I'm listening to The Demon Under the Microscope by Thomas Hager read by Stephen Hoye.
It is a ripper. It's a non-fiction book all about the discovery of the first antibiotic, sulfa. One of my favorite ever subjects at university was The Ecological History of Humans and was all about how diseases have shaped human history. And boy have they! The outcome of wars, colonisation, trade - all of these major forces have been at the mercy of diseases and our ability to deal with them.
So, as an old history and philosophy of science nerd I am flipping loving this story tape. My only criticism is that I find the narrator a little dramatic. He has a habit of extending and then falling away on the last word of sentences, which sounds like he's narrating a movie trailer. You can listen to a sample.