The Decibel - What the spread of bird flu signals about another pandemic

Episode Date: December 9, 2024

In November, Canada’s first case of avian flu in a human was confirmed – a teenager in British Columbia, who remains in critical care and on a ventilator. Dozens of cases have been reported in the U.S. too, as it appears transmission from infected animals to people has increased. Some scientists and public health officials have warned that this virus has potential to be the source of the next pandemic.André Picard, the Globe’s health columnist, joins the show to talk about the hard-won lessons of the COVID-19 pandemic and why we should be paying attention to what comes next with avian flu.Questions? Comments? Ideas? Email us at [e-mail]

It began with pink eye and quickly turned into a severe lung infection. That's how BC's health officials describe the symptoms of a teenager who's sick with avian flu, Canada's first confirmed case in a human. The patient remains in critical care and on a ventilator a month after getting infected. Avian flu has been on the rise this year, with dozens of cases reported in the U.S. It's believed the virus is transmitted to people from infected animals. If this is all sounding a little familiar, that's the problem. Some scientists and public health officials say this pathogen could be what leads to the next pandemic. Andre Picard is The Globe's health columnist.

He'll tell us what we know about how avian flu is spread, the lessons learned from COVID-19, and what should happen now to make sure we're prepared. I'm Mainika Raman-Wilms, and this is The Decibel from The Globe and Mail. Andre, thank you so much for taking the time to be here. Hi. So let's just start with the basics here. When we say bird flu or avian flu, what exactly are we talking about? We're talking about a flu that spreads in birds. You know, every species has some form of

flu. And this particular bird flu called H5N1 is the one we're really concerned about. It's been kicking around since about 1996, when it was first discovered. But then it moved into livestock of poultry in 1997, with a really damaging outbreak in Hong Kong, 18 cases, six of whom died. So that really got the world's attention. We started worrying then about a possible pandemic. And since then, it's come and gone in waves and it's moved its way around the world. So it's moved to China, Europe, and now it's come to North America. Interesting. Okay. So from what you're saying, it sounds like this can be a fairly serious flu for birds and other animals. Is that the case? It's quite deadly. We've actually seen millions of birds dying, wild birds in the last decade or so. It's really ramped up in recent

years. And it's moved into hundreds of species. So we've had mass die-offs of seals, for example, and we see it in all kinds of animals, skunks, everything you can imagine, cats. Every type of animal has had some bout of this flu. Wow. And when we're talking about an avian flu like this and how it's spreading from animal to animal, does it spread, I guess, similarly to how things spread with humans, like sneezing, things in the air? Is that how it works? Well, it works between a species. So within a species, that's how it spreads, coughing, etc. But it's very rare that flus jump between species. So that's what's unusual. That tends to happen because of scavengers. So animals that eat dead birds are getting it. Cattle is exposed

because wild birds fly over them, intermingle. That's why poultry got infected in large numbers, because they interact with wild birds. But you don't generally, you wouldn't generally say catch the flu from a chicken, because the species are very different. You have to have some fairly serious contact. Okay. And so how concerning would you say is this, that now we know it is spreading to other livestock, as you said, cows, and now we're hearing pigs as well. What does that mean to you? I think the pigs is the most worrisome. That's where a lot of our flu starts. It always starts in poultry or in swine. That's where humans have the most interaction with animals in the world. So swines are actually considered a really ideal mixing bowl. They're very similar to humans in their makeup biologically. So they have very similar

flu viruses to us. So that's the most concerning. As far as we know, only one pig has been infected with H5N1. But once it starts spreading in swine, I think we would have to worry a lot more than in poultry or in cattle, which is what we're seeing now. Yeah. Can you tell me about that pig that's been infected? Where is it? What do we know about that situation? We know there was on a farm in Oregon. We know that farms had both poultry and swine. So there was probably some interaction there. Often waste is fed to pigs of all sorts and vice versa. So it's probably that way. So it looks like it was fairly limited. There's no evidence that it spread to other pigs, which is really good. But again, there's so much flu out there that you can't help but think this is going to repeat itself and it could start on a larger scale somewhere else.

And can I ask you a little bit more about this flu in cattle, Andre? I guess, what are the ramifications of it then in cattle? Yeah, so it is a big economic issue. So right now in the US, it's in dairy cattle. There's almost 600 herds that have been affected. So they get isolated. Unlike poultry, we don't slaughter cattle. That would cost way, way more money.

So we're just trying to contain it, make sure those cattle don't go to other farms, for example. But it's spread quite widely, especially in California. What's the risk? The risk is right now, if you drink raw milk, this virus has been found in raw milk in two places in California. So technically, theoretically, humans could contract it from milk. The good news is we know pasteurization works. There's a lot of reasons to not drink raw milk, but this is another one. Yeah. Okay. So you mentioned birds being slaughtered as well, which is kind of a way of us, I guess, controlling the flu. How many birds have we actually killed because of this now? Well, there's been a massive campaign to try and address this.

