How Did Nearly-Eradicated Polio Wind Up In Rockland County?

We use the appearance of a case of polio, which had been nearly eradicated in the US, as a lens to explore public health, and the relationship between tiny pathogens and broader society. On Today's Show: Alan Dove , science journalist, virologist and co-host of the This Week in Virology (TWIV) podcast, answers questions about the case of polio in Rockland County - after apparently having been eliminated -- and what needs to happen to prevent further infections.