Epidemic & Pandemic | Sociological Terms | UPSC

Derived from the Greek (epi = upon; demos = the people).
Refers to a sudden increase in the rate at which a disease affects the people of a given geographic area at a specific time.
The key factor here is that the rate of incidence (the number of fresh cases reported per unit of time, such as a day, week, or month) has to be substantially higher than the ‘normal’ rate.
This can be a partly subjective judgement.
If a disease has a high but constant rate of incidence in a specific geographical area (i.e., there is no sudden increase) it is called an endemic disease.
An epidemic that is not restricted to a given geographical area but is more widespread (i.e., it is at a national, international or even global level) is called a pandemic.

Epidemic and Pandemic