66

Perhaps the most conspicuous triumph of men in this field is the conquest of smallpox. Two hundred years ago about one-tenth of our ancestors died of this disease and a pox upon you was one of the common curses. It is estimated that from 80 per cent to 90 per cent of the population had smallpox at some time during their lives and few faces even among the royal families were not pock-marked. In 1722 the town of Ware, England, contained 2,515 inhabitants of whom 1,601 had previously had smallpox. An epidemic came and only 302 were left untouched. In Iceland in 1707 some 18,000 or 60 per cent of the total population of 30,000 died in one epidemic. In 1752 Boston, England, had a population of 15,684 of whom 5,998 had survived an earlier attack. An epidemic came and some 5,545 contracted the disease, 2,124 were inoculated with it following a custom which had been developed in Turkey in the effort to overcome the disease. Deducting those who fled, only 174 remained who had not been sick. In Montreal in nine months of 1885 some 3,164 died in one epidemic. With the nineteenth century came vaccination with the virus of “cowpox" and the steady disappearance of the disease. The facts are clearly shown by the condition in the different countries. In the years 1893 to 1897 smallpox caused the deaths of some 275,502 in Russia, while in Germany only 274, thanks to a good system of compulsory vaccination. During this period Spain lost from smallpox 563 per million; Russia, 463; but Germany only 1, and Germany has had no epidemic since 1874. At the time the Americans entered the Philippines it is stated that there were in five provinces some 6,000 deaths yearly from smallpox. In 1905 and 1906 some 3,000,000 vaccinations were made and in the following year there were no

deaths from the disease. Yet today misguided individuals would persuade us that vaccination is useless and dangerous. Dr. Schamberg reports that in 6,739,902 cases there were only 476 deaths which by any stretch of imagination could have been charged to the vaccination, a rate of .007 per cent. In the 3,500,000 vaccinations in the Philippines there were no deaths and no serious infections. From 1901 to 1905 some 500 persons in Philadelphia died of smallpox, but not one of these had been successfully vaccinated within ten years. It is not too much to say then that smallpox is vanquished if man so chooses. The financial gain can be seen from the estimate that the epidemic of 1891-1892 cost Philadelphia alone over $21,000,000, while the total cost of vaccinating, disinfecting stations, public instruction, etc., at the same time was some $750,000.9

In the United States we are probably safe in saying that the danger from those great scourges Asiatic cholera and bubonic plague is very small in view of our present knowledge." Epidemics of both have occurred elsewhere in which more than a quarter of a million persons were attacked and nearly half as many were killed. In the single year 1885 cholera cost Japan a hundred thousand lives and inflicted a loss that could not have been less than two hundred million dollars. In the city of Hamburg the cholera epidemic of 1892 destroyed eight thousand lives and cost that commercial city twenty-five million dollars or more.' " 10 In the fourteenth century the bubonic plague under the title "Black Death" swept over Europe destroying some 25,000,000 people, or one-fourth

? SCHAMBERG, J. F. Vaccination in Relation to Animal Experimentation, 1911.

10 MAYO, E. The Cost of Disease, The Outlook, May 13, 1911.

of the total population. During three months in 1911 some 50,000 died of it in Manchuria. So far as is known every person stricken with the disease died. In the four days ending December 27, 1912, some 1,714 deaths occurred at Mecca from cholera with over 10,000 pilgrims present in the City.11 The battle with this enemy, which increases so fast that at the end of twelve hours one germ is reported to have become 17,000,000, and is so small that it takes 625,000,000 to cover a square inch, is not over but the outlook is hopeful. Thanks to an American, Dr. Richard P. Strong, we now know that both forms of the disease are caused by a bacillus which lives in a small fur-bearing animal of Manchuria, the tarbagan. If transferred to a person by a flea or by chance inoculated in some other way, it becomes the dreaded bubonic plague. If however it reaches the lungs it is the pneumonic plague.12 By destroying the animals such as rats and squirrels from which it might be passed to man, the medical authorities were able to stop the epidemic of 1909 at San Francisco. Here then is a case when knowledge gives only partial control, but it is unlikely that Europe or America will ever endure again the plagues of the Middle Ages. It is now possible to secure some immunity against bubonic plague. "A large series of numbered prisoners were confined in a jail where plague prevailed. Those who bore even numbers were inoculated, while those having odd numbers were not inoculated. Among the uninoculated there occurred ten cases of plague, six of which were fatal; while among the inoculated there were three cases, all very mild and all of the patients recovered." 13 11 New York Independent, Jan. 9, 1913.

12 Fighting the Black Death, World's Work, Dec., 1913, p. 219. 13 McCoy, G. W. Relation of Animal Experimentation to Plague, p. 9.

Recently, 45 per cent of those uninoculated died, and but 17 per cent of the inoculated.

One of the greatest discoveries of the ages was made in 1900 by Dr. Walter Reid of the United States Army when he found that yellow fever was given to man through the bite of the female stegomyia mosquito. We now know that this mosquito must bite a fever-stricken patient within the first three days of his illness. Then for some twelve days the germ incubates in the body of the mosquito and may thereafter be transmitted to man. This germ chances to be animal. At once the yellow fever patient ceased to be considered a direct source of danger. He must be so screened that no mosquito could get at him, for in no other fashion can he pass on the disease.

Yellow fever kills about 25 per cent of those attacked. Its native home appears to have been the shores of the Caribbean and the southern coast of the Gulf of Mexico. After the appearance of the Europeans the sailing ships carried it to Havana where it became endemic after 1762. It was taken to Africa by 1494 and is there endemic on the West Coast. It is now endemic in the Western Hemisphere as far south as Rio Janeiro and as far west as Vera Cruz.

During the nineteenth century the deaths from yellow fever at Havana had frequently run as high as 1500 per annum, or at the rate of 428 per 100,000; but they stopped abruptly and absolutely in 1902. The record from 1890 follows:

90

80

60

40

The marked drop in 1901 shows the significance of Dr. Reid's discovery. The following diagram is also sug

gestive:

Jan.

57.1

2

0

1

89.3

90.2

62.1

MORTALITY YELLOW FEVER

HAVANA

Monthly Average for 20 Years Preceding 1900. Lower Dotted Line Shows 1901 Mortality

In 1793 in Philadelphia 4,041 out of a population of 40,144 died of yellow fever between August and the middle of September. When the epidemic of 1878 struck the southern cities people fled by untold thousands, and the cost is estimated at $100,000,000 not to mention the loss by death. In 1905 this would have been repeated had it not been for the discovery of Dr. Reid and his associates. General Leonard Wood is quoted as saying that this discovery saves the world each year more than the entire cost of the Cuban war.

In 1880 Laveran found the microbe which causes malaria, and in 1898 an English physician, Dr. Ronald Read, discovered that this organism must pass part of its life in