Little risk seen to the public at the moment

[00:00:00] Host Amber Smith: Upstate Medical University in Syracuse, New York invites you to be "The Informed Patient," with the podcast that features experts from Central New York's only academic medical center. I'm your host, Amber Smith. Just how concerned should we be about bird flu? I'm turning to Dr. Stephen Thomas, the director of the Upstate Global Health Institute. He's a professor of microbiology and immunology, and a doctor who specializes in infectious disease. Welcome back to "The Informed Patient," Dr. Thomas. This

[00:00:31] Stephen Thomas, MD: It's good to be with you. Thank you.

[00:00:33] Host Amber Smith: Bird flu keeps making headlines, especially in communities that have large poultry farms. Is this a potential threat to humans that we should be concerned about?

[00:00:43] Stephen Thomas, MD: Well, I think the first part, is that yes, this is something that can be a potential threat to humans because it's made people ill in the past; it's killed people, unfortunately, in the past. But the answer to the second part of the question is, I think, currently in the United States, the concern can be low to very low at this time.

But, obviously, we're paying very close attention to what's going on with poultry, what's going on with cattle, and what's going on with, the people who interface with those two populations.

[00:01:11] Host Amber Smith: So we've heard about it in chickens, but does this affect -- is it possible to be in -- all birds?

[00:01:16] Stephen Thomas, MD: Maybe taking a step back, there's a couple of different names that people have been using. They use avian flu, they use highly pathogenic avian influenza. Influenza viruses, they have two main components that we kind of use to name them. There's the H component, which is the hemagglutinin protein, on the virus. And then there's the N component, which is the neuraminidase component. And there are 16 different H components and nine different N components. And they can be mixed in all sorts of different ways, so when we think of seasonal flu, that's H3N2. When we had the novel influenza pandemic back in 2009, that was H1N1.

These are being, some of them are being, confirmed as H5N1, and those combinations may just seem like a word salad. But they're really important, because each of these viruses have different characteristics and they have different tropisms, if you will, or different types of cells and different animals and animal species and humans for where they like to infect. And then that can change their ability to be transmitted from animals to humans or to make people sick and these kinds of things, so that's kind of the background to the whole thing.

But to get to your question, all sorts of birds can get infected with these viruses, and they can kill the birds. In July, the CDC had reported that over 9,500 different birds across the country had been infected. And it's everything from robins and sparrows and bald eagles and owls and crows. And the list goes on and on.

[00:02:51] Host Amber Smith: Does the bird flu kill the birds? Do they die from this?

[00:02:56] Stephen Thomas, MD: They can. Yes. many of the reports that the CDC (Centers for Disease Control and Prevention) and departments of health list are based on the equivalent of autopsies, basically, investigating why the bird died.

[00:03:08] Host Amber Smith: Now, you mentioned cattle. Does this spread,from birds to cattle? Does it spread to other animals as well?

[00:03:15] Stephen Thomas, MD:

This has been in the news recently because I think the count now is about 157 dairy herds across the country that have been affected, meaning they've had cows that have tested positive for the influenza virus. And poultry, which is where we started. I mean, the count there isalmost a hundred million affected.

The concern is that humans obviously engage with these animals. Some people have poultry in their backyard, right? And we've had, backyard herds, if you will, that have been infected. And there's the commercial (poultry farms), where they've had lots of, flu. And now in commercial dairy we've seen these infections, and people who work closely with them, either as part of the commercial enterprise or in terms of outbreak investigations or culling of animals, we've seen humans get infected. Fortunately, not a lot. I think the total number since 2022 has been nine, four following exposure to dairy cows and five following exposure to poultry.

But the concern is that that's going to become more and more common and people are going to become much sicker than what we've seen.

[00:04:20] Host Amber Smith: Now when you say exposure to poultry or birds, does a human have to touch the animal, or are they breathing the air that the animal's breathing? How does it spread to the person?

[00:04:32] Stephen Thomas, MD: Back to the earlier conversation about these H and N proteins based upon the proteins and the combination of proteins, these viruses can preferentially infect certain types of cells, and it can get into secretions, so from the respiratory system, but it can also get into excretions from, like, the gastrointestinal tract. And so, you can have urine and feces, and these things can dry out, and they become powdery, and then you have wind blowing them up and people breathing them in. And so folks can get infected that way.

