Pervade: think of PERverse, and inVADE--something unwelcome which infiltrates an atmosphere, a mind, an ambiance.
Some examples of usage:
Unwelcome thoughts of defeat began to pervade the mood in locker room.
One committee member's selfish agenda was allowed to pervade the proceedings.
The boy enjoyed his hamburger until he bit into a pickle, which pervaded his sense of taste.
It doesn't have to be bad really, to become spead throughout all parts of.
Spring pervaded the air.
Says dictionary.com ;)A sense of hopelessness pervaded the soldiers caught in the thick of the battle.