In college I took a sculpture class in which one part of our grade required making something out of baling wire. My evil professor gave me an ancient roll of wire that was covered in rust. Needless to say, I repeatedly cut myself on the sharp ends of the twisted wires in the course of making a giant ear (don't ask) and became paranoid about contracting lockjaw.
However, tetanus does not come from rust. It comes from sh- er, the digestive tract of farm animals and humans. (pdf) This information allowed me to complete my project with some peace of mind, but evidently it is not commonly known, so I present it for your edification.
(Alas, my research on tetanus was perhaps the most I learned over the course of that sculpture class, as any attempt to make representations of humans was pooh-poohed, regular or geometric designs were disparaged as being "something a CMCer would do" (this to a artsy Pomona student, who rapidly came up with something else), and my desire to make something that I wouldn't mind looking at every day in my apartment was confused with a desire to make arts and crafts. Oh well)
UPDATE: The rusty nail myth rears its ugly head in the comments to this post. Get well soon, Ms. Fowler.