"According to the tenets of Voodoo, a dead person can be revived by a bokor, or sorcerer".
"In modern films, zombies are often depicted as being created by an infectious virus, which passes on via bites and contact with fluids. Harvard psychiatrist Steven Schlozman has termed the condition of zombies Ataxic Neurodegenerative Satiety Deficiency Syndrome".
"Other origins shown in films include radiation from the planet Venus (Night Of The Living Dead), as well as mutations of existing conditions such as prions, mad-cow disease, measles and rabies. 28 Days Later depicts the outbreak of an engineered "Rage virus" which transforms its victims into a zombie-like state; however, they maintain higher cerebellar function". Wiki