TETANUS 



103 



rated from cultures by filtration through a Berkefeld filter, 

 and causes typical tetanus when introduced into animals. 

 Its action is weakened by exposure to light and entirely 

 destroyed by heating to 55° C. and over. Like diphtheria 

 toxin, tetanus toxin, when injected in small and gradually 

 increasing doses into horses, produces in the serum of 

 these animals an antitoxin. In fact, the toxin-antitoxin 

 reactions, which have become so imi^ortant in diph- 

 theria, were first studied in connection with the bacillus 

 of tetanus. The serum of immunized horses protects 

 laboratory animals against experimental tetanus, and 

 it w^as thought that the same might be used in the 

 treatment of tetanus in man. But, unfortunately, 

 tetanus symptoms develop late, anywhere from four to 

 fourteen days after inoculation, while, to be of service, 

 the antitoxin must be given before the toxin has spread 

 through the system. To obtain the best results the anti- 

 toxin should be injected intraspinally. Nicoll, of New 

 York, has used the antitoxin in this way and has saved a 

 considerable proportion of cases. If for any reason spinal 

 injections cannot be given, the antitoxin should be injected 

 intravenously. In such a case 10,000 units (U. S. stand- 

 ardization) should be given and repeated every eight to 

 tweU'e hours. 



(Tetanus antitoxin is prepared like diphtheria anti- 

 toxin, but its standardization is not uniform, each 

 country having its own standard unit.) 



Inasmuch as tetanus bacilli are not uncommonly pres- 

 ent in garden earth all patients whose wounds have been 

 contaminated with earth, as on the battlefield, should 

 receive an immunizing dose (1500 U. S. units) of tetanus 

 antitoxin. 



