Another Strain Of Bird Flu Discovered In California

FLORA LICHTMAN: This is Science Friday. I’m Flora Lichtman. Later in the hour, what’s left behind when a home burns down? We’ll get into the chemistry of it. Plus, what researchers are finding in samples from the asteroid Bennu. But first, this week, according to the USDA and the World Organization for Animal Health, a different strain of bird flu has turned up in the US– H5N9. It caused a November outbreak of a highly pathogenic avian influenza on a California duck farm.

The dominant bird flu strain currently circulating, H5N1, has led to massive culling of bird flocks worldwide and is now affecting dairy cattle. The US reported its first human death from H5N1 bird flu earlier this month. Joining me now to talk about this and other stories from the week in science is SciFri’s Charles Bergquist. Hi, Charles.

CHARLES BERGQUIST: Hey, Flora.

FLORA LICHTMAN: So a new kind of bird flu, huh?

CHARLES BERGQUIST: Yeah. I mean, this gets a little bit weedy. But when we talk about different kinds of flu, there’s the super big level. First, what type of influenza? A, B, C, D. A and B are the kinds of flu you think about when we talk about people getting affected with seasonal flu. C is a kind that can affect people, but it’s usually mild. D is mainly a cattle thing. All of the viruses we’re talking about here with the bird flu are flu A.

But then you get into these H and N designations. That talks about what specific form of two proteins, called hemagglutinin and neuraminidase, are on the surface of the virus. Then there can be even like finer distinctions called clade, subclades. But what we’re talking about here is influenza A H5N9 as opposed to influenza A H5N1, which is what’s been mainly affecting bird flocks. So we’re looking at a difference in the neuraminidase protein.

FLORA LICHTMAN: Do we know where the strain came from?

CHARLES BERGQUIST: So this could have been brought in from somewhere else or another animal host. But viruses have this weird ability called reassortment. If you have a host that gets infected with a couple of different viruses at the same time, sometimes the viruses can actually swap bits of code. I think of it like if you have enough kids at the birthday party, sooner or later somebody’s going to be wearing somebody else’s socks.

FLORA LICHTMAN: I’ve lived it, Charles.

CHARLES BERGQUIST: Exactly, right? Whose socks are these? This new one was found in a duck farm. And ducks are thought to be pretty resistant to the bird flu. It turns out they can be infected without getting very sick. And they just carry the flu around. So a duck farm like this, where this outbreak occurred, can be a good place for that kind of mixing and matching reassortment process to happen and create new viruses.

FLORA LICHTMAN: Should we be concerned?

CHARLES BERGQUIST: So officials say that this specific H5N9 virus doesn’t look like it poses an immediate threat to humans. But having more kinds of viruses spreading around in animal reservoirs just sort of ups the chance of it making the jump to another species, also ups the chance of it mutating into something more threatening. So this is definitely something to keep an eye on.

FLORA LICHTMAN: Let’s move on to another microorganism story. There was a spacewalk on Thursday that involved microbes. Tell me about it.

CHARLES BERGQUIST: Right. Thursday, there was this multihour spacewalk from the International Space Station. This was Suni Williams and Butch Wilmore. They’re the two astronauts that have been having an unexpectedly extended stay on the ISS. They were the ones who went up on that Boeing Starliner craft that had had thruster problems. So they’ve been up on the ISS for a while. It’s nice they finally were able to get outside for a bit of EVA and look around.

FLORA LICHTMAN: Fresh air.

CHARLES BERGQUIST: Fresh air in the spacesuits. They spent over 5 hours outside on Thursday. And mostly, they were working to remove a failed piece of communications equipment that needed some repair. Apparently, this was a bit stuck in place. Wilmore said he had to jiggle, jiggle, jiggle to get it to come out. But while they were out there, they also took swabs of the outside of the US portions of the ISS, looking for bacteria.

FLORA LICHTMAN: Why?

CHARLES BERGQUIST: So stuff is clean when it’s sent up into orbit. Sterilization is a big deal in the spaceflight world. But humans aren’t clean. And the ISS has been in orbit for a long time. They were mainly swabbing around exterior vents from the life support system.

And there are other chances for microbes to move around. Say, like an astronaut touches a spacesuit or a tool inside the ISS and then goes outside and uses that spacesuit or tool. There’s a chance for bacteria to make the transfer.

FLORA LICHTMAN: And why do they care whether there’s a microbe on the outside of the ISS or not?

CHARLES BERGQUIST: Yeah. So the Russian crew has done similar swab studies before. This is the first one on the US side. And the question here is whether or not any bacteria that made it outside could survive on the outside, because if there are bacteria that could survive on the outside of the station, you’re in vacuum. You’re exposed to solar radiation. First, that has implications for finding life elsewhere. What can a bacteria really take and still be viable? It also would raise questions about what we would have to do to protect other worlds from being contaminated with our own life.

FLORA LICHTMAN: Right. If microbes can survive the vacuum of space, we got to be even cleaner than we already are.

CHARLES BERGQUIST: Exactly. Just wiping it with the bleach wipe isn’t good enough.

FLORA LICHTMAN: While we’re on the subject of human bodies, there’s new research into itching and scratching?

CHARLES BERGQUIST: Yeah. When you have an itch, it can feel really, really satisfying to scratch it.

FLORA LICHTMAN: Sure.

