Apr. 8, 1918 



Sources of Hog-Cholera Infection 



103 



obtained on sterile cotton swabs, each swab being immediately rubbed 

 up in 10 c. c. of sterile salt solution. The feces were shaken up in sterile 

 salt solution, and the coarse particles were allowed to settle before 

 injecting; the rather thick suspension was filtered through gauze and 

 administered in doses of 10 c. c. The material was administered to the 

 susceptible pigs in each instance by subcutaneous inoculation. 



The results of this experiment are shown in detail in Table II. 

 . This experiment shows that the blood and urine were virulent on the 

 first day after injection, the feces on the second day, while the eye and 

 nose secretions were virulent on the third day. As the pig which furnished 

 the test materials did not develop fever until the fourth day and ex- 

 hibited no visible symptoms until the fifth day, the experiment shows 

 that the virus circulated in the body of the cholera-infected pig before 

 the onset of fever and before the development of any visible symptoms. 

 It is clear also that the virus was thrown oJBf in the excreta and secretions 

 during this time. 



Table II. — Results of Experiment I on infectiousness of blood, excreta, and secretions 



of infected pigs 



MATERIALS COLLECTED AND INJECTED ON OCTOBER 12, I916 (PIRST DAY) 



Material injected. 



Result. 



5 c. c. of tail blood Died October 28. Cholera lesions. 



.do. 



5 c. c. of eye-swab dilution ... 



....do 



5 c. c. of nose-swab dilution. . . 



....do 



5 c. c. of urine 



....do 



10 c. c. of fecal suspension 



....do 



Do. 



Remained well. 



Do. 



Do. 



Do. 

 Sick October 20-24. Recovered. 



Do. 

 Remained well. 



Do. 



MATERIALS COLLECTED AND INJECTED ON OCTOBER 13, I916 (SECOND DAY) 



5 c. c. of tail blood 



....do 



5 c. c. of eye-swab dilution. . . 



....do 



5 c. c. of nose-swab dilution. . 



....do 



5 c. c. of urine 



.do. 



15 c. c. of fecal suspension. 

 ....do 



Died October 30. Cholera lesions. 



Do. 

 Remained well. 

 Do. 

 Do. 

 Do. 

 Killed in moribund condition No- 

 vember 14. Cholera lesions. 

 Sick October 24 to November 17. 



Recovered. 

 Killed in moribund condition No- 

 vember 14. Cholera lesions. 

 Died November 12 . Cholera lesions. 



o These pigs were subsequently infected with virus blood to test their immunity and all developed typi- 

 cal hog cholera except 1038 and 1052. Pig 1038 suffered no ill effects from the virus infection and evidently 

 possessed a high degree of natural unmunity. Pig 1 052 showed a temperature reaction following the virus 

 injection but no visible symptoms. 



41812°— 18 3 



