I read a book around 2007 that was about scientists that worked for the CDC and their investigations into some of the diseases that are commonly known today - Ebola, Legionaries disease, Listeria. The book was something like 800 pages long.
A similar book is Hot Zone, but that's a much shorter and more dramatized version.
I'm trying to google it but not having any luck, I'll try again tomorrow but figured I'd see if anyone here might know it.
Writing this post jogged my memory enough to have a successful Google search - "The Coming Plague".