294 IMMUNOLOGY 



general tetanus appear, it is evident that toxin has ah-eady com- 

 bined with nerve cells of the central nervous system. Wasser- 

 mann and Takaki discovered that brain tissue forms a very firm 

 combination with toxin, which fact may account for the ineffec- 

 tiveness of the serum treatment of general tetanus. 



In evaluating statistical studies relative to the efficiency of 

 serum and other treatments of tetanus, it should be remembered 

 that there is a definite relationship between the observed incuba- 

 tion period and the mortality rate of the disease. When the in- 

 cubation period is short, i.e., four to six days, the mortality is ap- 

 proximately 90 per cent, while it is only 50 per cent when the 

 incubation period is ten days or longer. The longer incubation 

 period permits the body to develop active immunity which is not 

 possible when the incubation period is short. There are perhaps 

 a number of other factors that affect the outcome of the disease. 



In the preceding chapter attention is called to a new method of 

 treating acute tetanus reported by Ramon (1940). He has called 

 it combined (active-passive) treatment. A more extensive clinical 

 application will determine its value. 



Those interested in the methods of preparation of commercial 

 antitoxin are referred to an excellent discussion of the subject in a 

 paper by McCoy (1928) and to the more recent publications of 

 Predtechensky (1931) and of Sneath (1934). An interesting dis- 

 cussion of the present status of tetanus is contained in a paper 

 by Miller and Rogers (1935). Reference to improved methods 

 of antitoxin production are mentioned elsewhere in this chapter 

 and in a preceding chapter. 



Gas Gangrene. — There are five pathogenic anaerobes, any one 

 alone or any combination of which may gain entrance into a 

 wound and produce either gas and local necrosis or a fulminating 

 gangrene with severe systemic manifestations. In the latter case 

 death may follow within a few hours. Such tyj)es of infection 

 are designated as "gas gangrene." The five anaerobes listed in 

 the order of their frequency of occurrence in such conditions are : 

 CI. welchii, CI. septicum, CI. oedematiens {B. novyi), CI. fallax, 

 and CI. Jiistolyticum. It is generally agreed that the first four of 

 these organisms produce soluble toxins, but there is some disagree- 

 ment in the case of 67. Imtolyticiim. Zinsser and Bayne-Jones 



