The new public health

Front matter

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Preface

spectively president and secretary of the Minnesota State Board of Health, Drs. B. M. Merrill and C. F. More, members of the Censorship Committee of that Board, and Mr. W. L. Klein, publisher of the Journal- Lancet, for their advice, deep personal interest, and cordial co-operation. To Dr. F. F. Wesbrook, now President of the University of British Columbia, then Director of the Minnesota State Board of Health Laboratories, to Dr. A. J. Chesley, then a colleague, now the writer's successor in the Division of Epidemiology, to Professor F. H. Bass, ex-Director of the Division of Sanitary Engineering of the Minnesota State Board of Health, to Mr. Christopher Easton, at one time Secretary of the Minnesota Anti-Tuberculosis Association, to Dr. J. P. Sedgwick of the Medical Department of the University of Minnesota, and to Professor S. Quigley of the Department of Pedagogy of the same University, the writer acknowledges with pleasure most friendly and valuable consultation on the more technical portions.

It is not possible to list all who have aided the writer directly or indirectly in this work; still less possible would it be to attempt to list those whose appreciation and good wishes made the work a pleasure. But it would be unseemly to omit reference to one other, who was unconnected with the official family either in Minnesota or in London. The great reconstructing force in Public Health has been bacteriology, but the application of the laboriously sought out and, to Public Health

PREFACE

principles, in general, often barren, work of the Bacteriologist, must be acknowledged as due to an administrator of keen insight and logical mind, Dr. Chas. V. Chapin of Providence, whose " Sources and Modes of Infection " marks the real beginning of scientific public health in America.

That this book may further aid in giving to all who read it a definite view of the chief problems of public health, and of their chief solutions, is the aim of the writer ; that it may prove a satisfaction to many friends, his hope.

Contents

CHAPTER PAGE

1 DEFINITIONS 1

II THE OLD PRINCIPLES AND THE NEW ... 7

Chapter I Definitions

Public Health is a term which includes all knowledge and all measures tending to (a) foster health or (b) to prevent disease.

These two objects are far from identical. True, certain personal measures to promote health, classed under hygiene, i.e., proper care and cultivation of, say, the muscles, necessarily also avoids those " diseases/' which may result from neglect or misuse of those muscles ; incidentally, perhaps, of other parts of the body also. To care for properly and develop sight to its highest efficiency necessarily includes eliminating the train of evils connected with eye strain. But such cultivation of the body forces to secure high efficiency will not and cannot prevent those accidents or diseases which originate from outside sources. A bullet will travel equally as far through the soldier who is physically perfect as through him who is a physical wreck.

Public Health may be divided into Hygiene and

Sanitation. Hygiene deals with the individual and

l his physical perfection. The causes and sources of those diseases which come from the outside, from the surroundings of the individual, are dealt with under the term Sanitation. Just as Hygiene deals with measures which (a) promote health and, some of them (b) prevent disease, so Sanitation also presents two subdivisions, the measures, dealing with surroundings, which intrinsically (a) promote health or (b) prevent disease. Thus, proper ventilation, while securing the best available conditions for the body so far as atmospheric surroundings are concerned, necessarily eliminates those " diseases " which might arise from the reaction of the body to " poor ventilation/' and so far Sanitation and Hygiene are intimately interdependent. But good ventilation, although invaluable to the general welfare and efficiency of the body, has no necessary relation to the elimination of certain outside injurious forces, such as lead poisoning or alcoholism or accidents or invasions of the body by micro-organisms. Each of these must be met by specific measures, adapted to the elimination of the particular factor involved. Moreover, such specific measures will eliminate the specific trouble, whether such general physical efficiency and high health as may be secured through good ventilation be secured or not.

The greatest advance made of recent years in public health is the generalization from such facts, long known in detail, that measures promoting bodily health and efficiency do not necessarily eliminate those ex-

DEFINITIONS 3

ternal and insidious factors of disease by invasion from without, particularly of the invaders which produce the infectious diseases.

