The Centers for Disease Control is silent on zombie-like parasites that live in creatures’ brains. Zombie viruses have pretty much been debunked, but certain insidious parasites can induce zombie-like symptoms in hosts.
The CDC published a tongue-in-cheek warning about surviving a zombie attack, but then a series of cannibalistic attacks actually required them to placate public concerns about a zombie apocalypse. CDC spokesman David Daigle told HuffPost, “CDC does not know of a virus or condition that would reanimate the dead (or one that would present zombie-like symptoms).” Phew!
Well, that’s true as long as you ignore the Toxoplasma gondii and other creatures like it. These little guys have an odd lifecycle. Basically, they need to be inside of cats in order to experience the sexual stage of their development. But there’s a problem: how do you get into a cat?
For Toxoplasma gondii, the easiest solution is to hang out in bird and rat food, get eaten, and then make your way into the animal’s brain and drive the animal around like a car. This causes infected birds and rats to seek out cats in a literal sacrificial offering. These terrible parasites can also survive in humans, capable of causing “neuroticism, increased aggression and schizophrenia.”
This is pretty much the closest thing we’ve got to a zombie virus, but don’t be afraid: this isn’t likely to transform our society into brain-munching undead. Because we eat other animals and no animal consistently eats us, parasites don’t have a chance to evolve mechanisms to control the human brain. So, creepy? Yes. World-ending? No.