Mosquitoes and Yellow Fever 577 



They were entirely unable to confirm the findings of Wasdin 

 and Geddings,* that Bacillus icteroides was present in blood 

 obtained from the ear in 13 out of 14 cases, and concluded 

 that both Sanarelli and Wasden and Geddings were mistaken 

 in their deductions. 



In lieu of the remarkably interesting discoveries of Ronald 

 Ross concerning the relation of the mosquito to malarial in- 

 fection, the commissioners, remembering the theory of 

 Finlay,t who in 1881 published an experimental research 

 showing that mosquitoes spread the infection of yellow fever, 

 and the interesting and valuable observations of Carter J 

 upon the interval between infecting and secondary cases of 

 yellow fever, turned their attention to the mosquito. Secur- 

 ing mosquitoes from Finlay and continuing the work where 

 he had left it, they found that when mosquitoes (Stegomyia 

 fasciata sen calopus} were permitted to bite patients suffering 

 from yellow fever, after an interval of about twelve days 

 they became able to impart yellow fever with their bites. 

 This infectious character of the bite, having once developed, 

 seems to remain throughout the subsequent life of the 

 insect. So far as it was possible to determine, only one 

 species of mosquito, Stegomyia calopus, served as a host 

 for the parasite whose cycles of development in the mosquito 

 and in man must explain the symptomatology of yellow 

 fever. 



In order to establish these observations, experimental 

 inoculations were made upon human beings in sufficient 

 number to prove their accuracy. Unfortunately, Dr. 

 Lazear, one of the victims of the experiment, lost his life 

 from an attack of yellow fever. 



Reed, Carroll, and Agramonte came to the following 

 conclusions : 



1 . The mosquito C. fasciatus (Stegomyia calopus) serves 

 as the intermediate host of the yellow fever parasite. 



2. Yellow fever is transmitted to the non-immune indi- 

 vidual by means of the bite of the mosquito that has pre- 

 viously fed on the blood of those sick with the disease. 



* " Report of the Commission of Medical Officers Detailed by the 

 Authority of the President to Investigate the Cause of Yellow Fever," 

 Washington, D. C., 1899. 



f "Annales de la Real Academia," vol. xvm, 1881, pp. 147-169. 



t "New Orleans Med. Jour.," May, 1900. 



\ Pan-American Medical Congress, Havana, Cuba, Feb. 4-7, 1901; 

 Sanitary Department, Cuba, series 3, 1902. 



37 