A third relationship, long believed and taught as existing between the measures for promoting health and those for eliminating disease, is fast losing its alleged importance. This belief is that which regards high health as not indeed abolishing infection, but as conferring an immunity against infectious diseases. It is beginning to be recognized that as " good ventilation " does not eliminate " eye strain," as good lighting does not correct " poor ventilation," so all through hygiene and sanitation specific troubles must be met by specific measures directed specifically against the real specific cause of that trouble. Taught for, lo these many years, that general cleanliness is a protection against disease, we are beginning to realize that only a specific cleanliness, that which actually eliminates disease germs, is of real value for this purpose; taught also that general high health protects against disease, we are beginning to understand that the only form of bodily condition which secures this end is the possession by the body of a specific protection against each specific disease. 1 Even should we admit that perfect health may theoretically

i It is far from certain that the process of securing such specific immunity through an attack of the disease in question does not involve permanent damage to the body incompatible with the subsequent attainment of the highest physical perfection.

prevent the inroads of smallpox or typhoid fever or pneumonia or colds, we would also have to admit that such high health is very readily upset, by a chill, a missed dinner, a day's overwork, a temporary indigestion; and since this is so, that the protection against infection afforded by such high health, if it exist at all, is too vague and uncertain, too subject to sudden alterations and even complete loss, to be worthy serious consideration as a real factor in the control of disease, in ordinary life. The value of high health, of hygiene, lies in the physical efficiency and bodily comfort which it bestows ; in the sense of well being, in the energy, alertness and keenness which result from it. That it does not protect against infection, that it actually indirectly contributes to infection from the very fact that the energy and alertness it bestows take its possessor out where infection lies awaiting him, does not lessen its real value, but only makes the removal of the infection itself an even more important duty to the race. The man of " torpid liver " and bleary eye, the muscular wreck, lacks that vigor and aggressiveness which carry the possessor of high health out into the busy haunts of men and women ; and to the extent that he escapes contact with his fellows, he tends to escape infection, just as the invalided soldier escapes the effects of bullets by not encountering them.

To hold that weaklings only, or principally, suffer from diseases of this nature is to hold a view which represents a complete reversal of the facts; indeed, if

DEFINITIONS 5

this view were true, infectious diseases would long since have weeded out all such weaklings and left a race of physically perfect giants, free from all diseases because of their exceeding physical perfection; whereas exactly the contrary is true, and we hear the cry everywhere that physical degeneracy is the bane of modern citizenship. Scarcely one-fifth of the young men examined for the U. S. army meet the much modified army requirements as to physique; moreover, that selected fifth, disciplined, exercised, fed and cared for at the highest level of hygiene that we know succumbs to infections quite as easily as their rejected brothers; and modern armies find high health and physical development so little a protection against these infections that every new specific, like vaccination, is seized upon eagerly to take its alleged place. Surely it is time to cease misleading the public and ourselves with a will-o'- the-wisp since the very teachers that lend their weight to the doctrine find in practice that no high health they can. compass for their trained armies protects those armies in any adequate sense.

STJMMAEY

Modern Public Health recognizes that health means much more than the mere absence of disease ; and under Hygiene classes all measures to secure the best internal workings of the human frame to keep it at its best; thus eliminating the internal poisonings, and the results of deprivations and excesses which produce certain diseases or disabilities. But it recognizes further that surroundings, through direct action on the body, perfect or imperfect, may injure or destroy the best just as the worst ; and under Sanitation, strives to provide surroundings which may eliminate external conditions leading to disease or injury.

The chief advance of recent years is that which recognizes the specificity of cause and effect, both in Hygiene and in Sanitation; and meets each separate source or cause of each such trouble with a specific measure to prevent it.

Against the visible outside causes of disease, those causes which can be seen and recognized by every one, (the chemical poisons, accidents, etc.), the weapons are education and elimination or proper handling of those causes, if they cannot be eliminated.

Against the invisible and, to the general public, unrecognizable causes which produce the infectious diseases, the warfare must necessarily be directed to their elimination, under such preliminary education as will permit the establishment of the necessary mechanisms.

CHAPTEE II THE OLD PKINCIPLES AND THE NEW

THE REVOLUTION"

The statement that there is a " New Public Health " may shock those who, although familiar with recent changes in scientific thought, yet have not fully realized what those changes mean; but the shock will be far greater to those who have not appreciated that changes were going on.

