Organism - A living being that can reproduce, grow, react to external stimuli, and maintain its internal equilibrium.⏎
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.⏎
Pathogen - A biological agent that causes disease.⏎
Reservoir - An organism in which a parasite that is pathogenic for some other organism lives and reproduces without harming its host.⏎
Reproduction - The process by which parent organisms create new offspring by either sexual or asexual means.⏎