This class employs One Health, a public health approach that emphasizes the interconnectedness of human health, animal health, and the environment, to provide an understanding of factors involved in the natural history of emerging infectious diseases (EIDs), and of approaches required for sustainable control and prevention of these diseases. The number of reported EIDs is steadily increasing and some EIDs (e.g., influenza, chikungunya, methicillin-resistant Staphylococcus aureus [MRSA] and, recently, SARS-CoV-2) have had enormous global public health impact. Localized outbreaks can often be quite severe, particularly in certain settings (e.g., Ebola in West Africa and COVID-19 in China). EIDs are vector-borne and/or zoonotic, and a wide range of social, behavioral, and physical environmental factors contribute to their emergence. In this class, case studies of specific EIDs are used to illustrate the multi-factorial nature of disease emergence and spread. Emphasis is on understanding the natural history and pathogenesis of these EIDs, and the laboratory methods commonly used for their diagnosis and surveillance. At the course conclusion, students will be able to apply the principles they have learned to analyze and determine the factors involved in the new emergence or re-emergence of an infectious disease; essential knowledge for determining appropriate control and prevention strategies.