Radiolab - Fungus Amungus

Episode Date: September 4, 2020

Six years ago, a new infection began popping up in four different hospitals on three different continents, all around the same time. It wasn’t a bacteria, or a virus. It was ... a killer fungus. No one knew where it came from, or why. Today, the story of an ancient showdown between fungus and mammals that started when dinosaurs disappeared from the earth. Back then, the battle swung in our favor (spoiler alert!) and we’ve been hanging onto that win ever since. But one scientist suggests that the rise of this new infectious fungus indicates our edge is slipping, degree by increasing degree. This episode was reported by Molly Webster, and produced by Molly and Bethel Habte, with production help from Tad Davis. Special thanks to Julie Parsonnet and Aviv Bergman.  If you caught this segment in our radio broadcast and want to hear the segment it aired with, check out Covid Crystal Ball here. Support Radiolab today at Radiolab.org/donate.   Further Fungus Reading: NYTimes feature on the mysterious rise of Candida auris.   Arturo's paper: “On the emergence of Candida auris, Climate Change, Azoles, Swamps, and Birds”, by Arturo Casadevall, et al. “On the Origins of a Species: What Might Explain the Rise of Candida auris?”, a report from the CDC.  

Hey, I'm Chad Abumarad, this is Radio Lab, and today, a story from our very own Molly Webster. So yes, today we're talking about a medical mystery. Oh good, let me put mine on my wool cap then. Because. He really is putting on a wool cap. OK. OK. A medical mystery.

Yeah. Starts with a woman. Hello. Hi, I'm trying to reach Joveria, please. Named Joveria Farouki. This is Javaria. How are you? She works at a hospital at the teaching hospital in Pakistan. in Karachi. The Alkan University. And I'm a medical doctor, specialized in medical microbiology. Javaria works in the hospital lab.

And so when someone has an infection, she gets sent you know, some blood or urine or something and she tries to figure out which bug is causing the problem. So the very first month that I was in the lab. In the fall of 2014. The third week of October. I found three bugs. In the blood of three different patients.

Which looked exactly the same. And like nothing she'd ever seen before. Creamy in texture it had a whitish rim and had another ring of light brown around it, white center and I'm very very white. It's sort of like when you put UV light on white and it sort of shines with a bluish stint. And what she saw wasn't a bacteria or a virus. It was actually a fungus.

A yeast. But beyond that, she sort of had no idea what it was. I shared it with all my friends who were working in other labs and I asked them if they had encountered something like this. And they all said no, but the patients were all very, very sick. Yeah, well, so what happened is that we started seeing patients with fever, high white cell count. So the three patients, those samples that come come from were all the same hospital under the

care of this guy. Dr. Fasselman Muehbaam in infectiouses specialist here at the Archand University. And all three of them were patients in the ICU. Older patients, folks who have been in the hospital for a week or two weeks. You know, with patients like that, they definitely deal with fungal infections from time to time. So the symptoms were really nothing spectacular, nothing weird. But when you found out that they all came down with the same mysterious fungus all at the same time, when it was identified, we're like, okay, that's weird.

Maybe some kind of coincidence. But then, while I was looking at those, I encountered yet another one. Another one popped up. Exactly the same yeast.. Another one popped up. Exactly the same yeast. And another one popped up. In the same hospital, but this time not from the ICU. And I thought, oh my God. Which was really strange because they

have never seen this fungus before. And suddenly it's popping up all over the hospital. I would have been OK if it was just one case. Or two cases in a whole year, that's all right. However, to encounter them in a whole, in a cluster, is alarming. What's it doing in our hospital, behaving so angrily and killing people off? I mean, two of our patients had died by then. You know, we just sort of kept seeing them, tuck, tuck, tuck, tuck. I think within six months we had like 19 cases. And by then, six months in

eight of the patients had died. So this fund is pretty nasty. Yeah, I mean, the people who get it seem to have on other sicknesses as well, but once you got it, the mortality rate's like 20 to 60%. Oh, damn. And that's about the same time when Javaria sent some streams to the US CDC.

