224 SCHROEDER 



half months, and under usual circumstances may transmit virus from one 

 to five and a half months. 



Hurst and Pawan (1936) believe that there are six forms of rabies 

 seen in bats : 



1 . Furious form followed by paralysis and death. 



2. Paralysis, not preceded by a furious form, with death. 



3. Furious form with recovery. 



4. Furious form followed immediately by death. 



5. Sudden death with no symptoms. 



6. Symptom free carrier. 



However, the usual course seen in bats experimentally infected closely 

 follows that of other mammalian hosts, which is 



1. Period of incubation. 



2. Prodromal or invasive stage. 



3. Period of excitement ( furious form ) . 



4. Paralysis of an ascending type. 



5. Death. 



In man it is reported that the early symptoms of rabies following bat 

 bite are a burning or tingling sensation at the site of the wound, followed 

 in five to seven days by ascending paralysis and death. In cattle there is 

 progressive ascending paralysis with early loss of sensory reflexes. There 

 are licking paroxysms and the temperature may be elevated. Paralysis 

 starts in the hind quarters, causing knuckling over at the fetlock and a 

 drifting walk, with complete paralysis by the end of the third day. The 

 eyes are sunken, with an anxious expression, the ears constantly flopping, 

 the head usually turned to the right. The animal is prostrate with flaccid 

 paralysis on the fourth day but conscious to the last, with death due to 

 respiratory failure on the fifth day. 



Rabies is a preventable disease. Prevention practices did not change 

 much from the time of Pasteur until Johnson, Koprowski and Cox 

 (1948) led the way with the preparation of a chick embryo modified live 

 virus vaccine, Johnson had isolated a strain of virus from the brain of a 

 child from a family named Flury, at Macon, Georgia, and directly car- 

 ried the Flury virus strain in day-old chicks by intracerebral inoculation 

 at the Rockefeller laboratories. Koprowski secured from Johnson frozen 

 samples of chick brain bearing rabies which had been serially passed in 

 excess of one hundred twenty times, and promptly inoculated intracere- 



