The search for "contagious" delivered 2 verses in 2 songs on 2 records.
The dragon searched for the following: "contagious" as keywords
Here are the matching verses:
Black Sabbath: Dehumanizer
10. Buried Alive
It might be contagious
It might change the plan
Get back in your tiny boxes
Even if you can't
We say you can
Dio: Angry Machines
4. Hunter Of The Heart
Contagious, something like a virus of love
Making the pleasure seem real