The controversy begins with a mass grave of 16th-century plague victims on the Venetian island of Nuovo Lazzaretto. The remains of a woman there apparently had a brick shoved in her mouth, perhaps to exorcise the corpse in what may have been the first vampire burial known in archaeology, said forensic anthropologist Matteo Borrini of the University of Florence in Italy.

Vampire superstitions were common when plague devastated Europe, and much, if not all, of this folklore could be due to misconceptions about the natural stages of decomposition, Borrini said. The recently dead can often appear unnervingly alive. As the corpse's skin shrinks and pulls back, for example, hair and nails may appear to grow after death.

The remains of the woman were apparently wrapped in a shroud, based on the position of her collarbone, Borrini suggested. A corpse might appear to have chewed through its shroud because of corrosive fluids it spewed as it decayed, perhaps frightening gravediggers into thinking it was a vampire.