I don't see how they couldn't be dead. Being exposed to the heat, dead bodies (including eating of them) among other things. That would kill living humans in no time.
The only theory of them somehow just being "infected" and alive would be that the virus they are exposed to makes them EXTREMELY resilient to disease, climate conditions, malnutrition, pain and apparently most anything else that would ail and ultimately kill a regular human.
Reanimation just makes more sense (in a science-fiction type way). At least then, you know what a normal dead person is and can just calculate in the virus which reanimates the corpse basic motor functions and gives them the yearning to spread the virus.
Bookmarks