Explain why the COVID-19 virus has been described as being sporadic, then epidemic and now pandemic. - look up the definitions of sporadic, epidemic and pandemic and relate them to COVID-19 Describe a couple of ways in which normal flora interact symbiotically with their host. - look up why normal flora is beneficial to the human host What is the difference between the science of epidemiology and the practice of medicine. - Look up the definition of epidemiology and relate it to the practice of medicine. Explain the incidence pattern shown on the graph. What are probable modes of transmission? What changes would you recommend before the ship books more cruises after March 3? - You will see a graph with this question. Be sure to understand incidence patterns and how they relate to transmission. There are some examples of these graphs in your text and in the PowerPoint lecture. Why is it that we can't use Koch's postulates to prove the cause of every infectious disease? - There is a good PowerPoint slide that describes this