508 A MANUAL OF BACTERIOLOGY 



the wound probably play an important role in the pro- 

 duction of tetanus by causing tissue damage and inhibition 

 of phagocytosis, so that the tetanus bacillus is able to 

 grow and multiply and form its toxin. 



So-called " idiopathic " or " rheumatic " tetanus also 

 occurs in which there is no obvious wound. This may 

 be due to infection of some slight wound which has 

 practically healed. Hamilton suggested that tetanoid 

 organisms in the intestinal tract might be the cause of 

 this form of tetanus. An alternative suggestion is that of 

 Semple, 1 who found that tetanus spores are occasionally 

 present in the human intestinal tract. He injected 

 guinea-pigs with washed spores, and tetanus did not ensue, 

 but the tissue at the site of inoculation, examined five to 

 seven months later, still contained the living spores. 

 Semple suggested that such latent spores may in some 

 instances be disturbed and become active by trauma or 

 by the hypodermic or intra-muscular injection of quinine, 

 owing to the tissue necrosis and inhibition of phagocy- 

 tosis produced by the drug (tetanus has followed on many 

 occasions injections of quinine). 



Antitoxin. If an animal is cautiously injected with 

 tetanus toxin, commencing the treatment with a weakened 

 toxin, and increasing the dose very gradually, a high 

 degree of immunity is ultimately obtained, and the blood- 

 serum acquires marked antitoxic properties. The toxin 

 is obtained by growing the tetanus bacillus in glucose 

 broth in an atmosphere of hydrogen, or in sulphindigotate 

 broth, for about three weeks, and filtering through porous 

 porcelain. To obtain an active serum treatment has to be 

 prolonged for several months. 



The antitoxin may be standardised by the Roux or by 

 the Behring method (see p. 335), but methods analogous 

 to those used for standardising diphtheria antitoxin are 



1 Sc. Mem. Gov. of India, No. 43, 191 1. 



