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CU Boulder mycologist Alisha Quandt says there’s little reason to fear a fungi-zombie apocalypse like the one imagined in the HBO hit TV series ‘The Last of Us’

Alisha Quandt prepared herself in advance to be asked by students and others about Sunday’s season 2 premier of “The Last of Us”—the�� that imagines a post-apocalyptic future where a fungal infection on a massive scale turns the majority of humanity into zombie-like creatures seeking to infect the last pockets of civilization.

It’s not that Quandt is a super-fan of the TV show (“I’m not into zombies, honestly,” she confesses), but as a mycologist—a scientist who studies fungi—she is used to getting asked about the TV show, specifically whether the grim future it imagines is anything people need to be worried about, or whether it’s simply harmless entertainment.

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“I’m happy if it gets people excited about fungi. They’re so incredible,” says Alisha Quandt, a CU Boulder assistant professor of ecology and evolutionary biology.

“Especially when the TV show first debuted, it was definitely a topic people wanted to discuss,” says Quandt, a ����������Department of Ecology and Evolutionary Biology assistant professor.

“And it seems like the topic (of infectious fungi) comes up in popular culture every five to 10 years. When I was starting my PhD, people were fascinated by the ‘Planet Earth’ TV series by David Attenborough, where this ant infected by�� staggers around, being controlled by the fungus. Then later, the Last of Us videogame came out, which really got people excited about (zombie) fungi.”

Quandt did her PhD research studying Cordyceps-like fungi, which is the type of pestilence the TV show identifies as the culprit for turning civilization into a hellscape populated by��. For the record, Quandt finds that scenario very unlikely, for a variety of reasons.

No need to panic

For starters, the TV show imagines a worldwide outbreak is caused by Cordyceps-contaminated food. However, Quandt says most fungal infections in humans are caused by inhaling spores or through contact with the eyes or skin—and not through the digestive tract. She notes that in many parts of the world, people have been ingesting Cordyceps fungi for decades without incident, because they believe they contain beneficial properties.

“I’ve eaten Cordyceps in Asia, in Korea and China,” says Quandt, who remains unzombified. “It’s considered a part of traditional Chinese medicine, especially certain species. Even here in the U.S., you can find Cordyceps in coffees and teas, for example. They sell them at stores in Boulder.”

Quandt says another reason not to be overly concerned about Cordyceps is that many of them are “specialists” that have a very narrow range of hosts that they infect, down to a specific family of ant or spider. While some Cordyceps can transition from infecting one type of arthropod to another, or to jump from infecting an insect to another fungus, she says making the leap to a healthy human being is remote.

What’s more, the average human body temperature of 97 to 99 degrees Fahrenheit is not an environment that’s hospitable for many fungi, although Quandt acknowledges there are exceptions. “The Last of Us” imagines a future in which global warming has raised Earth temperatures to a point where mutated Cordyceps zombie fungi could live comfortably in human hosts, but Quandt notes that ambient temperatures of even 90 degrees Fahrenheit are still cooler than the human body.

“That’s a hard path for me to follow,” she says of an environmental change that would allow Cordyceps to evolve in such a way. “There’s a lot of assumptions that would go into that trajectory.”

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CU Boulder scientist Alisha Quandt finds the scenario from "The Last of Us" in which a Cordyceps-like fungi causes worldwide zombification very unlikely, for a variety of reasons. (Photo: HBO)

Beyond those arguments, Quandt says there is an even more important one as to why humans don’t need to start doom prepping for a fungi apocalypse.

“My argument about why we shouldn’t be worried about a fungal pandemic is that our bodies, when fully immunocompetent—meaning healthy human bodies—are extremely well equipped to deal with fungal propagules (spores) that come into contact with our bodies, mostly through our lungs,” she says. “Fungi have this cell wall that is made up of stuff that our bodies do not make. So, our bodies are really good identifying and dealing with that.”

