Avian flu is evolving. How worried should the world be?

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Jordan Heath-Rawlings This is a story that could be absolutely terrifying. An investigation is underway in Cambodia into the possibility of human transmission of H five N one, or the bird flu. It was sparked after an 11 year old girl in that country died from the disease. Seals in Peru are being tested for bird flu or H5N1, which is spreading through the region. And taking with it, hundreds of sea lions, bird flu has killed more than 200 million birds across the globe since the beginning of 2021. The incoming chief scientist at the World Health Organization said governments should invest in vaccines for all strains of bird flu that exist in the animal kingdom as an insurance policy in case of an outbreak in humans. It also could not be terrible and devastating. We just don’t know. But if you talk to the experts who study avian flu, they will point to a huge spike in cases and birds transmission to mammals, some human cases, and even a rare human death. And the conclusions they draw from that is that something is changing. That doesn’t mean we are headed for another pandemic, but it is a troubling sign. It’s a blinking warning light, and by now we should know how to handle blinking warning lights when it comes to infectious diseases with respiratory symptoms. Right? I mean, if we haven’t learned. That lesson by now, it’s just not one we’re ever gonna learn. So what do we know about the massive rise in avian flu? What’s changing about it? How concerned should global health officials be and what should we be doing right now? You know, just to be safe and prepared. I am Jordan Heath-Rawlings. This is The Big Story. Dr. Shayan Sharif is the acting Dean of the Ontario Veterinary College and a professor at that college and the Department of Pathobiology. Hello, Dr. Sharif.

Dr. Shayan Sharif Good morning. I have asked this question to a doctor before a year ago, but since some people might have been tuned out then and are much more tuned in now. I will start with it. What is Avian flu and specifically what is H5N1? So, avian Influenza Virus is a member of a very large family of influenza viruses, including, seasonal flu viruses and many other types of, influenza viruses that don’t necessarily infect birds. They can infect all different kinds of species like pigs, horses, dogs, cats, et cetera, et cetera, belong to this large family of influenza viruses. H5N1 is the so-called highly pathogenic avian influenza virus. And what we mean in my scientific lingo is that this virus has the capacity to mortality, and also it has the capacity to cause severe disease in poultry. That’s why it’s called highly pathogenic avian influenza virus. So that’s what an H5N1 virus is all about.

Jordan Heath-Rawlings How long has this particular virus been present in Canada? Been infecting poultry, and other animals?

Dr. Shayan Sharif So this particular strain. H5N1 came to Canada almost 13, 14 months ago in December of 2021. But there are other H5N1 strains in Canada that have been present in Canada for many, many years. As a matter of fact, many of these H5N1 viruses have been present in water, in micro arteri birds in Canada for many years, perhaps for decades. Uh, usually we consider it pathogenic for poultry, but they’re not pathogenic, meaning that they don’t cause disease in micro arteri birds, most micro arteri birds. Like geese and so forth. So as a result of that, those micro arteris act as a reservoir for the virus. They catch the virus, but they don’t show clinical signs, and they just simply shed the virus into their environment.

Jordan Heath-Rawlings What is difference, however, this particular strain of virus that we’ve begun seeing it in December of 2021?

Dr. Shayan Sharif Is the fact that it cannot only affect wild birds, it can sometimes kill them. And as a matter of fact, there are now variety of species of birds that can succumb to disease caused by this highly pathogenic influenza virus. So far, we’ve mostly covered, similar territory as we did last year, but last year when I discussed this, the primary concern was just a decimation of the poultry industry, in North America and elsewhere as a whole.

Jordan Heath-Rawlings You kind of touched on it a little bit there. What is the concern now? How has that changed over the past year?

Dr. Shayan Sharif Uh, so the number of things have changed. First of all, now we have a much better understanding of their range of avian species that this virus can. Perhaps last year this time, uh, we had a very limited understanding of the wide range of avian species that it can infect and not only it can infect, but can also kill those avian species. So now we have a much better understanding that birds of prey could actually succumb to disease perhaps last year. We had a limited understanding of that. So that’s one component of that daily component is that now we also have record. A few cases of transmission of this virus from birds to, to mammalian species. Sometimes, you know, scavenging mammals like skunks and raccoons and so forth, and sometimes other, mammalian species like mink, like sea lion and seals. As an example, so that’s also added under the component. Also, last year, what we didn’t know and we were hoping we would never encounter is the possibility of transmission to humans. At this moment, we do know that this virus could potentially jump to humans, but it doesn’t do it very often. Thankfully, on very, very rare occasions it does do that. But when it does do that, then it could potentially have complications and implications for human and public health.

