Beginning typically with a vigorous chill, sometimes so suddenly as to wake the patient out of a sound sleep, followed by a stabbing pain in the side, cough, high fever, rapid respiration, the sputum rusty or orange-colored from leakage of blood from the congested lung, within forty-eight hours the attacked area of the lung has become congested; in forty-eight more, almost solidified by the thick, sticky exudate poured out from the blood-vessels, which coagulates and clots in the air cells.
So complete is this solidification that sections of the attacked lung, instead of floating in water as normal lung-tissue will, sink promptly.
The severe pain usually subsides soon, but the fever, rapid respiration, flushed face, with or without delirium, will continue for from three to seven or eight days. Then, as suddenly as the initial attack, comes a plunge down of the temperature to normal. Pain and restlessness disappear, the respiration drops from thirty-five or forty to fifteen or twenty per minute, and the disease has practically ended by "_crisis_."
Naturally, after such a furious onslaught, the patient is apt to be greatly weakened. He may have lost twenty or thirty pounds in the week of the fever, and from one to three weeks more in bed may be necessary for him to regain his strength. But the chief risk and danger are usually over within a week or ten days at the outside.
Violent and serious as are the changes in the lung, it is very seldom that death comes by interference with the breathing s.p.a.ce. In fact, while regarded as a lung disease, we are now coming to recognize that the actual cause of death in fatal cases is the overwhelming of the heart by the toxins or poisons poured into the circulation from the affected lung. The mode of treatment is, therefore, to support the strength of the patient in every way, and measures directed to the affected lung are a.s.suming less and less importance in our a.r.s.enal of remedies. Our att.i.tude is now very similar to that in typhoid, to support the strength of the patient by judicious and liberal feeding, to reduce the fever and tone up his blood-vessels by cool sponging, packing, and even bathing; to relieve his pain by the mildest possible doses of sedatives, knowing that the disease is self-limited, and that in patients in comfortable surroundings and fair nutrition from eighty to ninety per cent will throw off the attack within a week. So completely have we abandoned all idea of medicating or protecting the lung as such, that in place of overheated rooms, loaded with vapor by means of a steam kettle, for its supposed soothing effect upon the inflamed lung, we now throw the windows wide open. And some of our more enthusiastic clinicians of wide experience are actually introducing the open-air cure, which has worked such wonders in tuberculosis, in the treatment of pneumonia. In more than one of our New York hospitals now, particularly those devoted to the care of children, following the brilliant example of Dr. William Northrup, wards are established for pneumonia cases out on the roof of the hospital, even when the snow is banked up on either side, and the covering is a canvas tent. Nurses, physicians, and ward attendants are clothed in fur coats and gloves, the patients are kept m.u.f.fled up to the ears, with only the face exposed; but instead of perishing from exposure, little, gasping, struggling tots, whose cases were regarded as practically hopeless in the wards below, often fall into the sleep that is the turning point toward recovery within a few hours after being placed in this winter roof-garden.
In short, our motto may be said to be, "Take care of the patient, and the disease will take care of itself."
Though pneumonia is one of our most serious and most fatal of diseases, yet it is one over whose cause, spread, and cure we are obtaining greater and greater control every day, and which certainly should, within the next decade, yield to our attack, as tuberculosis and typhoid are already beginning to do.
CHAPTER IX
THE NATURAL HISTORY OF TYPHOID FEVER
Why should not a disease have a natural history, as well as an individual? At first sight, this might appear like a reversion to the old, crude theory of disease as a demonic obsession, or invasion by an evil spirit, of which traces still remain in such expressions as, "She was _seized_ with a convulsion," "He was strong enough to _throw off_ the illness," "He was _attacked_ by a fever," etc. But apart entirely from such conceptions, which were perfectly natural in the infancy of the race, while clearly recognizing that disease is simply a perverted state of nutrition or well-being in the body of the patient, a disturbance of balance, so to say, yet it is equally true that it has a birth, an ancestry, a life-course, and a natural termination, or death.
This recognition of the natural causation and development of disease has been one of the greatest triumphs, not merely of pathology, but of intelligence and rationalism. It has done more to diminish that dread of the unknown which hangs like a black pall of terror over the mind of the savage and the semi-civilized mind than any other one advance. It contributes enormously to our courage, our hopefulness, and our power of protection in more ways than one: first of all, by revealing to us the external cause of disease, usually some careless, dirty, or bad habit on the part of an individual or of the community, and thus enabling us to limit its spread and even exterminate it; secondly, by a.s.suring us that nearly all diseases, excepting a few of the most obstinate and serious, have not only a definite beginning, but a definite end, are, in fact, if left to themselves, self-limited, either by the exhaustion and loss of virulence of their cause, or by the resisting power of the body.
