Infectious diseases have always been a part of human existence, but man has manipulated his environment to allow new patterns of disease to emerge. We no longer fear smallpox, but can this terrible disease return? Should we worry about Ebola, Zika, or the newest virus dominating the headlines – COVID-19 (Coronavirus)? Learn the real story of influenza, how to ensure safe travel to exotic places and how to avoid the nastiest germs.