Jordan Heath-Rawlings When we say that, it’s rare that it jumps to humans, what kind of numbers are we talking about and how do we know?And, you know, this is something, that I’ve said a few times, I’ve learned a lot more about infectious diseases the past couple of years than I ever have before. But how do we know if it is making the jump more often and we’re just not testing for it, not seeing it, et cetera.

Dr. Shayan Sharif So that’s a very good question. Jordan, the the reality is that, we know what we know. We can’t really know what we don’t know, meaning that if we are not testing, then obviously we are not gonna be able to find the virus. So it is quite possible that we are just looking at the tip of the iceberg. The tip of the iceberg at the moment is only a handful, of confirmed cases of H5N1 infection, but it doesn’t mean that there’s been no other transmission events happening between, birds and humans. I would imagine that there’ve been probably a lot more, I can’t really say. An order of magnitude more or maybe a few orders of magnitude more, or perhaps less. I can’t really say that, but I think it’s quite likely that we’ve had a lot of exposures. Some of those exposures probably did not lead to an infection, meaning that the virus didn’t get a chance to propagate even though it was exposed to human tissue and human upper respiratory system. And potentially could have infected those individuals, but probably for whatever reasons it couldn’t infect them. And then on top of that, it’s possible that some of those individuals that became exposed to the virus, contracted the virus, but they didn’t show any clinical signs and symptoms as a result of that. They remained asymptomatic. Maybe some of them were in some remote areas of the globe. And as a result of that, they had no access to very sophisticated medical care.

Jordan Heath-Rawlings Even if you have access to sophisticated medical care. If you present with respiratory signs, would a doctor take a swab from your nasal cavity and send it for viral detection?

Dr. Shayan Sharif It’s probably not very likely unless you’ve been exposed to poultry and you tell that to the doctor that, Hey, look, my, my poulty, contracted H5N1, and as a result of that, I might have actually been exposed to H5N1. I think it’s pretty clear, that many of our physicians probably wouldn’t take the time to test for avian influenza virus. So I think there are a lot of unknowns, a lot of missing links here that lead me to believe that probably we are only looking at the tip of the iceberg. But like I said, at the moment, the tip of the iceberg is composed of, I would say a handful of cases confirmed.

Jordan Heath-Rawlings What does that kind of transmission as well as the transmission, that we just sort of mentioned between animals? Tell us about this virus and how it’s changing. We’ve learned a lot about this, obviously from covid in different strains. Is that what’s going on here?

Dr. Shayan Sharif It, it is precisely what is going on here because you know, first of all, this virus, if you go back to the original virus, the ancestral virus, the ancestral had infectivity for birds, for avian species, and it became adapted to avian species. So much so that it was quite successful in spreading transmitting and infecting birds, all different kinds of birds. It may or may not cause disease in those birds than ancestral virus. This one, however, has kept its transmissibility and infectivity, so it can infect a lot of birds. But it seems that it’s also gained some variance in terms of killing some of those bird species. But maybe those bird species that are succumbing to disease are the ones that are becoming newly infected. Maybe not the reservoirs. The traditional reservoirs are somewhat resistant to, to this virus.

Jordan Heath-Rawlings So that’s one component of it.

Dr. Shayan Sharif The other component is that when this virus started adapting itself and when that does happen, it tells us that the virus has probably mutated. And also one thing that is really critical to understand for influenza viruses is that they can not only undergo mutations, meaning that they would do mutations at one or two of their nucleic acids that they require for assembly of their genome, they can also swap their genome with other viruses, meaning that if you have two viruses, they can actually exchange their genetic material. So as a result of that, you could all of a sudden have a completely. New virus because the, the protein of two viruses that have exchanged their genetic material has some resemblance to its parental viruses. So this virus seems to be actually doing probably some of those as as it goes along. And the more it has the opportunity to exchange its genetic material and create mutations, it has the capacity to adapt itself. To its hosts, whatever those hosts are, either avian or mammals. Our concern is that this virus at some point of time may have the capacity to jump from. Avian to mammals, and then perhaps from mammals to humans, and then be transmitted from humans to humans. If that does happen, we could be looking at yet another pandemic and who really needs to have another pandemic. And by the way, COVID 19 pandemic hasn’t really ended officially. We are still, hopefully not in the middle of a pandemic, but maybe towards the tail end of the Covid 19 pandemic. So that’s what the main concern is at the moment.

