>>134439630Yes, they have infection virus, which is what all virus are. Parasitic =/= regular infection. Witches maybe retain memories but they are psycho as fuck so I really couldn't care less, it probably is a state of mind between being life and death, where upon death the zombie mind completely takes over.
>>134439540The Flood is sort of the same deal, since after taking control of the host's body they completely mutate and alter it, turning it into one of their own.
Compare it with for example some alien lifeform that could be removed from the host using human bodies. Now that one is really bad.
Or if you want a real life example, take a look at the ant infecting fungi, or some other form of microorganism that can control the nervous system.