^ 01 ACUTE INFECTIOUS DISEASES. 



I J T 



The dysentery germ appears to reproduce itself always, or un- 

 der favorable circumstances, in the body of the infected person, and it 

 would seem that the dejections of the patient contain the contagion 

 thus formed, or its components ; for, while it has not been proved that 

 one person catches dysentery from another, it is more than probable 

 that the disease may be communicated to healthy persons through the 

 dejections of dysentery patients, or by the night-stools, bed-pans, or 

 enema syringes that have been used by them. This causes dysentery 

 to resemble cholera, while it speaks against the asserted connection 

 between it and malaria. Why should not the same or similar influ- 

 ences, such as high temperature and moisture, favor the development 

 of various specific low organisms, just as it does the increase of differ- 

 ent varieties of higher plants and animals ? 



Catching cold, getting wet, great fatigue, the use of unripe vege- 

 tables, and other injurious influences, have been advanced as causes of 

 dysentery, and it cannot be denied that persons exposed to these influ- 

 ences are more readily affected than others. Nevertheless, infection 

 with a specific poison is the sole cause of this disease, and the part that 

 the above influences play in the etiology is only to render the organ- 

 ism more sensitive to the action of the poison ; in other words, they 

 increase the predisposition to dysentery. 



ANATOMICAL APPEARANCES. The anatomical changes found in 

 the intestines of dysentery patients, on autopsy, are a type of diph- 

 theritic inflammation. The diseased portions of mucous membrane are 

 infiltrated with a fibrinous exudation, and, as a result of their compres- 

 sion by the exudation, are necrosed and changed to a slough. If the 

 slough be cast off, a loss of substance in the mucous membrane re- 

 mains. According as this loss of substance is superficial and of slight 

 extent, or deep and extensive, the destruction of the mucous mem- 

 brane is, or is not, capable of complete repair. In the former case only 

 can the intestine become perfectly well, while in the latter, in place 

 of the membrane destroyed, there is a callous cicatricial tissue, which 

 not unfrequently constricts the intestine. 



In the mildest grades of dysentery we find the mucous membrane 

 of the large intestine, especially the summits of the folds projecting 

 inward, deeply reddened by ecchymosis and injection, and to some 

 extent infiltrated by a grayish-white, soft exudation, covering the epi 

 thelial coating. In these cases, it looks as if the diseased part were 

 covered by a bran-like coating ; but if we scrape off this coating with 

 the handle of a scalpel, there remains a superficial loss of substance, 

 which shows that the exudation did not lie on the mucous membrane, 

 but entered into it. The submucous connective tissue is infiltrated 

 with serum, and swollen. The serous coat appears cloudy and dull 



