Popular Science Monthly/Volume 34/December 1888/Infant Mortality and the Environment
|INFANT MORTALITY AND THE ENVIRONMENT.|
IT is a startling fact, which meets the student of vital statistics at the outset of his investigations, that from one third to one half of all persons born into the world die before reaching the age of five years. Or, to face the terrible reality from another point of view, so great are the dangers of infancy, that a child which has completed its fifth year actually has an expectation of life more than twelve years greater than it had at birth.
The exact proportion of deaths varies greatly in different countries and localities, at different times and under different circumstances. Statistics are of value only in showing average results. In Norway, for example, the proportion dying under five is stated by Dr. Farr to be 204·5 per 1,000 born; while in England it is 338 per 1,000, and in Italy 567 per 1,000. In fifty-one so-called "healthy districts" of England and Wales, according to the same authority, the mortality under five is 175 per 1,000 born, while in the Liverpool district, representing the most unfavorable sanitary conditions, it is 460 per 1,000.
In the different parts of our own country, we find nearly as great a variety as on the continent of Europe. Even in the same latitude, the proportion varies greatly, according as city or country districts are considered. In the State of Vermont, which contains no large cities, and represents essentially a rural population, the number of deaths under five, for the year 1883, was 23·8 per cent of the whole number of deaths; in the State of Massachusetts, which embraces several large cities within its limits, for the twelve years ending in 1884, it was 34·74 per cent; and in the city of New York alone, for the seven years ending in 1873, it was exactly 50 per cent of the entire mortality.
The younger the child, the larger is the death-rate. According to Dr. Jacobi, more than half of those who die under five years of age die in the first year. Dr. Curtiss states that, in all the great cities of North America, out of every one hundred live-born children, about twenty-five die before the end of the first year, and from forty to fifty before the close of the fifth year.
Death-rates like these—and the figures might be multiplied indefinitely—challenge our earnest attention and demand our careful consideration. Let us first inquire what are the diseases which are the immediate cause of the great bulk of infant mortality. These may be grouped in four main classes, namely:
(1) The acute infectious zymotics, of which the chief are measles, scarlet fever, small-pox, diphtheria, and whooping-cough. These are collectively responsible for from fifteen to twenty per cent of the deaths under five.
(2) The acute lung-diseases, chiefly bronchitis and pneumonia, which together cause from ten to fifteen per cent of the deaths under five. In America, more than twice as many deaths occur from pneumonia as from bronchitis, while in England nearly the reverse is true.
(3) Tubercular and constitutional diseases, such as consumption, scrofula, meningitis, and hydrocephalus, which are responsible for from ten to fifteen per cent of the entire infant mortality.
(4) The diarrhœal diseases, comprising infantile diarrhœa, cholera infantum, inflammation of the bowels, dysentery, and some others. These are the cause of at least one fourth of the entire infant mortality the world over; while in America cholera infantum alone is responsible for nearly or quite one fifth.
But the problem before us is not one which can be solved by a simple rehearsal of the names of diseases and the number of their victims. These only show the form and manner of death, while the ultimate causes lie far in the background.
The real questions at issue relate to those influences which are at work upon so large a proportion of infants and young children the world over, tending to break down in them the power of resisting disease, lessen their chances of a vigorous, healthy life, and render them unduly liable to go down to early graves. What is the nature of these influences? What circumstances tend to increase their activity? Under what conditions and to what extent may they be rendered inert, or their usual dire effects be avoided? By what means may an unfavorable environment be changed to a favorable one, and the vitality and longevity of the race be thereby increased?
In considering these questions, it must be remembered that the causes of infant mortality are also the causes of adult mortality, only in a less degree; and that the health of a delicate infant is the most sensitive measure which we possess of those influences which are deleterious to health, either in infancy or adult life.
The first of these deleterious influences in the order of time, and unquestionably also of importance, is heredity. A very large proportion of all children born into the world are either weaklings or invalids from the beginning. They are born wrong. They come from poor stock. The influences which determine their weakness to-day have been at work for ages upon ages. That was no sarcasm, but the plainest statement of scientific truth, on the part of Oliver Wendell Holmes, when, after declaring his conviction that every disease might be cured if taken in season, he added, significantly, that in some cases it would be necessary to begin a hundred years before the patient was born. This is a hard world, and no weakling ever has half a chance. "The survival of the fittest" is a merciful provision of nature. "The strongest live and the weakest die." A race of criminals, paupers, and idiots deteriorates with each successive generation, and goes down to speedy extinction. It is the robust, sturdy, clear-headed, strong-handed toiler of to-day, whose sons and daughters will inhabit homes of wealth and occupy positions of responsibility a few years hence.
