Among the 5 million species of fungi in the world, many pose a danger to humans, including the infamous “zombie fungi.”
What are “Zombie Fungi”?
This term refers to fungi belonging to the Cordyceps genus. There are hundreds of species within the Cordyceps genus, each infecting different species of insects, including larvae, moths, ants, dragonflies, cockroaches, aphids, bees, and beetles.
The spores of “zombie fungi” infect and germinate inside the host’s body, taking control of its behavior. Once the host loses control over its body, it crawls out of its nest, perilously hangs from a leaf, and waits to die. At this point, fungal hyphae penetrate the host’s body and release spores into the air.
Out of the 600 species of “zombie fungi” in the Cordyceps genus, only about 35 species are capable of controlling the host’s brain. For example, Ophiocordyceps unilateralis infects ants.
The first signs of infection from this fungus manifest as erratic and unusual behavior in the host. Scientists believe that the parasite physically takes control of its host by developing fungal cells around the brain, thereby commandeering the insect’s nervous system to control its muscles.
Zombie fungi infect and germinate inside the host’s body, subsequently taking control of that species’ behavior – (Image: STEEMIT)
Geneticist Ivan Will, a fungal expert at the University of Central Florida (USA), stated that “zombie fungi” release a chemical that alters the host’s DNA, though the exact mechanism remains unclear in scientific terms.
This process is evidently lengthy. It is clear that these fungi have been parasitizing their hosts and evolving over a long time, at least 45 million years ago.
Are Humans at Risk of “Zombie Fungus” Infection?
The answer is “not clear.” Explaining this issue, João Araújo, a parasitic fungi expert at the New York Botanical Garden, noted: “For this fungus to transition to any warm-blooded animal would require a long evolutionary process. If the fungus truly wanted to infect mammals, it would need millions of years of genetic changes.”
Each “zombie fungus” species has evolved to target a specific insect species, so the most toxic fungi are less likely to affect organisms outside their intended host. For example, a “zombie fungus” evolved to infect one species of ant in Thailand cannot infect a different species of ant in the USA.
If it’s challenging for one ant species to jump to another, then jumping from animals to humans is even more difficult.
However, scientists caution that “difficult does not mean there is no risk.” All organisms on this planet are evolving every day, and they could potentially cross species barriers, transforming in “substance” once they reach a certain “threshold.”
Even without the threat from parasitic “zombie fungi,” there are numerous other fungal species that pose greater dangers to humans.
Temperature could be a decisive factor in this infection.
It is estimated that millions of fungal species exist worldwide, with several hundred known to be dangerous to humans. One factor that protects us from severe fungal infections is our warm body temperature. At around 37 degrees Celsius, the human body is too warm for most fungi to spread infections.
However, one reason we experience skin fungal infections is that they can infiltrate the folds of the skin. These areas are moist, dark, and cooler than the body’s overall temperature, allowing fungi to thrive.
As the Earth warms, the temperature difference between the environment and body temperature will diminish. This will enable evolved fungal species to better withstand higher outdoor temperatures, allowing them to potentially thrive inside the human body as well.
There is one type of fungus capable of infecting humans that scientists believe may be linked to rising temperatures, known as Candida auris. This fungus was not even recognized in scientific literature until 2007. However, in 2011 and 2012, it was unexpectedly discovered on three different continents and quickly became a significant concern.
When it enters the bloodstream, Candida auris manifests symptoms similar to bacterial infections. For individuals with weakened immune systems, it can lead to a range of severe health issues and even death.
