TYPHOID FEVER. 173 



Etiologic Relations of the Bacilli to Typhoid Fever 

 in Human Beings. In view of their constant presence in 

 all cases of typhoid fever, and of their occurrence exclu- 

 sively in this disease, the Eberth-Gaffky bacilli may be 

 considered as the exciting agents of typhoid fever, although 

 experimental development of typhoid fever by means of the 

 bacilli has not been induced. The bacteria that gain 

 entrance into the digestive tract with the food obtain lodg- 

 ment, in the presence of the necessary predisposition on the 

 part of the individual, in the follicles and plaques of the 

 intestinal wall. The period of incubation for typhoid fever 

 is from one to three weeks. During this time the bacteria 

 slowly give rise to the anatomic process that constitutes the 

 basis of the disease, the swelling of the plaques, and, later, 

 their ulceration. At the same time the bacteria multiply 

 and gain entrance probably by way of the lymph-paths 

 especially into the mesenteric glands, also into the liver 

 and the spleen. To this point typhoid fever is a truly in- 

 fectious disease. The toxic activity of the bacteria is, how- 

 ever, of equally marked importance. Brieger and Frankel 

 have demonstrated in bouillon-cultures of typhoid-bacilli a 

 chemic poison that they place in the class of toxalbumins. 

 R. PfeifTer also held the view with regard to typhoid fever 

 that the peculiar poison resides in the bodies of the bacteria. 

 (See General Section, p. 31.) This can be readily obtained 

 by destroying young agar-cultures carefully by means of 

 chloroform-vapor or by exposure for an hour to a tempera- 

 ture of 54 C. (129.2 R). From eight to ten mg. of the 

 bacterial mass suffice to destroy a guinea-pig. There is no 

 doubt that also in the body of the typhoid patient a specific 

 poison is generated by the bacteria, and is absorbed. The 

 characteristic mental dulness, and the peculiar febrile course 

 may be considered as expressions of this intoxication. Not 

 rarely cases of typhoid fever are observed in which the intes- 

 tinal lesions are subordinate to the toxic state. These are 

 instances of typhoid fever with most profound mental con- 

 fusion and high fever, but with mild intestinal manifestations, 

 in which after death only a few ulcers of small extent are 

 found in the bowel. Cases have even been reported in which 

 during life the characteristic stools, and after death the 

 typhoid ulcers, were entirely wanting : the diagnosis of 

 typhoid fever being based solely upon the demonstration at 

 the autopsy of typhoid-bacilli in the greatly enlarged spleen. 



