In the HBO series The Last of Us, could the mushroom one day turn people into zombies? That’s what biologists say

The fungal pathogen that is wiping out much of humanity in HBO’s latest series The Last of Ut’s real, but could the Cordyceps fungus actually turn humans into zombies one day?

“It’s highly unlikely because these are organisms that have adapted really well to infecting ants,” Rebecca Shapiro, an assistant professor in the University of Guelph’s Department of Molecular and Cellular Biology, told Craig Norris, host of CBC Kitchener-Waterloo’s The morning edition.

In the TV series, the fungus infects people’s brains, turning them into zombies. In real life, it can only infect ants and other insects in this way.

Shapiro believes the series does a good job of realistically portraying the fungus and its behavior, but it would actually take millions of years for it to find a way to adapt to humans and infect them the way it does The last of us.

Humans are too warm and too complex for this particular fungus to infect humans, she said.

However, there are many fungi that infect humans, although they rarely cause deadly conditions like yeast infections and athlete’s foot, James Scott, a professor at the Dalla Lana School of Public Health at the University of Toronto, told CBC Metro morning.

Fungi can also easily infect people who are immunocompromised or have an underlying disease, as happened in India in 2021 when more than 4,000 COVID-19 patients died from mucormycosis fungal infections.

“There’s this growing population of people who are living with vulnerabilities and underlying diseases or who are immunocompromised, and as that percentage of the population increases, we have more people who are susceptible to fungal diseases,” Shapiro said.

In Ontario, Scott said, there are two main types of fungi to worry about. One is called Blastomyces, which can cause lung infection and often presents as a skin lesion that can be fatal.

Scott said it’s a common fungus found on the north shore of Lake Superior and the east side of Georgian Bay. In 2021, the fungus infected more than a dozen people in a small First Nations community in northern Ontario, killing two people.

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The other was found in Ontario, Histoplasma capsulatumis associated with the accumulation of bird and bat droppings.

“As the populations of these other animals are affected by these types of diseases, there will be negative consequences for us. So not a direct threat to our lives yet, but still a big problem overall,” Scott said.

Climate change and new pathogens

With climate change on people’s minds, Shapiro said there’s reason to believe rising global temperatures may result in new fungal pathogens emerging in our environment.

Fungi are found in soil and trees and are well adapted to ambient temperature, she explained.

“As ambient temperatures rise, they adapt better to those warmer temperatures, and that starts to more closely match the temperature of a human body,” Shapiro said.

Scott also said that human activities, such as logging of rainforests and other activities that drive climate change, may also increase opportunities for humans and fungi to interact.

Drug resistance to certain fungi is also an issue.

Candida Auris, for example, is a fungal pathogen of concern that has emerged recently, both Scott and Shapiro point out. The U.S. Centers for Disease Control and Prevention says the fungus is resistant to multiple drugs, is difficult to identify, and can have outbreaks in healthcare settings.

The weather is certainly changing, as seen in many parts of Southern Ontario over the past week, with warmer-than-average temperatures.

Environment Canada meteorologist Geoff Coulson said that as our climate changes, flora and fauna will change.

“There are species of wildlife that are encroaching further north that are impacting wildlife that were already nesting here before they arrived. Plant species too,” he said.

“These changes are definitely occurring. There are things that could not have survived a winter 20, 30, 40 years ago that now stay in our climate all year round.”

As the weather changes, there could be more invasive species, too, he said.

Climate change and evolving health patterns all sound like ideal situations for a fungal pathogen outbreak, but Shapiro said this information and the fictional series shouldn’t scare people.

A “fresh take” on zombies

Kitchener, Ontario video gamer Alex Pinto Lobo hasn’t watched the HBO series yet, but he often plays the video game it’s adapted from. The video game franchise was first released in 2013.

“It’s a really great story with a lot of great characters,” said Pinto Lobo.

He said The last of us Video game was a “refreshing change” from typical war games, such as call of Dutythat were popular at the time.

“The story was a new take on zombies and made nature scarier than people realize.”

However, he does not worry about the plausibility of a mushroom-zombie apocalypse. He has read the science and understands that the chances of a cordyceps fungus takeover are unlikely.

“Now that we’ve weathered the pandemic, I don’t think we’re capable of destruction that quick,” Pinto Lobo said.

Shapiro said she’s pleased to see an increase in awareness of fungal pathogens thanks to the show, but also wants to remind people that fungi are a vast kingdom with millions of species.

“There are a few of them that can cause disease in humans, but they also play this really amazing role in our lives and do incredibly useful things that support human life,” she said.