Tetanus is a bacterial disease that affects the nervous system in humans. The disease is caused by the bacteria Clostridium tetani. This organism, which is a common inhabitant of soil, dust, and manure, can contaminate an abrasion in the skin. Small cuts and pinpoint wounds can be contaminated. Because the organism can survive and grow in the absence of oxygen, deep wounds, such as those caused by puncture with a nail or a deep cut by a knife, are especially susceptible to infections with Clostridium tetani. The disease cannot be transmitted from one person to another.

In addition to being able to grow in oxygen-free environments, such as is found in a deep wound, Clostridium tetani is able to hibernate in environments such as the soil. This is because the bacteria can convert from an actively growing and dividing state, when conditions...