Quant says fungal infections do pose a risk to people whose immune systems are compromised—particularly if they have taken a heavy dose of antibiotics, because those can kill off good bacteria, which can lower resistance to harmful fungi.

“Once our immune system goes away, which could handle those types of (fungi), we have so few antifungal drugs to treat fungal infections compared to the myriad of antibiotics that we have to treat bacterial diseases,” she says.

For the immunocompromised, Quandt says one of the most concerning fungi—which just cropped up in recent years and has spread worldwide—is��

“It is a really concerning human pathogen because it is what we call nosocomial, meaning it is�� hospital related. People get these infections in hospitals, and once it’s in a hospital, it can be almost impossible to get rid of it,” she says.

“People will use all kinds of bleach and ethanol but it’s very hard to get rid of the yeast once it gets into a hospital room. And the fully immunocompetent, like nurses and doctors who are not sick, can end up spreading it from room to room to sick, often elderly, patients. Unfortunately, there’s not a good defense on the ground, so to speak, once Candida auris takes hold.”

But while “opportunistic pathogens” like Candida auris can pose a risk to the immunocompromised, the number of fungal diseases that could be described as “primary pathogens”—meaning they can infect and potentially cause serious health issues for healthy individuals—is less than a handful, Quandt says.

One primary pathogen that can be found in the United State is��, which is primarily located in New Mexico, Arizona and southern California. Farming, construction or other practices that disrupt the soil can release the fungi’s spores, which people can then breathe into their lungs. Once inhaled, Valley Fever can potentially cause fever, cough, tiredness, shortness of breath and, in limited cases, serious conditions such as pneumonia and meningitis.

“But those are the rarer things, and I’m still not worried about them becoming common because they’re still not being spread from person to person,” she says.

In contrast with the way “The Last of Us” portrays fungi as an existential threat, Quandt sees a type of virus that’s already well-known to the scientific community and the public alike as a much greater risk for causing a global pandemic. The World Health Organization estimates the killed 14.9 million people worldwide between January 2020 and December 2021.

“As we’ve recently seen, unfortunately, there are a lot of other places to look for more likely suspects for (global pandemics). Things that were predicted by a lot of great investigative journalists and epidemiologists, like coronavirus and other zoonotic diseases (which jump from animals to humans), pose a much greater threat to mankind,” she says.

And now, back to the show

Even beyond the fact she’s not into zombies, Quandt says her training as a mycologist can get in the way of her enjoyment of “The Last of Us” as entertainment, based upon the few episodes she has watched.

“I’m probably a little too close to watch the show—especially the fruiting bodies,” she says. “Sometimes they would show a person who is dead up against a wall, and the fruiting structures look life shelf fungi,” she says.

“Those are related to mushrooms—they’re not related to (fungi) that are molds, like Cordyceps. The artistry was beautiful, so they did a good job visually, but it’s just completely inaccurate. So, it does take you out of it a little bit to watch as an expert; you have to really suspend belief.”

Another scene that inspired disbelief for Quandt was a flashback episode—prior to the fungal pandemic—when a mycologist in Jakarta is asked by representatives of the country’s military to provide guidance on how to proceed after a group of workers in a building are found to be infected with early cases of the Cordyceps contagion. After surveying the infected, the mycologist gives the military members a chilling one-word answer: “Bomb!” (As in, bomb the entire country to try to prevent the infection from spreading.)

“My husband was watching the show with me. He paused it there and he’s like, ‘What should they do?’ I was like, ‘Get all the antifungals that you can. Get all the major ones and then get the rare ones—and start pumping these people with IVs, or all the people that you think might be exposed and get going on it.’ But the fact she said ‘bomb!’ I almost found it funny, but I was also like, ‘Oh, my God, that’s so dramatic.’ Still, it’s a TV show, and I acknowledge that.”

While Quandt may opt not to watch more episodes of “The Last of Us,” she says if the TV show raises public awareness about fungi—even if the details in the show are not entirely correct—she is all for it.

“I’m happy if it gets people excited about fungi,” she says. “They’re so incredible.”

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