CHARLES BERGQUIST: But at the same time, that scratching is not good for your skin. If it gets out hand, you scratch too much, it can lead to more damage and inflammation, which makes you uncomfortable, which makes you want to scratch more. And dermatologists call this the itch-scratch cycle. But that thing of scratching an itch feeling good has been a bit of a mystery. If it’s just a damaging thing, you’d think that we would have evolved not to enjoy scratching.

FLORA LICHTMAN: Right, right. It’s a paradox.

CHARLES BERGQUIST: Yeah. But this week in the journal Science, researchers report that apparently, at least in mice, scratching can also boost immune defenses against bacterial infections right at that injury site. So there’s actually some benefit to scratching.

FLORA LICHTMAN: OK. OK, it sounds like we scratched the itch on that mystery.

CHARLES BERGQUIST: Yeah.

FLORA LICHTMAN: What’s it good for? Why are people researching this?

CHARLES BERGQUIST: So they say that this new immune response pathway might be something that they could target with a drug. So that may be a benefit there. There are also people with a chronic itch condition. They always are itchy. And learning more about why we scratch could potentially lead to hopefully some kind of relief for them.

FLORA LICHTMAN: Let’s move on to something that makes me feel itchy sometimes, artificial intelligence. It has been a busy week.

CHARLES BERGQUIST: Yes. It seems like every other minute, some company is announcing a new revision to their AI model. It’s more accurate. It’s faster. It’s more realistic. Late last week, a Chinese company made big news with this model called DeepSeek-R1. And then later this week, the Chinese mega company Alibaba announced its own updated AI model that it said is even better than that.

FLORA LICHTMAN: What was up with DeepSeek?

CHARLES BERGQUIST: Yeah. So the big thing here is that all AI systems take a lot of computing power, a lot, a lot of computing power. And the DeepSeek and Alibaba products both apparently have come up with ways to be much more efficient, training and giving results with a lot less computing power, and so less cost. And this was to the point that when DeepSeek demonstrated this R1 model, the stocks of the computer company NVIDIA and a few other companies had significant drops because if these models hold up, maybe the high-powered computer processors these companies make are going to be less in demand.

FLORA LICHTMAN: OK. Besides the stock hit, why else do we care? Why do we care that there’s another AI company pushing a new technique or model?

CHARLES BERGQUIST: Yeah. So there’s all different layers of drama here. So some people are worried that this represents a shift in AI leadership away from the US, which, true. It might be. But then there are other complaints, similar to the ones that you see centered around the media app TikTok. If you use this model, you’re sharing all your data with China, potentially its government. Who knows what happens then?

And then to add on to all of that, OpenAI– those are the ChatGPT folks– are complaining that DeepSeek may have copied some of its work or trained its model on ChatGPT output, which is somewhat ironic, given the concerns over these models training on data around the web and books and art without necessarily getting permission from the creators in the first place.

FLORA LICHTMAN: It’s a pot-kettle situation.

CHARLES BERGQUIST: Exactly.

FLORA LICHTMAN: This all sounds very messy.

CHARLES BERGQUIST: Yeah. Messy is definitely a good word for it. We should also note that a lot of these models from private commercial companies, they’re black boxes. We don’t see the code. We don’t see what it’s doing in there. So we really only have the companies’ claims on some of these efficiency measures.

So yeah, we’re going to really have to see how this all shakes out. And on top of that, there’s probably going to be something new next week and the week after that. It’s sloppy out there.

FLORA LICHTMAN: I think that leads right to our last story. Ancient vomit is in the news this week. I would like to hear every single detail.

CHARLES BERGQUIST: Yes. So this is a story about a fossil hunter discovering what is apparently fossilized 66 million year old fish vomit. This is from a sample in Denmark. And the fossil hunter found what looked like a bunch of mixed up bits of fossilized sea lilies embedded in a piece of chalk.

These sea lilies apparently have a bunch of calcium-rich parts that are not particularly digestible. So something, probably a fish, chowed down on a bunch of lilies and then yakked up the bits it couldn’t digest. And now fast-forward 66 million years. And it’s going to be in a museum.

FLORA LICHTMAN: Sea lilies were found in there? What is that?

CHARLES BERGQUIST: Yeah. So don’t think of lilies like frogs sitting on a lily pad. Sea lilies are actually crinoids. They’re these delicate, almost feathery looking things that live at the bottom of the sea. And the thought is that in the Cretaceous, these were a tasty meal for some fish but just couldn’t stomach some of the harder parts of the lilies. This sounds goofy. Why do we care? But fossils like this can give a better idea of the food chain in some of these early situations, where tracing out who ate what is an important thing to know.

FLORA LICHTMAN: And probably hard to figure out without ancient vomit.

CHARLES BERGQUIST: Right. We have so many gaps that any clues like this are helpful.

FLORA LICHTMAN: What does it look like?

CHARLES BERGQUIST: Well, I mean, first, it’s embedded in chalk. So this is all sort of a beigeish white stuff. And there are cylindrical chunks jumbled up next to each other.

FLORA LICHTMAN: Chunks. That makes sense.

CHARLES BERGQUIST: Exactly.

FLORA LICHTMAN: That adds up.

CHARLES BERGQUIST: Yeah. And I know that you like fun words. So just as fossilized dung has a name– coprolite– fossilized vomit apparently has the delightful name of regurgitalite.

FLORA LICHTMAN: Regurgitalite?

CHARLES BERGQUIST: Regurgitalite. And now you know.

FLORA LICHTMAN: I am so glad to know that. Charles Bergquist, Science Friday’s senior producer.

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