HISTORY 



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1897-98 it was epidemic in Georgia, Florida, and Texas. In 1901 

 it occurred in Penang and Asia Minor; in 1902 in Hong Kong, 

 Singapore, Madras, Rangoon, and Upper Burma. In 1906 it 

 occurred in Saigong on a Frencli warship, and recently it has been 

 prevalent in Singapore, West Australia, and Ceylon. Manson says 

 that an epidemic or pandemic takes place about once in twenty years. 



The discovery of the disease, therefore, appears to have been 

 first made by Pazzio and Bylon, and the first full clinical description 

 given by Dickson in 1828. 



The first attempt to find a causation for the disease was by 

 McLaughlin in 1886, who found micrococci in the blood, but this 

 was disproved by Klein, Wright, Crookshank, and Macfadyen. In 

 1903 Graham stated that he had observed small hyaline, unstainable 

 rods or dots in the red blood-corpuscles, which he considered to be 

 protozoal parasites of the nature of Plasmodia. This discovery 

 has been refuted by Carpenter and Sutton, Guiteras, Agramonte, 

 Kiewiet de Jonge and Hahn, Still and Ashburn, and Craig. Graham 

 fed Culex fatigans Wiedemann on patients suffering from dengue, 

 and claimed to have found his parasites in these mosquitoes up to 

 the fifth day after feeding. He did not find any ookinetes or 

 oocysts, but he says he found spores in the cells of the salivary 

 glands of the mosquitoes from forty-eight hours to one month 

 after they had fed on infected blood. Further, he states that he 

 caused a typical attack of dengue by injecting subcutaneously a 

 solution, in normal saline, of the salivary glands of a mosquito 

 which had bitten a dengue fever patient twenty-four hours pre- 

 viously. He only performed one experiment, because the illness 

 caused was very severe, but he succeeded, after an incubation of 

 four to six days, in infecting healthy people by the bites of mos- 

 quitoes [Culex fatigans) fed on dengue fever patients. 



Though Ashburn 3,nd Craig (in 1907) have not supported Graham 

 by finding the parasite, they have supported him by proving that 

 a typical attack of dengue can be produced by the intravenous 

 inoculation of filtered and unfiltered blood from an infected patient, 

 and that the disease can be, and usually is, transmitted by the bite 

 of Culex fatigans Wiedemann. 



In 1912 and 1913 Laloir drew attention to Stegomyia calopus as 

 the carrier of dengue. Cleland, Bradley, and McDonald demon- 

 strated that the virus of dengue fever was carried by Stegomyia 

 calopus, in which it underwent development Archibald found that 

 the same insect was the only possible carrier in certain parts of 

 the Sudan. These observations support Legendre's earlier views 

 with reference to Hanoi. The leucocytic formula has been carefully 

 studied by Ashburn and Craig and by Archibald. 



Climatology. — ^The history of the disease indicates roughly its 

 geography, which lies mostly in the tropics, but can extend to 

 the subtropcal zones. Cases have been reported from Southern 

 Europe. Its usual boundaries are 32° 47' N. and 23° 23' S., but 

 during warm weather it may spread to 36° 10' N., and even to 



