236 PASSIVE IMMUNIZATION 



a study of its bactericidal power in vivo, 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 pos- 

 sible, 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 meningo- 

 coccus 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. 



The subcutaneous or intravenous use of the serum is to be depre- 

 cated, as the results following this method of administration are no 

 better than under the expectant plan of treatment. 



One question of great practical importance which has arisen in 

 connection with the serum treatment of meningococcus meningitis is 

 whether any danger due to anaphylaxis is to be anticipated from the 

 repeated injections, particularly since these are made into the subarach- 

 noid space, and since Besredka has shown that the direct injection of 

 the alien serum into the central nervous system is particularly fatal 

 to guinea-pigs. So far as we can tell, this danger is really a negligible 

 quantity, especially as the daily injections in the early course of 

 the treatment do not enter into consideration, and the patient usually 

 is beyond the need of serum by the time that anaphylactic reactions 

 would be expected to occur. But even in cases where the injections 