All infectious diseases, and many others, tend to run a definite course of so many days, or so many weeks, within certain limits, and at least ninety per cent of them tend to terminate in recovery. It is a most serious and fatal disease which has a death-rate of more than twenty per cent. Typhoid, pneumonia, diphtheria, and yellow fever all fall below this, smallpox barely reaches it, and only the bubonic plague, cholera, and lockjaw rise habitually above it. The recognition of this fact has enormously increased the efficiency of the medical profession in dealing with disease, by putting us on the track of imitating the methods which the body itself uses for destroying, or checking the spread of, invading germs and leading us to trust nature and try to work with her instead of against her. Our ant.i.toxins and anti-serums, which are our brightest hope in therapeutics at present, are simply antidotes which are formed in the blood of some healthy, vigorous animal against the bacillus whose virulence we wish to neutralize, such as that of diphtheria or septicemia.
Diphtheria ant.i.toxin, for instance, the first and best known triumph of the new medicine, is the antidotal substance formed in the blood of a horse in response to a succession of increasing doses of the bacilli of diphtheria. Similar antidotal substances are formed in the blood in all other non-fatal cases of infectious diseases, such as typhoid, pneumonia, blood-poisoning, etc.; and the point at which they have acc.u.mulated in sufficient amounts to neutralize the poison of the invading germs, forms the crisis, or "turn" of the disease. So that when we speak of a disease "running its course," we mean continuing for such length of time as the body needs to produce anti-bodies in sufficient amounts to check it.
The princ.i.p.al obstacle to the securing of ant.i.toxins like that of diphtheria for all our infectious diseases is, that their germs form their poison so slowly that it is difficult to collect it in sufficient amounts to produce a strong concentrated ant.i.toxin in the animal into which it is injected. But the overcoming of this difficulty is probably only a question of time.
Obviously, if infectious disease be, as we say, "self-limited," that is to say, if the body will defeat the invaders with its own weapons, on an average in nine cases out of ten, our wisest course, as physicians, is to back up the body in its fight. This we now do in every possible way, by careful feeding, by rest, by bathing, by an abundance of pure water and fresh air, with the gratifying result that we have already reduced the death-rate in most fevers, even such as we have no ant.i.toxin against, or may not even have discovered the causal germ of, to one-half and even three-fourths of their former fatality. The recognition of the fact that disease has a natural history, a birth, a term of natural life and a death, has already turned a hopeless fight in the dark into a victorious campaign in broad daylight. Huxley"s pessimistic saying that typhoid was like a fight in the dark between the disease and the patient, and the doctor like a man with a club striking into the melee, sometimes. .h.i.tting the disease and sometimes the patient, is no longer true since the birth of bacteriology.
Nowhere can the natural history of disease be more clearly seen or more advantageously studied than in the case of typhoid fever.
The cause of typhoid is simplicity itself, merely drinking the excreta of some one else, "eating dirt," in the popular phrase; simple, but of a deadly effectiveness, and disgracefully common. The demon may be exorcised by an incantation of one sentence: _Keep human excreta out of the drinking water._ This sounds simple, but it is n"t. Eternal vigilance is the price of health as well as of liberty.
We can, however, make our pedigree of typhoid a little more precise. It is not merely dirt of human origin which is injurious, but dirt of a particular type, namely, discharges from a previous case of the disease.
Just as in the fight against malaria we have not the enormous problem of the extermination of all varieties of mosquito, but only of one particular genus, and only the infected specimens of that, so in typhoid, the contamination of water or food which we have to guard against is that from previous cases. From one point of view, this leaves the problem as wide as ever, for, obviously, the only way to insure against poisoning of water by typhoid discharges is to shut out absolutely all sewage contamination. On the other hand, it is of immense advantage in this regard,--it enables us to fight the enemy at both ends of the line, to turn his flank as well as crush his centre.
While we are protecting our water-supplies against sewage, we can, in the meantime, render that sewage comparatively harmless by thoroughly disinfecting and sterilizing all discharges from every known case of the disease. A similar method is used in the fight against yellow fever and malaria. Not only are the breeding places of the two mosquito criminals broken up, but each known case of the disease is carefully screened, _so as to prevent the insects from becoming infected_, and thus able to transmit the disease to other human victims.
