killer fungi may be coming for us thanks to global warming

One of scientists’ biggest fears about fungi and global warming is slowly starting to play out as temperatures soar.

After living through a pandemic, those of us who were paying attention learned a bit about what scientists consider to be the biggest and most potent candidates for the next global health crisis. In some ways, COVID was expected to happen in some form as different strains of coronaviruses caused outbreaks since the early 2000s. We just didn’t know which strain would become infectious enough to break through or when, although wet markets were always suspected as a hotspot where zoonotic diseases can make the jump to humans.

Coronaviruses were also a blind spot in our vaccine development, and we’re still not quite there with pan-coronavirus vaccination, although this was being actively worked on before medical research was taken over by a pro-disease activist. But, for the time being, we have microbes and flu more or less under control. We probably won’t have another surprise like COVID for a bit, statistically speaking. The next prime candidate for pandemic status right now is bird flu.

The only thing left are fungi, some of which are dangerous and incredibly hard to treat because they seem so much like our cells from a biochemical standpoint. Medication meant to kill fungal spores attack our tissues as well, meaning that treatment options will be extremely limited given our current understanding. At least these spores can’t survive in our bodies for long. Or so we hoped.

As the planet warms, researchers worry that very nasty and infectious fungi can start evolving to tolerate higher temperatures well enough that our bodies become the kind of hospitable environments their spores can call home.

Our core temps of 98.6 °F, or 37 °C are more than hot enough to kill fungal infections, which we think is due to evolutionary selection. Cold blooded creatures tend to get a lot more fungal incursions into their bodies than warm blooded ones. But if our bodies are no longer how enough, doctors worry that we have few tools to fight these fungal invaders and there will be more opportunities for them to jump from fish, reptiles, and amphibians to us because they’ll also get infected more often.

Meanwhile, as more and more spores can already opportunistically infect people with weakened or compromised immune systems spread to new territories, four species in particular are on the rise. Every more than 75,000 patients in the U.S. are hospitalized as a result of their spores with a mortality rate of nearly 1 in 10, that number is growing by 8.5% per year, and that’s not even mentioning the 9 million outpatient visits for low grade infections.

Doctors are also worried about resistance to old anti-fungal medications making up their arsenals. Treatments of last resort are more or less a gamble already. How much worse could the problem get? Well, one study from 2022 looked at fungi which cause serious lung infections is considered a major red flag. Not because it found that those infections are getting worse, but because it confirms that climate change it allowing a lot of spores to migrate to new territories and find new victims.

The fungus which causes histoplasmosis and trigger the onset of meningitis managed to spread from parts of the American Midwest and parts of the Southeast to nearly all states. In the Southwest, the Coccidioides fungus responsible for Valley Fever, moved from the border into at least 35 states. Blastomyces expanded from its usual territory Ohio and the Mississippi River Valley to 40 states.

But none of them are as mobile as the drug resistent Candida auris, originally found in Japan, which spread to 47 countries ranging from South America, to Africa, to Siberia and the Far East. As temperatures keep rising, its world tour is nowhere near done as it continues to prey on vulnerable patients often undergoing long term treatment for a chronic illness, causing sepsis and organ failure.

Of course, the worst thing we can do about this is panic. First of all, we can still clean up our act and slow down global warming and climate change. Secondly, we need to make it a clear priority to train more primary care doctors on fungal diseases. Third, we need invest in more research into threatening strains and anti-fungal medication, despite the fact that basic medical research in the U.S. is now overseen by someone who thinks infectious disease is no big deal and denies basic germ theory.

And fourth, and most importanlty, take this threat very seriously and make sure we’re minimizing our chance of developing these infections with good hygiene and exercise. Experts keep ringing the alarm bells. When do we finally start listening?

See: Jingdi Li, Guttmann Nele, et al. (2024) Excess mortality of infected ectotherms induced by warming depends on pathogen kingdom and evolutionary history, PLOS Biology, DOI: 10.1371/journal.pbio.3002900

Mazi, Patrick, et al. (2022) The geographic distribution of dimorphic mycoses in the United States, Clinical Infectious Diseases, DOI: 10.1093/cid/ciac882

note: this post was originally published on 01.24.2023 on the old blog. It was updated and expanded with new research confirming the study on which the original post was based and providing additional nuance.