In the U.S., they've culled 111 million birds. Canada, about 12.9 million. Currently, we have in B.C. a fairly large outbreak in the Fraser Valley, so there's been more than a million birds culled just in the last month or so. So this is an ongoing issue. It's been going on for years, but again, this is fairly recent in North America. We saw these mass cullings in China, in parts of Asia, and then in Europe over the years.

And now it's North America's turn. So from what it sounds like and the way you were talking before about how flu spreads, this seems like kind of a global phenomenon. And this is not just something that's isolated to North America right now. This is happening in other parts of the world then, too. Oh, yeah, it's happening all over the world. We're kind of late to the party just because of the way the flu moves. But, you know, in China, they dealt with this in the late 90s and in Europe in the 2000s. And now it's. This is obviously the most concerning thing here. If humans are infected with avian flu, what are the symptoms and how serious is it? Well, the flu is essentially the same.

The symptoms are always the same. You have the cough, you have the fever, the breathing problems. It's when it gets further into your lungs, perhaps if you have other immune issues, that it becomes serious. It can develop into meningitis, pneumonia, and that's what kills people. Now, this flu in particular, because we have no natural immunity to it, that's why it's concerning. It's a new reassortment of the flu viruses. So the H5 and the N1 joining together. So far we know of 904 people in the world who've had that infection, and 464 of them died. So that's half of people who are getting this infection are dying. But we have

to be careful that there may be other cases out there that are mild, we don't know about them. But the mortality rate is not to be dismissed out of hand, I guess I would put it that way. Can I ask you about the case of the teen in BC, because this has really made headlines in Canada Mortality rate is not to be dismissed out of hand. I guess I would put it that way. Can I ask you about the case of the teen in BC? Because this has really made headlines in Canada in the last month or so. What do we know about that situation? Yeah, this story has made headlines around the world in a lot of scientific journals because it is very unusual. So we know it's a young person.

We don't know the gender, the age, but we know it's a teen. Don't know how they contracted the H5 but we know it's a teen, don't know how they contracted the H5N1. That's the most concerning. From the genetic analysis of the virus in the person's body, it likely came from a wild bird. So we're thinking probably this teen handled some sort of dead bird and contracted it. So that's concerning because it shouldn't be that easy to catch the flu doing that. It suggests that the virus is getting a little easier to transmit. And then this person also got very, very sick. They're on a ventilator, on life support for a while, seem to be getting better now. But again, that tells us that this flu is adapting to humans. It's moving further down into the lungs.

Because we've had several cattle workers in the U.S. infected, and they had very mild symptoms. All they had was pinkeye, conjunctivitis, and that's fairly minor. So this case has really got a lot of attention around the world. Yeah, yeah, it sounds like it. And you mentioned those cattle workers in the U.S. Is the understanding that they contracted it from the cows they worked with or do we know? It's almost certain that they got it from the cows they work with. We think that it's spreading in cattle through milking machines. So cows are, you know, it's a very industrial process. They

get milked every day. A lot of them go on the same machine. The workers touch this. It's fairly messy work. And they would breathe in this virus and get infected. And we know of 58 cases so far. Do we know, are these situations where humans have contracted it from animals? Or is there human-to-human transmission happening? We don't have any evidence so far, luckily, of human-to-human transmission. That would raise the alarm a lot higher. But as far as we know, these are all individual isolated cases of people being in touch with poultry or cows or some combination of the two. So I guess then I wonder, so if we don't really have the human to human transmission happening yet, and there seems to be only a handful of cases of other people being infected by animals, is this something that we need to worry about then? The flu comes along all the time.

We don't get these new novel pathogens too often. So we should be concerned. I wouldn't say worried, but I think we should be vigilant. I think that's the important thing. What's concerning about what's going on in the U.S. is that there's no effort to sort of track what's going on. So there could be, the assumption is that there's a lot more of this in cattle than we know.

And the industry doesn't really want to know. The government is friendly to industry in the US, especially the cattle industry. So they're not really pushing this. So that's the worry. If there's a lot of flu in cattle, it's going to get into more humans. And eventually there will be human to human transmission. That's what we should be worried about. We'll be back in a moment.

So, Andre, it sounds like this is a disease that, as we know now, is being transmitted from animals to humans. I think that might remind a lot of us about the origins of, of course, COVID-19. I guess I wonder, André, have we learned anything from the COVID-19 pandemic that could really help us be ready here if avian flu becomes more serious? Yeah, I'm not sure as someone who's written a lot about COVID, I'm not sure we learned anything from the pandemic. Unfortunately, we seem to always repeat the same mistakes. And again, we're seeing them with H5N1. We're seeing this complacency. I think that was the biggest lesson of COVID

is you can't be complacent when something new comes along because it's easy to tackle it when it affects a few people, a few animals. Once it gets into the general population, you can't put the genie back in the bottle. So we should be worried, and we should be worried even if it's a mild virus. You know, pandemic doesn't necessarily mean something's deadly. This could be a very mild

form of the flu, as we saw during the last pandemic, flu pandemics in 2009 of H1N1. It was actually very mild. Not that many people died, even though it was a novel virus. So these things are complex. But I think that's the big lesson of COVID for me, that we just have to be vigilant and we should track this stuff and not just pretend it's not going to matter. But it does sound like there's a possibility then for this potentially to be the next kind of pandemic that we do see. Yeah, absolutely.

