In "The Last of Us," zombies sprout Cordyceps tendrils that sprout from their heads and mouths, reaching out for new victims.
It is true that cordyceps exist, but it only takes over the bodies and brains of other insects, most notably ants.
The fungus develops inside an ant's body, prompting it to climb up, after which it emerges from the ant's head and disperses spores in an attempt to spread far.
Cordyceps cannot infect us because it cannot thrive at human body temperature. However, certain fungal species produce chemicals that have psychoactive properties and can influence human behavior.
Fungal illnesses can spread from animals to people. But the concept that a fungus-like Cordyceps could change enough to make the huge leap from insects to people while still being able to successfully affect behavior is far-fetched.
However, in the infectious-disease field, "never say never," according to Tom Chiller, chief of the fungal disease branch of the U.S. Centers for Disease Control and Prevention, via Insider.
"A fungal pandemic is definitely possible," Norman Van Rhijn, a mycologist researching fungal infections at the University of Manchester, told Insider in an email.
No known species of fungus poses a pandemic threat to humans right away, especially not in the way that the television program depicts it. However, researchers are concerned that the number of people at risk is growing as fungal diseases are on the rise throughout the world.
Some people are even concerned that the kingdom of fungi may produce brand-new super-pathogens.
"The potential is huge for what can emerge and become a pathogen," Chiller added. "I am not going to be surprised that more fungi emerge as human pathogens, that become more challenging to treat and more infectious."
Psilocybin, the hallucinogenic ingredient found in magic mushrooms, is perhaps the most obvious example. Ergot, a fungus, is also known to affect the human mind.
Some historians link the Salem Witch Trials to ergot sickness, claiming that after eating contaminated rye, women began acting oddly and accusing each other of witchcraft. Ergot is the source of the hallucinogenic drug LSD.
Cryptococcus fungus can also travel from the lungs to the brain, causing meningitis (inflammation) that might change behavior.
Unlike on TV, though, the mind-altering fungus "doesn't jump into our body and affect a behavior that enables future transmission," according to David Hughes, a Cordyceps researcher who advised on the video game "The Last of Us."
Instead of contact with other people, the environment is where the majority of fungal diseases originate. Fungal spores are constantly entering your lungs. Normally, the immune system of humans takes care of that. However, if you have a weakened immune system from an illness or medications, that fungus may flourish inside of you.
Because of this, outbreaks are more likely to occur in hospitals and jails. When immunocompromised individuals congregate or when a large number of people are in close proximity to one another and share a single surface, the majority of human-infecting fungus propagate most effectively.
"The real-life nightmare scenario is that fungi like this cause more damage and turn from relatively mild infections to life-threatening infection," Van Rhijn said.