HISTORY OF THE ORGANISM 



We shall give below reasons why carriers do not become infected, and it 

 is possible that monkeys may be resistant except when damaged by an opera- 

 tion like trephining or otherwise below par ; moreover, the meningococcus is 

 often damaged in the drawn fluid and degenerated on cultivation, for we have 

 seen it fail to infect a monkey after five generations of growth of the same 

 organism which was infective during the second generation. 



We now turn to inquire in what way the human body reacts to the organism. 

 Davis showed in 1907 that at the end of the first week agglutination up to 

 I in 50 could be obtained, and in the eighth week up to i in 200, and pointed 

 out that the agglutinins were thermostable, resisting a temperature of 65° C. 

 for an hour, while they appear to be practically absent from the cerebro- 

 spinal fluid, but many observers, including ourselves, have found this test 

 uncertain. 



Davis in 1905 showed that the coccus multiplied in two normal defibrinated 

 bloods, but in four other bloods it was killed, as it was by the blood from 

 patients after the tenth day. He noted that the meningococcidal power of 

 the blood serum of patients which seemed to be greater than that of normal 

 blood serum was diminished by heating to 60° C. for thirty minutes. He 

 found that the phagocytic index was 13 for normal human serum, o for serum 

 heated to 60° C. for thirty minutes, while in meningitic serum from cases 

 between the second and seventh week of convalescence it was 1 1 • i . Normal 

 cerebro-spinal fluid did not contain opsonins. 



Houston and Rankin in 1907 found that opsonins were exceedingly low in 

 normal serum, and lower still in cerebro-spinal fluid, while in cases from the 

 sixth day onwards they rose remarkably, except in two fatal cases, while in 

 one relapse the rise was postponed till the eleventh day. 



MacGregor observed that the highest indices occur in the second and third 

 week of the disease, but that the degree of immunity after recovery, as 

 measured by the opsonic index, was variable, and concluded that a high 

 opsonic index was a sign of forcible reaction to a fairly severe infection. 



Meakers and Dopter have shown the presence of immune bodies in the blood 

 of meningitic patients by means of complement-fixation, and McKenzie and 

 Martin have also demonstrated the presence of these bodies by injecting the 

 serum of recovered cases intraspinally into other acute cases with fair results. 

 It would therefore appear that immune bodies are formed in patients' systems, 

 which is in support of the causal action of the meningococcus. 



We now turn to see whether specific serum treatment and vaccine therapy 

 will help the problem. 



With regard to the serum treatment, Jochmann in 1905 experimented with 

 a specific immune serum which was afterwards manufactured by Merck. He 

 tested his serum by the opsonic test, the bactericidal test, and by agglutina- 

 tion, 



KoUe and Wassermann also made an immune serum upon which they 

 reported in 1907. 



In 1906 Flexner wrote upon a specific serum which protected monkeys and 

 small animals. Later this serum was made from immunized horses, and has 

 been extensively used. 



With regard to vaccine treatment, Davis in 1907 was the first to inject killed 

 meningococci into normal persons and into patients suffering from the disease, 

 and CoUis in 19 13 tried specific serum treatment together with vaccine therapy. 

 In the same year Sophian reported on his experimental inoculation of eleven 

 niedical students, and eleven months after these inoculations Merck re-tested 

 eight of them, comparing the results with those of a normal person and a 

 recently recovered case, and concluded that a person so vaccinated may consider 

 himself to be immune for at least one year. 



In October, 19 15, Surgeon-General RoUeston reported upon sixteen cases of 

 vaccine treatment with four deaths and twelve recoveries ; the vaccine, how- 

 ever, was never used alone, but combined with serum treatment in some form 

 or with soamin. In his report lumbar puncture alone in thirteen cases re- 

 sulted in four deaths and nine recoveries, serum intrathecally alone forty- 

 three deaths and nineteen recoveries, or alone and combined with vaccine, 



