﻿ETIOLOGY OF DENGUE FEVER. 127 



much congested and the face is flushed. Has slight frontal headache, and is very 

 nervous. He complains of palpitation of the heart. Tongue moist and clean. 

 Appetite poor. 



September 5: Is feeling very nervous this morning and was delirious last 

 night. Has pain in head, back, arms and legs. No appetite. Tongue moist, with 

 heavy, yellowish coating. Bowels loose. 



September 6 : Spent a restless night, but is not so nervous this morning. 

 Complains of severe pain in the back and legs. Tongue moist, with yellowish 

 coating. There is a faint, slightly elevated, sparse, macular eruption over the 

 chest and back. 



September 7 : Patient had a comfortable night and this morning has but little 

 pain. The eruption is well marked over the abdomen, chest, back and arms. 



September 8 : Feeling very comfortable. The eruption is fading a little. 

 Bowels constipated. Appetite good. 



September 9 : Was delirious during the early morning hours and is nervous 

 and restless this morning, but free from pain. The eruption has largely disap- 

 peared. 



September 10: Began to feel better at 4 p. m. yesterday arid now feels quite 

 well. Slept well, but perspired very freely during the night. The eruption has 

 almost disappeared from the body, but is marked upon the forearms and wrists. 



September 11: Feeling well. Eruption is fading slowly and very slight de- 

 squamation is present in patches. 



September 13: Feeling well, except that appetite is still poor. The eruption 

 lias almost disappeared. 



September 15: Returned to duty. 



Remarks. — The symptoms in this case were very severe, especially those con- 

 nected with the nervous system. The subject of the experiment was of a highly 

 nervous temperament, and this fact accounts, in our opinion, for the severity of 

 the nervous symptoms. 



The temperature curve in this case might be used as an illustration of an ideal 

 dengue curve, so perfectly does it agree with the type described by every observer 

 as characteristic of this disease. It should be noted, however, that the tempera- 

 ture is higher in this case than it usually is in naturally acquired dengue, or in 

 our other experimental cases, with the exception of Case 9, also produced by the 

 intravenous inoculation of filtered blood. 



The eruption in this case appeared on the fourth day of the disease, and had 

 disappeared on the third day following the crisis, lasting in all ten days. 



We regard these two cases of dengue produced by the intravenous injec- 

 tion of filtered dengue blood as the most typical cases of the severe type 

 of the disease which we have observed and we believe that these two ex- 

 periments prove conclusively that dengue can be transmitted by blood 

 which has been passed through a filter which retains organisms as small 

 as 0.4 ju in diameter (the measurement of M. melitensis) . It also proves 

 that in all probability the causative agent is ultramicroscopie in size, 

 for the reason that neither in fresh nor stained blood smears nor in the 

 filtrate obtained from dengue blood, can any organism be demonstrated 

 with the microscope. It may be possible that in some other fluid or 

 organ of the body, or in some phase of its life history in an insect, the 

 organism may be visible, for Novy, in his work upon T. lewisi, has proved 

 that even so large a parasite as this trypanosoma may exist in a form so 



