The constant presence or usual prevalence of a disease in a population within a geographic area is described by which term?

1. The amount of a disease usually present in a community is its baseline or endemic level. 2. Endemic therefore names constant presence or usual prevalence in a defined area. 3. Sporadic describes a disease occurring infrequently and irregularly, which is the opposite of constant. 4. Epidemic and pandemic both describe case numbers above the expected level, not the expected level itself. _Source: CDC Principles of Epidemiology in Public Health Practice, 3rd Edition, section Level of Disease_