Javaria basically sent them an email and just said, hey, will you look at this thing? And this is when the mystery of this fungus went way, way beyond one hospital in Pakistan. We were informed by colleagues in Pakistan that they were having a large outbreak. One of the guys that got that email eventually was Tom Chiller. Chief of the Micotic Diseases Branch here at the Centers for Disease Control and Prevention in Atlanta, Georgia.

And he and his colleagues pretty quickly identified the fungus as Candida Oris. This is a Candida Oris and I'm like, Candida what? No, Candida is kind of a big group of fungus. It lives on our skin and in our guts and can cause yeast infections and thresh and babies. But this particular Canada was totally new. It was first isolated from an ear infection of a Japanese patient. And that was in 2009 and it was really just causing some sort of goopy goop to leak out of this woman's ear. On the skin where we know some candidate species can be,

and we didn't think honestly much of it. Until six years later, they hear from Jovieria that this candidate orus is getting into people's blood and causing serious infections. You know, horrible bloodstream infections and even death. And so we thought, okay, this thing that we saw once that we did not think was a big deal is now killing people, so what's going on?

And so he started poking around and he came across reports of Canada or South breaks in South Korea, in India. And South Africa had described clusters. And we figured we found out that it's popping up all over the world. And actually while looking into this colleagues from London were We're talking to us about a very similar phenomena with the same organism.

A hospital in London had an outbreak. To the point where they had to close their intensive care unit for a period of months. So what we saw were that there were essentially four different clades for lack of a better word that were emerging in three different continents all about at the same time. Meaning it wasn't like it started in one place and then went to all these other places.

It couldn't be explained by travel. It couldn't be explained by the fact that these were in some way related, except that they were the same species of organism. They truly were emerging at around the same time in four parts of the world. So the big question that arises out of this moment is why now? Yeah. Wait, just so make sure I'm getting this, you have one fungus appearing

in four totally different parts of the world. Simultaneously. Simultaneously. Weird. It's definitely not normal. No, it's absolutely abnormal and you know people around the world are trying to figure out how this happened, why it happened, why is it, and we, so this is Nygda Valbenani and she was part of the team at the CDC that was tracking the fungus and trying to figure out what was going on. So initially we thought

like could is it possible as some contaminated medical product or something that got distributed, something that got distributed to these hospitals, but then they thought four different hospitals on three different continents. I mean, you don't expect it to be that worldwide. So it's like sketch that. Maybe it's the way, you know, different antifungal drugs have been used around the world. Like we all use, you know, antifungals in our body, but the more important thing is is is farms using anti-funcles where they spray their crops. So it's maybe the fungus are adapting to fungicides and it's just getting stronger.

So it would be that the farmers are training the fungus and those fungus are then somehow getting away from the farm and into the hospitals or? Yeah. Okay. But that still doesn't explain why it would happen in all these separate places in this one particular moment.

Why now? Right. You need something that was happening to all of these fungus in different places at the same time. That's why people are looking for more of this not just environment, but sort of a bigger picture ecological analyses. Meaning what? Well, um, I just, uh, at this point, feel like I should just start talking about dinosaurs. Um, we love it, we love it. It is a little bit of a detour, but I promise it will pay off.

No, it's my relish for dinosaurs in general. Yeah. Oh god, here we go. There is a lot of history there. Ladies and gentlemen, please welcome to the stage. Your host for this evening. John Aberrad and Robert Kohlwitz! But trust me, it'll be worth it. To loop everybody in about seven years ago,

we did a live show called Apophyliptical that had life-sized dinosaur poppits, traveled 21 cities, super fun, but it completely broke us and we all nearly died. Yes, it's true. But part of that live show is a story that I reported for you guys about an asteroid that hit the earth and put an end to the dinos. So it turns out on that day, as the fire was raging above on the surface, somewhere in

a little hole in the ground happened to be a furry little animal. And about how, after the cataclysm, his mammal, small little mammal, crawled out of its little money burrow into a dino-less world and became the... Great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, great, Stop there because we were getting away with something and I didn't want to push it too far. All of a sudden it was just you and me. Yeah, though. There was a miss Robert.

