20 LOSS THROUGH [NSECTS THAT CABRY DISEASE. 
of Havana, undertaken under the direction of Gorgas, with startling 
results. 
Yellow fever had been endemic in Havana for more than one hun- 
dred and fifty year-, 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 they had not been constantly reinfected 
from Havana. By ordinary sanitary measures of cleanliness, im- 
proved drainage, and similar mean- the death rate of the city was 
reduced, from 1898 to 1900. from 100 per thousand to 22 per thou- 
sand; but these measures had no effect upon yellow fever, this disease 
increasing as the nonimmune population following the Spanish war 
increased, and in 1900 there was a severe epidemic. 
Stegomyia calopus was established as the carrier of the fever 
early in 1901. and then antimosquito measures were 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 30 districts, and to each district an inspector and 
two laborers were assigned, each district containing about a thousand 
house-. 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 offense 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 Xew 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 was 
as widespread as during the terrible epidemic of 1 S 7 S . There had 
been up to that date 1 L2 death- from a total of 913 cases, as against 
L52 deaths from a total of 519 cases in L878. 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 calopus. The disease began almost immediately 
to abate, and the result at the close of the season indicated !<><> death-. 
as against 4.040 in 1878, a virtual saving of over .°>..~>00 lives. The 
