Dang, I suppose now would be a bad time to reveal that I adore the show... LOL

I like that they don't focus too much on the zombies, the most interesting aspect for me are the humans and how they react to the world falling apart. Season 1 and 2 were great, 3 was bad but 4 was a terrific return to form in my opinion. The show is getting pretty damn dark.

The video game blows it out of the water though. I will unabashedly admit that it made me cry [i]a lot[/i]. It'd be incredible if they made a TV series based on the game! I think with zombie stories, suspension of disbelief is absolutely essential so weird logic doesn't bother me as much as it should. I barely flinched when Clementine opened a can of beans with the same knife that had previously been lodged into a walker's shoulder.

What you said about the walker blood makes the most sense but the reason I mentioned the saliva aspect is because the characters in TWD often cover themselves up with walker gore to mask their scent. Living as rough as they do, there's gotta be micro-cuts that the gore could seep into but they never get infected this way in the show, comic or game. I think we could say that it's possible to get infected this way but the cut would have to be fresh, deep and you'd have to get a substantial amount of walker blood in this way.