So I would avoid at all cost raw materials from poultry. But the reality is that if we haven't really had this issue in Canada, the issue arose in the US and it seems to be a US issue. But it has also happened in the past in Europe. For example, in Poland a couple of years ago, we had a very similar situation with raw pet food that caused infection, H5 infection, in domestic cats. Dr. Mubarka, are we in a situation right now

where we are going to be thinking about, at least, having to vaccinate the whole population of the province of Ontario to deal with this? Well, I think at this stage, there are some populations that are higher risk, and aiming to vaccinate those individuals would be the priority. And aiming to vaccinate those individuals would be the priority. And they would be who?

So individuals who might be involved in some of these Departments. Working on farms, that kind of thing? Exactly. Handling wild birds, individuals, for example, in our fields that are working with the virus itself. So it's important to be able to protect people whenever possible.

But I do want to draw attention to the fact that at the moment, if this table were wood, I would be knocking on it. We have not seen sustained human-to-human transmission. However, there was a major shift last year in that we did start seeing sustained transmission among mammals, and that's the dairy cattle story. And some would even argue that the mink farm outbreaks might have been you know sustained transmission we are not sure if that's from contaminated feed or or actual sustained transmission between mink but clearly there's sustained transmission

between cattle so we're not at that point with humans where we've seen sustained human to human transmission but I think this is what preparedness is about. And I think the fact that we have some vaccines stockpiled, people are starting to think about what the next steps are and how we can integrate lessons from the pandemic, the COVID-19 pandemic, so that we don't find ourselves in a similar situation. Now is the time for that.

This is the window. You know, Dr. Shreeif, I'm trying to remember. I think it was a character on Saturday Night Live who once upon a time said, it's always something. And it feels like, you know, we had COVID, and now we've got this. And, you know, a few years from now, it's going to be something else.

Are we in a new normal now where it's always going to be something? Obviously, there's always going to be something. I can tell you that if you had asked any virologist 10, 15 years ago, can you look into your crystal ball and let us know what would be the next pandemic? They would have probably pointed out maybe not two viruses on the top of their agenda, coronaviruses and influenza

viruses. And look what happened. We had COVID-19. It doesn't mean that there would be no more pandemic caused by coronaviruses. No, I think, you know, coronaviruses are here to stay. So it may not be COVID-19. It may be, you know, something else. Dr. Mubarak has been at the forefront of fighting COVID-19,

and she was also at the forefront of fighting SARS at the time. So she knows a lot about these pandemics, if and when they happen, and how they happen and how they unravel. In the case of influenza, I can tell you one thing. The fact of the matter is that over the last hundred years or so, since we've recorded pandemics caused by influenza viruses, including the 1918 pandemic, all of the pandemic viruses have had components of avian influenza viruses in them. Influenza viruses have a natural host, which is essentially avian species, be it chickens,

turkeys, migratory birds, or other kinds of birds like seabirds, shorebirds, etc. So these viruses are going to be in the environment. They're going through a lot of changes, evolutions that happen to them. Dr. Mubarka talked about changes in their genetic structures. She called it reassortment. What it means is that they exchange their genetic material. So it's really like breathing a new virus, or they undergo mutations.

So they change their genetic material all the time. Every second you have a new virus erupting. So it's just your luck, whether or not that virus is going to be the next pandemic virus, or that virus is going to be, let's say, a benign virus that doesn't do anything. So it's really your luck. But we can say one thing for sure.

There is going to be another pandemic. It may not be H5N1, but it's highly likely that it's going to be caused by either coronavirus or an influenza virus. When that would happen, no one knows. In our last 20 seconds here, how prepared are we to handle this right now? We are more prepared than we were with COVID-19.

We're building on decades of influenza virus research. Are we 100% prepared? No, we still have a lot of work to do. Okay. Well, I want to thank both of you for coming on our program and helping us out with this tonight. We know a lot more about it now than we did 22 minutes ago. Dr. Shahin Sharif and Dr. Samira Mubarakha.

Thanks so much to both of you. Thank you so much.