The effects of unfavorable heredity may be manifested in various ways. In the first place, the child may be born with the disease already developed. Examples of this class may be seen in hypertrophies, atrophies, and inflammations of various organs; in exudations, as hydrocephalus; in infantile syphilis; in new growths, such as nævus, tumors, and certain forms of cancer; in the pre-natal deposition of tubercles, parasites, and some inorganic products; in arrests of development, such as cleft-palate, hare-lip, spina bifida, and that defective closure of the heart which produces cyanosis; and in those unusual developments known as monstrosities. Secondly, the disease may be transmitted, although its manifestations are not developed at birth. This may be the case with some of the diseases already mentioned as also occurring in the first class, as well as with many others. Examples are seen in scrofula, cancer, consumption, epilepsy, rheumatism, gout, insanity, and the "specific" disease. Again, there may be no actual disease, but only a tendency to disease, in the shape of an inherited weakness of some special organ or in some particular direction. These tendencies render their possessors unduly liable to suffer from particular diseases, but do not make it necessary that they should do so, provided that their environment is favorable. Lastly, the faulty heredity may be manifest only in a general weakness of the whole system, a lack of vigor and vitality, which renders its possessor an easy victim to whatever malady may attack him. This is the cause of many of the deaths which are registered under the heads of infantile debility, diarrhœa, brain-disease, and other common affections of infancy.
To the actual diseases, special weaknesses, and unsound constitutions resulting from unfavorable heredity, add now the environment of poverty, with its usual accompaniments of ignorance, carelessness, and inefficiency on the part of the parents, resulting for both parents and children in privation of food, clothing, shelter, and fuel, and we begin to have some faint conception of the perils which surround infant-life in a large proportion of cases. Without adequate nourishment, and improperly cared for in every respect, life is one sharp struggle with want, and it is little wonder that want often gains the victory. In England, for the ten years ending with 1875, an average of eighty-two deaths annually was assigned to starvation alone. But privation and destitution exercise a controlling influence over the mortality of infancy under other names than this. What the form of death shall be is determined by various circumstances. It occurs largely from the diseases of denutrition and debility, rickets, scrofula, consumption, and other constitutional diseases.
Exposure to cold and wet, especially in the sharp vicissitudes of our winter climate, and more particularly when this is added to the causes already named, results in a largely increased prevalence of the acute lung-diseases. These are extremely fatal even in adults, and the mortality is proportionately large in children. Says Routh, in his work on "Infant Feeding": "Among the most pernicious influences among young children we may include cold. It is a household word among us, which takes its origin from the Registrar-General's returns, that a very cold week always increases the mortality of the very young and the very aged." The same statement is true in America, though it may be in a somewhat less degree, owing to the fact that our houses are better provided against extreme cold than are those of the English. Throughout England, one sixth of all deaths from lung-diseases occur under five. In London, forty-four per cent of the deaths from pneumonia and bronchitis take place under that age. In Massachusetts, the proportion of deaths from pneumonia under five is thirty-four per cent. These deaths occur largely in the inclement portions of the year. In England, both bronchitis and pneumonia attain their maximum in the first quarter of the year, decline during the second quarter, reach their minimum during the third, and begin to increase during the fourth. In Michigan, Dr. H. B. Baker has shown that the greatest prevalence of the acute lung-diseases is in February, and the least in August. In Massachusetts, March has the largest number of deaths, and August the least.
