What is the theme in The Coming Plague: Newly Emerging Diseases in a World Out of Balance by Laurie Garrett?

One of the primary themes conveyed within the novel is the idea that although bacteria, viruses, and parasites are the cause of disease, there are social and political aspects that cause epidemics. Issues such as prostitution and drug use tend to help spread blood born disease, while poor housing, improper medical care, and a lack of access to drugs cause even more issues. In third world countries, the reuse of needles causes issues, as does the lack of sterile working conditions.