CHAPTER XXL 

 BACILLUS FEBRIS ENTERICS. 



Introduction. 



Section I. Experimental inoculation, p. 367. 



A. Inoculation of viruses of ordinary virulence, p. 368. B. Inoculation of viruses 

 of exalted virulence. Methods of increasing virulence. Infection with viruses of 

 exalted virulence, p. 368. C. Infection by the alimentary canal, p. 369. 

 Section II. Morphology, p. 370. 



1. Microscopical appearance and staining reactions, p. 370. 2 Cultura 

 characteristics, p. 371. 

 Section III. Biological properties, p. 373. 



1. Bio-chemical reactions, p. 373. 2. Variability of flagella, p. 376. 3. Viability 

 and virulence, p. 376. 4. Toxins, p. 376. 5. Vaccination, p. 380. 6. Serum-therapy, 

 p. 383. 7. Agglutination and the serum diagnosis of enteric fever, p. 384. 8. Absorp- 

 tion of agglutinins, p. 389. 9. Complement fixation, p. 390. 

 Section IV. Detection, isolation and identification of the typhoid bacillus, p. 390. 



THE causa] organism of enteric fever was originally discovered by Eberth 

 in the spleen, lymphatic glands and Peyer's patches of persons suffering from 

 the disease. Its morphological characteristics were more fully described by 

 Gaffky. 



The bacillus of enteric fever 1 is always present in the spleen, liver, mesenteric 

 glands, glandular follicles of the intestine and bone marrow and less frequently in 

 the lungs, meninges, testicles, tonsils, etc. A certain number of cases of enteric 

 fever have been recorded in which there was no intestinal localization. 



For a long time it was thought that the bacillus did not pass into the blood stream 

 (Chantemesse and Widal, and others). It is, however, now recognized that the 

 failure to find the bacillus in the blood was due to the defective technique then 

 employed and that, as a matter of fact, in enteric fever the bacillus does pass into 

 the blood stream and that the disease is in reality a true septicaemia. In all cases of 

 moderate and severe infection the organism can be isolated from the blood from 

 the fifth day until the end of the third week of the disease (Courmont). 



The bacillus can often be isolated from blood taken from the rose spots (Thiemisch 

 and Neuhaus, Besson, etc.). 



Remy's experiments have proved that, contrary to the opinion formerly held, 

 the bacillus is present in the stools of enteric fever patients as early as the third day 

 of the disease and before ulceration of the intestine has begun. The number of 

 organisms present in the stools increases until the end of the first week and then 

 gradually diminishes until at the end of the fourth week they can as a rule no longer 

 be found. The bacilli have, however, been isolated from the stools of persons who 

 have recovered from the disease for more than a month (Remy, Chantemesse and 

 Decobert) and it will be shown later that in some cases they persist for a still longer 

 period. 



1 In the remainder of the chapter and elsewhere the organism is termed for the sake 

 of convenience the typhoid bacillus. 



