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‘Last of Us’: Cordyceps – The Zombie-Creating Fungus Inspired By Real Science

4 Minute Read
Jan 30 2023

The Last Of Us has us all talking about the fictional plague that sweeps the world. But this fictional fear was inspired by real fungi.

The Cordyceps Brain Infection is the humanity-altering plague featured in HBO’s The Last Of Us. While what we’ve seen on screen so far has been pretty terrifying, according to the source material, we’re still in for a few more surprises. And of course, as pointed out in the show itself, this sensationalized fungi is inspired by a very real one. But what is the Cordyceps Brain Infection within the fiction of The Last of Us? And how similar is it to its muse?


via HBO

While the timelines and specifics between the Last of Us video game and TV show have some slight differences, the basics are fairly similar between the two.

In 2013’s video game, a mutated strain of the Cordyceps fungus spread to the United States in late September 2013 from South Africa. Humans were infected with contaminated crops, and players can see through a newspaper article that it has caused hospital spikes of 300% as well as massive recalls of contaminated crops.


In the new TV show, the starting point of the Cordyceps Brain Infection is much less vague and less difficult to uncover. After multiple hints in the first episode pointed to the possibility of the fungus coming from contaminated flour, episode two confirmed it when we see a flashback to Jakarta, Indonesia. Within the fiction of the show, this was the first known instance of a human Cordyceps infection in September 2003 (ten years earlier than in the video game). But it’s also the real-world location of the world’s largest flour mill.

In both versions, many people were infected very quickly after eating contaminated food products and began spreading the virus throughout much of humanity.


Stages and Spread

In both the video game and the TV show, the Cordyceps Brain Infection can be spread if an infected person bites an uninfected one. But the game adds another level of terror that the show doesn’t seem to be exploring with airborne spores. For much of the map, players wear gas masks to avoid inhaling spores that would travel to the victim’s brain and infect them.


Instead, the show’s take on the fungus includes a massive system of interconnected vines of fungus, growing on the ruins of the world that was once there. These fibers can grow for more than a mile uninterrupted and allows the infected to act as a hive mind. If a part of the vine is disrupted, harmed, or even just touched, all of the infected in the area will be immediately and simultaneously alerted and known to come running.

Once bitted or spored, an individual will follow multiple stages of infection. At first, the fungus will grow inside of the host while they are still alive. This time can be recognized by strange but minor movements such as unusual twitches. Two or fewer days after infection the host loses their higher brain function and becomes hyper-aggressive as well as incapable of reason or rational thought. This is known as a “Runner”. They are known for their speed and attack in hordes.

About two weeks after that the second stage of infection the fungus begins to grow over the infected’s head and through their visual cortex, altering their sight and resulting in a “Stalker.” After about a year the fungus spreads all over the victim’s body, covering their eyes completely and blinding them. These “Clickers” are forced to use echolocation to find their prey, but they have enhanced strength.

These three stages have already been encountered in the TV version, but we have not yet met the “Bloater.” After about a decade of infection, the fungus leaves its victim blind and slow, but incredibly strong with a natural armor plating. Bloaters are able to use part of their bodies as spore weapons. But without the inclusion of spores in the show, we are not yet sure what direction they will take just yet.


Ophiocordyceps Unilateralis

The real-world Cordyceps is commonly known as the Zombie-Ant Fungus, and there are quite a few places where you can see where it inspired the infection in The Last of Us.


An ant is infected with a yeast form of the fungus, which will take over its body and begin to manipulate its behavior patterns and cause full-body convulsions in the ant. These behaviors culminate in the ant climbing to a leaf in an ideal location for the fungus, clamping down on the leaf’s vein with its mandibles to secure itself and becoming fixed in place. From there the ant dies and the fungus spends four to ten days growing out of its head and releasing spores that will infect more ants.

Despite inspiring the stuff of many of our nightmares, this is only seen in ants. But I still recommend reading up on Ophiocordyceps Unilateralis and zombie-ants more on your own. If nothing else, they’re very interesting.


How are you enjoying The Last of Us so far? Do you like the show or the video game’s take on the Cordyceps Brain Infection? Did you know about zombie-ants before Last of Us let us know how real they are. Let us know in the comments!

Happy Adventuring!

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