Today, pop culture includes vampires of all shapes and sizes, from the lovelorn teenagers of the Twilight and True Blood franchises to the bloodthirsty antagonists of the Blade series to the militant version of Dracula found in Castlevania. All modern vampires can trace their origins to Bram Stoker's Dracula, which was published in 1897, but the aristocratic shapeshifter in Stoker's novel can trace his origins to diseases that ravaged North America and Europe. In the 18th and 19th centuries, epidemics like tuberculosis and rabies swept across populations almost unchecked. Since disease and its causes were poorly understood, contemporary medicine offered little help. Facing the very real possibility of a fatal illness, many people turned to superstition for something to blame: vampires.