From the ArcaMax Publishing, Vocabulary Newsletter:
http://www.arcamax.com/news/vocabulary/s-362802-369542
pandemic \pan-DEM-ik\ (adjective) - Affecting a whole people or a
number of countries; everywhere epidemic.
(noun) - A pandemic disease.
"Once a pandemic is upon you, the prime focus has to be for you to
extricate yourself from any urban areas or areas of high population
density." -- Alex Haynes, 'The Apocalypse Handbook'
Pandemic ultimately derives from Greek pandemos, "of all the people,"
from pan-, "all" + demos, "people."