The Hot Zone- Part 4

Part 4 was rather interesting, but shorter than the other sections. The ending of the book really sealed the book while focusing on the HIV virus. In part 4, I learned that Richard Preston travels to Africa and wants to see if he can figure out where the Marburg and many other viruses may have originated. The virus has survived for thousands of years in an unknown host in the jungle and eventually becomes into contact with humans. Preston still makes sure to keep the book very detailed and draws attention to readers. I also learned that there are several different kinds of viruses in the world and some of them we can't cure. Questions that I still have is: what is the cure to the Marburg and Ebola virus? And why did Preston decide to try and find where the Marburg and other viruses originated so late in the novel?