Jordan Heath-Rawlings You know, that’s terrifying, right? Just to listen to that, that description of how it, the steps that need to happen.

Dr. Shayan Sharif I, I, I couldn’t agree more with you, Jordan. It is very terrifying and if you ask me what keeps me up at night, there are a lot of things, but this is definitely one of the, one of the big ones.

Jordan Heath-Rawlings Where are we now in that process and what do we know about how this is transmitted? I know that one of the reasons Covid became a pandemic and became so deadly is because it was very infectious and easily transmissible, uh, through aerosol. How are humans catching this? Is it, you know, really close, direct contact with infected birds?

Jordan Heath-Rawlings Like what’s the, what’s the rate of transmission, I guess?

Dr. Shayan Sharif So you’re asking, a very good question that, that probably, we can’t really answer it very clearly. I can give you a, an answer, but you know, it’s primarily based on epidemiological data and not so much based on laboratory evidence. Based on epidemiological data. When you look at poultry barn that have become infected, you could make some connections with migratory birds. And when you think about migratory birds and how they operate and how they behave, it’s quite possible that they’re contaminating areas in close proximity of those poultry barns. And then potentially viruses get around.

Jordan Heath-Rawlings How do they get aerosolized?

Dr. Shayan Sharif I can’t really tell you. There are a number of hypothesis that we can put forward, and as a matter of fact, my lab is looking at some of those hypothesis to determine what is the contribution of, for example, touching, contacting, you know, subsurface and because of those contacts, then.

Jordan Heath-Rawlings Poultry could catch the virus, or is it possible that large droplets play a significant role? And I’m sure that you remember all the debates we had about, um, surfaces versus, or fomites.

Dr. Shayan Sharif Yep. Meaning, you know, those surfaces were inanimate objects that could be contaminated and uh and humans in the context of covid, you know, could touch them and then put their finger in their mouth or touch their their nose or touch their eyes and then get infected with covid 19.

Jordan Heath-Rawlings Totally. That exists for influenza viruses, but what is the relative contribution of that compared to large droplets or aerosolized, uh, materials?

Dr. Shayan Sharif We, we have very limited understanding of that, but based on what I’m gathering from the literature and from epidemiological data, it appears to me that aerosols and droplets face a significant role. Probably aerosols would play a very important role in transmission of the virus, which, in my opinion would make it even more concerning because when you have aerosols, very tiny droplets that can travel long distances, then it would make the process for control of transmission quite difficult, in some cases, even impossible to control the virus. So overall, We can’t really rule anything out in the process of transmission.

Jordan Heath-Rawlings Okay. So your concerned and your concern has me concerned. What about the global health authorities that, you know, we sort of looked to at the beginning of the Covid 19 pandemic for guidance. What are they saying and what could we be doing right now to prepare for, you know, God knows what happens next. Hopefully not much, but you know, what should we be doing?

Dr. Shayan Sharif Yeah. I, I, what I said about, you know, the potential pandemic, I’m really, really, really hopeful. They would never happen. So this, this is the least thing you know, that any of us would want to see happen because this virus is a highly pathogenic virus. And if it does cause disease in, unfortunately this virus, if it does become pathogenic for humans, and if it’s transmissible to humans, could actually have a fatality rate of far greater than what we’ve seen for, for Covid-19. Probably it would resemble what we saw for the Spanish flu. It, it killed approximately 50 to a hundred million people in 1918. Our concern is that this virus could actually be something similar. And I think it has some of the capacities and potentials of what we saw in the, in the 1918 pandemic.

Jordan Heath-Rawlings So what are the global health authorities doing at the moment?

Dr. Shayan Sharif At the moment, they’re looking at all different options, both for animal health and also mostly, mostly for human health, which includes surveillance, which includes, uh, vaccination. And I think we have to not begin looking at it. We should have begun looking at vaccination probably months ago. But it’s still not too late to do that. Doing it now, it’s much better than doing it, let’s say two months from today or three months from today. We have to get moving as quickly as possible, looking at all of our options for, you know, the, maybe in a unlikely scenario that there is gonna be a pandemic.

Jordan Heath-Rawlings Do we have vaccines right now for this kind of virus? And I mean, shouldn’t we?

