CHAPTER IX.

MAN AND THE GNAT.

Almost at the beginning of their great task the Americans were faced with a problem which involved the success or failure of the whole enterprise. I have said something about the climate and health conditions at the isthmus. It is fairly certain that yellow fever and malaria would have wrecked the French undertaking even if there had been no other obstacles to its success. It is not less probable that if the Americans had been in no better a position to wage war with these plagues, their work at the isthmus would also have been in vain. The French had built excellent hospitals and provided efficiently for the comfort and recovery of those who were stricken with these diseases. But being totally ignorant of the sources and method of transmission of malaria and yellow fever, they could do nothing effectual in the way of prevention and eradication. They could only take the individual victim when they found him and do their best to cure him. They still believed that malaria was produced by climatic conditions, by marshy emanations, mists, and so forth. The fleecy clouds which gather round the isthmian hills in the rainy season were given the very undeserved title of "the white death" by the French workers at the isthmus. Yellow fever, again, was just as mistakenly attributed to the climate, and especially to filthy ways of living. It is not surprising that, with these misconceptions, medical skill should have been almost useless during the French occupation, and that the employees at the isthmus should have died in their thousands.

But since the days of the Lesseps company, science had thrown a flood of light on the nature of these tropical scourges and the secret of their transmission. As these medical and scientific pioneers made a Panama Canal possible, though their names are not directly linked with its construction, we may look back for a few moments at their triumphs of discovery. The credit for first discovering that malaria is not due to poisonous emanations or contagion but is carried from people infected with the disease by the _anopheles_ mosquito belongs to Major (now Sir) Ronald Ross, formerly of the Indian Medical Service, who devoted himself to this subject during the last years of the 19th century. By a series of experiments he proved that malaria is due to the presence in the human blood of an organism which is conveyed from person to person by this mosquito, and that the mosquito is harmless unless it has become infected with the germ by biting a person who has caught malaria. The value of this discovery was soon shown by practical applications. Major Ross was engaged by the Suez Canal Company to deal with the malaria which had become firmly established at Ismailia, a little town of 10,000 inhabitants on that canal. No fewer than 2,500 cases had been supplied in one year by this small population. The new methods founded on the new discovery proved so effectual that in three years the disease was stamped out, and there has been no relapse ever since. The same results were achieved at Port Said.

Now, if malaria is thus caused by mosquito bite, there was some _a priori_ reason for thinking that yellow fever might be transmitted in the same way. At any rate the insect was again laid under a very grave suspicion. The opportunity for studying this further question was afforded during the Spanish-American war, when a serious outbreak occurred among the troops occupying Havana, in Cuba. The doctors were quite unable to deal with this most terrible of all diseases. Knowing nothing whatever of its cause, their treatment of it could be only experimental and casual. So a board of inquiry was formed consisting of four army surgeons serving in Cuba--Walter Reed, James Carroll, Jesse W. Lazear, and Aristides Agramonte. The experiments were begun in June 1900, and continued into the next year. Of these four, Dr. Agramonte was not liable to the disease, and Dr. Reed was called away on duty to Washington. The other two determined to experiment on their own persons rather than risk the lives of other people.

Dr. Carroll first allowed himself to be bitten by the mosquitoes, not the _anopheles_ but another variety known as the _stegomyia_. He fell ill with a bad attack of yellow fever, which very nearly cost him his life. Later, in the yellow fever hospital, Dr. Lazear deliberately allowed a mosquito to feed on his hand. In four days he was down with the disease in so acute a form that he died of it--a true martyr, if ever there was, to the cause of science and the welfare of mankind. These and other experiments proved conclusively that yellow fever, like malaria, is transmitted by mosquito bites, but it was still uncertain how soon after biting an infected person the mosquito becomes itself harmful and how soon a person stricken with malaria is able to infect a healthy mosquito. So further experiments were necessary, and volunteers were invited to offer themselves for this service. Everybody in the army knew what had happened to Doctors Carroll and Lazear, but in spite of this plenty of willing martyrs appeared. The first to present themselves were two young soldiers from Ohio, John R. Kissinger and John J. Moran. Dr. Reed talked the matter over with them, explaining fully the danger and suffering involved, and stating the money consideration offered by General Wood. Both young men declared that they were prepared to undergo the experiment, but only on condition that they should receive no pecuniary reward. When he heard this declaration, Dr. Reed touched his hat with profound respect, saying, "Gentlemen, I salute you!"[8] Kissinger took the disease from the mosquito bites, and recovered. A room was prepared for Moran, a sort of mosquito den into which fifteen gnats, all suffering from yellow fever, had been admitted. Major Reed describes what happened:--

