TETANUS 



101 



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 important 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 was 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 

 twelve hours. 



(Tetanus antitoxin is prepared like diphtheria anti- 

 toxin, but its standardization is not uniform, each 

 country having its own standard unit.)- 



In New York City during the last few years appar- 

 ently good results have been obtained with immuniz- 

 ing doses; 1500 (U. S.) units have been injected in cases 

 where any suspicion of infection existed, mainly in 

 Fourth-of-July wounds, and no cases of tetanus have 

 developed where this method was pursued. 