It does have that potential because it is a novel virus. But again, it doesn't mean it'll be another COVID. It doesn't mean it'll be the 1918 flu. It just means that there's going to be a new risk, a different kind of risk. We don't know exactly. And we have to be cautious about that, especially for people who have underlying risks, older people, people with weaker immune systems. those are the ones who are really affected by these new diseases. So I guess what are we doing to prevent this from becoming more serious, becoming a pandemic? Because you mentioned earlier, Andre, that in the US, there hasn't really been an effort to even track cases. So what are we doing? Yeah, I think in Canada so far, I think we should give credit to our agencies like the

Canadian Food Inspection Agency. So they've been fairly vigilant watching, especially cattle moves back and forth across the border. We don't do a lot of trade in milk, but we have to watch that as well. But I think that that's the key is make sure that if it does get into a Canadian farm, and I think it's almost certain we saw that with birds. Then we have to try and contain it. You know, I think in the short term, it's about biosecurity. It's making sure that this doesn't spread beyond a single farm if it happens. Okay. So it sounds like from what you're saying, tracking and kind of just even being on top of the numbers, a little bit of a surveillance there is maybe the first step to understanding what kind of situation we're in.

Yeah. And again, this takes us back to a lesson of COVID. We didn't do good surveillance at the beginning until it really got out of control. So yeah, that early tracking is important. Just knowing that it's out there is important. What we're doing with birds, you know, these mass cullings, you have to keep doing that. I think we have to consider new things. In Europe, they're doing vaccination of poultry. That's something that needs to be explored. China did it in very massive numbers, the vaccination. It seemed to work.

So there's other things we could be doing rather than just sitting on our hands and saying, well, I hope this doesn't get into humans. It's interesting because you mentioned vaccination in poultry. I wonder, has there been work to develop a vaccine that would be okay for humans as well when it comes to H5N1? Well, it's fairly easy to develop flu vaccines. We've had them for many years. We do have H5N1 vaccines available. There was a story just a couple of days ago that Britain has purchased 5 million doses of H5N1 vaccine. The U. The US has a stockpile of 5 to 10 million. As far as I know, Canada hasn't purchased any yet. But that's the kind of thing we should have some ready. But we have to be careful to what exactly is the virus going to look like when it moves into

humans? Will we have to adapt to the latest version of it before we create a vaccine. But yeah, the technology is there. It's easy enough to do. Very different from COVID. COVID, we're starting from scratch. Here, we know how to make flu vaccines and make them easily. Okay. So of course, Andre, we are now entering flu season in the Northern Hemisphere. So a lot more of those viruses circulating as well. I wonder, could that have an impact on the development or the evolution, I guess, of avian flu? Yeah, that's always another concern is during flu season, there's more co-mingling. So often that's where new reassortments of viruses happen. So we develop these new flus, but usually we have some immunity to them already.

But if you put H5N1 into the mix, that could allow it to co-mingle with something that's already around, like H1N1 is very prevalent these days in the flu. And then it would get much more dangerous. Again, it becomes much more easy to spread in humans. So yeah, that's something people are watching carefully. You know, most people, when they get the flu, they just stay home. They don't get tested or anything. But the sicker cases, people get tested. And we do track that stuff. We look to see what are the commonly circulating flu viruses.

And if H5N1 starts to pop up, then alarm bells will go off. I just wonder if I can ask you, Andre, obviously, you've been following this very closely. You also followed COVID very closely. How concerned are you about avian flu? You know, I think being worried about this stuff isn't too, too helpful. There's always flu circulating. But I think, again, it's just about being aware of what's going on. To me, what concerns me about H5N1 is how all these little things are going on around the world,

almost independently, but they're all sort of building towards a greater likelihood of a pandemic. Seeing it in a person like in BC, which is unusual, seeing it in a pig in Oregon, seeing the big outbreaks in chicken poultry farms, the massive wild bird die-offs, all these little things add up to say, this is building a head of steam and it's coming towards humans. And we just have to be aware of that.

So I guess for other people out here who might be listening to this conversation and might themselves be a little concerned, I guess any advice for them about how they should be thinking about this? I think you just have to take precautions about the general flu. We should be concerned about that, not take it for granted. A lot of people are very dismissive. We forget that the flu is still quite deadly. It kills several thousand people a year. We've kind of forgotten about the flu because of COVID. COVID has kind of displaced it, but it's still out there. It's still deadly. And what we don't want is an even more deadly flu coming and taking

its place. So we have to be vigilant, but get on with life. Andre, really appreciate you taking the time to be here. Thank you. Thanks. A pleasure. That's it for today. I'm Mainika Raman-Wellms. Our producers are Madeline White, Michal Stein, and Allie Graham. David Crosby edits the show. Adrian Chung is our senior producer, and Matt Frainer is our managing editor. Thanks so much for listening, and I'll talk to you tomorrow.