BEHAVIOR OF BACTERIOPHAGE IN DISEASE 467 



Considering the cases from the point of view of the time when the bacteriophage 

 appeared in the stools, and on the manner in which it remained there, the obser- 

 vations may be divided into two groups. 



Group One: 



Case Go. J Mrs. Go. J. (chart 15), aged 33 years, entered the hospi- 

 tal on April 21. The disease began 8 days before admission, the symptoms being 

 fever, anorexia, insomnia, and head-ache. Upon admission the abdomen was 

 but slightly distended, and not painful. The tongue was coated. The heart 

 sounds were normal; the pulse of good quality. A blood culture yielded B. 

 typhosus. The curve which is reproduced here shows in parallel the temperature, 

 and the virulences of the intestinal bacteriophage for the typhoid strain from the 

 patient, for a laboratory strain of B. typhosus, for a colon bacillus, and for a 

 strain of B. dysenteriae Shiga. 



In brief, the case was one of typhoid fever of a moderate severity, in which it 

 was possible to demonstrate a lytic principle active for the infecting bacillus 

 throughout the entire course of the defervescence. 



Case Ma . . . Mr. Ma . . . ., aged 34 years (chart 16), entered the hospital 

 on April 23. For the past two weeks he had complained of head-ache, pains in 

 the lumbar region, a general fatigue, and for the past 8 days he had had some fever. 

 Upon admission to the hospital the abdomen was neither tender nor distended. 

 The symptoms of typhoid fever were not severe. Vomiting was frequent. Rose 

 spots were present. The pulse was good. 



The case was one of typhoid fever of moderate severity, in which it was possible 

 to demonstrate a lytic principle active for the bacillus causing the infection. 

 This lytic principle was present throughout the entire period of the defervescence. 



Other illustrative cases of this type might be included, but they would simply 

 duplicate the two cases which have been presented. 



A consideration of this first group permits the following conclusions: 



In a certain proportion of typhoid fever cases, at the same time that the dis- 

 ease shows regression, when the temperature falls, one may find in the stools of 

 the patient a lytic principle (the bacteriophage) which in vitro destroys the in- 

 fecting bacillus. This_lytic principle is of maximum activity, in general, at the 

 time when the period of defervescence begins. Often, when the temperature has 

 reached normal, the lytic principle disappears. In our observations we have not 

 found any definite relationship between the lytic power of the bacteriophage for 

 the infecting bacillus and its lytic power for the stock strains of the bacteria 

 which were tested. 



Group Two: 



Case Fe . . . (chart 17) Mrs. Fe. entered the hospital on April 21. She had 

 been sick for about 9 days. Rose spots were present. The pulse was good. The 

 blood culture yielded B. typhosus. Chart 17 shows the observations made. 



To summarize this case: A patient having a moderately severe typhoid fever, 

 in which, at one time there appeared in the stools a bacteriophage very active for 

 the bacillus causing the disease. This bacteriophage disappeared almost imme- 

 diately, and it was impossible to discover it again. The beginning of convales- 

 cence coincided with the appearance of the bacteriophage. 



There is no point in presenting any further cases of this same type, for they 

 add no new points of interest. 



