So, as someone who played the original video game "Last of Us" sometime ago (actually come to think, its quite a while now, almost 10 years ago) and now seeing the success of the TV series adaptation on HBO, some of my friends are coming up to me (some only half-jokingly), about how real the threat of Cordyceps is. I can't believe I have to remind them that "humans zombified by cordyceps" is fiction. But seems like a lot of folks have suddenly taken an interest in this fungus in any case. So here is the quick lowdown on what exactly Cordyceps is, in case anyone is interested to know:
Cordyceps is a fungi (plural for fungus), like mushrooms. Fungi is similar to plants in some respects but can be distinguished from it by lacking chloroplast (the thing within plant cells used for photosynthesis, turning sunlight into energy, and what make leaves green in color). Most fungi also lacks an efficient system to transport water and nutrients, unlike plants.
What "Last of Us" gets right is that yes, Cordyceps (which has around 500-600 species) is parastic, it requires a host to reproduce and survive, either insects (or other arthropods) or in some cases, other fungi. It releases spores in the forest, and once attached to say, an ant, it indeeds body control the ant and forces it to do its bidding. Eventually, its fruiting body will burst out of its head, killing the creature and then renew its life cycle and release spores. So yes, in that sense, it does "zombified" ants:
But as the video says above, each Cordycep species target one species of insect. So its not like they can just spread to just any animal. In short, each Cordycep fungus are highly specialized to target one particular insect species. And it also says the ant colony themselves are not entirely defenseless, as they can sometimes detect and remove "zombified" members from their colony. Now a mammalian species like us humans are much different, and our immune system is vastly different and far far more complex with a body temperature inhospitable to Cordyceps. Its also important to remember it took millions of years for Cordycep to develop this ability, so for it to just mutate quickly and jump to be parastic on humans with the snap of the fingers, its...pretty unlikely.
In fact, Cordyceps, like some mushrooms, are edible and has beneficial health effects. Its been used in traditional Chinese medicine for thousands of years and is in high demand for some health markets. Cordyceps actually can be very very expensive:
So you are not going to lose sleep over any Cordycep zombies coming after you, right?