well, we dont know anthing of any known virus that causes zombification so theres no real answer. Maybe if there heart stops after time they will most likely re-animate.
if you suspect infection hogtie the victim if they wake up salivating for your brains, give 'em some high speed lead pain relief, if not, prepare yourself for a wrongfull imprisionment lawsuit.
jesse also a good point about the ammo. Im benfittin from our imput but the reason i say shot em if there recently dead there blood will not have coagulated yet im just saying to avoid splatter but a blade could do that or id crush there head with my boot
if it comes to life or death in every aspect it wouldnt matter if you got a little blood on your shirt. Ammo is something that you need, and is not going to be in readily supply
since there is no real proof of how it is contracted or how it will spread, there is nothing you can do. only be paranoid and wait to go insane. since there are a few parasites on the planet that we have encountered and studied. we do know there are things out there that can cause an infection, but yet to see something in human size.
myself, im just going to wait for either the news broadcast or some psycho chewing on someones head in the middle of the street.