As seen in ...
28 Days Later
What is it?
In the movie, it was a virus that turned human beings into mindless killing machines. In real life, we have a series of brain disorders that do the same thing. They were never contagious, of course. Then, Mad Cow Disease came along. It attacks the cow's spinal cord and brain, turning it into a stumbling, mindless attack cow.
And, when humans eat the meat ...
How it can result in zombies:
When Mad Cow gets in humans, they call it Creutzfeldt-Jakob disease. Check out the symptoms:
- Changes in gait (walking)
- Lack of coordination (for example, stumbling and falling)
- Muscle twitching
- Myoclonic jerks or seizures
- Rapidly developing delirium or dementia
Sure, the disease is rare (though maybe not as rare as we think) and the afflicted aren't known to chase after people in murderous mobs. Yet.
But, it proves widespread brain infections of the Rage variety are just a matter of waiting for the right disease to come along.
Chances this could cause a zombie apocalypse:
If the whole sudden, mindless violence idea seems far-fetched, remember that you are just one brain chemical (serotonin) away from turning into a mindless killing machine (they've tested it by putting rats in Deathmatch-style cages and watching them turn on each other). All it would take is a disease that destroys the brain's ability to absorb that one chemical and suddenly it's a real-world 28 Days Later.
So, imagine such an evolved disease, which we'll call Super Mad Cow (or, Madder Cow) getting a foothold through the food supply. Say this disease spreads through blood-on-blood contact, or saliva-on-blood contact. Now you have a Rage-type virus that can be transmitted with a bite.
Just like the movie. With one bite, you're suddenly the worst kind of zombie:
A fast zombie.