I know. Anyhow, continue. Story goes like this. With dinosaurs out of the way, the idea is that mammals crawl out of the hole and they just inherited the earth. So big reptiles out, crafty little mammals in. But there is a new idea about this fungal friend of ours, this one we've been talking about, that sort of messes

this story up a little bit. So here we are in the realm of hypothesis speculation. We don't really know what happens 65 million years ago or 100 million years ago. The idea comes from this doctor and microbiologist Arturo Cassadavall at Johns Hopkins University and he says the first few beats of our story are all good. Right. We know that there was a catastrophe. The asteroid hit the Yucatan and we know that the Earth had a really bad day and the animals that then follow are, is the H-omamils.

Yeah, because I feel like we took down all those dinosaurs and there's a big hole and we're like, oh, and we crawled out of it. Yeah, I think that people thought that, you know, because the dinosaurs were wiped out that he created a space. This is absolutely what I think. Right. So there is a little bit of a problem with what in my mind was that. And I, and I, and I add that this is my problem.

But I'll show you what the thinking is. If you look at our world today, we still have reptiles. A crocodile and a festive riverbank. We have alligators. This is a gaboon viper from West Africa. We have lizard. A monitor lizard is out hunting, looking for the entrance to the galleries in which the mammals take shelter during the daylight hours.

So clearly, some reptiles survived the catastrophe. There were reptilian creatures that were living in the river bank in the same way that the mammals were and got out of the fires in the ash and came out. And it's always bothered me. How come we didn't have a second reptilian age? So you actually have a moment when either of them could have taken the crown. I thought the idea was it just we got lucky.

I mean, we would have had to be really lucky. Because according to our tarot, reptiles had two big advantages over us, straight out the gates, first one being... Reptiles in two big advantages over us, straight out the gates, first one being... Reptiles in contrast to mammals don't need that much food. Which you know is great because at the time most of the plants had burned up, the planet was covered in ash, there really wasn't that much food, and whereas mammals have to eat all the time like reptiles can just chill for a while.

So that's definitely a win for reptiles over mammals. They also reproduce a lot faster. The second one is that they just make more babies. They can spread a lot faster, their chances of survival are greater. So our tour was like, if the reptiles are able to do well with less food and they reproduce faster, why didn't they just take off and create a whole new world, which is Reptilian 2? Now, his idea for why this didn't happen, why there wasn't a second Reptilian age, is that there is another player on the Dino Free stage, a small and visible yet powerful player, and to understand you have to know that before the asteroid hit...

It was a forested planet that was in fact a lot warmer than it is today. There were forests in many parts of the world. The cataclysm is taught to have led to rapid temperatures that fell. And you also had no sun. So imagine a dark, cold world of decaying vegetation. This cataclysm was associated with a massive proliferation of fungi. And actually, if you look at the right above the KT boundary, that line that remarks no meteor, meteor, dinosaur, no dinosaur. If you look right above there,

it's the soil is filled with spores. No. And so everyone knows it's really well documented that it was- Wait, so as a layer after the impact. Yes. There is a layer I wanted to up, which is filled with fungi spores.

Yes. That's interesting. And so we said it's very well known that there was fungus growing on things that got burned fungus probably just growing because it's wet and damp and why not There's mold and mushrooms everywhere. It's also dead bodies. There's like things decomposing which fungus like they love I've heard at parties parties. So it looks like you have a couple of shrew-like creatures walking around. You've got some alligators, but you've got a crap load of fungus. And you've got a crap load of fungus.

