APPENDIX G. 



EPIDEMIC POLIOMYELITIS. 



DURING the past twenty years, the occurrence at one time and 

 place of groups of cases of acute anterior poliomyelitis has favoured 

 the idea that the condition might be of an infective nature. 

 This view was supported by the work of Landsteiner and Popper, 

 who, in 1909 in Vienna, succeeded in producing the disease in a 

 monkey by the intraperitoneal injection of an emulsion of the spinal 

 cord of a child who had succumbed on the fourth day of illness. 

 The occurrence in New York in the summer of 1907 of an 

 epidemic in which probably over 2000 cases occurred, 762 

 of which were carefully investigated by a Commission, 

 concentrated attention in America upon the condition, and a 

 recrudescence in the summer of 1909 furnished Flexner with 

 material for investigation. In earlier experiments it had been 

 observed that the cerebro-spinal fluid was non-infective, and 

 that, while it was possible to infect monkeys with the disease, 

 the transference of the condition from monkey to monkey w T as 

 not successful. Flexner found that if for intraperitoneal 

 injection intracerebral inoculation was substituted, the brain and 

 cord of the infected animals was infective for other monkeys, 

 the incubation period being from four to thirty-three days. In 

 this way the disease was kept up by subdural and intravenous 

 injection, and also by injection into the sheath of nerves such as 

 the sciatic, the intraperitoneal and subcutaneous methods being 

 found also to give results. The disease produced resembled in 

 every way the disease naturally occurring in children, and 

 frequently resulted fatally, as in the natural illness. When 

 the virus was injected into the sheath of a nerve, the paralytic 

 symptoms first appeared in relation to that part of the cord 

 from which the nerve emerges. Infective material preserved in 

 glycerin retained its virulence, a fact which rather militates 

 against there being a bacterial virus, and the virus could also 

 withstand prolonged freezing and drying for a considerable period. 



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