﻿rx. B, 1 Ward et al.: Transmission of Rinderpest 75 



at half an hour and left in the corral for seven days contracted 

 rinderpest. Another exposed at seventeen and one-half hours 

 and left for six days contracted rinderpest. Two placed in the 

 corral twenty-four hours after the sick animals were removed, 

 and left there six days each, failed to contract rinderpest. The 

 results emphasize the fact that rinderpest virus perishes in a 

 bare corral in less than twenty-four hours. 



Experiment 11. — Two head of cattle infected with rinderpest 

 and confined in a small inclosure were found to be infective to 

 other cattle by contact on the seventh, eighth, ninth, and tenth 

 days, reckoned from and including the date that they were 

 injected with virulent blood. This period coincided with the 

 decrease of febrile temperature regularly exhibited in cases of 

 rinderpest and included the period when symptoms were most 

 marked. Subsequent to the period of temperature decline, 

 neither the surviving infected animal nor the infected surround- 

 ings of the animal communicated the disease to susceptible ani- 

 mals exposed thereto. 



The experiment is important in defining the infective period 

 of a case of rinderpest and in demonstrating that virus does 

 not remain infective in a corral beyond twenty-four hours. The 

 results emphasize the importance of close association of animals 

 in transmitting rinderpest. 



Experiment 12. — A carabao and a bull infected with rinder- 

 pest and kept together in a small corral transmitted the disease 

 at eight, ten, eleven, twelve, and thirteen days after they had 

 been injected with virulent blood. This period corresponded to 

 the stage of an attack of rinderpest, extending from the second 

 day of febrile temperature until the final fall of temperature. 

 It was again shown that neither the surviving animal after 

 the decline of temperature nor its surroundings were capable 

 of transmitting the disease to susceptible animals. The results 

 confirmed those of the previous one as to the infective period 

 and as to the failure of the infected corral to transmit the 

 disease. 



Experiment 13. — A carabao infected with rinderpest was 

 shown to be infective by contact to other susceptible carabaos 

 at ten, eleven, and fourteen days after inoculation. The corral 

 was not infective on the day following the death of the infected 

 animal. The results verify those of the two preceding exper- 

 iments. 



Experiment lU. — The blood of an animal during an attack 

 of rinderpest was shown to be capable of transmitting the dis- 

 ease at seven, nine, and eleven days after it had been injected 