Dr. Shayan Sharif We just mentioned that it’s been here for more than a decade, so we do actually have vaccines. For poultry. But the problem is that those vaccines are not good enough for this particular strain. So there is a bit of a mismatch between what those vaccines can protect against and this particular virus. So there is very limited amount of efficacy for humans. There are actually some vaccines for humans. I would say add the experimental level and perhaps for very targeted use in humans. But what we also discovered in the context of Covid-19 was that we needed to have surge capacity. And then I’m sure that you remember, and the audience would remember all the bickering that we had over countries, uh, putting embargo on vaccines produced in their countries because they said, you know, why do we have to ship vaccines to other countries while, you know, our citizens are dying of covid 19. I don’t really think that we are gonna be going into any uncharted territory in that sense. So we’ve been there, done that, and we know how to increase our capacity for vaccine production. I would really think that, you know, this is a call for action for all governments. Including the Canadian government to think very carefully about not only finding a good vaccine, but actually how to produce the vaccine at the level required by the nation and how to distribute it.

Jordan Heath-Rawlings We’ve covered a lot of the potential worst case scenario here already. What’s the best case scenario and how far are we away from that right now? You know, we’ve talked about how bad this could get and how this virus could change. What’s the likelihood that it just doesn’t, and we end up with, you know, human cases here and there like we are seeing.

Dr. Shayan Sharif Right. And as a matter of fact, if you go back 20 years ago, actually more than 20 years ago in the nineties, in ’97, the ancestral virus of H5N1 emerged, in China. And, uh, from 97 to 2003, 2004, it killed quite a few people, but most of those individuals were becoming, I would call them terminal hosts, meaning that they would catch the virus. Unfortunately, many of them died, but many of them also survived. Fatality rate was approximately 50%, but when you look at mortality, at that time, it was around 450ish in total. Of individuals that contracted H5N1 all around the globe. Only 900 confirmed cases, which is almost nothing compared to what we saw for Covid 19. So there is that, that history that this virus could actually go in a different direction. And it could actually become maybe a little bit, uh, less pathogenic, less variant. And as a result of that, it could become what we call endemic, meaning that it’s just going around in the same region or many regions of the world, but it wouldn’t really cause any disease. However, there’s a big difference between Covid 19 virus. Influenza virus or influenza viruses. Like I said, they undergo mutation, but they can also make some drastic changes in their genome. So that’s why we need to really keep an eye out on, on any emergence of novel viruses, novel and new viruses in the same family of influenza viruses.

Jordan Heath-Rawlings One last quick question. What would you say to somebody who’s listened to this interview and is anxious or freaked out?

Dr. Shayan Sharif I would say first and foremost, this is not time to panic. This is not time to freak out. I think this is really time for us globally to take action. We cannot afford doing nothing the same way that we did for Covid-19, for months on end, and we pretended that nothing is happening around. And look what happened. It really caught us off guard if there was a silver lining in the pandemic was the fact that we learned a lot of hard lessons. This is really truly the time for us to get ready for maybe the unlikely event of another pandemic. It’s. Definitely in the cards, and I think, you know, this virus has served us notice that it is changing and we have to get adapted to the virus because this virus, you know, has no mercy. It could actually change overnight or it change overnight. Meaning it could become endemic, lose its pathogenicity, or it could actually become more pathogenic. We can’t really rely on the virus. We have to rely on our systems, including our scientific systems and our government systems to protect us in the future.

Jordan Heath-Rawlings Well, I hope we’ve learned a few lessons anyway, Dr. Sharif, thank you so much for this. I’m gonna try to go to sleep tonight.

Dr. Shayan Sharif By all means, me too.

Jordan Heath-Rawlings Dr. Cheyenne Sharif, acting Dean of the Ontario Veterinary College. That was not an episode I wanted to bring you, but it’s one of those times when if you see something, should say something that’s not panic. Let’s be prepared. That was the BIG story. For more head to the big story podcast.ca, if you wanna talk to us, email hello at the big story podcast.ca. Follow us on Twitter at the big story fpn and call us. Leave a voicemail, four one six nine three five. 5 9, 3 5. You can find this podcast anywhere you get your podcasts. I’ve told you this before, but if you got a smart speaker, try it. Ask, get to play the Big Story podcast. Thanks for listening. I’m Jordan Heath Rawlings. We’ll talk tomorrow.