...particular case of Wilfred Doricent,3 an adolescent schoolboy from a small village in Haiti. One day, Wilfred became terribly ill. He experienced dramatic convulsions, his body had swelled tremendously, and his eyes had turned yellow. Eight days later, Wilfred appeared to have died. This was confirmed by not only the family and family friends present but also by the local medical doctor who could detect no vital signs. Wilfred’s body appeared to show bloating due to rigor mortis and gave off the foul stench of death and rot. He was buried soon thereafter.
Some time afterward, the weekly village cockfight was interrupted as an incognizant figure appeared. The villagers were shocked as they gazed upon the exact likeness of Wilfred. The person was indeed Wilfred, as his family verified by noting scars from old injuries and other such details. Wilfred, however, had lost his memory and was unable to speak or comprehend anything that was said to him. His family had to keep him in shackles so that he wouldn’t harm himself in his incoherent state...
...This provides an explanation for how Wilfred could have been made to seem dead, even under the examination of a doctor. However, we have already said that the TTX paralysis was unlikely to have affected his brain. How does one account for Wilfred’s comatose mental state? The answer is oxygen deprivation. Wilfred was buried in a coffin in which relatively little air could have been trapped. Wilfred’s story probably goes something like this: slowly, the air in Wilfred’s coffin began to run out so that, by the time he snapped out of his TTX-induced paralysis, he had already suffered some degree of brain damage. At that point, his survival instincts kicked in, and he managed to dig himself out of his grave—graves tend to be shallow in Haiti. He probably wandered around for some time before ending up back at the village. This topic was the subject of a horror film, The Serpent and the Rainbow.
Neuropsychiatrist Dr. Roger Mallory, of the Haitian Medical Society, conducted an MRI of zombiefied Wilfred’s brain. He and his colleagues found lesions of the type normally associated with oxygen starvation. It would seem that zombiefication is nothing more then a skillful act of poisoning. The bodily functions of the poisoned person suspend so that he appears dead. After he is buried alive, lack of oxygen damages the brain. If the person is unburied before he really dies from suffocation, he will appear as a soulless creature (“zombie”), as he has lost what makes him human: the thinking processes of the brain.
The good news is it's illegal to create a zombie in Haiti!
Of course, the possiblity always exists for a plague of the shambling undead to be unleased, so it's good to be prepared. I encourge everyone to have a copy of the incredibly useful Zombie Survival Guide, and if you have the means, one of these: