Classic Secrets of the Dead episode! There's a direct genetic connection between survivors of 14th century plague epidemics and modern people who are resistant to HIV. This episode tells the story of a modern-day detective tale which combines epidemiology, modern DNA analysis, and old fashioned detective work. The video is available on YouTube, Vimeo, and from online retailors. More info: http://www.pbs.org/wnet/secrets/mystery-black-death-background/1488/