Whether you’re a video game lover or just discovered the horrors of a fungal apocalypse through HBO’s The Last of Us television series, the idea of zombie-like creatures roaming the Earth is still a terrifying thought.
And while the story of a world overrun by hordes of humans infected by a mutated strain of fungus is horrific enough, you have to wonder – could a fungal pandemic really be the end of it all?
Meet the real-life, zombie-making fungus
Cordyceps (Ophiocordyceps unilateralis), the fungus that almost wipes out humanity in The Last of Us, is real. It’s even known as the “zombie fungus” in the scientific community — though in the real world, it only impacts insects. What it does to insects, however, is eerily similar to what video game players and television audiences can see happening to people in The Last of Us.
There’s a reason for that similarity too — the game’s co-creators, Neil Druckmann and Craig Mazin, were inspired by BBC’s Planet Earth documentary discussing how cordyceps turn ants (and also some spiders) into zombie-like creatures.
Cordyceps attack the body of ants by taking over their motor functions first, draining their bodies of nutrients while “injecting” it with fungal spores that grow and reproduce as the virus spreads.
As the fungus takes over, the ants experience extreme confusion and erratic behavior, which is why scientists refer to cordyceps as having “mind control capabilities.” The confusion has a purpose, however – it causes the ants to climb onto higher ground, where they are exposed to higher temperatures and more sunlight, two conditions that help the fungus spread even quicker.
Once the infected ant dies, the fungus “breaks out” from the ant’s head, releasing spores in the process and infecting any insects that just happen to be nearby.
Luckily for humans, the similarities end there
In both the game and show, infected people mutate into zombie-like creatures that look less human and more fungus-like as the disease progresses. They are often aggressive, salivating for their next bite (the way by which they spread the infection), and often move using echolocation rather than sight.
Crazy ants bent on attacking and biting everything around them sounds scary enough, but in the animal world, cordyceps don’t turn insects into violent killing machines. So there’s no reason to think it would cause that effect in humans either. University professor and fungi expert Charissa de Bekker says the game’s violent symptoms are more similar to what you would see in mammals infected with rabies, rather than a fungal infection.
So could we really be at risk at all?
The closest answer scientists can give us about a potential fungus pandemic is “no, but…”
Technically speaking, cordyceps are very much species-exclusive. Although the fungus has been around for millions of years, it still continues to infect mostly ants and has never crossed into other animals, including mammals. It also would be basically impossible for a fungus to manipulate the human brain, which is not only much more complex than the brain of an insect, but also vastly different biologically.
Fungal infections do affect (and kill) people, just not in a zombie-like manner. In fact, over 300 million people suffer from fungal infections every year, and over 1.5 million of those infected die. The problem with fungal infections, according to scientists, is that they’re not easy to treat.
This is mainly because “fungi are more closely related to humans than they are to viruses or bacteria,” which means it’s tricky to get rid of them without killing ourselves in the process. There’s also little research in place to try to understand them and even less research done on how to cure them, so doctors aren’t yet well-equipped enough to deal with it.
While scientists aren’t too worried about a cordyceps apocalypse happening anytime soon, some do believe climate change and warming temperatures could result in more frequent and more aggressive fungal infections.
One of the reasons for that is that fungi thrive in environmental temperatures lower than the average temperature of the human body. But as the planet warms up, humans might, at some point, become a better hosting place for fungi than the planet itself. According to infectious diseases expert Ilan Schwartz, “it’s not outlandish … that global warming has increased the thermal tolerance of a fungi.”
The possible factors operating on the emergence of Candida auris. Credit: Arturo Casadevall, Dimitrios P. Kontoyiannis, Vincent Robert Via Wikimedia Commons (CC BY-SA 4.0).
We are actually seeing the effect of global warming on fungus growth already. In 2009, scientists identified the multi-drug-resistant fungus Candida auris in over 30 countries around the world. For the first time ever, the World Health Organization (WHO) now has a list of fungal priority pathogens and the Centers for Disease Control and Prevention (CDC) has classified Candida auris as “a serious global health threat.”
So while a Hollywood-like fungal pandemic might not be in the books for us anytime soon, we probably should still start paying attention to other fungal threats coming our way.
By Diana Bocco, contributor for Ripleys.com
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