[quote=@Darkraven]
So... Do we become one of them if we get bitten? Or are the zombies a one off thing?
[/quote]

Anybody who dies becomes one of them. There's nothing particularly deadly about zombies bites, except for the tremendous amount of bacteria in a decaying corpses mouth means you're likely to get a very serious and probably lethal infection unless you thoroughly clean and treat the wound and get a strong course of antibiotics.