ABSTRACT
In the previous chapter we discussed the principles involved in the infectious disease process. In this chapter we focus on the transmission of diseases by looking at where the pathogens responsible for infection are found and at the mechanisms by which those pathogens are transmitted from the environment to a host, and from one host to another. We also consider the compromised host, which is a very important and integral part of the infection process. The more compromised the host, the greater is the risk of successful infection. We review some of the basic principles of epidemiology, the discipline that helps us to understand how infectious diseases are spread and thus to develop methods for prohibiting their spread. As this requires detecting infections in the first place, we will look into traditional and modern diagnostics, and how genetic engineering and some areas of biotechnology provide us with the information and tools to diagnose sooner and more reliably.