It cannot be too emphatically insisted upon that every case of typhoid, like every case of yellow fever and of malaria, _comes from a previous case_. It is neither healthy nor exhilarating to drink a clear solution of sewage, no matter how dilute; but, as a matter of fact, it is astonishing how long communities may drink sewage-laden water with comparative impunity, so long as the sewage contains no typhoid discharges. One case of typhoid fever imported into a watershed will set a city in a blaze.
The malevolent _Deus_ in the sewage _machina_ is, of course, a germ--the _Bacillus typhosus_ of Eberth. The astonishing recentness of much of our most important knowledge is nowhere better ill.u.s.trated than in the case of typhoid. Although there had been vague descriptions of a fatal fever, slow and lingering in its character and accompanied by prolonged stupor and delirium, which was a.s.sociated with camps and dirty cities and famines, from as far back as the age of Caesar, the first description clear enough to be recognizable was that of Willis, of an epidemic during the English civil war in 1643, both Royalist and Roundhead armies being seriously crippled by it. Since that time a smouldering, slowly spreading fever has been pretty constantly a.s.sociated with armies in camps, besieged cities, filthy jails, and famines, to which accordingly have been given the names, familiar in historical literature, of "famine fever," "jail fever," and "military fever."
So slowly, however, did accurate knowledge come, that it was actually not until 1837 that it was clearly and definitely recognized that this famine fever was, like Mrs. Malaprop"s Cerberus, "two gentlemen at once," one form of it being typhus or "spotted fever," which has now become almost extinct in civilized communities; the other, the milder, but more persistent form, which, like the poor, we have always with us, called, from its resemblance to the former, "typhoid" (typhus-like).
Typhus was a far more virulent, rapid, and fatal fever than its twin survivor, though as to the relations between the two diseases, if any, we are quite in the dark, as the former practically disappeared before the days of bacteriology. The fact of its disappearance is both significant and interesting, in that it was unquestionably due to the ranker and viler forms of both munic.i.p.al and individual filthiness and unsanitariness, which even our moderate progress in civilization has now abolished. There can be no question that, with a step higher in the scale of cleanliness, and further quickening of the biologic conscience, typhoid will also disappear.
Typhus, the bubonic plague, the sweating sickness, were alike plagues and products of times when table-sc.r.a.ps were thrown on the dining-room floor and covered daily with fresh rushes for a week at a stretch, and fertilizer acc.u.mulated in a living-room as now in a modern stable.
Clothing was put on for the season, shirts were unknown, and strong perfumes took the place of a bath. Michelet"s famous characterization of the Middle Ages in one phrase as _Un mille ans sans bain_ (a thousand years without a bath) was painfully accurate.
Doubtless certain habits of our own to-day will be regarded with equal disgust by our descendants. Typhus, by the way, may possibly be remembered by the dramatic "Black a.s.size" of Oxford, in 1577, in which not merely the wretched prisoners in the jail, but the jurors, the lawyers, the judges, and every official of the court were attacked, and many of them died.
It was only in 1856 that the method of transmission of the disease was clearly recognized, and in 1880 that the bacillus was discovered and identified by the bacteriologist Eberth, whose name it bears, so that it is only within the last thirty years that real weapons have been put into our hands with which to begin a fight of extermination against the disease.
What is the habitat of our organism, and is it increasing its spread?
Its habitat is the entire civilized world, and it goes wherever civilization goes. In this sense its spread is increasing, but, in every other, we have good ground for believing that it is on the wane.
Positive a.s.surance, either one way or the other, is, of course, impossible, simply for the reason that the disease was not recognized until such a short time ago that no statistics of any real value for comparison are available; and, secondly, because even to-day, on account of its insidious character and the astonishing variety of its forms, and degrees of mildness and virulence, a considerable percentage of cases are yet unrecognized and unreported.
It might be mentioned in pa.s.sing that this statement applies to the alleged increase of nearly all diseases which are popularly believed to be modern inventions, like appendicitis, insanity, and cancer. We have no statistics more than thirty years old which are of real value for purposes of comparison.
