Deadly Fungi Spreading Across the United States as Global Temperatures Rise

Coccidioides, a fungus that was largely found in the Southwest, is now being found in most states. Photo Courtesy of the CDC.

By Gabriel Gomez, Art Director

In the United States, dangerous fungal infections that pose a threat to humans are on the rise and a growing body of research suggests warmer temperatures might be the culprit.

The human’s average body temperature of around 98.6 degrees Fahrenheit has always been too hot for most fungi to thrive. As temperatures have risen globally however, some fungi might be adapting to endure more heat, including within the human body. Research shows climate change might also be creating conditions for these disease-causing fungi to expand their geographical range.

“As fungi are exposed to more consistent elevated temperatures, there’s a real possibility that certain fungi that were previously harmless suddenly become potential pathogens,” said Peter Pappas, an infectious-disease specialist at the University of Alabama at Birmingham, in an interview with the Wall Street Journal. 

This could be just the beginning, as fungi adapting to the heat isn’t the only consequence of warming temperatures and according to the journal “Proceedings of the National Academy of Sciences,” it could also be making certain fungi evolve at a faster rate than usual.

In the study, researchers focused on Cryptococcus, an invasive fungus known for causing deadly diseases and infections in those who are immunocompromised, which the CDC estimates is already responsible for 112,000 brain infection deaths per year worldwide.

Deaths from fungal infections are increasing due in part to the growing populations of people with weakened immune systems that are more vulnerable to severe fungal disease. According to the Centers for Disease Control and Prevention, at least 7,000 people died in the U.S. from fungal infections in 2021. 

Valley fever, which is a disease caused by Coccidioides, was once mostly limited to the Southwest. Now people are being diagnosed in significant numbers in most states. “As fungi are exposed to more consistent elevated temperatures, there’s a real possibility that certain fungi that were previously harmless suddenly become potential pathogens,” Peter Pappas said. 

The dangers of the fungi are not only being shown in reality. In fact, in “The Last of Us,” a video game and show that deals with the fallout of the pathogen infecting the world’s population, audiences are being shown the possibility of a fungus that infects people and turns them into fungal creatures. This fungus in the game is actually based on a real fungi genus, Ophiocordyceps.

There have been no known Ophiocordyceps infections in people currently, which is reported by infectious-disease experts. The rising temperatures that facilitated the spread of the killer fungi in the game and show may be, “pushing other fungi to better adapt to human hosts and expand into new geographical ranges.” The World Health Organization has identified Cryptococcus, Coccidioides, as being among the fungal pathogens of greatest threat to people currently.