[29] "Sanitation in the Canal Zone."
The total deaths among employees of the Commission from yellow fever during the 12 months October 1, 1904, to September 30, 1905, was 37, among about 17,000.[30] The total from yellow fever among the whole population, including Canal employees, during the four months May 1 to August 31, 1905, was 47, while the number of deaths from malaria during the same period was 108. The effect of malaria in impairing physical efficiency was even more in excess than these figures indicate, for the fatal cases are a small proportion of the whole in malaria, and a very large proportion in yellow fever. The moral effect of the imminence of the more sudden and fatal form of disease was, however, as these reports show, much the greater, and it was this moral effect which caused the crisis above described.
[30] In 1883-84 the French Company lost by yellow fever 66 men out of about the same number of employees.
Previous to February, 1905, the Department of Sanitation had done little to improve the hygienic conditions of Colon and Panama, chiefly owing to the opinion until then maintained by the legal advisers that there was no authority to expend money in those cities, which are not within the Canal Zone.
In April the yellow fever broke out; the number of men employed by the Department of Sanitation was increased to the huge total of 4,100, and the battle with yellow fever began in earnest. All cases were either transported to screened buildings, or, if left in their own homes, these were carefully screened with fine-meshed copper gauze. The object of this isolation was to prevent the patient from infecting healthy stegomyia mosquitoes.
Every dwelling in Colon and Panama was thoroughly fumigated with pyrethrum powder or with sulphur, and then cleared of dust and refuse, which, with the insensible but not always dead mosquitoes, was then burnt. The complete, and, it is hoped, final freedom from yellow fever in Colon and Panama has been obtained by means of a proper water supply and universal paving with brick or cement, as well as the supply of proper drainage. Formerly water for domestic use was stored in cisterns, tanks, tubs, jars, and so forth, and, after rain, water stood stagnantly in a thousand ruts and holes in the unpaved squares, streets, and lanes. These breeding-places of the stegomyia have now been done away with completely in Panama, and almost completely in Colon. The latter city is so low-lying and flat, and subject to such heavy rainfall, that pools of stagnant water will form. They can, however, be oiled, which kills the larvæ, and, moreover, it is Panama, and not the wind-swept, salt-saturated, town of Colon, which has been the chief source of yellow fever.
The last case of the disease in Panama occurred in November, 1905, and in May, 1906, there was an isolated case in Colon. The infection is considered to be at an end in a city three months after the last case, that being the lifetime of stegomyia. After this period, all infected stegomyia having died, those that remain are powerless for harm. Nevertheless, the stringent measures for their destruction are not relaxed, as, while stegomyia exists, the germ, if re-introduced, will be rapidly disseminated.
Thus the yellow fever, having taken toll for four hundred years of those who crossed the Isthmus, has been completely eradicated by. Colonel Gorgas and his assistants. It is a triumph of science and of despotic government combined; and only in this combination can preventive medicine achieve full success.
There is one other aspect of the yellow fever campaign which must be mentioned before going on to describe the fight with malaria.