Originally posted by psychopotatoe
Yes, get killed by a nuke, you get 1 other one aswell I think.
Thats how I got it on the Xbox.
EDIT: May be 2 nukes..
No that's toxic. Infected is earned by either getting nuked or knifed by someone who already has the title. IW gave it to a few players, and they're seeing how fast it'll spread. Also, if there's another one like this called STD, that you earn by stabbing someone who already has that title. The guy who nuked you probably had Infected already
EDIT: at least this is what CODwiki says, I've seen elsewhere though that you get infected by getting nuked while you're winning the round. I'm not sure...