The Hot Zone Part Four

I found the final part of the book very boring.  I understand the need to include that information in the book, so that we are aware of what happened after the monkey house and if they made any further advancements on finding the origin of Ebola, however, I just didn't find it interesting.  I learned that one virus can mutate itself into different types of the same string of virus and have different effects on different species. The questions I still have are: Why does the monkey house have a For Lease sign in front of it? If there is a possibility that the virus could still be living in a crevice somewhere in the building, why would you want to take the risk of infecting humans with it again by reopening the building as something else?