﻿116 ASHBURN AND CRAIG. 



INOCULATION EXPERIMENTS. 



Having thus failed to demonstrate any organism in either fresh or 

 stained specimens of blood or in our blood cultures, we directed our 

 attention to the possibility of producing the disease by the inoculation of 

 blood from the dengue patient into the healthy man; fortunately for 

 the success of our work we were dealing with a disease which, in the young 

 and robust, is not dangerous to life, and for this reason we felt justified 

 in making such experiments. We hoped in this way to determine the 

 presence or absence of the infective agent in the blood, for should such 

 experiments prove successful they would demonstrate that the cause of 

 the disease is in the blood, and that therefore, insect transmission, 

 is possible, whereas negative results would prove that the blood does 

 not contain the organism unless it be one that first has to undergo a 

 developmental cycle outside of the body, as in an insect, before it can 

 produce the disease in man. 



In order to secure subjects for experiment a call for volunteers was 

 issued to members of the Hospital Corps serving at the United States 

 Army Division Hospital, and four men volunteered, in all of whom 

 we succeeded in producing dengue by the intravenous inoculation of 

 blood from cases of the disease. "We desire to express our admiration of 

 the courage and devotion to duty of these men, who. with no prospect of 

 pecuniary reward, cheerfully placed themselves in our hands for experi- 

 mentation. 



As more men -were needed and as no more Hospital Corps men were 

 available, we consulted Major General Leonard Wood, United States 

 Army, commanding the Philippines Division, who authorized us to offer a 

 reward for volunteering, as a result of which we secured many more 

 volunteers than we needed and were forced to refuse a large number, as 

 we were limited to sixteen, including the men we had already used. 

 Unfortunately, of the fourteen men we have experimented upon, seven 

 came from Fort "William McUinley having passed unharmed through the 

 dengue epidemic. 'and of these men we found two absolutely immune, 

 three relatively immune, and one doubtful. Of the same number of 

 Hospital Corps men who had not been exposed to dengue, we found 

 only one immune. 



Of the fourteen soldiers who volunteered for this work, seven be- 

 longed to the United States Army Hospital Corps, three to the Eighth 

 United States Calvary, two to the Sixteenth United States Infantry, one 

 to the Thirteenth United States Infantry, and one to Company B., 

 Engineer Corps. 



