What's the difference?

EPIDEMIC. PANDEMIC.

Reference: The Grolier International Dictionary, Vol. 1. page 440.

EPIDEMIC - spreading rapidly and extensively among many individuals in an area.
said especially of contagious diseases.



Reference: The Grolier International Dictionary, Vol. 2. page 947.

PANDEMIC - widespread. epidemic over an especially wide geographic area.


The swine flu is called pandemic, because it is not confined to only a place, but is spreading in different states/ countries in different continents at almost the same period.