Four distinct but closely related causes combine to produce the diarrhœal diseases, which result in one fourth of the entire mortality under five. These are heat, improper feeding, filth, and overcrowding. The influence of heat is seen in the facts that, in our climate, the overwhelming majority of cases in these diseases occur during the hottest months of the year; that their prevalence is greater in the southern portions of the temperate zone than in the northern, and in unusually hot summers than in those whose average temperature is less; and, in general, that the number of deaths from these causes is directly proportional to the elevation of temperature, especially if it be long continued. Thus, of 3,216 deaths from the diarrhœal diseases in Vermont, New Hampshire, Massachusetts, Rhode Island, and Connecticut in 1883, 2,745, or eighty-five per cent, occurred during the months of July, August, and September. The same States showed an increased mortality from these causes during the unusually hot summers of 1880 and 1882. In the city of Boston, for the nine years from 1867 to 1875 inclusive, the mean temperature of the months of July and August varied from 68·6° in 1874 to 72·3° in 1870, and averaged 70·5°. The highest death-rate was in 1872, when the mean for the two months was 71·9°, and for the hottest single month was 73·1°; and the lowest was in 1867, with a mean for the two months of 69·8°, and for the hottest month of 70·4°. In New York, during the month of July, 1872, the mean temperature was 79·57°, or 3·43° higher than the average for the ten previous years. As a result, the mortality for the quarter was the highest ever known in the city, and that notwithstanding that the other two months were not unusually hot.
It must be stated that, fatal as is the effect of heat upon children under five, the proportionate mortality is still greater when the investigation is limited to infants under one year of age. Dr. Blackader says that a very hot summer month will triple or even quadruple the mortality of infants under one year, though that of children from one to five is barely doubled. During the year 1872, in New York, nearly sixty per cent of all deaths were under one year of age, and more than forty per cent took place in the summer quarter.
The effects of improper feeding are seen in the fact that, whether in city or country, in hot summers or cool, only a very small proportion of deaths from infantile diarrhœa occur among infants who are properly nursed upon the milk of a healthy mother—which must be considered the only natural and proper method of feeding young infants.
Sir Hans Sloane showed years ago that the mortality of those properly nursed upon breast-milk was to that of those who were bottle-fed as 19·2 to 53·9 per cent. Dr. J. Wilmarth reports that in a country practice in Massachusetts, out of one hundred and one children nursed wholly, or nursed and fed with nursing after a few months to weaning-time, and who were under his observation for a series of years, there were twelve deaths from various causes, none of them from cholera infantum; while among nineteen children artificially fed, there were during the same time eight deaths, six of them from cholera infantum. Says Messener: "Cholera infantum attacks only those children who have been raised without breast-milk, those who have been weaned too early or too hastily, or those to whom, on account of the failure of the mother's milk, other foods have been injudiciously administered. Under other circumstances than these, children enjoy a complete immunity."
The artificial feeding of infants often results from physical inability on the part of the mother to nurse them, and this inability in turn is the result of defective heredity. "The mother makes the child," and the mother's weakness ofttimes results in the death of the child, or even of the children's children.
When we turn to consider the merits of the different forms of artificial feeding, we realize the intimate relation of improper feeding to the next cause, namely, filth. Cow's milk, the most common and generally advisable substitute for mother's milk, when exposed to the air at a summer temperature, soon ferments and develops a peculiar poison known as tyrotoxicon, which is a most potent factor in the causation of cholera infantum. It is also, says Prof. Lister, "a pabulum for all kinds of organisms; nearly all varieties of bacteria will live in it." In addition to this, it often absorbs and becomes the carrier of various other forms of filth, both organic and inorganic, all of which either directly or indirectly increase the tendency to disease. These evil results may be avoided, in a large measure at least, by the modern process of sterilization of milk, whereby existing germs are destroyed, air excluded, and fermentation prevented.
But filth may be introduced in other ways than in milk or food of any kind; and, however introduced, its effects are always disastrous. Says Mr. Simon: "Nothing in medicine is more certain than the general meaning of high diarrhœal rates. The mucous membrane of the intestinal canal is the excreting surface to which nature directs all the accidental putridities which enter us. Whether they have been breathed, or drunk, or eaten, it is there that they settle and act. As wine gets into the head, so these agents get into the blood. There, as their universal result, they tend to produce diarrhœa."
In August, 1883, the health-officer of New Haven, Conn., in a paper entitled "A Practical Argument for Sewers," reported the following, which well illustrates the evil effects of impure air: "There were forty-three deaths in New Haven from infantile diarrhœa in July. The forty-three deaths occurred in thirty-two different streets and in thirty-eight different, houses. But the most remarkable fact is that thirty-four of the forty-three victims were living upon streets in which there is no public sewer, and in houses about which are still tolerated those beastly abominations called cess-pools and privy-vaults. In most of the nine cases where the houses had sewer connections, they were only for kitchen and laundry purposes, and the stinking vault still maintains its position in the back yard. Observe this fact also: a considerable majority of the population of New Haven resides upon the sewered streets, and yet only nine out of forty-three deaths from a disease which is chiefly caused by foul air occur among the majority; while thirty-four of the forty-three are among the minority, who reside in dwellings surrounded by the fragrant companionship of time-honored filth-pits. Any person can draw intelligent inference from the above plain facts."
