Long before vampires were glittering sex gods — back when we were deathly afraid of them — much of vampire lore was rooted in pre-industrial cultural ignorance of the physiology of death and decomposition. So before Tuberculosis was fully understood by the populations affected by it, victims of the silent wasting syndrome were believed to have fallen prey to evil entities such as vampires.
In fact, this misapprehension precipitated vampire panics, such as the notorious Mercy Brown incident of 1892. After several members of the Brown clan of Rhode Island fell to consumption, the community performed exhumations to inspect the deceased for traces of vampiric possession. When it was discovered that the heart of Mercy Brown still contained some blood in it, she was declared undead. Ignoring that the frozen ground she was buried in sustained the organ like a meat locker, her heart was removed, burned and made into an elixir to feed another stricken family member. Edwin Brown died two months later.