﻿IX, B, 1 Ward et al.: Transmission of Rinderpest 73 



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INFECTIVENESS OF ANIMALS AFTER RECOVERY 



Experiment 26. — The question of whether or not apparently 

 recovered animals continue to spread infection afterward, like 

 "bacillus carriers," is highly important in connection with com- 

 bating the disease. The assembling of 58 head of cattle that 

 had been infected with rinderpest for a period varying from 

 three weeks to three months previously gave opportunity to 

 test the matter. Three susceptible bulls, 2998, 3053, and 3065, 

 were placed among them at pasture on May 16, 1911, and 

 removed June 9, after an interval of twenty-five days. They 

 did not contract rinderpest, but later their susceptibility was 

 proved by attack with rinderpest after suitable exposure. 



It is concluded that apparently recovered animals capable of 

 spreading rinderpest by natural exposure were not present 

 among the 58 head tested. 



GENERAL RESULTS BY EXPERIMENTS 



Experiment 1 . — A corral which had contained many cattle and 

 carabaos infected with rinderpest during the preceding three 

 months and also three sick animals during the fifteen days 

 preceding the removal of the sick did not prove infective to 

 susceptible animals placed therein twenty-four hours after the 

 removal of the infected animals. The corral was bare of vege- 

 tation, was but scantily shaded, and contained a carabao wallow. 

 The weather was generally clear. Six different susceptible 

 animals were used to test the infectivity of the corral at various 

 intervals varying from one to fourteen days after the sick were 

 removed, and they each were kept in the corral for periods vary- 

 ing from one to four days. 



Experiment 2. — There was employed a corral well shaded by a 

 tree, but containing little or no vegetation. Infected animals 

 had been in the area for nineteen days before all were removed. 

 Four susceptible animals were employed to test the infectivenesa 

 of the corral, with negative results. Intervals of from one to 

 eleven days elapsed after the removal of the sick before admitting 

 the test animals, which were kept therein. The weather was 

 generally clear with little rain. 



Experiment 3. — The same corral, as in the preceding exper- 

 iment, was employed, but the weather was cloudy and rainy. 

 Four susceptible animals failed to contract rinderpest after in- 

 tervals of one and two days, after the removal of the sick ones. 

 They were left in the corral for periods of three and four days. 



Experiment 4. — In this case the corral used in the first exper- 