With the cows, they have found high levels of infectious virus in the milk. That's why they're saying, "Don't drink raw cow milk." Those are some ways that you can get exposed.

[00:05:16] Host Amber Smith: So what about eating chicken? If the chicken was infected with bird flu and gets packaged and sent to the grocery store, could a person catch it from eating that chicken?

[00:05:28] Stephen Thomas, MD: I am not familiar with any reports of that occurring. My guess is that, similar to milk, where a pasteurization process makes the milk safe, my guess is that the process of slaughtering the chickens and cleaning the chickens and packaging the chickens and then ultimately cooking the chickens, that that would make the chicken non-infectious. But I'm not sure. I have not seen any reports about human infections resulting from eating infected chickens.

[00:05:59] Host Amber Smith: Now, once a human is infected, can they spread it to other humans?

[00:06:04] Stephen Thomas, MD: With highly pathogenic avian influenza, we have not seen that yet, which is a good thing. But that's always been the concern. If you want to go way back, before COVID, say 20 years ago, and you talk to a bunch of infectious disease people and epidemiologists and people that think about pandemic preparedness, if you had asked them, "Well, what do you think the next pandemic is going to be?" people would've said it would be a strain of influenza. And the doomsday scenario would be a strain of influenza that is as contagious as what we see with seasonal influenza, but that it would be as pathogenic - meaning ability to cause severe disease in people - it would be as pathogenic as these highly pathogenic avian influenzas. So that combo of highly transmissible and making people very, very sick, that would be kind of the pandemic doomsday scenario that everyone was very worried about. And then COVID came along, different virus, similar concerns. But now we're back on the highly pathogenic avian influenza bandwagon again in terms of what we're concerned about.

[00:07:09] Host Amber Smith: This is Upstate's "The Informed Patient" podcast. I'm your host, Amber Smith. I'm talking with Dr. Stephen Thomas about bird flu.

So are all farmers with chickens at risk, potentially?

[00:07:24] Stephen Thomas, MD: Well, according to the CDC, 48 states have outbreaks in their poultry. So that's pretty much all of them. And so I think the potential is there.

My understanding is that testing has not been as widespread and pervasive and aggressive as, certainly, the people who care about pandemics would hope. And I can understand there's another perspective on that, the perspective of the farmer, and this is their livelihood. And so I can understand the concern with that. So I would say that yes, if you have a poultry farm in the United States, then you should be concerned. You should be observant. If you're seeing die-off of birds, or you're seeing employees getting ill with flu-like illnesses -- and we could talk about what that looks like -- then fast testing and isolation and potentially culling of animals would be the best thing that you can do, both for bird health and human health. But it's a very complex issue that involves discussion, and more than just the viruses.

[00:08:29] Host Amber Smith: What about those people, though, with the backyard chickens? I mean, this would be a concern for them too, right?

[00:08:36] Stephen Thomas, MD:

Both commercial flocks and backyard flocks have been impacted. To the people that have backyard flocks, I have the same advice to them as the folks who have commercial flocks, which is you just need to be informed, stay informed, be observant, be vigilant that if something doesn't look right, or your birds aren't healthy or something like that, call your local department of health, and they can help facilitate getting some testing done.

[00:09:03] Host Amber Smith: There's not any sort of vaccine available or any preventive steps people can take to, make sure their birds stay healthy?

[00:09:12] Stephen Thomas, MD: They have licensed a couple of human vaccines, and there are a number that are in development. They have not been widely deployed. They were kind of made and then not stockpiled, per se, but put up on the shelf, and I think they're now dusting those off and breaking them out and offering them. I think we just saw that the government has issued a very, very large award to one of the messenger RNA vaccine manufacturers to develop an H5N1 vaccine.

So, they're out there, for humans. For animals, not that I'm aware of. Certainly not for poultry, that I'm aware of.

