Originally Posted by DieselDiner
After the scientest had tested their blood, I *think* what the scientist told Rick is that all of them are already infected - which means that they when they die, they will turn (unless "measures" are taken by the living).
That would explain his seeming lack of surprise when he observed that the security guards were not bitten.
hmm... Then how did the security guards "die" without any wounds or signs of starvation?
I do like the idea of them all already being infected though, that puts a fresh spin on "The Walking Dead" as in, still alive but technically a dead man walking..