At noon on the same day, five minutes after the mosquitoes had been placed therein, a plucky Ohio boy, Moran by name, clad only in his night-shirt and fresh from a bath, entered the room containing the mosquitoes, where he lay down for a period of thirty minutes. Within two minutes of Moran's entrance he was being bitten about the face and hands by the insects, that had promptly settled down upon him. Seven, in all, bit him at this visit. At 4.30 p.m. the same day, he again entered and remained twenty minutes, during which time five others bit him. The following day, at 4.30 p.m., he again entered and remained fifteen minutes, during which time three insects bit him; making the number fifteen that had fed at these three visits. On Christmas morning, at 11 a.m., this brave lad was stricken with yellow fever, and had a sharp attack, which he bore without a murmur.

But still the demonstration was not complete. It was necessary to prove by equally undeniable evidence that yellow fever is not conveyed by contagion with the clothes and persons of infected people. These experiments were even more trying and heroic than those which preceded. A small wooden hut, 14 by 20 feet, was prepared, and into this was stored a large amount of bedding and clothes which had been used and worn by persons suffering from the fever. The building was carefully guarded against the intrusion of mosquitoes, and a temperature of seventy-six degrees, with a sufficient moisture, maintained. For twenty consecutive days Dr. Clarke and his men went into this room, handled, wore, and slept in the contaminated clothing, although the stench was so offensive as to be almost appalling. They emerged from the ordeal in perfect health, proving beyond possibility of dispute that the disease was not contagious, and that the mosquito was the sole method of transmission.

When distributing the credit for the new channel of world-traffic through the isthmus of Panama, let us not forget Dr. Lazear who sacrificed his life and the many others who cheerfully risked their lives to establish truths and facts without which the construction and continued operation of the canal would almost certainly have been impossible.

One mosquito may look very much like another, but the _stegomyia_ and the _anopheles_ differ in many important respects. The latter finds its most favourable breeding-places in stagnant pools of fresh water, such as are left by the heavy rains of the isthmus. It is essentially a gnat of the country-side. The _stegomyia_, on the other hand, inclines to a more frivolous town life. Cisterns and tanks and other receptacles for storing water are his favourite haunts. In length of life and power of flight the species also differ, though these details are not yet fully ascertained. The _stegomyia_ is said to live three months. Dr. Cornish states that it becomes dangerous only by attacking man during the first three days of yellow fever, and that, even then, twelve days elapse before its bite is infectious. Six days after a man has been bitten by an infected _stegomyia_ he falls ill with yellow fever, and for the next three days he is capable of transmitting it to the healthy mosquito. Mr. Bishop informs us that if there is no fresh case of yellow fever within a period of sixty days after the latest one in an epidemic, it is a safe conclusion that the disease has been stamped out, because there is no mosquito alive to carry the parasite. After a period of ninety days all doubt on the subject is removed.[9] If a community, therefore, which has thus got rid of its last case of yellow fever could be completely isolated, yellow fever could never possibly return. It could only be reintroduced from outside. It should be possible, with a proper system of sanitation and quarantine, to free any district entirely from this awful scourge.

The case of the _anopheles_ and his little contribution to human suffering is very different. Whereas the victim of yellow fever either dies or gets better and quickly ceases to be a source of infection to the mosquito, the victim of malaria seldom dies of the disease, but he remains infectious to the _anopheles_ for three years. The disease does not simply attack new-comers or white people. Natives of the isthmus and the West Indies are subject to it, and, indeed, seem to be in a chronically malarious condition. It is said that 50 per cent. of the population of the isthmus were found in 1904-5 to have the parasite of malaria in their systems. It is difficult to estimate or imagine the part played by this widespread malady on conditions of life and civilization within the tropics.

