Changes in the environment and climate, as well as fungicide overuse in agriculture, have resulted in an increase in fungi globally.
By Toibah Kirmani
What if a parasitic fungus became a threat to humankind’s survival? That is the scary premise of ‘The Last of Us’, a popular American post-apocalyptic drama television series on HBO. The story takes place in 2023, 20 years after a fungal infection of the brain renders victims ferociously insane and savage, destroying their sight, and leaving them with little choice but to use echolocation to locate other humans. But is there any science behind this fiction?
Well, the answer is yes. More than 1.6 billion people die from fungal infections each year, despite the fact that fungi typically mutate more than 10,000 times slower than viruses. According to research, the majority of fungi are found in the soil or on plants in the natural environment. They cannot thrive in humans because of the body temperature. Fungi prefer a temperature range of 77°F to 86°F; human bodies at roughly 98°F are not very conducive for their growth.
However, if the earth were to get warmer, would that be a good reason for fungi to evolve? Already, changes in the environment and climate, as well as fungicide overuse in agriculture, have resulted in an increase in fungi, capable of infecting humans and resisting antifungal medications.
Candida auris (a species of fungus), known to have caused hundreds of disastrous outbreaks in hospitals throughout the world, is a recent example of fungi adapting to higher temperatures. It is able to grow at higher temperatures than its other closely related species.
Does that mean fungi can cause a future pandemic? Dr Nicola Simone, a First Check member, biologist and researcher based in Italy, believes that it is unlikely – because of the fungi size (easily stopped by filters or masks) and their typically low ability to move.
“If a fungal pandemic starts, the main problem will not be related to its transmission, but to drugs and therapy. The majority of antifungal drugs act on DNA replication or protein synthesis, and, of course, being eukaryotes, even our cells could be ‘targets’ of the drug effect,” warns the biologist.
“Drugs such as itraconazole (one of the most common antifungal drugs) have many contraindications and side effects, some of which are severe and involve the liver, kidneys, and heart,” he adds.
Bottomline: Despite being one of the craziest end-of-the-world scenarios depicted in a science fiction television show, fungus is unlikely to spark a global pandemic.
(Update 27.02.23 - This article has been revised/updated to reflect new information or changes.)