Mindy Yoakum, age 9, of Marion, Ohio, for her question:

WHAT CAUSES TETANUS?

Tetanus is a serious disease that affects the muscles. It is caused by toxins or poisons produced by bacteria called tetanus bacilli. These germs thrive in dust and dirt and need no air to live. Any dirt in a wound may contain tetanus germs.

Tetanus is sometimes called lockjaw because severe muscle contractions of the jaw muscles make it hard for the victim to open his mouth.

Tetanus can be prevented. All wounds should be cleaned thoroughly.

Persons may also be immunized against infection with injections of tetanus toxoid, a substance made from specially treated toxins of the bacillus. But if tetanus develops, doctors treat the disease with antitoxin injections.

Symptoms of tetanus usually start from five days to five weeks after infection. The victim feels depressed, has headaches and soon has trouble opening his mouth or swallowing. After a while, all of his body muscles may tighten and spasms may interfere with his breathing.