A 61-year-old mycologist in Kolkata, India recently went to his local doctor’s office complaining of throat pains and trouble swallowing. CT scans revealed ulcers filled with pus near his windpipe and, when further tests were conducted, the researchers failed to find any bacteria in the discharge. 

Instead, they found hyphae, root-like fibers that were originally rooted in the man’s throat. Specifically, the fungus that had taken root in the mycologist’s throat was originally a fungus that only infected plants — Silver Leaf disease. This is the first-ever case of a fungus that only affects plants infecting a human being. 

If climate change continues its current path, this will be the first of many more dangerous fungal infections transmitted from plants.  

So why hasn’t this happened before? Plant fungi didn’t ever infect humans before because they can’t survive inside our bodies since they can’t survive in our internal temperature, which is around 98.6 degrees Fahrenheit. The average temperature of the planet has slowly been increasing, however, which means there is a big possibility that fungi have evolved to be able to survive in climates like this. 

The case study on the patient stated that no fungus was found in his lungs which are much warmer than his trachea and this means that fungi, at least in the case of silver leaf disease, still have a difficult time establishing themselves inside a human body. 

Despite this, there is a chance that plant fungi can further evolve and become more adept at growing in much hotter climates since the temperature of the planet is still slowly rising.  

There are other reasons that climate change could make fungi more dangerous to the human race as well. Extreme weather events could spread fungi into houses because of damp conditions indoors. This would mean that people would experience adverse reactions to mold growth more frequently because extreme weather events are becoming more and more common with climate change. 

Injuries resulting from these major events could also become gateways to more fungal infections, which would only become exacerbated if fungi can transfer from plant matter to a human being. Contact with any dead plant matter could become a risk of infection if the situation continues to worsen.

The man in Kolkata had no immune system issues. He wasn’t taking any immunosuppressive drugs, nor did he have any diseases such as HIV or diabetes. Usually, people with no pre-existing conditions do not get sick from mold and fungus like this which makes this case a bit more worrying. 

Fungi are also becoming harder to fight with antifungal drugs. Farmers using fungicide in their agricultural practices is causing the fungi that affect humans to become resistant to treatment. The development of effective vaccinations and treatments that can prevent or manage infection is a serious problem because fungal and mammal biochemistry are comparable.

Another, more dangerous possibility is that a fungus that can take over insects would be able to infect a human. Ophiocordyceps unilateralis, or Cordyceps, is a fungus that takes over the brain of insects and forces them to move to more humid areas. 

Once the victim reaches a place with the perfect condition for the fungus to sprout, the Cordyceps bursts out of the insect’s head finally killing it and using its body to spread the spores to nearby insects, repeating the process. Cordyceps cannot infect human beings… yet. There are only two reasons that the fungus can’t infect humans right now. 

The first is that jumping from an ant to a person would be too complicated for the fungus to accomplish. However, we’ve already seen that a fungus, silver leaf disease, can jump from plant to human. Wouldn’t it mean that it’s possible for a fungus to jump from an insect to a human being?

The second reason is because the fungus cannot survive in the human body’s internal temperature, but fungi are evolving to be able to survive in those temperatures because of climate change.

If we don’t want “The Last of Us” to become a reality, we as a society need to act sustainably. Not only are the animals and the environment at risk because of global warming, we could be looking at another pandemic, one that’s much harder to fight.