Rising temperatures may be cause of increase in dangerous fungal infections
This will sound uncomfortably familiar to those that have watched The Last of Us TV show.
There has been an increase in dangerous fungal infections in the United States and more and more scientific research suggests that rising temperatures may be a cause.
As reported in the Wall Street Journal, the US Centers for Disease Control and Prevention says that at least 7,000 people died in the country from fungal infections in 2021. This is up from only hundreds of people each year around 1970.
And while the human body’s average temperature of 98.6° F has long been considered too warm for most fungi to thrive, research suggests that, as a result of a global rise in temperatures, some fungi might be adapting to endure more heat stress.
“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, an infectious-disease specialist at the University of Alabama at Birmingham told WSJ.
This will sound alarmingly familiar to those who have watched the new TV adaptation of the video game The Last of Us.
It revolves around a fungus - based on the real genus Ophiocordyceps - that turns those infected into monstrous, zombie-like creatures.
The series even opens with a scientist (John Hannah) in the late '60s hypothesising that the fungus, that infects and kills insects, could evolve to infect humans as it adapts to stand rising temperatures.
While there have been no known Ophiocordyceps infections in people, WSJ reports, a recent study in the journal Proceedings of the National Academy of Sciences showed that higher temperatures may lead to some disease-causing fungi evolving quicker to survive.
Researchers at Duke University in North Carolina grew 800 generations of a type of Cryptococcus, a group of fungi that can cause severe disease in humans, in conditions of either 86° F or 98.6° F.
According to WSJ, researchers used DNA sequencing to track alterations in the fungi’s genome with a particular focus on “jumping genes”.
These are DNA sequences which can move from one location on the genome to another.
Study co-author and postdoctoral researcher in Duke’s Molecular Genetics and Microbiology Department Asiya Gusa explained that the movement of these genes can lead to mutations and alter gene expression.
She added that, in fungi, this movement could play a role in enabling fungi to adapt to stressors such as heat.
Researchers discovered that the movement rate of jumping genes was five times higher in the Cryptococcus grown in warmer temperatures.
The US Centers for Disease Control and Prevention has said that at least 110,000 people die globally annually from brain infections caused by Cryptococcus fungi.
Meanwhile, an analysis published in 2022 in the journal Clinical Infectious Diseases stated that some potentially deadly fungi found in soil, including Coccidioides and Histoplasma, have significantly expanded their geographical range since the '5os in the US.
Co-author of the analysis and an associate professor of medicine at Washington University School of Medicine in St. Louis Andrej Spec told WSJ that warming temperatures, along with other environmental changes associated with climate change, may have played a role in this spread.