﻿ETIOLOGY OF DENGUE FEVER. 



101 



Table showing the strength of each company, the number of cases of dengue fever, and the 

 percentage infected in the Eighth Cavalry. 



Name of organization. 



Eighth U. S. Cavalry. 



Strength. 



No. of 

 cases. 



Percent- 

 age 

 infected. 



Band _. 

 Troop A 

 Troop B 

 Troop D 

 Troop E 

 Troop F 

 Troop H 



7 

 32 

 20 

 28 

 16 

 .52 



5 



From the above tables it will be seen that the greatest ratio of infec- 

 tions in any one company was in Company H of the Thirteenth Infantry 

 where 58 per cent of the men were infected, while in Company E of 

 the Sixteenth Infantry only one man was infected, but this company left 

 the post during the early days of the epidemic and thus can not be 

 considered in this relation. It should also be remembered that Com- 

 panies A, B, C, D of the Thirteenth and E, E, G-, H of the Sixteenth 

 were absent from the post after August 12, 1906. 



In considering this table it will be noticed that the epidemic of 

 dengue began in the Sixteenth Infantry upon July 1, reached the 

 Thirteenth Infantry July 7, and the Eighth Cavalry not until July 29. 

 It should be stated that the barracks of the Eighth Cavalry are at 

 a considerable distance, at least 1 mile, from those of the Sixteenth 

 Infantry, which, if we consider the disease to be mosquito-borne, will 

 account for the long period of time elapsing between the infection of 

 the two organizations. 



On August 1, 1906, the First Battalion of the Thirteenth Infantry 

 and the Second Battalion of the Sixteenth were ordered for field service 

 in Leyte, P. I., and were still absent on this duty on November 1, 1906. 

 At the time the First Battalion of the Thirteenth Infantry left Fort 

 McKinley, 58 men had been sent to the post hospital suffering from 

 dengue. No cases developed in this battalion on its voyage by boat to 

 Leyte, nor have any cases developed in the battalion in Leyte. If dengue 

 were a contagious disease this certainly would not have been the case, 

 but removal from the focus of infection and from the disseminator of 

 the infection — that is, the mosquito — resulted in a complete disappearance 

 of dengue from this battalion. 



At the time the Second Battalion of the Sixteenth Infantry left 

 Fort McKinley, on August 12, dengue had just appeared, this battalion 



