CHAPTER XX. 

 BACILLUS DYSENTERIC EPIDEMICS. 



Introduction. 



Section L Experimental inoculation, p. 357. 



1. Shiga bacillus, p. 357. 2. Flexner bacilli, p. 358. 

 Section II. Morphology, p. 358. 



1. Microscopical appearance and staining reactions, p. 358. 2. Cultural charac- 

 teristics, p. 359. 

 Section III. Biological properties, p. 359. 



1. Biochemical reactions, p. 359. 2. Vitality, p. 360. 3. Toxin ; p. 361. 4. Vaccina- 

 tion and serum therapy, p. 361. 5. Agglutination, p. 363. 6. Precipitins, p. 363. 

 7. Immune body, p 363. 



Section IV. Detection, isolation and identification of the dysentery bacilli, p. 364. 

 Serum diagnosis, p 364. 



The bacillus dysentericus El Tor No. 1, p. 365. 



THE bacillus of epidemic dysentery was discovered by Chantemesse and 

 Widal in 1888 : Shiga amplified their observations and adduced additional 

 evidence in proof of the specific relationship of the bacillus to the disease. 



The term dysentery is applied to a clinical syndrome indicating certain lesions of 

 the large intestine and aetiologically includes two distinct diseases, one caused by 

 an amoeba and the other by a bacillus. The former is an endemic disease of warm 

 climates and is frequently complicated by abscess of the liver : the latter is an 

 epidemic disease not complicated by abscess of the liver and prevalent both in warm 

 and especially in temperate climates. 



It is possible that in rare cases symptoms of dysentery may be due to certain other 

 parasites which up till now have received little attention, such for example as Balan- 

 tidium coli, Spirilla, or Trichomonas. 



[Dysentery bacilli have been isolated from a number of cases of infantile diarrhoaa 

 (quite unrelated to any epidemic of dysentery) by Bassett and Duval in the United 

 States ; and in South Africa, Birt found dysentery bacilli in 7 out of 10 cases of 

 this disease. In London, however, Morgan failed to find any bacilli of the dysentery 

 group in cases of infantile diarrhoea. 



[Asylum dysentery has been shown to be a bacillary dysentery and bacilli of the 

 dysentery group have been isolated from cases of the disease in England, Germany 

 and America (Eyre ; Aveline, Boycott and W. F. Macdonald ; Kruse ; Vedder and 

 Duval). 



[Sporadic cases of dysentery are said to occur in England though rarely (Marshall ; 

 Bainbridge and Dudfield). Ledingham's investigations would appear to show that 

 dysentery bacilli are occasionally found in the stools of healthy persons. ] 



In patients suffering from bacillary dysentery the organism is found in 

 large numbers in the intestinal mucous membrane and in the stools especi- 

 ally in the mucous flakes. It does not become generalized, and with the 



