I haven't heard of any deaths from it, though I won't argue that it doesn't happen. Though for that matter, even routine shots like vaccinations can kill.
I did a young pea a year and a half ago and gave her 1/2 cc. The link that I attached references an avian vet at Texas A & M, and I did contact him directly. The virus behind the infection will likely never go away, and is possibly transmitted through the egg. As far as the bacteria causing the swelling goes, the only way to know exactly what is causing it (and the best treatment for it) would be to do a culture. If the infection is still there, I don't see any signs of it and the swelling never came back. Which I found surprising since it is likely Mycoplasmosis and I have heard that it will flare up when the birds get stressed due to temps or anything else. -38F temps, and no sign.