20 LOSS THROUGH INSECTS THAT CARRY DISEASE. 



of Havana, undertaken under the direction of Gorgas, with startling 

 residts. 



Yellow fever had been endemic in Havana for more than one hun- 

 dred and fifty years, and Havana was the principal source of infec- 

 tion for the rest of Cuba. Other towns in Cuba could have rid 

 themselves of the disease if the}'' had not been constantly reinfected 

 from Havana. By ordinary sanitary measures of cleanliness, im- 

 proved drainage, and similar means the death rate of the city w^as 

 reduced, from 1898 to 1900, from 100 per thousand to 22 per thou- 

 sand; but these measures had no effect upon yellow fever, this d"sease 

 increasing as the nonimmune population following the Spanish war 

 increased, and in 1900 there w^as :i severe epidemic. 



Stegomyia calojms was established as the carrier of the fever 

 early in 1901, and then antimosquito measures Avere immediately 

 begun. Against adult mosquitoes no general measures were attempted, 

 although screening and fumigation were carried out in quarters 

 occupied by yellow-fever patients or that had been occupied by 

 yellow-fever patients. It was found that the Stegomyia bred prin- 

 cipally in the rain-water collections in the city itself. The city was 

 divided into about 80 districts, and to each district an inspector and 

 two laborers were assigned, each district containing about a thousand 

 houses. An order was issued by the mayor of Havana requiring all 

 collections of water to be so covered that mosquitoes could not have 

 access, a fine being imposed in cases where the order was not obeyed. 

 The health department covered the rain-water barrels of poor fami- 

 lies at public expense. All cesspools were treated with petroleum. 

 All receptacles containing fresh water which did not comply with the 

 law were emptied and on the second otfense destroyed. The result of 

 this work thoroughly done was to wipe out yellow fever in Havana, 

 and there has not been a certain endemic case since that time. 



In what is termed the New Orleans epidemic of 1905 a striking 

 illustration of the value of this recently acquired mosquito-transmis- 

 sion knowledge is seen. The presence of yellow^ fever in the city was 

 first recognized about the 1st of July, but it was the 12th of August 

 before the Public Health and Marine-Hospital Service was put in 

 complete control of the situation. By that time the increase in new 

 cases and deaths rendered it practically certain that the disease w^as 

 as widespread as during the terrible epidemic of 1878. There had 

 been up to that date 142 deaths from a total of 913 cases, as against 

 152 deaths from a total of 519 cases in 1878. The Public Health and 

 Marine-Hospital Service, under Doctor White, took hold of the situa- 

 tion with energy, basing its measures almost entirely upon a warfare 

 against Stegomyia calopiis. The disease began almost immediately 

 to abate, and the result at the close of the season indicated 4G0 deaths, 

 as against 4,046 in 1878, a virtual saving of over 3,500 lives. The 



