Under a Microscope

On today’s show: Peter Piot reflects on founding UNAIDS and his career chasing some of the world’s most dangerous viruses, like Ebola and HIV. The co-directors of the new documentary “Ikland,” about the Ik tribe in Northern Uganda, who have been called the most depraved people on earth. Jess Walter talks about his new novel, Beautiful Ruins. Plus, industrial safety expert Monona Rossol explains the hazards of fire retardants.