Think about it

[Raivu]

Considering they move they have to have blood flow so they have to be "alive" even if their mental capacities have been lowered.

Exactly. And anything alive with or without a mental capacity dies eventually anyway. So they'll more than likely starve.

---------- Post added at 04:27 PM ---------- Previous post was at 04:17 PM ----------

Too bad zombies will never exist, except in fiction books.

The possibilities of it actually happening are surprisingly good.
Think about it.
It's an infection.
We're still coming across new infections with different results, and new ones are constantly being created through different actions and results.

Infection Side-Effects:
-A drastic craving to eat
-Lower mental capacity/deterioration of instinct (similar to that seen in Alzheimer and Cancer)
-Uncontrollable craving to flesh or meat (Primal instincts, often seen in Cannibalism)

We see those every day. People develop eating disorders, infections have known to cause deterioration in our mental state, and Cannibals have proven that eating other people IS possible and some infections have caused intense cravings toward awkward things or stuff we wouldn't normally eat.

So these 3 symptoms in 1 infection can easily either be man-made or naturally produced since all of it is anyway.