TETANUS (Lit., front Gk. rerav6s. spasm, tension, from reivetv, teinrin, to stretch. strain), or LOCKJAW. An infectious disease character ized by tonic spasms of the voluntary muscles, with marked exacerbations. The contractions may be confined to the muscles of the lower jaw (trismus), to certain other groups of muscles, or involve all the muscles of the body. The disease is dependent on a bacillus, discovered by Nieolaier in 4R54, and cultivated by Kitasato in 5S9. The bacillus forms a slender rod with rounded ends, and exists in dust and surface soil. This accounts for the fact that wounds infected by dust are often followed by tetanus. The organism gains entrance to the tissues often through wounds so slight as to be overlooked. The disease may follow surgical operations or childbirth. infecting the mother through the par turient canal and the child via the cut um bilical cord. Vaccination wounds are sometimes the port of entry for the bacillus. In a very few instances the disease is claimed to be idiopathic and to follow exposure to cold or damp.
After an injury the disease sets in usually within ten days. Without any warning the pa tient feels a stiffness at the back of the neck, and then in the jaws, so that he is unable to open his mouth widely or to masticate properly. These symptoms continue for a day or two, or the patient may rapidly come to the stage of general rigidity, in which the muscles of the trunk and extremities are affected. The back becomes rigid and arched (opisthotonus) ; the muscles of the abdomen become hard and board like: respiratory movements are limited by the rigid muscles. By this time the jaw is firmly closed by contraction of the masseter mnseles. and the other muscles of the face drawn into the painful smile known as the risus sardoniens. When this stage has been reached violent con vulsion; of the hitherto rigid muscles supervene. During a paroxysm the patient's teeth are tight ly clenched. while the breathing process is held
in temporary suspension, with imminent. danger of death. The spasms are intensely painful, and occur at first at intervals of half an hour or more with gradually increasing frequency as the disease progresses. Muscular contractions are sometimes so forcible as to rupture a muscle or break a bone. In a majority of eases the dis ease progresses to a fatal end in a few days: the paroxysms become more violent and fre quent and death comes from exhaustion, fixa tion of the respiratory muscles, or spasm of the glottis. There may he little fever during the attack, hut before death an extraordinary rise in temperature may take place.
The treatment of tetanus is unsatisfactory. About 90 per cent. of the traumatic cases die, and about 50 per cent. of other eases, the result depending to a great extent on the size of the wound and severity of the infection. The bacilli multiply and produce their toxins in the neigh borhood of the injury, and when this can be found it is to be opened freely and treated with antiseptics to prevent further infection. The drugs having the best restilts in tetanus are chloral. potassimn bromide, and calabar bean. with the occasional use of chloroform to control violent spasms and opium to produce sleep. In many cases cure follows the injection of an anti tetanic serum, derived from the blood of a ,horse that has been rendered immune by repeated in jections of a culture of the bacillus. (See RUM TIIERAPY.) A great many cases of infantile tetanus can be prevented by antiseptic treatment of the stump of the umbilical cord. Tetanus in infants ( trisin us nasecntium) is very fatal, being uninfluenced even by antitoxin. Consult: Moscheowitz, Tetanus (Philadelphia, 1900) ; Bassano, Recherches experimentales sac rori gin,c mierobicnne du taanos (Paris, 1900).