DENGUE IN INDO-CHINA. 25 



The epidemics of 1895 and 1896 raged principally at Saigon. According to 

 Nogue, who has described them, they spread thence over all Indo-China. The 

 Loire, the Pourvoyens, and the Baiomette, war ships of the navy, and the mail 

 boats of the "Messageries Maritimes" which were anchored in the Saigon River, 

 were affected. The Adoiir of the French navy was at that time visited by dengue 

 in Tonkin. The epidemic prevailed among the civil as well as the military popu- 

 lation of Saigon. The writer does not give us the figures, but it seems that 

 it extended over a considerable part of the town. He has published nine observa- 

 tions in detail, those of 5 sailors, 3 soldiers of the '"infantei'ie de marine," and 1 

 civilian. Four cases were fatal. The post-mortem examinations were only par- 

 tially made in 2 cases, but completely in 2 other. Among the most characteristic 

 symptoms must be noted a high fever during five to six days with two paroxysms. 

 There were also cephalgia periorbital pains, rachialgia, muscular and articiilar 

 pains, a coated tongue, and constipation. The recovery was rapid. Pulmonary 

 complications were not rare. Nogue found them in the post-mortem examinations ; 

 these were the only lesions which were mentioned. However, twice it seemed he 

 found a slight inflammation of the meninges. 



There is no doubt that Nogue describes true dengue. His examinations of 

 blood were always negative and quinine had no effect. The epidemic broke out 

 in the Saigon River and chiefly affected those people recently arrived from 

 France. Seven out of 8 officers of the Pourvoyens, who had landed a week 

 before, contracted the disease and entered the hospital on the same day. Nogue 

 tliinks that the dengue is endemic in Saigon; he connects these epidemics of 

 1895-6 with those of 1866, desci'ibed by M. d'Armay, the head of the medical 

 service in Cochin-China. It is not possible to find out from the memoir of 

 Nogue, if the Annamese really had the dengue. At any rate he does not 

 mention any cases among natives in Saigon or on the warships, but the 

 administi-ator's reports speak at the same time of a disease in the interior, 

 wliich was endemic, but which does not seem to be dengue. 



ETIOLOGY. 



The majority of writers on dengue have remarked for some time that 

 it is propagated only in countries where mosquitoes abound. 



Graham, who studied an epidemic in Beyrouth in 1901, was able to specify 

 the role of mosquitoes in the dissemination of the infection. 



Ashburn and Craig, in the Philippines, lately have given decisive arguments. 

 They have shown that the blood contains the infectious germ, and that intra- 

 venous inoculation of the blood of a patient into a healthy man reproduces the 

 illness after an incubation period of from two and one-half to seven days. 

 They have even succeeded in transmitting dengue fever by mosquito bites [Cidex 

 fatigan^ Wied.). The epidemiologic "facts favorable to the transmission of the 

 disease by mosquitoes abound throughout the memoir. 



E. R. Stitt also writing of the Philippines said that an epidemic affected 

 all the patients of the Cavite Hospital, full of mosquitoes, while it did not 

 spread in the Cauacao Hospital near by where tliere were no mosquitoes. The 

 Baltimore sent part of its crew to Cavite; 20 out of 24 men caught the disease, 

 while tliere was not a single case on board. 



Our own observations argue in the same sense. During all the epi- 

 demics in Indo-China, the abundance of mosquitoes lias been commented 

 upon. 



