Avian flu is not going away. Here’s how scientists are tackling it

NINA MOINI: This Saturday, agriculture regulators will begin testing milk produced in Minnesota for H5N1, the virus commonly known as avian influenza or bird flu. The disease has forced poultry farmers to kill about 9 million birds just in Minnesota since 2022. Just two weeks ago, a turkey grower in Dakota County lost nearly 80,000 birds. And as you may have noticed, the situation is contributing to driving up the price of eggs.

Last spring, the virus showed up in cows, and Minnesota had its first case in dairy cattle in June and saw nine total outbreaks last year. No humans in the state have gotten sick with H5N1 as far as we know, but there have been confirmed cases in humans elsewhere in the country.

Public health and veterinary experts say this problem is not going away, and some are pointing out what they say are missteps in the response so far. Joining me now with some perspective on this is Carol Cardona, a professor in the Department of Veterinary and Biomedical Sciences at the University of Minnesota. Professor, thank you for joining us.

CAROL CARDONA: Oh, thank you.

NINA MOINI: So this is something not going away. I want to start with the basics of how H5N1 spreads. It can't be transmitted from person to person. Correct? People are getting it from cows or birds. What are the main ways the virus is getting around?

CAROL CARDONA: Well, I'm a veterinarian, so of course, first, I think about animal-to-animal transmission. And that's going to be through either direct or indirect means. And it'll be similar for humans at this point, who are connected to animals that might be infected.

So the way that direct transmission happens is sort of this exchange of secretions. And that's usually between like species. But what we see usually for an indirect transmission route is going to be fecal, oral, or through what we call a fomite.

So the feces of an animal, for example, contaminating your boots and being spread to your home, and then your cat somehow gets in contact with that, with your boots, and can get infected that way. Then you might get it from your cat, if your cat got onto your counter and contaminated that, and you prepare food there.

So those kinds of pathways of indirect transmission are what are happening now. The other way that it can happen is in animals and agriculture. It can happen through the normal daily things that happen. So if you milk a cow or milk cows part-time and collect eggs part-time, you could be the fomite that's moving between those two populations.

NINA MOINI: Hmm. So what are your biggest concerns about the virus?

CAROL CARDONA: Well, this virus, since it emerged originally in 1996, has changed all the rules. So it has done things that we said always flu viruses can't do or won't do. For example, in 1997, it was the first time we'd seen the transmission of this virus directly from birds into humans. Now, you've heard about that many times now, here in the United States, especially among people that are culling infected birds. But we didn't think that that was a possibility back then.

So I want to say that because I think we have failed to imagine how big this could get. We failed to imagine how many species it could infect, how far reaching across our country it could be and across the globe. And so because of that, we haven't responded enough, and we haven't responded early enough.

So what I fear the most, I guess, is the damage that this virus can do while we figure out how we plan to respond. So I think an example of that would be there are species that could become extinct because of infections with this virus. And I would fear those consequences as things we can't come back from. And so that's what, I guess, I fear the most.

NINA MOINI: Why do you think that that is, that the response has not been up to the point that you would think would be more helpful? One of my producers mentioned that you really don't like calling H5N1 bird flu. Do you think people--

CAROL CARDONA: That's right.

NINA MOINI: --just don't understand it, or they think that it doesn't impact humans in any way, so it gets overlooked? Or what are your thoughts around the urgency there?

CAROL CARDONA: I think that's definitely part of it. So the way we talk about things impacts how we feel about them and how we think about them. And so when we think about birds, we think, ah, far away, very different from us, not important to us.

Now, I think we're starting to understand that H5 in birds, in poultry, can affect our food prices dramatically. It can affect mental health, and it can infect humans. So the fear of a pandemic is maybe several steps down the road. But the fear of human cases is very real. And that can happen today. So I think that what we have failed to do is not, for example, start immunizing poultry or dairy workers, not immunizing poultry or dairy animals, so that we can protect and prevent those things from happening.

And we just keep thinking, well, it can't get any worse. It does. It has. It will continue to get worse. That is just simply what flu viruses do. And I think it's just been this failure to imagine what more could happen and sort of the wish it will just stop and go away.

NINA MOINI: With that in mind, we mentioned at the top that Minnesota's joining some other states in testing milk for H5N1. Is that a step in the right direction? What would a more effective response look like to you moving forward?

CAROL CARDONA: So getting an idea of where the virus is, is certainly important. But we also need to understand how to help dairy producers either allow their animals to recover in a safe way and be able to bring naive or uninfected animals on to their farms without infecting them, or we need to start using vaccination.

So the next step is about this actual response piece. So right now, we would know that infection is somewhere, but we might not do anything about that. We would just say, ah, there it is, go about your business. And I think we know very well that going about your business is exactly how this virus spreads.

So what we have to do is change how you go about business. And that's very possible. But it does cost money, it does cost time, and it does cost resources. So there has to be a consensus that that's what we're going to do. And there has to be financial and, frankly, community support for producers who have to do that work.

NINA MOINI: Well, because they've been dealing with it in the poultry industry for years. What impact have you seen on the producers and the farmers that you know, and is it worsening?

CAROL CARDONA: Well, producers are not in a good mood to talk about, in their case, highly pathogenic avian influenza. It's been devastating. We know that it has exacerbated a number of conditions that they were already facing. So, for example, you know, the financial straits that some of our poultry producers are in is dire.

Although they get paid if they depopulate their birds, there are many expenses that are not covered. In addition, and not everybody in that food chain of production is paid, right? So the hourly worker, who's suddenly out of work, is not going to be indemnified for the work they lose. They simply have to go find another job.

So I think the point is that it exacerbates that financial tightrope that producers are walking. In addition, it is mentally and emotionally draining to watch your birds die or know that your financial reservoir is being drained. It's extremely difficult for people on the farm and off the farm to watch what happens and to have to experience it.

NINA MOINI: Everyone is sort of connected, right, from the economy to the humans to the animals. Carol, thank you so much for being on with us and telling us more about this.

CAROL CARDONA: My pleasure.

NINA MOINI: That was Carol Cardona, a professor in the Department of Veterinary and Biomedical Sciences at the University of Minnesota.