I work at a clinic where all I seem to do is give shots...recently I gave somebody a TD-vaccination, and that person ended up with red streaks above and below the site, pain, swelling and drainage from the site, within 24 hours post injection. Has anyone seen something similar before? (I gave it Z-trac, in the deltoid). Almost sounds like sepsis, but from what?!

That sounds like a sterile abscess. I've seen that after flu shots. Is there pus? If so then you may be looking at bacterial infection. In my state this is a reportable adverse event. Make note of the batch number of the td and any other facts surrounding it. If it is a contaminant there may be several more who either didn't react as strongly or went elsewhere to be seen.