Is it fungi? Fun guy? Fun guy. Is it a fun guy or is it a fun guy? Probably fun guy. No, probably whatever you tell me. No, seriously. Some people pronounce it fun guy. Some he the fun guy? Probably fun guy. I would say whatever you like. No, probably whatever you tell me. No, seriously. Some people pronounce the fun guy,

some people pronounce fun guy. Okay. Or fun guy. Anyways, whatever you call it, if you are an animal or reptile or a mammal, fun guy can be deadly. That's right. And while reptiles could skip meals

and make a bunch of babies, when it came defending off fun guy, we had an advantage. We have two pillars to protect us. a bunch of babies when it came defending off fungi, we had an advantage. We have two pillars to protect us. One of them is that we have advanced immunity. The immune system is obviously like the Kung Fu fighter. It really takes up the weight of keeping something out.

But the other thing that we have, the frogs don't have, and the trees don't have, and the insects don't have, is that we're really hot relative to the environment. We're warm. We're warm-blooded. Mammals actually use some of their energy to keep their bodies warm. So if you think about us, it could be really cold outside. It could be really hot outside, but we stay at a steady,

basically, 98.6. Now, if you're a fun guy, you actually like it kind of cold. They do very well until about 30 degrees. Like, 86 degrees Fahrenheit. Right. Any hotter than that? It can be nature them irreversibly. The proteins start to fall apart, the cells start to melt.

And so, if a post-apocalyptic fungi got into a post-apocalyptic, very warm mammal, it would die. These high temperature creates a heat barrier. And this heat barrier means that the majority of fungal species out there cannot grow or replicate inside your body because you're too warm. Our heat keeps the fungus out. You got it. If you are a reptile, you're cold-blooded, you don't have a way to keep yourself like steady and warm. You have to go look for ways to become warm. You know, have you ever seen lizards lie in rocks? You know where they're just like out in the sun,

soaking up the heat. So that will warm their bodies up. But also, and I never knew this, it also will clear, like, fungus from their body. So if they're sick, because it warms them up so much, that warmth attacks the fungus. Do they not do fevers? They can't do fevers. So their way of getting as hot as possible is doing that sunscape thing. I know. So he was saying that if you're a reptile and you get a fungus, but there's no sun,

to warm yourself in because the apocalypse has just happened. Great, kicked up the dust, blocked out the sun, nuclear winner. Mm-hmm. So you die because you can't withhold the fungus, but if you're a mammal, a fungus comes, your body temperature naturally kills it. And so suddenly, history goes.

You have mammals filling the hole and really flourishing in a way they never did before because fungus helped them do the mammalian explosion. Right, because we went through this fungal filter. And therefore, we are not a fungal filter at the end of the critatious. Wow. Now it gets even weirder, because then our tour decided he wanted to find out if you are warm-blooded. What was the optimal temperature by which you get the most protection against the fungi? temperature by which you get the most protection against a fungi and yet you don't have to eat all the time.

What is the optimal temperature to keep us from eating all the time but still give us defense? The reason we eat three meals a day is to stay warm and functioning. We were less warm, we could eat less. So it's like how little can we eat and still be protected against fungus and stuff. That's correct. And what Aviv did. And so what our touro did was he got together with this mathematical biologist, Aviv Bergman. And first they just gathered some numbers.

What is the temperature susceptibility of fungi? Like, most fungi don't like it above 86 degrees Fahrenheit. And then he looked at the well-known formulas for calorie use. And then he asked the question, if you put these two formulas together, what is the best temperature that keeps out most fungi, but doesn't require you to have to eat all the time.

They basically crunched a number that had to do with like how many calories you need a day and like just like the energy that would take of eating and then keeping out pathogens. And what he found was that our temperature is that temperature that best balances protection against the fungi versus the need to eat food. Whoa. Bing, bing, bing. We were amazed and tickled by it. He's saying the reason our bodies are precisely 98.6 degrees is because of fungus, like they shaped us to be that.

