The death of global health pioneer Dr. Paul Farmer is being felt around the world. Farmer is credited with building community health systems where there were none, in countries including Haiti, Rwanda and the US. He died yesterday of a heart attack at one of the hospitals in Rwanda that he had helped to create. Dr. Atul Gawande, who is currently head of global health at the US Agency for International Aid, and who has known Farmer since medical school, speaks with The World’s host Marco Werman.