1.) The fictional disease, based loosely off
Ebola, which appeared in the movie Outbreak. It was later referenced in an episode of
Clerks: the Animated Series.
2.) Any "bug" which afflicts masses of people living in close proximity--typically college
dorms, offices, etc--with no explainable cause or origin.
3.) A "bug" which is more psychological than physical, and spreads rapidly amongst people with little to no physical contact.