Sir Ronald Ross, the greatest living authority on the subject, made some interesting remarks in an address at the Royal Colonial Institute in January of this year. He said:--

Nothing has been more carefully studied of recent years than the existence of malaria amongst indigenous populations. It often affects every one of the children, probably kills a large proportion of the new-born infants, and renders the survivors ill for years; only a partial immunity in adult life relieves them of the incessant sickness. Here in Europe nearly all our children suffer from certain diseases--measles, scarlatina, and so on. But these maladies are short and slight compared with the enduring infection of malaria. When I was studying malaria in Greece in 1906, I was struck with the impossibility of conceiving that the people who are now intensely afflicted with malaria could be like the ancient Greeks who did so much for the world; and I therefore suggested the hypothesis that malaria could only have entered Greece at about the time of the great Persian wars. One can scarcely imagine that the physically fine race and the magnificent athletes figured in Greek sculpture could ever have spent a malarious and splenomegalous childhood. And, conversely, it is difficult to imagine that many of the malarious natives in the tropics will ever rise to any great height of civilization while that disease endures amongst them. I am aware that Africa has produced some magnificent races, such as those of the Zulus and Masai, but I have heard that the countries inhabited by them are not nearly so disease-ridden as many of the larger tracts. At all events, whatever may be the effect of a malarious childhood upon the physique of adult life, its effects on the mental development must certainly be very bad, while the disease always paralyzes the material prosperity of the country where it exists in an intense form.

The isthmus of Panama was beautifully adapted to the breeding of the _anopheles_ and the widest dissemination of malaria. In fact, the canal zone taken over by the Americans was perhaps the most malarial strip of territory in the world. The heavy rains leave the country covered with those marshes and pools from which these little ghostly insects are always rising in swarms, ready to carry the germs of disease from the sick to the healthy and thus perpetuate and extend the domain of this distressing malady. The reader will notice that, as the yellow fever victim is only infectious to the mosquito for three days, while the malarial person can convey the poison for three years, it is a much more practical problem to eradicate yellow fever than to stamp out malaria. It is true the causes of malaria are now fully known and the only effective methods of propagation ascertained. If one could isolate all malarial patients, including all who are capable of transmitting the disease, in buildings screened with fine copper-gauze to keep out the mosquitoes and thus gradually diminish the area of infection to vanishing point, it would not be necessary to deal with the breeding-places of the mosquitoes, and man and the gnat might live together in perfect amity. But with fifty and even seventy per cent. of the people malarially infected, such a heroic course is obviously impossible, and one can hope only to diminish to a considerable degree the prevalence of the disease.

The first two and a half years of the American occupation of the isthmus was spent in looking round and preparing for the great work. It soon became evident that the most pressing and immediate task was one of cleaning up and sanitation. In July 1904, Colonel W. C. Gorgas, whose name will always be associated with the triumphs won over disease at the isthmus, became the head of the department of sanitation under the Canal Commission. He quickly recognized that everything depended on the efficiency and success of his own department. "The experience of our predecessors," he wrote, "was ample to convince us that unless we could protect our force against yellow fever and malaria we would be unable to accomplish the work."[10] When the Americans took over, yellow fever, though present, was quiescent, but the figures began almost at once to mount up. In December 1904 there were six cases on the isthmus and one death. In January 1905 there were nineteen cases and eight deaths, seven and one respectively among the canal employees. In May there were thirty-three cases, twenty-two on the canal, with seven deaths in all, including three employees. In June there was an alarming advance. Sixty-two cases occurred on the isthmus, thirty-four of them among the employees. There were nineteen deaths, six on the canal. Something like a panic then set in among the Americans engaged on the canal works. Many threw up their positions, and the homeward-bound steamers were filled with employees fleeing from this real "yellow peril." In the annual report of the Commission for 1905 we read:--

A feeling of alarm, almost amounting to panic, spread among the Americans on the isthmus. Many resigned their positions to return to the United States, while those who remained became possessed with a feeling of lethargy or fatalism, resulting from a conviction that no remedy existed for the peril. There was a disposition to partly ignore or openly condemn all preventive measures. The gravity of the crisis was apparent to all.

