In TETANY the nature of the spasm different, and it especially involves the hands and feet.
In HYSTERIA. some symptoms of tet anus may be simulated, but the presence of other hysterical phenomena and the history of the case should preclude error. A bacteriological diagnosis is also pos sible, and should, whenever possible, be made by means of cultures and stained preparations from pus of the wound and from the earth of the locality where the wound was received. A mouse inocu lated with pus from a tetanus-infected wound will die within a few days: a fact which may be made use of in diagnosis.
Etiology.—The disease was at one time especially common in infants in the West Indies, and in all countries new born children are particularly suscepti ble. After the first month of life, how ever, infants seem less liable to the dis ease than adults, the period of greatest danger being from 30 to 45 years. In general, males are more frequently af fected than are females, and the negro races are more susceptible than are the white. Horses, cattle, sheep, and other animals are also frequently attacked. All forms of the disease are much more common in hot countries than in tem perate climates. The disease is often especially frequent in certain localities (endemic tetanus), the soil seeming in such places to be peculiarly rich in tetanic bacilli. In almost all cases of tetanus there is traceable trauma, and many even doubt the possibility of the occurrence of the disease without a solution of con tinuity of tissue sufficient to permit the entrance of the pathogenic organism.
Idiopathic cases following exposure to cold do, however, occur. The most favor able forms of wounds for the develop ment of tetanus are lacerated and con tused wounds, especially where nerves are involved. Injuries in hands or feet are more apt to permit infection than are wounds in other parts. The disease, however, may follow surgical operations, extraction of teeth, vaccination, burns, frost-bite, insignificant scratches or puncture injuries from splinters, nee dles, tacks, etc. It may follow child birth in women, although of late years this puerperal form of tetanus has been much less common than it was before the days of asepsis. In all wounds how
ever received the probable source of con tamination is the soil. A clean wound, of course, involves much less danger than a dirty one.
Bacteriology. — The tetanic bacillus growing under favorable conditions is a characteristically drum-stick-shaped or ganism, whose peculiar feature is a con siderable enlargement at one end, in which enlargement a bright, round spore can be seen. The non-spore-bearing bacilli are long, slender, having rounded ends, are motile, and are numerous when conditions of temperature and other req uisites to perfect development are un favorable. The organism will not grow in the presence of the smallest amount of oxygen, which fact renders its suc cessful cultivation a matter of some dif ficulty. It stains readily by Gram's method, and with ordinary watery solu tions of the aniline colors. It is widely distributed in Nature, but especially com mon in certain soils in thickly-inhabited countries; in particular, soils which have been manured. It is also present in the atmosphere, especially a dust-laden at mosphere, and has been shown in the scrapings of the walls and floors of hos pitals in which tetanic cases have been treated. It is always found in the pus or other discharge from tetanus-infected wounds, and is frequent in the intestinal discharges of men and animals affected with the disease.
The organism possesses exceptional powers of resistance, retaining its lence for months in dried pus, and viving many antiseptic solutions and ex posure to heat, etc., which would prove quickly fatal to other pathogenic germs. The specific powers which cause the symptoms of tetanus are generated by the bacteria in their processes of growth and nutrition, and have been isolated by Brieger from filtrates of several-weeks old cultures in the shape of two basic substances: tetanin and tetanotoxin; and Brieger and Fraenkel have also isolated from these culture-products an intensely poisonous toxalbumin.