[00:09:45] Host Amber Smith: And it sounds like we're not there yet in terms of needing to be worried about it. But a lot of people keep bird feeders, and naturally, there's a lot of birds around. But we don't really need to be concerned about that at this point?

[00:09:58] Stephen Thomas, MD: Yeah, it seems predominantly, in these high density, large population commercial flocks, primarily. Again, there have been home flocks, domestic backyard flocks impacted as well. But I think the main concern are these very, very large numbers. We're concerned about the animals for lots of different reasons, some of which are commercial in nature, food source, things of that nature.

But the concern from the infectious disease standpoint is just like the virus that causes COVID, every time a living being gets infected with this virus, that virus is going to go through millions of replication cycles in its normal course of infection. And every time it does one of those cycles, there's the potential that a mutation can occur. And we know they do occur, and they often occur, and usually it doesn't amount to anything. But if the planets align and the virus gets lucky, it can mutate into something that can reflect that doomsday scenario I was talking about, right? Where something that can easily jump from an animal to a human, and then the worst case scenario, from human to human.

So this is another reason why we want to kind of isolate these infections and stamp them out as quickly as possible. We're trying to not give the virus any more evolutionary advantage than it already has.

[00:11:24] Host Amber Smith: How does bird flu compare with seasonal flu?

[00:11:28] Stephen Thomas, MD: So highly pathogenic avian influenza, the mortality rate can be quite high in people who get sick. Fortunately, what we've seen so far, since 2022 when we started to track these cases, in the poultry and in the dairy, the people who have been infected, they have had flu-like symptoms, and so they have had fever, and they've had some cough and some chills, and they may have had kind of a sore throat or a runny nose. They've also had, interestingly, conjunctivitis and eye tearing. Conjunctivitis is what people would say is red eye, pink eye, that kind of thing. That's interesting because the types of receptors that these viruses like to attach to so they can infect the cells, the receptors in the eye are similar to some of the receptors in the respiratory tree. So it's plausible, and it's not unexpected, but it's been interestingly consistent with these workers who have been infected.

[00:12:28] Host Amber Smith: There have been no fatalities among these nine that I'm aware of in the U.S. so far. But with seasonal influenza we have -- just because of the numbers -- we have 20 to 30,000 people a year who die of seasonal influenza in the United States. We have about a million people who end up in the hospital because of it. So hopefully we don't get into those numbers with this highly pathogenic avian influenza that we're seeing right now. Is there a blood test to test and say, "yes, you have bird flu," or is it based on the symptoms?

[00:13:01] Stephen Thomas, MD: You know, I was always taught that clinicians make diagnoses, not tests, right? Tests are designed to support a clinical diagnosis. So if somebody were to come in with flu-like symptoms, in July of 2024, these clinicians should be asking very specific questions about not just the symptoms, but where have you been? What have you been doing? Have you had contact with any animals?

Because what do we have? What's going to happen in a couple of weeks? We're going to have a big, huge state fair. There might be poultry. There might be cattle there. Might be pigs, right? Pigs are also great for influenza viruses. So we have lots of agricultural activities here, farmers, et cetera.

So you just have to take a good, detailed history to say, OK, are they sick? Could this represent influenza? And do they have an exposure history that could be consistent with someone who's at risk for avian influenza?

You should test them for the routine sorts of things, right? But I think the only places you can get definitive H5N1 tests -- so tests for highly pathogenic, avian flu -- is at certain departments of health. And so I would immediately be on the phone with (New York State Department of Health) Wadsworth (Center, the laboratory investigations unit) and say, "I have a respiratory sample that I would like to have tested." And then care for that person accordingly, and isolate them accordingly.

People with flu, it's so common, we don't think so much about it. But people with influenza really should be isolating themselves routinely from other people because they can pass it.

[00:14:36] Stephen Thomas, MD: So I would treat them the same way if I thought it was seasonal flu or avian flu.

[00:14:40] Host Amber Smith: Well, I wanted to ask you about the spread of bird flu with the changing climate. Does that impact how respiratory viruses like the bird flu spread, either from animal to animal or animal to people?

