24 LOSS THROUGH INSECTS THAT CARRY DISEASE. 



flies coming- from the excreta of t3q)hoid patients. The prevalence of 

 typhoid fcA'er in the concentration camps of the United States Army 

 in the summer of 1898 brought about tlie appointment of an army 

 typhoid commission consisting of Drs. Walter Heed, U. S. Army, 

 Victor M. Vaughan, U. S. Volunteers, and E. O. Shakespeare, U. S. 

 Volunteers. A paper read by Doctor Vaughan before the annual 

 meeting of the American Medical Association at Atlantic City, N. J., 

 June 6, 1900, contained the following conclusions with regard to 

 flies: 



" 27. Flies undoubtedly served as carriers of the infection. 



" My reasons for believing that flies were active in the dissemina- 

 tion of typhoid may be stated as follows : 



" a. Flies swarmed over infected fecal matter in the pits and then 

 visited and fed upon the food prepared for the soldiers at the mess 

 tents. In some instances where lime had recently been sprinkled 

 over the contents of the pits, flies with their feet whitened with lime 

 were seen w-alking over the food. 



'■' 1). Officers whose mess tents were protected by means of screens 

 suffered proportionately less from typhoid fever than did those 

 whose tents were not so protected. 



" c. Typhoid fever gradually disappeared in the fall of 1898, with 

 the approach of cold weather, and the consequent disabling of the fly. 



" It is possible for the fly to carry the typhoid bacillus in tAvo 

 ways. In the first place, fecal matter containing the typhoid germ 

 may adhere to the fly and be mechanically transported. In the 

 second place, it is possible that the typhoid bacillus may be carried 

 in the digestive organs of the fly and may be deposited w'ith its 

 excrement." 



There were also many important conclusions which bear upon the 

 fly question. For example, it was shown that every regiment in the 

 United States service in 1898 developed typhoid fever, nearly all of 

 them within eight weeks after assembling in camps. It not only 

 appeared in every regiment in the service, but it became epidemic 

 both in small encampments of not more than one regiment and in the 

 larger ones consisting of one or more corps. All encampments 

 located in the Northern as well as in the Southern States exhibited 

 typhoid in epidemic form. The miasmatic theory of the origin of 

 typhoid fever and the pythogenic theory « were not supported by 

 the investigations of the commission, but the doctrine of the specific 



° This tbeory is founded upon the belief that the colon germ may undergo a 

 ripening process by means of which its virulence is so increased and altered 

 that it may be converted into the typhoid bacillus or at least may become the 

 active agent in the causation of tyi^hoid fever. 