The purpose of the writer is to formulate for both groups, the unconscious progressive and the unconscious conservative, a brief statement of the essential principles of modern professional public health work relating to the prevention of disease. To those who may feel skeptical as to the fairness of this exposition, the writings of Chapin, the great American pioneer of modern public health, of E. O. Jordan, and of M. N. Baker, may be offered as bearing directly upon these questions, while the whole of modern technical public-health literature may be offered as indirect evidence. Since the infectious diseases constitute the chief as well as the best understood group of preventable diseases or causes of death and disability, the infectious diseases are here chiefly discussed.

The old principles have merged gradually into the new, in keeping with the experiments, observations, and conclusions of many investigators in many individual sciences related to general public health. Within professional public-health circles, bacteriology, clinical observation, and mathematics have furnished most of the reconstruction. The bacteriologist, the epidemiologist, and the vital statistician, sometimes working together, more often alone, in the dark and even at cross purposes, have nevertheless all reached the same point, and to-day each finds his co-workers beside him. Much of the work done has consisted in clearing away the fallacies built up by tradition, but constructionwork has gone on also, and it is now possible to formulate the results.

The essential change is this: The old public health was concerned with the environment; the new is concerned with the individual. The old sought the sources of infectious disease in the surroundings of man; the new finds them in man himself.

The old public health sought these sources in the air, in the water, in the earth, in the climate and topography of localities, in the temperature of soils at four and six feet deep, in the rise and fall of ground-waters ; it failed because it sought them, very painstakingly and exhaustively, it is true, in every place and in every thing where they were not.

The new public health seeks these sources — and finds them — amongst those infective persons (or ani-

OLD PRINCIPLES AND NEW 9

mals) whose excreta or other constituents or body contents enter the bodies of other persons.

The old public health failed to find the sources of infection; it also failed in most instances to find the routes of transmission. It is true that public watersupplies were detected as at times transmitting infection ; but milk was hardly suspected twenty years ago ; flies (and other insects), suggested in 1887, 1 were not seriously considered until the Spanish- American war; mouth-spray 2 and hands have been only recently recognized as important. On the other hand, dirty clothes, bad smells, damp cellars, leaky plumbing, dust, foul air, rank vegetation, swamps, stagnant pools, certain soils, smoke, garbage, manure, dead animals, in fact everything physically, sensorially, esthetically, or psychically objectionable, were lumped together as " unsanitary " without much distinction of " source " or " route/' and were regarded as a sort of general " cause of disease " to be condemned wherever found, " for fear of epidemics."

THE OLD TEACHINGS

It was taught that infectious diseases " generated " in the foul, ill-smelling, unventilated, sunless hovels of the slums. In the vogue of those days, " the slum-dwellers

i Wm. H. Welch : Address at the Annual Meeting of the Medical and Chirurgical Faculty of Maryland 1887, quoted in Sewage and Local Drainage. — Waring, 1889.

2 By this is meant the fine droplets thrown out from the mouth in speaking, singing, laughing, sneezing, coughing, etc.

live like pigs, and thereby invoke the coming of smallpox, scarlet fever, typhoid fever, diphtheria." When these diseases invaded the home of the well-to-do, where this explanation was not seemly, a pinhole leak in some plumbing fixture accounted amply for diphtheria; rotten potatoes, forgotten in a dark corner of the cellar, for typhoid fever; scarlet fever was traced to a letter bearing " scales " from a friend who had had the disease months before; smallpox to unpacking books used by a patient a quarter of a century previously ; manure piles gave rise to cholera; and dampness to malaria, which was not recognized as transmissible at all. Tellow fever originated in impure water and was directly transmitted from person to person — a typical example of intense direct contagion; tuberculosis was non-infectious and hereditary ; bubonic plague was banished from the Egyptian Cairo " simply by improving the ventilation of the city" (!) 3

