What makes TB the world's most infectious killer?

In 2008, two 9,000-year old skeletons were found with their bones infected by an all too familiar bacterium. The ancient Greeks knew its effects as phthisis; the Incans called it chaky oncay; and today we call it tuberculosis, or TB. TB is still one of the world's most infectious killers, causing more deaths than malaria or even HIV. How has it persisted for so long? Melvin Sanicas investigates. [Directed by Augenblick Studios, narrated by Addison Anderson, music by GDM Production Music].