According to this article, "vampire panics" historically, mostly coincided with contagious diseases and in New England at this time, this was tuberculosis (TB). People in this period did not know about bacteria and so, jumped to supernatural entities as being the root cause of the death and sickness plaguing the area and its people.
When the overwrought New Englanders would dig up their dead, they would be met with corpses bloated and leaking blood, these natural signs of decay would, however, be interpreted as confirming their vampire suspicions. And so, there would follow, burning at the stake, beheading and other such horrors.
Books To Read
The Book of Strange New Things, by Michel Faber -an English pastor is sent to the planet of Oasis to teach its reclusive native inhabitants about Christianity.
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