How come u can't get infected door walker blood transmitted via the eyes, nose, ears of mouth? I know u can get infected either door a bite of a scratch. The characters get splattered with blood with each kill but live to fight another day. Thanks!

I think under the premise of this show, the bite floods u with a massive dose of the infection which makes u sick and die. Then is it the dying that actually triggers the change because as the scientist told Rick in season 1, everyone is already infected with the virus itself and it triggers in death. That's also why they do the double kill to someone who hasn't turned yet.

Everyone is already infected with the virus (Jenner zei so to Rick). So the bite of the scratch doesn't infect you, because you're already infected, it only gets u sick (fever) and then the fever kills you. Like laylastepford said, the virus gets triggered once you're dead only.