MOSQUITOES AND YELLOW FEVER. • 17 



against other ciilicids, and comprised the drainage of a large swamp 

 and the other usual measures. The initial expense amounted to 

 50,000 francs ($9,650), and the annual expenses since have amounted 

 to about 18,300 francs ($3,532). 



The results may be summarized about as follows: Since the be- 

 ginning of 1903 the ordinary mosquitoes have disappeared from 

 Ismailia. Since the autumn of 1903 not a single larva of Anopheles 

 has been found in the protected zone, which extends to the west for 

 a distance of 1,000 meters from the first houses in the Arabian 

 quarter and to the east for a distance of 1,800 meters from the first 

 houses in the European quarter. After 1902 malarial fever obviously 

 began to decrease, and since 1903 not a single new case of malaria 

 has been found in Ismailia. 



A very efficient piece of antimalarial work was accomplished in 

 Havana during the American occupation of 1901 to 1902, incidental 

 in a way to the work against j'ellow fever. An Anopheles brigade 

 of workmen was organized under the sanitary officer, Doctor Gorgas, 

 for work along the small streams, irrigated gardens, and similar 

 jDlaces in the suburbs, and numbered from 50 to 300 men. No exten- 

 sive drainage, such as would require engineering skill, was attempted, 

 and the natural streams and gutters were simply cleared of obstruc- 

 tions and grass, while superficial ditches were made through the irri- 

 gated meadows. Among the suburban truck gardens Anopheles bred 

 everywhere, in the little puddles of water, cow tracks, horse tracks, 

 and similar depressions in grassy ground. Little or no oil was used 

 by the Anopheles brigade, since it was found in practice a simple 

 matter to drain these places. At the end of the year it was very diffi- 

 cult to find water containing mosquito larvse anywhere in the suburbs, 

 and the efi'ect upon malarial statistics was striking. In 1900, the 

 year before the beginning of the mosquito work, there were 325 

 deaths from malaria; in 1901, the first year of the mosquito work, 

 171 deaths; in 1902, the second year of mosquito work, 77 deaths^ 

 Since 1902 there has been a gradual though slower decrease, as fol- 

 lows : 1903, 51 ; 1901, 44 ; 1905, 32 ; 1906, 26 ; 1907, 23. These results, 

 although less striking than those from Ismailia, involved a smaller 

 expense in money and show surely an annual saving of 300 lives, and 

 undoubtedly a corresponding decrease in the number of malarial 

 cases, which may be estimated upon our earlier basis at something 

 less than 40,000. 



YELLOW FEVER. 



Yellow fever has prevailed endemically throughout the West In- 

 dies and in certain regions on the Spanish Main virtually since the 

 discovery of America. Barbados, Jamaica, and Cuba suffered 

 epidemics before the middle of the seventeenth century. There were 



70951— Bull. 7S— 09 3 