Eemedial and preventive measures, based on such beliefs in the omnipotence of environment, naturally sought to remodel the lives and immediate home surroundings of the whole population to conform with a vast array of alleged " sanitary laws of health." Yet he who seeks for a scientific demonstration of the relations existing between disobedience of these " sanitary laws " on the one hand, and the incidence of disease and death on the other, will find only a " twilight zone "

3 Parke's Hygiene, 1891; eighth edition. This was a standard work of twenty-five years ago.

OLD PKINCIPLES AND NEW 11

in which move vague shadows of traditional fear, shadows which, on probing, fade mistily away. 4

While admitting freely that almost any item of an environment may act as a route of infection, at odd times, or under peculiar conditions, the New Public Health is not worried by elaborate theoretical possibilities, but concerns itself earnestly with practical probabilities. The occasional, unusual, bizarre routes of infection in the 1 per cent, of cases, do not distract its attention from the usual, practically constant, simple, ordinary routes concerned in the 99 per cent. Its main postulate is that the routes of infection are simply the routes of infected bodily discharges, which, again, are identical with the routes of ordinary uninfected discharges in ordinary life; and that if the 99 per cent, of commonplace cases are prevented, the 1 per cent, will not occur at all. Too often attention has been riveted on extreme precautions to avoid the 1 per cent., and no precautions worthy of the name have been directed to avoidance of the 99 per cent.

The old style " sanitary inspector " was expected to, and usually did, " condemn " everything in sight, from the garbage pail at the back door to the plumbing in the bath-room. But disease continued, because he was condemning, as a rule, so far as health was concerned, things largely " incompetent, irrevelant and immaterial." What availed it that the garbage-pail was emptied every day or a vent-pipe placed on the bath-

4 See Journal-Lancet of July 15, 1914.

water waste-trap, if the milkman delivered scarlet-f everinfected milk at the door, or an unrecognized case of measles sat next the children at school ?

The wooden knight of Alice in Wonderland who carried a mouse trap on horseback because mice might some day infest his horse, while riding so badly that he continually fell off on his head and was as continually in process of being restored to his saddle by kind friends, furnishes the most kindly yet realistic satire on prevailing public-health methods that could well be devised.

THE NEW IDEAS

The New Public Health sees in the garbage-pail merely a place where flies are fed and, possibly, bred. But the flies cannot carry infection if infected discharges are not accessible to them.

The Old regarded the garbage-pail as in itself and by itself intrinsically bad, disease-producing and deleterious to health. This, notwithstanding that employes in garbage-collection, garbage-destruction or garbage-rendering work average as healthy a body of men as any others of similar status.

" Defective plumbing," such a nightmare twenty years ago, has been conclusively shown to have nothing to do with disease-generation or disease-propagation whatever, unless perchance there be actual gross leakage of infected sewage. The employees connected with great sewage systems, even those continually employed

OLD PKINCIPLES AND NEW 13

in the great sewers of large cities, average well, like garbage workers, as to incidence of disease amongst them. , ^

The unventilated front parlor could not produce tuberculosis in a hundred years; diphtheria does not develop from the family well despite many a well-meant tirade on its evils; and typhoid fever, in sand or clay areas, is but seldom properly traceable to that source, either. Stagnant or old, longstanding water, is to this day often considered responsible for typhoid, despite the definite knowledge that no system of purification of typhoid-infected water is more reliable than impounding, which is merely keeping it standing !

The modern public health man cares nothing, so far as restriction of disease and death is concerned, for the dirty back yard or the damp cellar in themselves, but only as they may enter into the transmission of infected discharges. Then, at once, they become of vital importance. The sanitary inspection of the modern sanitarian, so far as relates to infection, begins and usually ends with the search for (a) the infected individual; (b) the routes of spread of infection from that individual ; (c) the routes of spread of the ordinary excreta of ordinary uninfected individuals to the mouths of their ordinary associates in ordinary life. These latter are sought for, not because of danger from such uninfected discharges, but rather because infected discharges, introduced into and following the same wellbeaten paths, will necessarily reach the same mouths.

To locate all the infective persons and to guard all their discharges would be wholly sufficient and is the ultimate goal of modern preventive measures, but since this cannot always be done perfectly, it is well to guard also the routes which unlocated infection may take.

