Tetanus causes

Association with rust
Colloquially, tetanus is often associated with rust, especially rusty nails, but this concept is somewhat misleading. Objects that accumulate rust are often found outdoors, or in places that harbor anaerobic bacteria, but the rust itself does not cause tetanus nor does it contain more C. tetani bacteria. The rough surface of rusty metal merely provides a prime habitat for a C. tetani endospore to reside. An endospore is a non-metabolising survival structure that begins to metabolize and cause infection once in an adequate environment. Because C. tetani is an anaerobic bacterium, it, and its endospores, will thrive in an environment that lacks oxygen. Hence, stepping on a nail (rusty or not) may result in a tetanus infection, due to the ideal bacterial breeding ground provided by the low-oxygen environment of a puncture wound.

Bacterial entry
A common way for Tetanus to form is for the clostridium tetani bacteria to enter the body through a wound. Any break in the skin, even a minor one, can allow the bacteria to enter into the body. The deeper the cut, the better off it is for the bacteria, because the tetani bacteria thrives in places with little to no oxygen (it is anaerbobic). Some of the common pathways are:


 * Burns
 * Animal bites
 * Tattoos and body piercings
 * Will mainly occur if unsterilized equipment is used.
 * Lacerations
 * Knife wound, broken glass, etc
 * Abrasions
 * Eye injuries