BEHAVIOR OF BACTERIOPHAGE IN DISEASE 439 



of the bacteriophage protobe is increased, both for B. coli and for the 

 pathogenic organism. 



These findings immediately suggest the idea that there may have 

 been in these three cases the beginning of an infection by these patho- 

 genic bacteria for which the virulence of the bacteriophage became mani- 

 fest, but that the infections were aborted because of the rapid adapta- 

 tion on the part of the intestinal bacteriophage, thus resulting in a 

 bacteriophagy in vivo (d'Herelle^^^-^^^). 



Study of the behavior of the intestinal bacteriophage in outspoken 

 disease shows us that this hypothesis is correct. 



2. THE BACTERIOPHAGE IN BACILLARY DYSENTERY 



The charts presented in this section show, much better than any 

 explanation, the relations which exist between the condition of the 

 patient and the virulence of the intestinal bacteriophage for the path- 

 ogenic bacterium. The upper tracing gives the number of stools in 

 24 hours; the single hne indicating stools without blood, the double 

 line those containing blood and mucus. On the lower portion of the 

 chart is indicated (1) by the dotted line, the virulence of the bacterio- 

 phage for the colon bacillus; (2) by the broken line, the virulence of the 

 bacteriophage for a stock strain of the Shiga bacillus which had been 

 maintained for a long time under laboratory cultivation; and (5) by 

 the solid line, the virulence for the Shiga strain recovered from the 

 patient himself. 



The five cases given as examples were treated at the Pasteur Hospital. 

 It was thus possible to follow them with all necessary attention and to 

 obtain material for examination as often as the investigation demanded; 

 at least once, often several times, during the course of each day. 



For these examples, cases of different severity have been selected. 

 In all of them B. dysenteriae Shiga was isolated from the stools at 

 the beginning of the disease. 



Case 1. GermaineMel (sixteen years, chart 1). This was 



a mild case of dysentery. The patient was an inmate in an institution 

 where there were about thirty young girls. During the period from the 

 12th to the 22nd of July about twenty of these girls presented intestinal 

 disturbances of sudden onset, accompanied by a profuse diarrhea, 

 followed by a rapid amelioration of symptoms. Within one or two days 

 after the onset all had again become normal. In only one or two cases 

 did the stools contain traces of blood. In order to establish a diagnosis 

 the directrix was asked to send a patient to the Hospital during the 

 earliest symptoms. 



