Are you a fan of the Twilight films or HBO's "True Blood," and looking to suck up more info on vampires? Then sink your teeth into longtime National Geographic staff historian Mark Jenkins' new book, Vampire Forensics, and its companion piece, the new National Geographic Explorer television special premiering in the U.S. Tuesday night at 10 p.m. ET/PT on the National Geographic Channel. Ford Cochran, editor National Geographic Blog Wild, spoke with Jenkins about the origins of vampire stories around the world.

Where did the belief in vampires originate?

Fear of the walking dead is old. Sucking blood isn't always part of it--sometimes they eat you, sometimes they just beat you up. There's some sort of deep layer of belief that crops up here and there, possibly something shared once in the Indo-European past that survived when the tribes became separate nations.

In twelfth-century England, William of Newburgh, a fairly good historian, wrote about prodigies, oddities well beyond the natural course of events. When you read his stories, they're pretty much about vampires and related characters--people who die in sin and come back as nasty monsters, like what we would call zombies today, spreading disease with them through the town.

In China, in particular, there's a living corpse that resembles a European vampire. One is tempted to say there might be a Silk Road connection, but it's too hard to prove it. The Chinese version doesn't swoop down on you: He can only hop. But he's a pretty nasty vampire--not one of the aristocrats, like Dracula, in a cape and evening attire. That's the work of 19th-century Romanticism. The Chinese vampire is based in the sort of gritty peasant superstition that was condemned by the pope in Europe in the 18th century.

India's also full of blood-sucking demons, possibly related to vampires. Many are the deformed spirits of people who weren't properly cremated, some no larger than your thumb. If you swallow one, it lodges in your intestines and banquets on what's down there. Sound like cholera? Possibly, as with the European vampire's connection to plague. Cholera is a deeply feared disease that came about by drinking water infected with human feces, and outbreaks were devastating in India.

In Europe, Greece could be the home of the vampire--the Balkans and Greece. Santorini became especially fertile ground for vampire beliefs, because the volcanic soil preserves bodies, slowing decomposition. Originally, when the dead came back, they weren't really malicious. There's a story of a shoemaker who came back and helped his family out by making shoes. Other dead people who were thought to have returned from the grave were seen out in the fields eating beans. Vegetarians, the gentle dead! But those are ancient-vintage legends, before the evil Slavic vampire overwrote them.

Check out the full interview on Nat Geo News Watch, and find out how to ward off vampires in six easy steps at Blog Wild.