DOOMSDAYThe Last of Us: Fungal Infections Really Can Kill – and They’re Getting More Dangerous

By Rebecca A. Drummond

Published 25 January 2023

Millions have been tuning in every week to watch the highly anticipated TV adaptation of “The Last of Us.” The show depicts a post-apocalyptic world where society has collapsed due to the outbreak of a dangerous, brain-controlling fungal infection that turns humans into hostile, cannibalistic “zombies.” Fortunately for us, a fast-spreading fungal pandemic is pretty unlikely – but this doesn’t mean fungi aren’t still a concern.

Millions have been tuning in every week to watch the highly anticipated TV adaptation of The Last of Us. The show depicts a post-apocalyptic world where society has collapsed due to the outbreak of a dangerous, brain-controlling fungal infection that turns humans into hostile, cannibalistic “zombies.”

The fungus which causes the pandemic is based on the real-life Cordycepszombie fungus that infects insects. Insects infected with Cordyceps have little control of their actions as the fungus takes over their nervous system, before eventually growing out of their bodies.

Fortunately for us, a fast-spreading fungal pandemic is pretty unlikely – but this doesn’t mean fungi aren’t still a concern.

Fascinating Fungi
The fungal kingdom is enormous – with an estimated three million different species worldwide.

Most fungi like colder temperatures around 10℃, meaning they’re typically unable to grow at the human body’s internal temperature of 37℃. This is one reason why most fungal infections in humans tend to stay on the skin where it’s cooler (think athletes foot and ringworm). It’s also why only a small number of fungi are able to cause infections in humans relative to the size of the fungal kingdom.

But a few species of fungi grow in warmer temperatures – and these are the ones that cause life-threatening infections. Some fungi, such as Candida yeast, can even live in our gut as part of the microbiome, and can escape into the blood and organs when we become ill with serious conditions (such as cancer).

And just as one of the characters in The Last of Us suggests, climate change may present new problems. Warming global temperatures mean fungi must adapt. This may increase the number of species which can cause serious infections in humans. There’s some evidence to suggest this may already be happening.

For instance, the fungus Candida auris is extremely concerning, since it’s resistant to nearly all antifungal drugs. It can spread rapidly around hospitals and care homes, causing serious infections in people with weak immune systems.

These infections are a bit like sepsis, where the fungus gets into the blood and organs, preventing them from working properly. But what really makes Candida auris stand out is its ability to grow at higher temperatures – able to withstand up to 42℃.

The emergence of Candida auris in three continents almost simultaneously has researchers theorising the warming global climate may have contributed to its rise. Whether further global temperature increases leads to more dangerous fungal super-bugs remains to be seen.