The past two decades have witnessed changes in how humans live. Travel and trade, rapid urbanization, limited access to health care as well as environmental degradation and other trends all create the conditions for epidemics to thrive and grow. At the same time, the science and knowledge around infectious hazards are constantly evolving, demanding better response to health emergencies. This introductory level online course aims to equip frontline responders with the latest know-how to manage outbreaks of known and emerging epidemic-prone diseases in the 21st century. This course focuses on 13 infectious hazards, offering the most relevant scientific, technical and operational knowledge through video presentations and self-tests. The course will take approximately 6 hours to finish.