“The Last of Us” Fungus Is Real - Should You Be Concerned?

What’s the story? 

• In the hit HBO series, “The Last of Us,” people are turned into zombies by an infectious fungus that exists naturally in our world — ophiocordyceps unilateralis, also called cordyceps.  

How does the fungus work?

• The fungus only infects insects, such as ants and spiders, but does perform a form of “mind control” on its hosts, similar to the infection in the show, which is based on a popular video game.  
• Like other parasites, cordyceps sucks all of the nutrients out of the host and fills it with spores that allow the fungus to grow. The fungus hijacks the mind of its host until it eventually loses all control over its body and is compelled to find a higher ground to die and spread the infection. 
• Several days after the insect has died, the fungus grows out of the insect’s head and expels spores over nearby insect colonies. 

What are experts saying?

• According to Bryn Dentinger, a biology professor at the University of Utah, the fungus is one of the most commonly found organisms with mind-controlling abilities, and scientists are still determining how it works. He said:

“There seems to be some combination of physical manipulation of muscle fibers, for example, possibly growth into the brain itself, that can impact its behavior. But there's also very likely some sort of chemical attack on the host...that end up manipulating brain behavior.” 

• Scientists like Dentinger emphasize the differences between cordyceps in real life and in “The Last of Us,” especially as discussion about the show grows. For example, infected hosts are not connected through a network and do not infect other hosts through the mouth, as in the series. 

Does the fungus infect humans?

• No, the fungus does not infect humans. Dentinger explained:

“Our body temperatures are high enough that most organisms, their proteins would denature at that temperature and so they can’t survive in our bodies.”

• While Dentinger reminded us that fungus could evolve, it’s unlikely to transfer to another species, especially humans. Dr. Charissa de Bekker, a microbiologist at Utrecht University, concurred. She said the cordyceps fungus has evolved over millions of years to attack specifically insect species. Dr. de Bekker stated: 

“[An ant’s] nervous system is simpler than ours, so it would definitely be easier to hijack the brain of an insect versus our brain, also their immune systems are very different from ours.”

Are other forms of fungi safe?

• It all depends; some fungi cause bacterial or viral infections, while some are edible, and some are popular for their hallucinogenic properties. 
• The World Health Organization has identified 19 different fungi that are a threat to human health. Dr. Neil Stone, a leading fungal expert at the Hospital for Tropical Diseases in London, believes there could be an imminent threat of dangerous fungi in the future. Many experts believe the danger will worsen due to climate change increasing favorable conditions for fungi growth. 
• However, many safe fungi exist that benefit human health: chanterelle mushrooms, oyster mushrooms, chicken of the woods, chaga mushrooms, shiitake mushrooms, and so on. These edible fungi support immunity, bone health, gut health, and more. 
• Additionally, some health experts are promoting psilocybin — magic mushrooms — for their potential medical benefits. Researchers, neuroscientists, and even the U.S. Food and Drug Administration have studied the various benefits of psilocybin as a breakthrough medicine.

Are you concerned about the fungus spreading to humans?

-Jamie Epstein

(Photo credit: iStock/Kevin Wells)