This paper will discuss the nature of Yellow fever and how it is carried within the cells of a fly. By understanding the way that it is carried, we can see how it permutated in the human body. Also, a discussion of certain traits and treatments of the diseases will also be covered. With all of these topics in kind, a complete analysis for the disease will be covered to give an explanation for the ways it exists. 5 pgs. Bibliography lists 4 sources.