However, when it comes to the number of deaths from the disease, there is a striking and gratifying diminution for twenty years past, which is increasing in ratio instead of diminishing. That we are really getting control of typhoid is shown by the, at first sight, singular and decidedly unexpected fact that it is no longer a disease of cities, but of the country. The death-rate per thousand living in the cities of the United States is lower than in the rural districts. For instance, the mortality in the State of Maryland, outside of Baltimore, is two and one-half times as great as that in the city itself. Our period of greatest outbreak in the large cities is now the month of September, when city dwellers have just returned from their vacations in the pure and healthful country, bringing the bacilli in their systems.
The moral is obvious. Great cities are developing some sort of a sanitary conscience. Farmers and country districts have as yet little or none. Bad as our city water often is, and defective as our systems of sewage, they cannot for a moment compare in deadliness with that most unheavenly pair of twins, the shallow well and the vault privy. A more ingenious combination for the dissemination of typhoid than this precious couple could hardly have been devised. The innocent householder sallies forth, and at an appropriate distance from his cot he digs two holes, one about thirty feet deep, the other about four. Into the shallower one he throws his excreta, while upon the surface of the ground he flings abroad his household waste from the back stoop. The gentle rain from heaven washes these various products down into the soil and percolates gradually into the deeper hole. When the interesting solution has acc.u.mulated to a sufficient depth, it is drawn up by the old oaken bucket or modern pump, and drunk. Is it any wonder that in this progressive and highly civilized country three hundred and fifty thousand cases of typhoid occur every year, with a death penalty of ten per cent? Counting half of these as workers, and the period of illness as two months, which would be very moderate estimates, gives a loss of productive working time equivalent to thirty thousand years. Talk of "cheap as dirt"! It is the most expensive thing there is.
Typhoid still abundantly earns its old name of "military fever," and its sinister victories in war are even more renowned than its daily triumphs in peace. Strange as it may seem, the deadliest enemies of the soldier are not bullets but bacilli, and sewage is mightier than the sword. For instance, in the Franco-Prussian War, typhoid alone caused sixty per cent of all the deaths. In the Boer War it caused nearly six thousand deaths as compared with seven thousand five hundred from wounds in battle, while other diseases caused five thousand more. In the majority of modern campaigns, from two-thirds to five-sixths of all deaths are due to disease and not to battle. It may be that we sanitarians will achieve the ends of the peace congresses by an unexpected route, and make war a healthful and comparatively harmless form of national gymnastics. Its battle-mortality rate, for the number engaged, is not so very far above football now!
Given the bacillus, how does it get into the human system? Here the evidence is so abundant and overwhelming that we may content ourselves with bald statements of fact. The three great routes of this pestilence are water, milk, and flies. Of the three, the first is far the most common and important. While only a rough statement is possible, probably eighty-five per cent of all cases from water, five per cent from milk, five per cent through flies, and five per cent through other channels, would fairly represent the percentage.
That it is conveyed through water is as certain as that the sun rises and sets. The only embarra.s.sment in proving it lies in selecting from the swarm of instances. There is the cla.s.sic case of the Swiss villages on opposite sides of the same mountain chain, the second of which drew its water-supply from a spring that came through the mountain from a brooklet running by the first village. Typhoid fever broke out in the first village, and twenty days later it appeared in the second village, twenty miles away on the other side of the mountain. Colored particles thrown into the brook on one side promptly appeared in the spring upon the other. Then there was the gruesome modern instance of Plymouth, Pennsylvania, in 1885. A single case of imported typhoid occurring on the watershed of a reservoir was followed, thirty days later, by an epidemic of eleven hundred cases in a population of eight thousand.
An equally vivid instance came under my own observation. A school and a penitentiary drew their water-supply from the same power-flume, carrying a superb volume of purest water from a mountain stream. Early in the autumn a single case of typhoid appeared in a small town near the head of the flume. The discharges were thrown into the swiftly running water.
Two weeks later an epidemic of typhoid broke out in the school, and three weeks later in the penitentiary. An unexpected freak, however, was the appearance of fifteen or twenty cases in another state inst.i.tution farther down on the same stream, which did not draw its water-supply from the flume, but from deep wells of tested purity. This was a puzzle, until it was found that, owing to a fall in the wells, the water from the flume had been used for sprinkling and washing purposes in the inst.i.tution, being allowed to run through the water-pipes only at night, while the well-water was used in the daytime. This was enough to contaminate the pipes, and a small epidemic began, which promptly stopped as soon as the cause was suspected and the flume-water no longer used.
