Zombie Illnesses: Rabies, Parasites and Prions

What kind of illness turns deer into stumbling, soulless shells of themselves-- bodies wasting away, but never truly dying? Or drives healthy young men into violent frenzies that leave them strapped to hospital beds, terrified of water? This week, we're diving into the terrifying world of zombie illnesses-- real diseases that hijack the brain and erase what makes us human.