One Word: Cordyceps

[NeoAcario]

This would make an awesome addition to the selection of diseases. A Cordycep fungus evolved to infect humans.

If you don't know what a cordycep is: https://www.youtube.com/watch?v=XuKjBIBBAL8

[Fruchtgummi]

I think this is pretty much what the neurax worm is. Infect the humans Brain and then use them to infect even more humans. I think the cordycep would be too similar to the neurax worm...

But thats just my humble opinion.

[Kas 身勝手の極意]

The Cordyceps is a funghus, which we already have though it's not exactly the mind controlling type

[意気消沈]

As fascinating as those sped-up sequences may be,Cordyceps are still fungi with no striking peculiarities... it'd be a redundant addition in my opinion.

@ DaedaeRE: while "mind-controlling" pathogens are everywhere in nature already, Cordyceps isn't. It doesn't alter the hosts' behaviour - it merely acts as any other parasite, albeit in a... more theatrical and popularised way than most.