My heart wants to say yes, but to caveat, he did say it could be totally correlational. Right. Obviously he's not been able to take the temperature of any of our ancient ancestors, but, you know, it is a very interesting idea that part of being a mammal is about being good at fending off fungi. Unless part of that equation changes. Which I will after the break. Science reporting on Radio Lab is supported in part by Science Sandbox, a Simon's Foundation

initiative dedicated to engaging everyone with the process of science. This is Radio Lab, I'm Jet, I'm Rod. I'm Molly Webster. Okay, where we left off, you told us the startling fact that our bodies may have chosen 98.6 degrees to fend off fungus, but then you said somewhat ominously that is unless the equation changes, which it will. Yeah, so this brings us, some might say, finally, back to our medical mystery, which is that Artura Wonders what if in light of this dino mammal fungus datant, this thing that seems new,

Candida Oris has actually been here the whole time. So say these fungi typically live outdoors in soil and on rocks, and they live in a place that's like, you know, normally 75 degrees. It's Hawaii. You want, okay. Let's say Hawaii, because they're Greek and too much from there. Their ideal temperature is 77 degrees. And if they go above that, they start to feel a little queasy, really start to fade and it's a struggle.

Okay, so one day, it's 81 degrees, and like the fungus are like, oh, this is hot. All fungi have the capacity to tolerate short burst of heat, but you can't. But what if the 81 degrees last for many days, not just one? A heat challenge. In that case, most of the fungus would die. But the more 81-degree days there are, the greater the chances that in the Russian roulette

of evolution, one day you would get a fungus. Who's like, you know what? I think I feel pretty okay. And the reason that fungus probably feels that way is because it has like a mutation of some sort. They've given the capacity to survive the heat. Maybe it can even fight a little harder. Turning on some of the defense mechanisms like heat shock proteins.

However it does it, this one fungus lives. And then it creates a copy of itself. And then that fungus has fungus babies. What is called a bud? And then that creates a copy of itself. And then that fungus has fungus babies. What is called a bud? And then that bud has buds. So the original cell may make 50 copies of itself before it basically runs out of dunes to make any more, but those things. And so suddenly you have a whole batch of fungus that's surviving 81 degrees.

Yeah, okay. And then after that you take the survivors and you expose them to 90 degrees. Let them sweat it out and then boom, you got a whole batch at 90 degrees. You got it. And you can just keep bumping this up degree by degree. Exactly. A string of 91 degree days. 92 degree days, 93 degree days, 94 degree days.

95 degrees. 96 degrees. 97 degrees. 95 degrees, 96 degrees, 97 degrees, 98 degrees, and ultimately 98.6 degrees. Now you have the capacity to survive inside the body of a human. It reminds me of water. Like if you're water and you go from 34 to 33, you're still water, and 33 to 32, you're still water. But there's this seemingly insignificant threshold between 32 to 31 that when you cross it, you become ice. And it is this almost minute transition

that our tour of things happened with Canada, Oris. That it was out there living in the environment and it gradually adapted to be able to grow a higher temperature. And when it did that, it acquired the capacity then to causes in people. Essentially, it's adaptation defeated our heat defenses. Wow. Yeah. Yeah.

So fungus are being trained by the rising temperatures, and they're adapting along with those rising temperatures. You got it. And then suddenly, it's not that far from like, you know, that fungus in a soil, getting caught on somebody's shoe who walks it into a town, that then goes into a hospital.

Into an IV line, it can get into a wound, and then it can colonize patients. Huh, that would explain why Candida happened in all those places simultaneously it was always in those places Being tracked in on boots into hospitals, but only now it gets tracked in with this new ability to Live in us. Yes. Wow Japan is suffering its hottest day on record. And this is an interesting thing, like, like, Alvesan that made me think about all the headlines you see around the world, and in India, it's rarely being this hot.

