﻿ETIOLOGY OF DENGUE FEVER. 145 



scarlatinal or rubeoloid type, influenza does not. Leucopenia and lym- 

 phocytosis point more strongly to dengue. 



Scarlatina.- — The occurrence or nature of the epidemic, the seasonal 

 occurrence, the almost entire absence of sore throat and cervical glandular 

 swelling, the age of the patient, the less marked toxic symptoms, the 

 temperature chart, the leucocyte count ami the usually slight desquama- 

 tion, will in nearly all instances set dengue apart from scarlatina. 



Measles. — The more sudden onset of dengue, the greater pain, the 

 absence of coryza, the appearance of the temperature chart, the epidemic 

 and its season, usually makes this differentiation easy. 



.Syphilis. — Confusion with syphilis will occur but rarely, and only 

 in individual cases. In such cases the history, the chart, the usually 

 less violent onset of symptoms, the examination for chancre, mucous 

 patches, etc., will practically always enable one to make a diagnosis. 



Tonsilitis. — The onset of acute, follicular tonsilitis is at times, in its 

 suddenness, its painfulness and fever, much like that of dengue. The 

 examination of the throat is usually sufficient for the making of a correct 

 diagnosis. 



Rheumatic fever. — Acute articular rheumatism is at times, but un- 

 usually, simulated by dengue. In the latter disease the joint involve- 

 ment, when present, is less marked and more ephemeral, while the other 

 dengue symptoms, especially the eruption, make the diagnosis clear. 



Small pox. — The sudden onset, the flushed face, the violent pain in the 

 head and back, the high temperature, make the early stages of smallpox 

 resemble those of dengue, and it is probable that smallpox developing 

 during dengue epidemics will often be mistaken for it. The history of 

 exposure to smallpox, the absence or great age of vaccination scars, would 

 point to that disease, while the evolution of the pocks would soon'put the 

 case beyond the realm of doubt. 



Meningitis. — Some of the cases of the "meningeal" type of dengue, as 

 described by other writers, can probably only be differentiated from 

 epidemic cerebro-spinal meningitis by the presence of the dengue epidemic 

 and the result of the bacteriological examinations of the fluid obtained by 

 spinal puncdnre. 



VI. TREATMENT. 



Prophylaxis. — We believe that our observations and the total failure 

 of all our attempts to transmit the disease by fomites or contact indicate 

 the character of the prophylactic measures. Protection from mosquitoes 

 is probably all that is necessary, but there is the posibility that other 

 transmission of infected blood may rarely occur, as for example through 

 other insects, infected hypodermic needles, and in a few other possible but 

 improbable ways. We believe that in the case of the military service the 

 screening of barracks would prevent such epidemics as the one which oc- 

 curred at Fort William McKinley, and it would appear that economy 



