Pathogenesis 643 



thelium of the blood-vessels of the intestine and spleen. 

 The liver-cells lying between the occluded capillaries undergo 

 necrosis and disappear. Later the foci of cells degenerate 

 and fibrin forms between them. Invasion by polymorpho- 

 nuclear leukocytes is rare." 



". . . Histologically the typhoid process is prolifera- 

 tive and stands in close relationship to tuberculosis, but the 

 lesions are diffuse and bear no intimate relation to the 

 typhoid bacillus, while the tubercular process is focal and 

 stands in the closest relation to the tubercle bacillus." 



The growth of the bacilli in the kidneys causes albu- 

 minuria, and the bacilli can be found in the urine in about 

 25 per cent, of the cases. Smith * found them in the 

 urine in 3 out of 7 cases which he investigated; Richardson, f 

 in 9 out of 38 cases. They did not occur before the third 

 week, and remained in one case twenty-two days after 

 cessation of the fever. Sometimes they were present in 

 immense numbers, the urine being actually clouded by their 

 presence. Petruschky J found that albuminuria sometimes 

 occurs without the presence of the bacilli; that their 

 presence in the urine is infrequent; that the bacilli never 

 appear in the urine in the early part of the disease, and 

 hence are of little importance for diagnostic purposes. 

 Gwyn has found as many as 50,000,000 typhoid bacilli 

 per cubic centimeter of urine, and mentions a case of Gush- 

 ing 's in which the bacilli persisted in the urine jor six years 

 after the primary attack of typhoid fever. Their occurrence, 

 no doubt, depends primarily upon a typhoid bacteremia, 

 by which they are brought to the kidney. After recovery 

 from typhoid fever, their persistence in the urine depends 

 upon continued growth in the bladder and not upon con- 

 tinuous escape from the blood. It is of importance from 

 a sanitary point of view to remember that the urine as well 

 as the feces is infectious. 



The bacilli pass from the lymphatics to the general 

 circulation, so that all cases of typhoid fever are true 

 bacteremias during part or all of their course. 



Ordinarily few bacilli can be found in the circulatory 

 blood, but blood from the roseolas contains them, and the 



* "Brit. Med. Jour.," Feb. 13, 1897. 



f "Journal of Experimental Medicine," May, 1898. 



% "Centralbl. f. Bakt. u. Parasitenk.," May 13, 1898, No. 13, p. 577, 



\ "Phila. Med. Jour.," March 3, 1900. 