[00:14:55] Stephen Thomas, MD: So, infectious diseases that are typically within certain animal populations, and if those animal populations have migratory patterns where they impact the density of animals coming together, moving together, that kind of thing, I guess that changes in ecology in general, changes in temperature could potentially impact that, for diseases, human diseases that are transmitted person to person, which this one we have not seen yet.

Temperature changes how people behave, right? And obviously being outside in the sun with lots of ventilation and everything reduces risk, for person-to-person transmission. But I'm not sure specifically about any climate / highly pathogenic avian influenza correlation, just yet -- with the caveat that they're actually investigating a poultry culling event where a couple of people were infected. And they think it's because, or what could be contributing, is that it was so hot, and there were fans going, and people were in personal protective gear, and they were sweating, and they think it could have potentially reduced the effectiveness of the personal protective gear. So that's an indirect way of how climate may have interestingly impacted a recent cluster of cases of people who went there to cull animals to try and stop the spread. So an indirect way the climate might've impacted.

[00:16:33] Host Amber Smith: Well, before we wrap up, I wanted to ask you if you can let us know about some of the projects the Upstate Global Health Institute has underway that are tied to respiratory viruses, because I know you're sometimes looking for people to volunteer to help with those studies.

[00:16:50] Stephen Thomas, MD: We're involved in a number of influenza studies. We're involved with great partners at the University of Maryland and the NIH (National Institutes of Health) in a universal influenza vaccine development project that's been going on for a couple of years now. And we'll have a study that's coming up relatively soon, so spring of next year.

And then we have other projects that we're involved in with combination COVID-influenza vaccines. We're involved in vaccine projects of people just trying to make better flu vaccines, vaccines that perform better by being a little more specific to the viruses that are circulating at the time.

We're working with the county, Onondaga County, on a respiratory virus project, which we hope to launch at the start of this season, so September, October of 2024. And, I will disclose, I've made a couple calls to folks who are doing H5N1 work to say, "you know, we would be great partners because we like to work on things that impact our community, and we have a lot of agricultural and dairy enterprises up here in Upstate in Central New York. And so we'd like to work on projects, which can help our community directly. So, we're not doing any H5N1 work right now, but I'm hoping that, just like with COVID, we'll be called upon to participate in these trials.

And COVID projects continue. We have a couple that are queuing up right now. I think that we have been successful in the work that we do. And a primary reason we're successful is that we have a very supportive community, and we have people who are interested in wanting to volunteer for these studies and to participate. I think they realize that nothing is going to get on a shelf, nothing's going to get in your doctor's office, nothing's going to get into your urgent care center or hospital or clinic, it's just not going to happen unless these studies are done. And these studies are not going to be done unless people are willing to volunteer. So we have an incredible amount of gratitude for Central New York and the people who participate in these studies.

[00:19:05] Host Amber Smith: And people that might be interested in that can learn more if they go to upstate.edu/globalhealth, online. They can kind of stay apprised of some of the projects you've got underway.

But in the meantime, they don't really need to fret too much or worry too much about bird flu?

[00:19:22] Stephen Thomas, MD: I think that that's true. And I think just like everything, people just have to be, they have to be informed by listening to programs like this. They have to be observant. They have to be aware. And then if something seems out of the ordinary, then they need to call their trusted clinician and express their concerns.

Again, it's people who are sick with an influenza-like illness and have had exposure to birds or other types of animals, those are the people that we would be concerned about and want to evaluate aggressively.

[00:19:57] Host Amber Smith: Well, thank you so much for making time for this interview, Dr. Thomas.

[00:20:01] Stephen Thomas, MD: Oh, it's a pleasure. Thank you.

[00:20:03] Host Amber Smith: My guest has been Dr. Stephen Thomas, an infectious disease specialist, professor of microbiology in immunology, and the director of the Upstate Global Health Institute. "The Informed Patient" is a podcast covering health, science and medicine, brought to you by Upstate Medical University in Syracuse, New York, and produced by Jim Howe.

Find our archive of previous episodes at upstate.edu/informed. If you enjoyed this episode, please tell a friend to listen too. And you can rate and review "The Informed Patient" podcast on Spotify, Apple Podcast, YouTube, or wherever you tune in. This is your host, Amber Smith, thanking you for listening.