AYESHA RASCOE, HOST:
The new HBO show "The Last Of Us" is a whopper. Climate change has fueled the rise of a new pathogen that has nearly wiped out humanity. The cause of the infection is a bit surprising.
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JOSH BRENER: (As Murray) Not bacteria, not viruses. So...
JOHN HANNAH: (As Dr. Neuman) Fungus. Yes, that's the usual response. Fungi seem harmless enough.
RASCOE: Yes, a fungus is the cause. As part of an ongoing series, NPR is looking at what might cause the next pandemic, and so "The Last Of Us" had us wondering if something like this could actually happen. Here's NPR's global health correspondent Michaeleen Doucleff with the story.
MICHAELEEN DOUCLEFF, BYLINE: For the past decade, I've reported on infectious diseases, and I've often asked scientists, what keeps you up at night? What types of pathogens could cause a horrible pandemic? I hear...
UNIDENTIFIED PERSON #1: Hendra virus.
UNIDENTIFIED PERSON #2: Influenza.
UNIDENTIFIED PERSON #3: Nipah virus.
UNIDENTIFIED PERSON #4: Coronaviruses.
DOUCLEFF: Basically, it's always a virus. I've never heard a fungus, and a fungus has never caused a massive pandemic similar to COVID. And that's because viruses have several big advantages over fungi. For one, they spread much, much faster.
AILEEN MARTY: Yeah, that's absolutely right.
DOUCLEFF: That's Dr. Aileen Marty. She's an infectious disease specialist at Florida International University.
MARTY: The big advantage, if you will, for viruses is one viral particle can become thousands in a very short period of time. And as it produces more viral particles, it has the propensity to have mutations.
DOUCLEFF: And that means viruses can evolve much faster than fungi.
MARTY: And that can lead to a new version that could be more dangerous.
DOUCLEFF: So that all of a sudden, the virus can start evading our immune systems, and in a flash, the whole world becomes susceptible. Marty says fungi really can't do this because they mutate 10,000 times slower. And as an aside, the fungus in "The Last Of Us" that controls people's brains - it's made up. It's totally sci-fi. Plus, Marty says, people who have healthy immune systems can fight off fungal infections before they become dangerous.
MARTY: The reality is that most immunocompetent people do not get sick from a fungus entering their body.
DOUCLEFF: If you had to put money on, you know, what's going to cause the next pandemic, would you put it on a fungi or a virus?
MARTY: I would put it on a virus. I really would. But that doesn't mean that we shouldn't pay attention to fungi because many, many, many people die every year from all these other types of issues.
DOUCLEFF: In fact, about 1.5 million people die from fungal infections each year, and there's a growing concern that number will go up because of climate change. So here's where the show "The Last Of Us" gets the science right. Most fungi live in the environment - outside - so they can't survive inside people. We're too hot. But as the scientist in the show explains...
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HANNAH: (As Dr. Neuman) What if that were to change? What if, for instance, the world were to get slightly warmer? Well...
DOUCLEFF: Laura Goodman studies pathogen genomics at Cornell University. She says there's evidence that warming temperatures have already led to the emergence of a new fungal disease.
LAURA GOODMAN: That one is pretty nasty because it is resistant to many of the drugs that we have available. And not only that, but it seems to have a strong advantage in changing in such a way that it can cause disease in people.
DOUCLEFF: The disease is called Candida auris. And again, Goodman says it's people with compromised immune systems who are at risk.
GOODMAN: For many people, it's probably harmless.
DOUCLEFF: But there's concern that could change.
GOODMAN: It definitely keeps me up at night because I see all the work that is done on bacteria and viruses and how much we know, and then we look over at the fungal pathogens and it is so much less.
DOUCLEFF: And with "The Last Of Us" raising all this awareness, she hopes that might change, too.
Michaeleen Doucleff, NPR News. Transcript provided by NPR, Copyright NPR.
