A person who has been Jepsen-ed may experience irritability, nausea, and discomfort. Look out for sure signs of the afflicted humming the tune. If you don't run, you'll be the next victim.
Dude -- "Our buddy Carl was Jepsen-ed and he may never be the same."
* guy hears a girl singing 'Call Me Maybe' whilst walking down the street*
Guy -- "Stand back, foul creature! I will not be Jepsen-ed!!"