As long as the United States held control at Havana the yellow fever was kept in check by fighting the mosquitoes, when this vigilance was relaxed the fever began to appear again and the Cubans found that it was necessary to keep up the fight against the mosquitoes if the island was to be kept free from the disease.
In the summer of 1905 came another opportunity to put the knowledge gained during these experiments to a practical test. Samuel Hopkins Adams in his article in _McClure's Magazine_, June, 1906, says of the beginning of this fight:
"Eight years before, the mosquito-plague had infected the great, busy, joyous metropolis of the south. Ignorant of the real processes of the infection, New Orleans had fought it blindly, frantically, in an agony of panic, and when at last the frost put an end to the helpless city's plight, she lay spent and prostrate. The yellow fever of 1905 came with a more formidable and unexpected suddenness than that of 1897. It sprang into life like a secret and armed uprising in the midst of the city, full-fledged and terrible. But there arose against it the trained fighting line of scientific knowledge. Accepting, with a fine courage of faith that most important preventive discovery since vaccination, the mosquito dogma, the Crescent City marshaled her defenses. This time there was no panic, no mob-rule of terrified thousands, no mad rushing from stunned inertia to wildly impractical action; but instead the enlistment of the whole city in an army of sanitation. Every citizen became a soldier of the public health. And when, long before the plague-killing frost came, the battle was over, New Orleans had triumphed not only in the most brilliant hygienic victory ever achieved in America, but in a principle for which the whole nation owes her a debt of gratitude."
For some time the authorities had been trying to keep secret the fact that the disease was prevalent, but the rapidity with which it spread made them realize that only united action on the part of all the community would be of any avail. The Citizens Volunteer Ward Organizations were organized for the purpose of fighting the mosquitoes which were everywhere. To many the fight looked hopeless. The miles of open gutters, the thousands of cisterns and little pools of standing water everywhere furnished abundant breeding-places for the mosquitoes. The ditches and ponds were drained or salted, the cisterns were screened, infected houses were fumigated, yet the fever continued to spread. Rains refilled the ditches, winds tore the screens from the cisterns, the ignorant people of the French quarter refused to coöperate. At last the city in desperation appealed to the President for aid. Surgeon J.H. White and a number of officers and men of the United States Public Health and Marine Hospital Service soon took charge of the work. This was continued along the same lines as before with the same object in view. But with the coming of the regulars the work was more systematically and thoroughly done. Every case of fever was treated as though it was yellow fever and every precaution taken to prevent mosquitoes from biting such a patient. The houses in which the fever occurred were thoroughly fumigated to kill any mosquitoes that might be there, and the neighborhood was thoroughly searched to find any places where the mosquitoes might be breeding. So confident were the authorities that the mosquito was the sole cause of the disease spreading, that besides fighting it no other work was undertaken save to make the sick as comfortable as possible.