Normally used in the form "the dreaded lurgy".
The term originates from an episode of the 1950s radio comedy "The Goon Show" in which an epidemic of "The Dreaded Lurgi" was said to be about to sweep across Britain. It turned out that the lurgi was in fact a ficitious disease created by brass instrument makers who had claimed that no brass band player had ever died of the lurgi (thereby increasing sales hugely).
"The Goon Show" was an anarchic and surreal radio comedy series that starred Peter Sellers, Spike Milligan and Harry Secombe. It was written by Spike Milligan and Eric Sykes.
He's not coming into work today, apparently he's coming down with a lurgy.
I'm not quite sure what's wrong. Just some form of lurgy.
Urgh. You've got the LURGY!