YELLOW FEVER - INSTITUTE. 



Treasury Department, Bureau of Public Health and Marine-Hospital Service. 

 WALTER Wl'MAN, Surgeon-General. 



Bulletin No. 11. 



Section C— TRANSMISSION, Asst. Surg. Gen. J. H. WHITE, Chairman of Section. 



VESSELS AS CARRIERS OF MOSQUITOES. 



By S. B. Gbubbs, 

 Pasted Assistant Surgeon, United Stales Public Health and Marine-Hospital Service. 



At the present time, when evidence is pointing with more and more 

 clearness to the mosquito as the sole means of transmitting yellow 

 fever, nothing is of greater interest to the quarantine officer than to 

 decide to what extent and under what circumstances these infecting 

 insects may be carried by vessels. 



This subject may be approached in three different ways: First, by 

 observations on the length of time after leaving infected ports vessels 

 may develop yellow fever; second, by experiments with mosquitoes 

 under artificial conditions made to simulate as much as possible those 

 of nature; and third, by actual observation of vessels arriving from 

 ports at the time infected or where the presence of the Stegomyia 

 fasciata render them liable to infection. 



While it will require data obtained by all these means and extend- 

 ing over a long period to arrive at any conclusions sufficiently accurate 

 to allow them to influence quarantine procedure, still I believe the 

 last method of observation cited will throw more light on the subject 

 than the first two. 



It is for this reason that every vessel arriving at Gulf Quarantine 

 Station from Stegomyia-infected ports has, since the 1st of J^ily last, 

 been carefully examined to ascertain if mosquitoes were present on 

 board, and, if present, their variety, where and when they came 

 aboard, and under what conditions. 



Gulf Quarantine Station is an especially good point for these 

 observations, from the fact that it is 10 miles from the mainland, and 

 because vessels bound here do not pass near land, and so but rarely 

 take on mosquitoes en route, and even these, as will be seen, are 



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