244 PASSIVE IMMUNIZATION 



however, has been shown to be erroneous, and the method is from 

 this standpoint therefore inapplicable. Other investigators have 

 suggested to use the bactericidal power of the serum in mw as 

 indicator of its therapeutic properties. The values which can thus 

 be obtained are, however, approximative at best, and the same is 

 to be said regarding Neuf eld's suggestion to gauge its strength by a 

 determination of its bacteriotropic titer. Kraus and Doerr, in 

 the belief that the efficiency of the serum depends upon its content 

 of antitoxins, suggest its standardization upon this basis, in a manner 

 analogous to the standardization of diphtheria antitoxin, but it is 

 extremely doubtful whether these actually play an important role, 

 and the suggestion has hence not met with favor. Under these 

 circumstances it is apparent that the main stress must be placed 

 upon the duration of the immunizing process, possibly coupled with 

 a study of its bactericidal power in mw, and its bacteriotropic 

 effect. 



Dosage and Mode of Administration. From what has just been 

 said, it is clear that the dosage of the serum still rests upon an 

 empirical basis. As initial dose, Flexner recommends an injection of 

 30 c.c., which may be repeated every twenty-four hours for three or 

 four days or longer. All injections should be made into the sub- 

 arachnoid space, care being taken that the serum is introduced very 

 slowly, so as to cause no symptoms of pressure. It is hence best to 

 allow at least as much fluid to escape as it is desired to introduce. 



As the best results are obtained in early cases (see below) every 

 effort should be made to reach a definite diagnosis as soon as possible, 

 and to this end spinal puncture is practically imperative. If this 

 reveals a turbid fluid the antiserum may be injected at once, the 

 microscopic and bacteriological examination being carried out later. 

 If this should prove that the case was not one of meningococcus 

 meningitis, no harm will have been done, while in the event of a 

 confirmatory diagnosis, valuable time will have been gained. The 

 appearance of the fluid at subsequent examinations, aside from 

 the physical condition of the patient, will then be a fairly good 

 index as to the necessity of repeating the injections. So long as 

 this is cloudy further treatment is needed. All in all it is better 

 to inject too much and too often than too little and too infrequently. 

 Late in the disease, however, when chronic hydrocephalus has 

 developed, the treatment is useless. 



