She has 'infected' everyone 'with' her enthusiasm. [=her enthusiasm has made other people feel enthusiastic too]
All the computers in the office were 'infected' by/with the same virus.
The virus has 'infected' many computers.
(..) - The antidote is cooking. - No, no, no. Connors is on the way. He's coming to you right now. He needs the device. He's gonna infect the whole city! Eight minutes left. You're gonna wait eight minutes after what I told you? You leave right now. I'll get everybody out. (..)2012 The Amazing Spider-Man