PARASITES 439 



obvious that the surest means of escaping this disease lies, 

 not in an effort to escape the bacteria for that is practically 

 impossible, but in keeping the body in a vigorous state of 

 health. Fear of this disease should be a strong stimulus 

 to sanitary living. Good food in moderate amounts, warm 

 clothing, plenty of exercise, and plenty of fresh air are the 

 best means of protection against this disease. 



A person who has suffered one attack of pneumonia shows 

 little or no increased resistance to a second attack. There- 

 fore, it seems that the organism does not form a soluble 

 toxine nor does it stimulate the body to form an antitoxine. 

 Consequently, we have no serum treatment for it of any kind. 

 It is not definitely known just how the body finally overcomes 

 the organism and recovers. 



511. Typhoid Fever. This is one of the most common 

 and important of all bacterial diseases (Fig. 275) and yet it 

 need not be if every one knew and practised some very simple 

 things concerning it. The disease affects 

 primarily the alimentary tract and is con- ^| *^| ^ 

 tracted almost wholly by taking the organism ^- -+- 



into the mouth with food or drink. The 

 organism escapes from the body of the 

 patient suffering from the disease with the Bacinis typhosus 

 wastes from the alimentary tract and in the -- 

 urine. Since the organism can not multiply or live for any 

 great length of time outside the human body, it is evi- 

 dent that it must be carried more or less directly from the 

 wastes of the sick patient to the alimentary tract of the next 

 victim. This transfer could be quite effectively cut off if 

 all the wastes from sick patients and convalescents every- 

 where were treated with disinfectants as soon as removed from 

 the body. If this is not done, however, there are many ways 

 in which the organisms may be spread to other persons. 

 Flies may carry them directly to the food or water used by 

 healthy persons; the nurse and other persons who wait upon 

 the patient may carry them on their hands to the food or 



