8l2 MICROBIOLOGY OF DISEASES OF MAN AND DOMESTIC ANIMALS 



As Stated above, the microbial origin of infantile paralysis was first 

 demonstrated by the inoculation of monkeys, Flexner and Lewis having 

 successfully carried the infection through a long series of monkeys by 

 successive intracranial injections of an emulsion of the spinal cord 

 taken from infected animals. The microorganism passes through the 

 Chamberland and Berkefeld filters with little or no loss in disease- 

 producing power. "Flexner and Noguchi, employing the technic 

 previously used for cultivating pathogenic spirochsetes, have succeeded 

 in obtaining from infected tissues cultures of a minute round organism 

 which they believe to be the cause of infantile paralysis." The virus 

 withstands freezing or drying for long periods of time but is quickly 

 destroyed by heating at a temperature of 50°. It is likewise quickly 

 killed by the ordinary disinfectants. Monkeys may be infected by the 

 subcutaneous, intraperitoneal, intravenous, Or intracranial injection 

 of material from an infected spinal cord, but attempts at infection 

 through feeding have been unsuccessful. The virus appears to be 

 eliminated from the body through the nasal mucous membranes. 



It appears probable that one attack of the disease protects frogi a 

 second attack. No cases of a second attack have been reported. 

 Furthermore, monkeys which have recovered from the infection appear 

 to be entirely immune as shown by Flexner. Active immunity in 

 monkeys has been established by repeated infections of gradually 

 increased amounts pf the virus. The blood of human beings and oi 

 monkeys that have recovered from an attack of the disease is capable 

 of neutralizing a certain amount of the virus. This protective quality 

 of the blood serum may be increased by repeated inoculations of virus, 

 and infection in monkeys can be prevented by injecting simultaneously 

 the virus into the brain and the serum into the sub-arachnoid space. 

 The serum treatment of this disease is, however, not developed to such 

 a state that it can be regarded as of practical use. 



LoupiNG III— Trembling in Sheep* 



This disease is known only in Scotland and is essentially a disease of 

 sheep. It is characterized by a variety of nervous phenomena, such as 

 trembling, irritabihty, and convulsive movements, which are followed 

 later by partial or complete paralysis. The chief lesions are found in 



• Prepared by M. Dorset. 