This last instance is peculiarly interesting, as ill.u.s.trating how typhoid infection gets into milk, the second--though at a long interval--most frequent means of its spread. It does not come from the cow, for, fortunately, none of the domestic animals, with the possible exception of the cat, is subject to typhoid. Nor is it possible that cattle, drinking foul and even infected water, can transmit the bacillus in their milk. That superst.i.tion was exploded long ago. Every epidemic of typhoid spread by milk--and there are scores of them now on record--can be traced to the handling of the milk by persons suffering from mild forms of typhoid, or engaged in waiting upon members of the family who are ill of the disease, or the dilution of milk with infected water, or even, almost incredible as it may seem, to such slight contamination as washing the cans with infected water.
Health officers now watch like hawks for the appearance of any case of typhoid among or in the families of dairymen. The New York City Board of Health, for instance, requires the weekly filing of a certificate from the family physician of all dairymen that no such cases exist. And the more intelligent dairymen keep a vigilant eye upon any appearance of illness accompanied by fever among their employees, some that I have known even keeping a fever thermometer in the barn for the purpose of testing every suspicious case. How effective such precautions can be made may be ill.u.s.trated by the fact that, in the past five years, there has not been a single epidemic of typhoid traceable to milk in Greater New York, even with its inadequate corps of ten inspectors, and the six states they have to cover. The moment a single case of typhoid appears, the dairy or milkman supplying that customer is given a most rigid special inspection, and, if any source of infection can be discovered, the milk is shut out of New York City until the department is satisfied that all danger has been removed. One or two lessons of this sort are enough for a whole county of dairymen. The danger of transmission of typhoid through milk has been enormously exaggerated, and, as in the case of all other milk-borne diseases, is entirely due to filthy handling, and may be prevented by intelligent sanitary policing. Even with our present exceedingly imperfect systems, probably not more than between five and ten per cent of typhoid is transmitted in this way; and, if the water-supply were kept clean, this would practically disappear.
Typhoid may not only be transmitted from the earth beneath and the water under the earth, but also from the heavens above, through the medium of flies and dust. The first method is bulking larger every day, especially in country districts and in camps. The _modus operandi_ is simplicity itself. The fly lives and moves and has its being in dirt. It breeds in dirt and it feeds on food, and, as it never wipes its feet, the interesting results can be imagined. Just to dispel any possible doubt, plates of gelatine have been exposed where flies could walk on them, then placed in an incubator, and within forty-eight hours there was a clearly recorded track of the footprints of the flies written in clumps of bacilli sown by their filthy feet. More definitely, flies have been caught in the houses of typhoid patients, put under the microscope, and their feet, stomachs, and specks found swarming with typhoid bacilli. A single flyspeck may contain three thousand.
Fortunately, we have a simple and effective remedy. We cannot disinfect the fly nor make him wipe his feet, but we _can_ exterminate him utterly! This sounds difficult, but it isn"t. Like the mosquito, the fly can only breed in one particular kind of place, and that place is a heap of dirt, preferably horse manure, but, at a pinch, dust-bins, garbage-cans, sweepings under porches or behind furniture, vaults,--anywhere that dirt is allowed to remain undisturbed for more than a week at a stretch. Abolish, screen, or poison these dirt acc.u.mulations, and flies will disappear, and with them not merely risks from typhoid, but half a dozen other diseases, as well as all sorts of filth and much discomfort and inconvenience. It was largely through flies that the disgraceful epidemic of typhoid, which ravaged our camps on our own soil during the Spanish-American War and killed many times more than fell by Spanish bullets, was spread.
It is also believed that typhoid bacilli may be carried in the infected dust of streets and camps. Here again we are dealing with a dangerous public enemy to both health and comfort, which can and ought to be abated by cleanliness, oilings, and sprinklings. Typhoid bacilli are also occasionally carried by sh.e.l.lfish, especially oysters, on account of the interesting modern custom of planting them in bays and harbors near the mouths of sewers to fatten them. The cheerful motto of the oysterman is, "The muddier the water the fatter the oyster." And nowhere do the bivalves plump up more quickly than near the mouth of a sewer.
The last method of transmission is by direct contact with the sick. This is a relatively rare means of spread, so much so that it is generally stated that typhoid is not contagious; but it is a real source of danger and one against which precautions should by all means be taken. The only method is, of course, by the soiling of the hands of the nurse or other attendant, and then eating or touching food, or putting the fingers into the mouth before thoroughly cleansing. If the hands be washed with a strong antiseptic solution after waiting upon the patient, and the cheerful habit sometimes indulged in of putting fruit or other delicacies into the sick-room for a day or so, in the hope that they may tempt the appet.i.te of the patient, and then taking them out and letting the children eat them as a treat, be abolished, and the nurse be not allowed to officiate in the kitchen, risk from this source will be done away with.
