LINDSEY FITZHARRIS, Queen Mary, University of London: Diseases that were much more likely to contribute to a fear of vampirism would be things like leprosy which really manifests itself in a very visible way, and would have been very scary. With leprosy there's facial deformities, the hands and the feet become very, very deformed. Another disease that we're all very familiar with during this period is the Black Death, or bubonic plague. Now, bubonic plague again is a very visible disease, and resulted in pustules all over your skin, they turned black they erupted with blood, it was horrible. Another disease that was very prevalent during this period was tuberculosis, again a highly visible disease, you would be coughing blood, you'd form pustules on the face, on the hands, and these kinds of diseases were very prevalent in the medieval period.

Dacre Stoker has even come across a revealing article in Bram Stoker's notes for Dracula that documents a genuine, vampire craze in the not so distant past. An outbreak of tuberculosis in early 20th-century America had folks fearing the undead.

DACRE STOKER, Great-Grandnephew of Bram Stoker: In Bram's notes for Dracula we find an article telling us that in New England in the United States there was a serious vampire scare in the late 1800s-early 1900s, and it turned out that this was simply tuberculosis but people were believing that this disease was vampirism and so they actually had state forensic authorities allowing exhumations from the grave and staking the hearts, burning the hearts, doing different ceremonial practices to rid these villagers of vampires and it was only TB.

It's difficult to know for certain which illnesses were common in Anglo Saxon England, but we do know that leprosy came right at the beginning of this period and that tuberculosis was endemic. It's possible the dead were scapegoats for these horrifying illnesses. Is there any evidence to suggest that belief in vampires was a way to explain disease? To find out, we need to return to Eastern Europe. In 2014, Bulgarian professor Nikolay Ovcharov discovered the bones of two bodies dating back to a time when the plague first hit Bulgaria.

NIKOLAY OVCHAROV, Bulgarian Academy of Sciences: Here we have a middle aged man probably in his 30s. The grave dates back to the first half of the 13th century. You can see that he was buried according to Christian tradition, hands placed across his chest. What was shocking here was that a blade from a plough had been thrust into the neck. This person had not yet turned into a vampire. This was an ordinary person, whose parents performed an anti-vampire ritual on him. Here is another skeleton buried in the necropolis. It has also undergone a ritual but it's different this time. On the left hand side of the skeleton we can see where a blade has been driven into the chest. This skeleton has also been dismembered. The right leg has been severed and left next to the body. This was done during the funeral. It's an anti-vampire ritual, a preventative measure.

It would seem that in 13th-century Bulgaria, the fear of vampires spreading disease was so great, the bodies of potential vampires were mutilated before they even had a chance to rise from their graves. One archaeological dig in Venice reveals an even more explicit link between a time of disease and evidence of a vampire ritual. In 2006, Dr. Matteo Borrini, a forensic anthropologist examining a burial site in Venice, found this: the skeleton of a 60-year-old woman, who had a large brick forced into her mouth, buried in a pit for victims of the plague.