Thanks Herald... at least you are applying reason behind the claims you are making. But let's think about this.
First of all I don't believe that your claim that rust "triggers" tetanus has any basis in fact. I would be happy if you could provide a link to back this up.
Rust has no biological link with Clostridium tetani. Rust does not cause tetanus and you can get the disease just fine from nails with no rust.
Tetanus is from nails exposed to the bacteria (generally found in the soil). It is not from rusty nails (although it is not suprising that people associate the two). In official and scientific papers on Tetanus rust is not mentioned as a cause (see CDC Fact sheet
But this is about a razor blade, presumably in a bath room. In a typical bathroom there is plenty of moisture that could lightly rust a razor blade. As a matter of fact, after the first use there will be rust on the razor blade (if you looked in a microscope). It doesn't hurt anyone until the blade becomes dull.
In this same bathroom is your toothbrush, and toilet paper and countless other things that are in the same environment with the same water and the same germs. Even though a toothbrush (not being made of iron) won't show rust it would have the same germs.
There is still no reason that this insane fear of a little rust.