20 LOSS THROUGH INSECTS THAT CARRY DISEASE. 
of Havana, undertaken under the direction of Gorgas, with startling 
result.-. 
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 means the death rate of the city was 
reduced, from 1898 to 1000, 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 attemp- 
ted, although screening and fumigation were carried out in quarters 
occupied b} r 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 
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 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 the Xew Orleans epidemic of 1905, a striking illustration of the 
valueof this recently acquired mosquito-transmission knowledge is seen. 
The presence of yellow fever in the cit}< was first recognized about the 
12th of July, and the plan of campaign adopted by the Board of Health 
under Dr. Quitman Kohnke, from the beginning was based on the 
mosquito conveyance of the disease. Available funds were rapidly 
exhausted, however, and on the 12th of August the Public Health and 
Marine-Hospital Service was put in charge of the situation and pro- 
vided with ample means. ¥>y that time the increase in the new cases 
and deaths rendered it practically certain that the disease was as wide- 
spread as during the terrible epidemic of 1878. There had been up to 
that time 1 12 deaths from a total of 913 cases, as against L52 deaths 
from a total of 519 cases in 1878. The work for the rest of the sum- 
mer was continued with great energy under Doctor White, and the 
measures Avere based almost entirely upon a warfare against the yel- 
low-fever mosquito. The disease began almost immediately to abate, 
and the result at the close of the season indicated 400 deaths, as 
against 4.04G in 1878, a virtual saving of over 3.500 lives. The 
