An epidemic occurs when an infectious disease spreads rapidly to many people. For example, in 2003, the severe acute respiratory syndrome (SARS) epidemic took the lives of nearly 800 people worldwide. A pandemic is a global disease outbreak such as Covid 19. Epidemics, Pandemics, and Outbreaks When is a disease outbreak a concern? And what is the difference between an epidemic and a pandemic? What is a disease outbreak? A disease outbreak happens when a disease occurs in greater numbers than ...