EXAMPLES OF MOSQUITO CONTROL. 
It is proposed in this section to describe briefly some of the most striking 
examples of successful warfare against mosquitoes that have been carried out 
since 1900 and bring them together into one consecutive account. Of many of 
them the details are not well known, on account of the inaccessibility of the 
documents of record. 
WORK IN HAVANA DURING THE AMERICAN OCCUPATION, 
1901-2. 
One of the most striking examples of clean, efficient anti-mosquito work is 
that done by the American troops in Havana at the close of the Spanish War, 
under the direction of the Army Medical Corps, and under the especial direction 
of Col. W. C. Gorgas, U.S. A. In the statements which follow, Colonel Gorgas’s 
published writings have been freely used. 
Yellow fever had been endemic in Havana for more than 150 years, and 
Havana was the usual source of infection for the southern United States. By 
ordinary sanitary measures, improved drainage and similar means, the death 
rate of the city was reduced from 100 per thousand in 1898 to 22 per thousand 
in 1902. But these measures had no effect upon yellow fever, this disease in- 
creasing as the non-immune population increased, and in fact in 1900 there was 
a severe epidemic. 
Aédes calopus was proved to be the carrier of yellow fever early in 1901, and 
then anti-mosquito measures were immediately begun. Against adult mos- 
quitoes no general measures were attempted, although screening and fumiga- 
tion were carried out in quarters that were or had been occupied by yellow-fever 
patients. It was found that calopus bred principally in the rain-water collec- 
tions in the city itself; that Culex quinquefasciatus bred everywhere, and that 
Anopheles albimanus bred principally in the suburbs in pools and puddles well 
protected by grass. Two mosquito brigades were started: one to take care of 
calopus, and the other of Anopheles. 
The work of the so-called “ stegomyia brigade” was confined to the built-up 
portions of the city. The city was divided into about thirty districts, and to 
each district an inspector and two laborers were assigned, each district contain- 
ing about a thousand houses. The mayor of Havana issued an order requiring 
all collections of water to be so covered that mosquitoes could not have access, 
a fine being imposed in case the order was not obeyed. The water supply of 
Havana was very hard, and it was customary for every family to collect rain- 
water in barrels. As the majority of the people in the large tenement houses 
were poor, and as each family had a rain-barrel, the Health Department covered 
these barrels at public expense, leaving a small screen opening through which the 
water could enter and placing a spigot at the bottom through which it could be 
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