'The Last of Us' might offer lessons for SC's climate future

In the opening scene of the first episode of the TV series “The Last of Us,” two researchers discuss the potential for a global pandemic on a fictional 1960s talk show. One puts forward the theory that such an event would most likely be driven by a viral illness, like influenza. The other presents a more terrifying prediction: A fungal disease that can take over the mind of the infected.

“Fungal infection of this kind is real, but not in humans,” the first researcher counters. The second admits that fungi cannot survive in a host if its temperature is over 94 degrees and, at least in the 1960s, fungi had no reason to evolve to withstand higher temperatures.

“But what if that were to change? What if, for instance, the world were to get slightly warmer?” he asks. “Well, now there is reason to evolve.”

Flash forward a few decades, and the world has been overtaken by zombies infected with cordyceps, a real-life fungus that can hijack the nervous system of insects. The show’s fictional concept, it turns out, is based on an element of truth. 

Now researchers at Duke University hope to gain a better understanding of how fungus might grow, evolve and affect humans in the wake of major hurricanes in a warmer world. They’ve gathered samples in areas of North Carolina hit hardest by Hurricane Helene in an effort to create more fungal-resilient communities across the country.

They haven’t seen an uptick in severe invasive fungal infections in the months since Helene, said Asiya Gusa, a researcher on the fungus project. But they’re concerned about how the storm and its aftermath have disturbed the soil where fungi live and thrive — while the overall temperature is increasing due to global warming.

“That puts pressure on those organisms in the soil to grow at higher temperatures,” said Gusa, a professor of molecular genetics and microbiology at Duke. “One of the main barriers that we have to disease, and fungal disease in particular, is our high body temperature.”

Gusa acknowledged the parallel to “The Last of Us.” While she said there’s no firm evidence that thermal adaptation could lead to more disease-causing fungi yet, and more research on how fungi are adapting to a changing climate is needed, she noted that researchers now are seeing once-benign species of fungi now causing diseases in humans.

“We’re trying to still understand what is the impact of climate change on this,” Gusa said. “We think it is connected.”

Meanwhile, research indicates fungi are becoming more drug resistant.

Natural disasters

Weather events such as Helene are becoming more common, changing the conditions in which fungi thrive.

Stronger hurricanes can mean more rainfall and flooding, and the increasing power of those events could lead to “breakdowns in the physical barriers between outdoor and indoor spaces of homes and buildings,” according to the U.S. Environmental Protection Agency. One of the Duke researchers’ early findings (their work is ongoing, and study of the results is still in the preliminary stages) was that mold was present in each sample collected, even after a site had been “remediated” — potentially indicating a gap in the post-disaster clean-up process.

Those storms also can have stronger winds, which can carry “endemic” fungi into areas where they didn’t previously exist.

Gusa said a fungal pandemic, while unprecedented, is possible.

One report from the University of Minnesota’s Center for Infectious Disease Research and Policy estimated that over 6.55 million people each year are infected by invasive fungi, which lead to more than 3.75 million deaths each year — more than 2.5 million of which are directly attributable to fungi. (Fungal infections can exacerbate other illnesses, similar to how COVID-19 can have co-morbidities.)

“We really need to have more novel antifungal compounds in the pipeline and being tested in clinical trials so that we’ll be able to combat a (potential) large-scale fungal pandemic,” Gusa said. She described fungal infections as a “silent pandemic.”

“When people are infected with severe fungal infections, it’s upwards of 50 percent mortality,” she said. “It’s really difficult to treat and it’s very underdiagnosed. Usually, by the time people are aware that they have a fungal disease, it’s almost too late to treat it.”

Living with fungi

A good approach to living with fungi might not be fighting an outright war but, rather, striking an harmonious balance.

One of the goals of the Duke project is to find a way to create mold-harmonious structures, explained Andrew Jones, a professor of civil and environmental engineering at the university and one of Gusa’s research partners. Jones said one of the goals of his research is to create building materials that can prevent the growth of harmful bacteria and fungi, and to determine what materials can be placed in a home to foster beneficial fungus and bacteria, essentially giving the good fungi the upper hand and helping them out-compete the bad fungi.

As humans have developed a better understanding of public health, Jones said they’ve steadily sterilized and sealed off buildings to keep bacteria and fungi outside. But he said that can result in an “over-correction,” as a certain amount of bacterial and fungal exposure can be beneficial for humans in the long-term. That’s not to say all mold and bacteria are good for you, but Jones said there is a balance that can be struck.

“We are living with bacteria and fungi,” he said. “Children that grow up playing in the dirt have better immune systems and better immune responses than children that do not grow up playing outside. Children that grow up with pets in the home have better immune responses than people that don’t.”

But if that mold peels off a wall and starts chasing you, safe to say you’ve got the “bad” fungus.