About like the country has been experiencing a deadly heat wave with dry air far hotter than the human body. It's the 10th straight day above 105 degrees in Delhi. All across the west. You know, or it's like... It was another day of a press of heat. Idaho is having the hottest August on record. The funerals were on the way in Karachi on Friday for some of the victims of the scorching heat wave.

You know, many people say when you tell them about this, but how can that be? You know, they say that the average warmth, it may be one degree centigrade. This is a so-called cooling station in Las Vegas. I say, that's not the right way to think about it. The right way to think about it is to imagine the triple digit temperatures. The number of really high days, because each high day, it's a hope you've got to jump through. And then just one last dash of interesting in looking at all this like fungus temperature stuff, just as the fungus are learning to jump through our hoops,

it turns out we are actually making it easier for them. What do you mean? So there was this paper recently that was talking about how the human body temperature has been declining, it's been steadily declining for decades, at a rate of like 0.05 degrees Fahrenheit per decade. Really? So we're not 98.60 more, what are we? They think it's actually more around like 97.5, but in fact, what do you get that a lot

when you measure your kids? Yeah, I'm always like, oh, you're not your colder. The one thing that the researchers were talking about though in the declining is that they looked at Western records. But you know, they say, well, they did a small study on people in Pakistan and they were more around 98.6. And the researchers were talking about how, essentially, how hard your body has to work to stay healthy and consequently, the healthcare system that you're in is what is affecting the temperature

decline. I don't think they think it's worldwide. I think it's a developed country, Western kind of thing. I see. So in countries where there's more advanced healthcare, you're going to see internal body temps start to lower. Basically, yeah. So essentially in some, there is, you know, this head to head

between fungus and us. And it is a very fine line going from being insignificant to, you know, king or queen of the castle. Many organisms that you recover from the environment can only grow at environmental temperatures, but some of them have, there is a whole range of temperatures susceptibilities or temperature resistance. That's a better way, I need to put it. And some of them happen to their maximum happens to be just below your temperatures.

And these are the ones that we worry about because many of them may have the capacity to cause disease, but they cannot do it because they cannot survive the higher temperatures. Wait, what are the other ones that are just below my 98.6? Well, there are probably... Yeah, I don't want to be alarmist, but there are probably in the... In the hundreds of thousands or even in millions.

I mean, I don't want to be alarmist either, but now I want to know what's like... What's like marching at my heels. Yeah. Right. Wow. That's just so weird. Like, out of all the things a climate change can do to me, I was not thinking about like, it's warming up microbes on the sidewalk.

And they're like, ah, finally, I can crawl into a human. And this is the moment we've been waiting for for millions of years. It's so much shit. Yeah. Wow. Molly, thank you. I guess for just giving me one more thing to have nightmares about.

Sure. I am always happy to see your fears. This story was of course reported by Molly Webster, produced by Molly with Bethel Hoppe, production help from Ted Davis. Special thanks to Luis Estroski. Until next time, I'm Chad Abumarad. Thanks for listening. I'm Chad Applemore on the channel. Thanks for listening. Hi, this is Katie from Boulder, Colorado. Brady Alab is created by Chad Alabmore with Robert Krohlich, produced by Thor and Wheeler.

Dylan Keith is our director of sound design. Susie left in Bergu's are executive producer. Our staff includes Simon Adler, Jeremy Bloom, Becca Bressler, Rachel Kusik, David Gable, Bethlehob, and Sarah David David David and burgers are executive producer. Our staff includes Simon Adler, Jeremy Bloom, Becca Bresler, Rachel Kusik, David Gebel, Bethlehob T, Tracy Hunt,

Matt Kilti, Tobin Lowe, Annie McEwan, Lattee Snaffler, Sarah Curry, Erie Ann Wack, Pat Walters, and Molly Webster, with help from Shima Oliali, Sarah Sandbach, and Russell Greg. Our fact-tucker is Michelle Harris.