Lolmat wrote:
I love to poke holes into people's arguments.
-Brain parasites: Yes, there are incidents with scientific research with such organisms entering the brain from cat litter and such (which is why pregnant women are warned to keep away from the litter box). But: One cannot go "batshit crazy". The personality change that the article oh-so-neglects to mention is actually a change in social life; in other words, the subject is more amiable to others, and may be more prone to more risky behaviors. Of course, this is much more observable in mice, who become "insane", and start hanging around areas with the smell of cat urine, and begin to become sluggish in their movements (so that the cats may ingest them).
However, these "parasites" are very real and present in the Insecta group, as there are instances of ants being taken over by various organisms to serve their own purpose (for instance, to take the organism back to the nest, or for sheep to ingest the blade of grass that the ant sits on).

-Neurotoxins: Any competant doctor will be able to realize that you're alive, with all the technology that hospitals hold.

-"Virus": First of all, Mad Cow disease isn't even a virus. It's caused by a group of defective proteins called prions, which are able to convert similar proteins to its own structure, inhibiting certain bodily functions. Yes, people can get Creutzfeldt-Jakob, or Kuru (which, incidentally, is only observed in cannibalistic cultures); however, kuru nor Crueutzfeldt-Jakob create aggression. (It is interesting to note that however [to me, anyways], kuru has been referenced in the Fallout games with its symptoms, and Dead Island uses a Kuru-like vector to create the zombies).

Neurogenesis- Incidentally, even if someone manages to do that, there is no base primal instinct in the human psyche to attack other humans. Even if someone managed to train them to attack humans, the brethren of the "zombie" will have the characteristics of an alive human... and Friendly Fire Will Not Be Tolerated!

Nanobots- The "doomsday" paranoia about nanobots is not of a zombie apocalypse (which, the nanobots can't think for themselves yet; it still requires a higher order), but of the act of self-replication of using every bit of matter. Incidentally, the zombification of a virus is impossible, since a virus simply cannot die (it has been agreed that a virus cannot live, as it cannot reproduce by itself).