When the bacillus has been introduced into the stomach through food or drink, it rapidly proceeds to diffuse itself throughout the tissues of the body. Because the most striking symptoms of the disease are diarrh[oe]a, abdominal distention, and pain, and the most striking lesions after death ulcers in the small intestine, it was supposed that the process was confined to the abdominal organs. This is now known to be an error, as cultures and examinations made from the blood and various parts of the body have shown the presence of the typhoid bacillus in almost every organ and tissue. This process of scattering, or invasion of the body, takes from three to ten days to accomplish; and the first sign of trouble is usually a feeling of depression, with headache, and perhaps slight nausea, before any characteristic bowel symptoms begin to show themselves.
The general invasion of the system throws an interesting sidelight upon the subject of premonitions. There are several well authenticated cases on record where individuals just before coming down with typhoid have been strangely impressed with a sense of impending death, and have even gone so far as to make their wills and set their affairs in order.
Because these strong impressions appeared before any clearly marked intestinal symptoms of the disease, they have been put down in popular literature as instances of the "second sight," or "sixth sense," which popular superst.i.tion believes many of us to possess under certain circ.u.mstances. Now, however, we know that the tissues of that individual were already swarming with bacilli, and his fear of impending death was simply the effect of his toxin-laden blood upon his brain centres. In other words, it was prophecy after the fact, like nearly all prophecies that happen to come true; and the "premonition" was an early symptom of the disease itself.
As it is, of course, difficult to fix the precise drink of water or mouthful of food in which the infection was conveyed, we were for a long time in doubt as to the length of time which it took to spread through the system,--the "period of incubation," as it is termed,--although we knew in a general way that it averaged somewhere about ten days. But, about a year ago, fortune was kind to us. A nurse in one of the Parisian hospitals, in a fit of despondency, decided to commit suicide. Like a true Parisienne, she would be nothing if not up to date, and chose, as the most _recherche_ and original method of departing this life, to swallow a pure culture of typhoid germs, which she abstracted from the laboratory. Three days later she began to complain of headache, and within a week had developed a beautiful crop of symptoms, and a typical case of typhoid, from which, under modern treatment, she promptly recovered,--a wiser and, we trust, a happier woman.
By just what avenue the infecting bacilli go from the stomach into the general system we do not know. Metschnikoff suggests that they can only penetrate the intestinal wall through wounds or abrasions of the mucous membrane, made by intestinal worms or other parasites. Certain it is that the average stomach has a considerable degree of resisting power against them, for in no known civil epidemic has the number of those who caught the disease exceeded ten per cent of the total number drinking the infected water or milk. In one or two camps in time of war the percentage has risen as high as eighteen or twenty per cent of those exposed, but this is exceptional. However, now that we know that intestinal symptoms do not const.i.tute the entire disease, and may even be entirely absent, we strongly suspect that many cases of slight depression, with feverishness, loss of appet.i.te, and disturbances of the digestion, which occur during an epidemic, may really have been very mild cases of the disease.
One of the singular features of the disease is that, unlike many other infections, we are entirely unable to say what conditions or influences seem either to protect against it or to predispose toward it. In the days when we believed it to be an exclusively intestinal disease it was naturally supposed that chronic digestive disturbances, and especially acute attacks of bowel trouble or dysentery, would predispose to it, but this has been entirely disproved. Soldiers in barracks with chronic digestive disturbances, and even with dysentery, have shown no higher percentage of typhoid during an epidemic than others. Nor does it seem much more likely to occur in those who are const.i.tutionally weak, or run down, or overworked, as some of the most violent and unmanageable cases occur in vigorous men and women, who were previously in perfect health.
So that, although we have unquestionably a high degree of resistance against it, since not more than one in ten exposed contracts it, and only one in ten of those who contract it dies, we have not the least idea in what direction, so to speak, to build up our resisting powers in order to increase them.
The best remedy is to destroy the disease altogether, and this could be done in five years by intelligent concerted effort. It was at one time supposed that typhoid fever was a disease exclusively confined to adult life; but it is now known to occur frequently in children, though often in such a mild and irregular form as to escape recognition. Something like seventy per cent of all cases occur between the fifteenth and the fortieth year, and it is, for some reason, though rarer, peculiarly serious and more often fatal after the fiftieth year.