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Pathology => Human Diseases => Tetanus
Tetanus
Tetanus, serious infectious disease of the nervous system, in which a bacterial toxin causes severe muscle spasm. Also called lockjaw, the bacterial infection occurs when wounds are contaminated with a bacillus, Clostridium tetani, which is found everywhere but which is especially likely to be present in street dirt. It is an anaerobic bacillus-that is, one that lives without oxygen, and thus when introduced into human tissue, usually at the time of an injury, it can multiply where the oxygen is deficient. This occurs both in deep, penetrating wounds and in crushing wounds with extensive tissue destruction. As the bacillus multiplies, large amounts of exotoxin are released into the surrounding tissues.
The incubation period varies from two weeks to several months, but generally is about two weeks. The first symptoms are usually headache and depression, followed by difficulty in swallowing and in opening the jaws. Stiffness of the neck develops and gradually a spasm of the cheek muscles sets the face in a peculiar, sardonic grin. Eventually, the spasms spread to other muscles of the body.
Treatment, besides cleaning the wound, involves eliminating the bacilli both surgically and with antibiotics, neutralizing the exotoxin with antitoxin, reducing muscle spasm, and supporting or aiding respiration. Although about 60 percent of all cases are fatal, active immunization with tetanus toxoid before an injury, with periodic reimmunization, or so-called booster injections, is extremely effective; tetanus rarely occurs in people so immunized. A series of three injections is recommended if the tetanus toxoid is combined with both diphtheria and toxoid pertussis (whooping cough) vaccine in the commonly administered DTP (diphtheria, tetanus, pertussis) injections. The supplementary booster injections should be given one year after completion of the primary immunization series and every five to ten years thereafter.
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