728 INFECTION AND IMMUNITY. 



V. DENGUE FEVEIl. 



Dengue occurs in numerous countries which af- 

 ford a warm climate. It is endemic in Egypt, 

 Arabia, Senegambia, Honduras, the Bermudas, 

 and the Sandwich Islands. Important centers for 

 the origin of epidemics are the lesser Antilles of 

 the Western Hemisphere, the Red Sea Coast, 

 and Senegambia (de Brun, cited by Scheube). It 

 occurs in our southern states and In Mexico. It 

 may be introduced into new regions by means of 

 infected ships. 



"Dengue fever is an acute infectious disease, 

 distinguished by the appearance of an initial and 

 terminal polymorphous eruption and accompanied 

 by severe articular and muscular pains." Corre- 

 sponding with the two eruptions, there are charac- 

 teristically two periods of temperature separated 

 by a short period of apyrexia. The intense muscu- 

 lar pains and asthenia resemble those of influenza, 

 the respiratory affections of the latter being absent, 

 however. The incubation period varies from a few 

 hours to four or five days, usually one or two, and 

 the entire duration from six to seven days. 



Eberle, in 1904, advanced the hypothesis that 

 clengue is transmitted by a mosquito (Culex fati- 

 gans). He described a "plasmeba" in the blood 

 of patients with the disease. Other observers have 

 failed to find protozoa in the blood. Ashburn and 

 Craig (1907) were able to transmit the disease to 

 healthy men by injecting the blood of infected 

 individuals. They were able to produce the dis- 

 ease by allowing mosquitoes, which had fed on 

 dengue patients, to bite healthy men. Their 

 studies also showed that the distribution of the 

 Culex fatagans corresponded with that of dengue. 