This loss of moral tone was the most dangerous symptom of all. A feeling of "let us eat and drink, for to-morrow we die" gained possession of the canal workers, and in the indifference of despair many tore down the nettings over the windows of the canal building and began to neglect all the sanitary precautions enjoined on them by the department. Evidently a calamity was in prospect which would have brought to an end, perhaps for ever, American canal ambitions at the isthmus. The restoration of public confidence and sense of responsibility seems to have been due largely to Mr. Charles E. Magoon, governor of the canal zone. He set himself to rebuke and remove the morbid bravado then prevailing. "He began by frankly and publicly declaring that he, personally, was afraid of the fever, and that in his opinion all non-immunes who professed not to be afraid were 'talking rot!' Then he ordered all the window-screens to be repaired and kept in place, and announced that if any man was caught leaving them open or tearing holes in them, something uncommonly unpleasant would happen to him. Now when a man of Judge Magoon's mental and physical stature admits that he is afraid, any lesser man is a fool to say he isn't; and when a man of Judge Magoon's resolution gives an order and prescribes a penalty for its violation, that order is very likely to be obeyed."[11]

Governor Magoon arrived at the isthmus in May 1905, just as the yellow fever epidemic was reaching its climax. From that moment he and Colonel Gorgas, to whom he gave the most complete support, set themselves to fight the fever. The first thing to do was to get all the patients within screened buildings, whether the hospital or their own homes, so that no _stegomyia_ mosquitoes could saunter in and take the poison. Then the towns of Colon and Panama were handed over to a campaign of spring-cleaning such as the world has never witnessed. Then the canal building was thoroughly fumigated with pyrethrum powder or sulphur, and not simply the official building but every single house in the city of Panama was similarly disinfected. Dust and refuse were everywhere burnt. A very efficient system of inspection was adopted, and a rigid quarantine enforced against all foreign places whence the yellow plague could be imported into the zone.

But more important than the immediate expedients were the more permanent sanitary improvements carried out in Colon and Panama. These towns were repaired with brick or cement, and provided with what they had never yet enjoyed, a proper system of drainage. Waterworks were also constructed outside the towns, and a supply of pure water made available for every household. Hitherto water had had to be stored during the dry season in tanks and cisterns, in which the _stegomyia_ mosquito revelled exceedingly. These were now no longer necessary, and stagnant water, wherever it collected in the town, was drained away. In order to expedite these splendid reforms, Governor Magoon withdrew the workers from the canal and concentrated all efforts on the sewers and waterworks. So speedily was the work carried forward that the water was turned on for public use from the main in the Cathedral Plaza on July 4.

The results of this drastic campaign were soon apparent in the dwindling of the yellow fever returns. In July there were still forty-two cases and thirteen deaths on the isthmus, with twenty-seven cases and ten deaths among the employees. August showed a great improvement, with twenty-seven cases and nine deaths on the isthmus, and twelve cases and only one death on the canal. The improvement continued through September, October, November, and in December only one case was reported on the isthmus and one on the canal. Three months having elapsed since the last case, and, therefore, every _stegomyia_ which could possibly be infected with malaria having departed this life, the epidemic was entirely past and over. As I have pointed out, there cannot possibly be any return of it under these conditions unless the infection is brought from without. And if any new cases are at once isolated and screened from afternoon calls of the mosquito, the outbreak may be easily and infallibly suppressed. We may say, therefore, that the yellow spectre at the isthmus has been shorn of all its terrors.

Malaria is, however, a very different proposition. A corresponding crusade has been carried on for six years against the little _anopheles_ gnat, the little criminal who carries the malarial poison. His happy breeding-grounds are in open country marshes and pools, and there is no lack of these in the canal zone. It was impossible to deal with the entire three-quarters of a million acres of that territory, but wherever the canal workers were settled determined war was waged against the mosquitoes. It should be remembered that the _anopheles_ can fly only about a hundred or two hundred yards. The jungle was therefore cleared away for a few hundred yards round each village and settlement, marshes and pools in this area were drained off, and into all the ditches where stagnant water had collected oil was poured, which so effectually turns the mosquito's stomach that it never recovers. Some 1,200 acres of the zone were thus treated, and of course the regulations as to house-screening applied to malaria no less than to yellow fever. The employees were also supplied freely and generously with quinine.