ENVIRONMENT

Has environment, then, nothing to do with infectious diseases ? Environment acts in two ways : First, unequivocally and without reserve, such environments as permit or encourage or, still worse, necessitate the exchange of human excreta in ordinary life, contribute in the long run to the spread of disease since they insure a similar exchange of infected excreta so soon as the latter are introduced. 5 Let us take one environmental evil, overcrowding, as an example. Overcrowding, if combined with lack of discipline and order, and lack of facilities for washing, especially for the washing of hands, contributes to the spread of infectious diseases; but not in itself; nor at all, unless infection be introduced into the community. Then overcrowding, because it tends to insure exchange of human excreta, tends also to insure that the infection will spread rapidly and extensively. But overcrowding, if the overcrowded be disciplined, intelligent, and take proper precautions to avoid exchange of excreta, does not necessi-

s An excellent exposition of this effect of environment on the spread of disease is given by Chapin in the Report of the Providence Health Department for 1910.

OLD PRINCIPLES AND NEW 15

tate the spread of infection, even if it be introduced. On the other hand, infection may spread, and frequently does, without overcrowding, if the essential factor of such spread exist, i.e., the transmission of infected excreta.

Second. Environments that are bad from a physiological standpoint (bad for the body, regarded as a delicate biological machine) are often held to act in spreading infection indirectly by " depressing vitality " to an extent which makes infection, if received, more likely to develop (and if it develop, more successful in injuring the body). It must be said, however, that the evidence on this point, except perhaps that relating to tuberculosis and pneumonia, is very slight. It is a debatable question whether or not overcrowding " depresses vitality " in the direction of increasing susceptibility to infectious diseases, whatever its effect may be in encouraging " general debility/' It is a very debatable question whether or not " poor ventilation/' to which the effects of overcrowding are often attributed, can or does " depress vitality " in the direction of lessening resistance to infectious diseases, whatever bad effects it may have on mental vigor or physical activity. It is true that there is evidence that such environments as lead to extremes (beyond the limits of compensatory adjustments by the body forces) of mal-nutrition, of temperature, of fatigue, and of alcoholism, probably may have an effect in insuring the development of infection, which under better conditions might be negatived by the body forces. Especially may these forms of bad physiological environment be influential when the dose of infection is small, infrequent, or low in virulence, for it is conceivable that under good environment the body might " throw them off more readily." But starvation, unsuitable temperature, fatigue, alcoholism, alone or together, cannot induce infection, nor will the converse conditions, alone or together, offset the effects of infection when the dose is large or frequently repeated or of high virulence.

Chapter III Infectious Diseases Facts

It would appear, then, that environment as affecting bodily functions has little to do directly with the incidence of most of the specific infections/ notwithstanding that nutrition, temperature, fatigue, and alcoholism are generally credited with some effect, especially in pneumonia and tuberculosis.

Damp, cold, and fatigue perhaps precipitate the pneumonias, although the relation is not clear, and of course no such effect is observed unless one of the infective agents be present. The environments if there be such at all, that precipitate tuberculosis constitute a problem as yet unsolved. Very much is widely believed, and even more is freely taught, concerning this subject, but the evidence is tangled and often contra-

i The terms contagious and infectious were formerly carefully used and carefully distinguished. Modern writers, however, fail to find any useful or basic significance in " contagious " as contrasted with " infectious." Hektoen, in Osier's Modern Medicine, discards " contagious " and " contagion " entirely.

In these articles " infectious " is used to mean " transmissible '* or "communicable."

dictory. " Poor ventilation/ ' dust, dampness, etc., have all been accused, but very little has been proved concerning the real factors actually at work or their mode of operation. In the other infectious diseases the effects even of extremes of the above factors are but rarely definitely recognizable.

Smallpox is contracted or escaped in exact ratio to the degree of exposure acting in opposition to the degree of specific immunity. No other known environmental factor, even acute alcoholism, is recognized as influential.

One thing, and one thing only, is absolutely established, namely, that tuberculosis, microbic pneumonia, and the other infectious diseases will develop under almost any circumstances if the dose of infection be large enough, virulent enough, or sufficiently repeated. Tuberculosis, microbic pneumonia, and the other infectious diseases will not develop under any circumstances without such infection.

