468 INFECTION AND RESISTANCE 



either when the invading germ was still localized or, at least, wnen 

 the septicemic condition was not yet thoroughly established. It may 

 be that the doses heretofore given have been insufficient, and indeed 

 recent experiences with pneumonia seem to indicate that this may 

 have been, in part, the cause of earlier failures. Yet in pneumonia 

 the septicemia probably does not represent the firm establishment of a 

 foothold by the pneumococcus in the circulation but rather a con- 

 tinuous discharge of new organisms into the blood from the localized 

 lesion in the lung. 



It is our own opinion moreover that septicemia as usually ob- 

 served clinically represents in most cases exactly this condition, that 

 is, a more or less continuous discharge of the bacteria into the blood 

 from some active focus with a continuous destruction of the organ- 

 isms after they have entered the blood stream. It is only when the 

 resistance of the body is overwhelmed, in the later stages of the 

 disease, that the bacteria can continue to grow and develop in the 

 circulation, and this stage probably does not occur until death is 

 imminent. In such septicemic diseases as streptococcus infection, 

 typhoid fever, plague, anthrax, and many others the presence of the 

 bacteria in the blood at the time when the patient is still in a condi- 

 tion of powerful resistance probably means that the bacteria are 

 being supplied to the blood from the local lesions. There is prob- 

 ably just such a continuous discharge of bacteria from the focus into 

 the blood with active destruction after the bacteria have entered the 

 circulation. This seems especially probable from the fact that in 

 many of these diseases the protective antibodies, bactericidal and 

 opsonic, can often be demonstrated in the blood serum in quantities 

 higher than normal at the very time when blood culture yields posi- 

 tive results. In typhoid fever, of course, it is well known that bac- 

 tericidal titres of over 1-50,000 are often present while the patient 

 may still be very sick, and in the more chronic streptococcus condi- 

 tions with malignant endocarditis we have often seen that opsonic 

 properties on the part of the patient's serum against the very organ- 

 ism invading him are considerably higher than normal. We take 

 this to mean that the injection of immune sera would simply aid in 

 more rapidly freeing the blood stream of the bacteria, the cure of 

 the disease, however, involving a destruction of the focus. This, of 

 course, is not possible merely by the injection of the serum. When, 

 as in some cases of streptococcus infection, the focus can be surgically 

 reached, the septicemia will often disappear and cure result, as we 

 have ourselves had the opportunity to observe. When the focus 

 cannot be reached surgically, it may nevertheless be a wise procedure 

 to inject considerable amounts of immune serum, for, by keeping the 

 blood stream free of bacteria, the case may be influenced favorably. 

 Pneumonia is an example of this. Former failures have recently 

 been turned into partial success by the work of Neufeld and of Cole 



