Infectious diseases are a threat to biosecurity both from intentional release and through natural expansions in the geographic extent of an infectious agent. The dynamics of change in infectious disease risk are related to global and local movements of people and animals, transitions in vegetation communities, the adaption and evolution of disease agents (including antibiotic resistant strains), and the effects of changes in abiotic factors such as temperature and precipitation. During this seminar, we will consider how the characteristics of disease systems affect the spatial spread of those diseases and how those, in turn, affect our ability to respond effectively to both intentional and naturally occurring outbreaks of infectious diseases.