Hence it must be evident that the sine qua non of all infectious diseases are their respective agents, and that, since the chief sources (infective persons) of these are known, the most logical efforts are those which concentrate on the prevention of the dissemination of these agents from these sources.

This is tenable, not only in theory, but in practice, and presents an infinitely simpler administrative problem than that presented by the older hypotheses, — not only in the " minor " infectious diseases, where these

INFECTIOUS DISEASES 19

principles have been practically accepted by all, but even in tuberculosis itself.

Thus, if " general environment " be the great factor in tuberculosis, the hundred million people of these United States must have each his or her own individual environment brought up to and kept at some standardlevel designed to maintain each individual in his or her own alleged " highest state of health."

If, however, the infectiveness of the disease be the great factor, only 200,000 people (the actively infective cases) need this supervision in the United States, and they need it, not for the improvement of their " general environment," but merely to prevent them from infecting others. This problem, even numerically, is but one five-hundredth the magnitude of the other. Consider the utterly impracticable expense and difficulty of the attempt to insure only the four quoted factors, — good food, proper temperatures, temperance, and repose, — to one hundred million people (to say nothing of the other " factors of safety " called for by those who lay chief emphasis on control of environment, i.e., abolition of foul air, smoke, dust, damp cellars, bad smells, dirty back yards, etc.), and contrast with this the expense of supervision of two hundred thousand people merely to the extent of confining their infective discharges to themselves.

Further consider that the same official mechanism which could control the tuberculous could also handle with but slight expansion the infectious persons needing supervision for the prevention of all the other infectious diseases, except the venereal, as well as the infective tuberculous. Remember also that improvement of the "general environment/' allowing that its effective achievement were conceivable, could not be expected to have any noteworthy effect on most of these other infectious diseases, even though it had some on tuberculosis.

Need any more be said to indicate the superiority of the new principles, as practical business propositions, over the old ?

The stumbling-block is that the general public still believes the teachings of twenty years ago concerning environment. These teachings were a mixture of the " old-wives fables " of the prebacterial age, with the early incongruities and half-truths of the new " theory " of bacteriology.

Bacteriology is now an old-established science; but despite the fact that it has changed public-health work even more than it has changed medicine or surgery, — and both of these it has completely revolutionized, — the public still clings to the belief that public health is a curious profession, absorbedly interested in cutting weeds in vacant lots ("to prevent epidemics"), in burying dead animals and suppressing noisome odors (" to prevent epidemics ") ; in inspecting plumbing and collecting garbage ("to prevent epidemics"). The " good " health officer according to the popular standard, still too prevalent, is he who keeps the streets clean

INFECTIOUS DISEASES 21

and the back alleys neat, who falls into a rapture over a newly whitewashed outhouse and into a rampage if a pile of old bones is found under the cellar steps. Yet many of those who know better let these ideas alone, or even acquiesce in them, " to save trouble." Nevertheless it is expected that the thus carefully uneducated, or miseducated, public opinion will demand up-to-date action! Is it any wonder that the public insists on thinking, acting, and legislating to suit the theories of twenty years ago instead of the scientific knowledge of to-day ?

Brief formulations of intricate principles are often misleading, incomplete, or fallacious; yet the temptation to formulate the new principles briefly is strong, because their intelligent presentation to the public is so vital. Such formulation is attempted here.

a. Sources of Infectious Diseases

1. Infectious diseases are infectious because they are due to the growth, in the body, of minute animal or vegetable forms (germs), the transmissibility of these germs from body to body being the sole explanation why these diseases are " catching."

2. Wherever in the body the germs develop, they leave it chiefly in the discharges, or by routes of the discharges, of the nose and throat, bladder, or bowel, i.e., from the main orifices of the body. 2

2 This applies to all the ordinary infectious diseases in this zone. Smallpox, leprosy, syphilis, and some forms of tubercu-

3. The discharges infect another person practically only when that person takes the discharges, in some form, into the mouth or nose, except in trachoma and the venereal diseases. 3