Respiratory Tract - The part of the anatomy that has to do with the passage of air and includes the nose, larynx, trachea, and lungs.⏎
Pathogen - A biological agent that causes disease.⏎
Outbreak - An unexpected increase in the incidence of a particular disease over a given time period and geographic range. A general term that may refer either to an epidemic or a pandemic.⏎
Pandemic - An increase in the occurrence of a particular disease over a very large region, such as a continent or the entire globe, that is greater than what is expected over a given period of time.⏎