The result has been not the eradication of malaria, but the reduction of the cases to about one-third the number at which they stood in 1906. Yet even so, among the 40,000 employees on the canal during the year ending June 30, 1912, there were 7,000 malaria cases in the hospitals, with 32 deaths, 22 of these being white people. The heavy rainfalls at the isthmus will probably prevent the complete sanitation of the country in this respect, for the simple reason that the destruction of the _anopheles_ mosquito or the eradication of the malarial germ can never be complete. There will always be people going about with the malarial organism in their blood, and always _anopheles_ mosquitoes ready to become infected with it and to carry the infection about. But, as we have seen, much can be done by the means described to reduce the ravages of the disease. In 1906, out of a working force of 26,000, there were 21,739 cases of malaria. We have seen how this figure had been brought down in 1912. In 1906 it was almost certain that any white person coming to reside at the isthmus would catch malaria. Now it is quite possible to live there in perfect health, quite free from any malarial infection.

It may be useful to mention that the entire death-roll among the employees on the Panama Canal and railway from the American occupation down to June 30, 1912--that is, about eight years--was 5,141, of whom 284 were Americans. Of this total, 4,119 died of disease and 1,022 from violence or accident. During the same period 49 American women and 87 American children died.[12] Sir Ronald Ross, as I have said, was told by the British Consul at Panama in 1904 that the French lost in the nine years of their occupancy some 50,000 lives, principally from malaria and yellow fever. This may be an over-estimate, but there is no doubt that the American figure shows an enormous improvement on the French.

It is easy to conclude that what has been done in sanitation at the isthmus of Panama may be done anywhere else in the tropics, where malaria and yellow fever prevail. That may be true, but we must also remember that the work of Panama had behind it all the wealth and resources of a mighty republic of 90,000,000 citizens. The expenditure on these hygienic purposes at the isthmus has been enormous, though not a penny has been wasted. Down to the end of December, 1912, the total outlay of the Department of Sanitation was $15,500,000. Waterworks, sewers, etc., accounted for another $2,500,000, so that we get a grand total expenditure on sanitation of $18,000,000. This will certainly rise to $20,000,000 before the canal is finished, so that for the ten and a half years of its construction there will have been an annual expenditure for all health purposes of $1,900,000. It is not likely that there will be many tropical areas of this kind with so large a sum available for the luxury of scientific sanitation. Again, it must be noticed that the administration had special advantages at the isthmus. It exercised something like military authority. It had absolute powers of deportation, and could enforce its regulations as it pleased. And in considering the statistics it must also be borne in mind that not only the physical but the moral and mental health of the work-people at the isthmus was promoted in every way. We shall look into the life of the Panama construction camps in the next chapter. The social interest and amusement provided for the employee must have counted for something beside the sewering and screening and mosquito-hunting. All the same, the success achieved at Panama is full of hope and promise for tropical life in the future. Colonel Gorgas writes encouragingly:--

I think the sanitarian can now show that any population coming into the tropics can protect itself against these two diseases (malaria and yellow fever) by measures that are both simple and inexpensive; that with these two diseases eliminated life in the tropics for the Anglo-Saxon will be more healthful than in the temperate zones; that gradually, within the next two or three centuries, tropical countries, which offer a much greater return for man's labour than do the temperate zones, will be settled up by the white races, and that again the centres of wealth, civilization, and population will be in the tropics, as they were in the dawn of man's history, rather than in the temperate zone, as at present.

Apart from the question of disease, it is far from certain that the white man can ever remain as "fit," as capable of bodily labour, in equatorial regions as in his native temperate conditions, or that his descendants will also maintain the same standard of health and strength. Ordinary non-professional opinion would perhaps discount Colonel Gorgas's forecast as a little too optimistic.

FOOTNOTES:

[8] "Sanitation of the Isthmus." Mr. J. B. Bishop in _Scribner's Monthly_, February 1913.

[9] _Scribner's Monthly_, February 1913, p. 248.

[10] _Journal American Medical Association_, July 6, 1907.

[11] "Four Centuries of the Panama Canal."

[12] See _Scribner's Magazine_, February 1913, p. 251.