86 Infection 



of alcohol introduced into the stomach through a tube. Salant* 

 found that alcohol was disadvantageous in combating the infectious 

 diseases because it diminished the glycogen content of the liver which 

 Collaf had found an important adjunct in supporting the resisting 

 power. 



It is a common clinical observation that excessive indulgence 

 in alcohol predisposes to certain infections, notably pneumonia, 

 and every surgeon knows the danger of pneumonia after anesthetiza- 

 tion with ether. 



Traumatic injury and mutilation of the body are not without 

 effect upon infection. The more extensive the damage done to 

 the tissues, the greater the danger of infection, and the more serious 

 the consequences of infection when it takes place. 



The mutilation of the body by the removal of certain organs is 

 of disputed importance. There is much literature upon the effect 

 of the spleen in overcoming infectious agents, but the experimental 

 evidence seems about equally divided as to whether an animal is 

 more or less susceptible after the removal of this organ than it was 

 before. 



Morbid conditions in general predispose to infection. The fre- 

 quency with which diabetics suffer from furuncles, carbuncles, and 

 local gangrenous lesions of the skin; the increased susceptibility of 

 phthisics to bronchopneumonia of other than tuberculous origin; 

 the apparent predisposition of injured joints and pneumonic lungs 

 to tuberculosis; the extensive streptococcus invasions accompany- 

 ing scarlatina and variola; the presence of Bacillus icteroides and 

 various other organisms in the blood and tissues of yellow fever 

 patients, and the presence of Bacillus suipestifer in the bodies of 

 hogs suffering with hog cholera, all show the diminution in the gen- 

 eral resisting power of an individual already diseased. 



MIXED INFECTIONS 



The general prevalence of bacteria determines that few can 

 enter and infect the body of a host without the association of other 

 kinds. Therefore their operation in the body is subject to modifica- 

 tions produced in them or in the host by these associated organisms. 



In experimental investigations this fact is not infrequently for- 

 gotten, and it is often remarked with surprise that the results of 

 inoculation with pure cultures of a micro-organism may be clinically 

 different from those observed under natural conditions. 



The tetanus bacillus, which endures with difficulty the effects 

 of uncombined oxygen, flourishes in association with saprophytic 

 organisms by which the oxygen is absorbed. The same thing is 

 probably true of other obligatory anaerobic organisms. 



* "Jour. Amer. Med. Assoc.," 1906, XLVII, 18, Nov. 3, p. 1467. 

 f "Archiv. Ital. de Biologic," xxvi. 