The remaining important factor in the production of infantile diarrhœa is overcrowding. This, indeed, is but the occasion of one of the most dangerous forms of filth, in the shape of air deprived of its vitalizing qualities, and charged with impurities derived from the breath and bodies of men and animals, which is sometimes known as "crowd-poison." "It is this air," says Dr. Richardson, "in our overcrowded towns and cities, where there is no vegetation to revivify it, which we distinguish as something so different from the fresh country air that streams over meadow and forest. It is the breathing of this air that makes the child of the town so pale and lax and feeble, as compared with the child of the country. It is this air that renders the atmosphere of the crowded hospital so deficient in sustaining power. It is this air that gives to many of our public institutions, in which large masses of our poorer, ill-clad, uncleansed masses are herded together, that 'poor-smell,' as it is called, which is so depressing both to the senses and to the animal power."
Cholera infantum is well known to be almost exclusively a disease of cities, and absolutely so in its epidemic form. The city of Manchester, N. H., contains only about one tenth of the population of the State, yet in 1883 it furnished nearly one half of the whole number of deaths from this disease; while in 1885, the three cities of Dover, Portsmouth, and Manchester, together containing less than one sixth of the whole population, reported considerably more than one half of the entire mortality from cholera infantum. The State of Massachusetts contains eighteen cities and towns of more than fifteen thousand inhabitants, while Vermont has none. The mortality from cholera infantum in 1883 was 3·49 per 10,000 in Vermont, and 9·53 per 10,000 in Massachusetts.
According to Dr. Farr, the mortality of districts increases with the density of their population; not, however, in the direct proportion of their densities, but as the sixth root of their densities. But while the total mortality increases in this proportion, the mortality imder five increases in a much greater ratio. Thus, with a density of 166 to a square mile, the death-rate at all ages is 16·94 per 1,000, while of those under five it is 37·8 per 1,000. This ratio increases gradually and with considerable regularity with the density of the population in the districts considered, until with a population of 65,823 to a square mile, the death-rate for all ages reaches 38·67 per 1,000, and for those under five, 139·52 per 1,000—that is, while the total death-rate is increased a little more than twofold, that under five was nearly-quadrupled.
Another fruitful cause of death, and one which especially helps to swell the mortality of infancy, is contagion, including in that term all those influences by which disease is communicated from one individual to another, either by direct contact or through the atmosphere. This is the prime cause of the large class of zymotic or germ diseases, which in their various forms carry off nearly one third of all children dying under the age of five years. In general terms it may be stated that, while contagion is the direct cause of these diseases, yet their prevalence and fatality are in inverse proportion to the general observance of the laws of public sanitation and private hygiene.
The depressing influences of extreme poverty, filth in all its forms, and the overcrowding of large cities, are great promoters of contagion, resulting in epidemics, plagues, and pestilences; while strict cleanliness, fresh air, pure water, and hygienic living, tend greatly to restrict its spread and prevent these results. Temperature, also, has much to do with the prevalence of zymotic diseases, some of which require a certain high degree of average temperature, while others thrive best in cold weather. Extreme degrees of heat and cold (boiling and freezing) destroy the life of most germs, but not of all. Thus, the first sharp frosts of autumn cut short the progress of yellow fever, while diphtheria is somewhat more prevalent in winter than in summer. The strict isolation of the sick, and careful disinfection of their surroundings, are also essential to the limitation or prevention of contagious diseases.
The death-rate among infants and young children is especially influenced by the five principal acute contagious or infectious diseases—namely, measles, scarlet fever, small-pox, diphtheria, and whooping-cough. According to English life-tables, these five diseases were the cause of 18·8 per cent of the entire mortality under five for the ten years from 1860 to 1870, while the average age of all persons dying from whooping-cough was 1·8 years, from measles 2·7 years, from diphtheria and scarlet fever 5·8 years, and from small-pox 11·9 years.
This latter disease, which was formerly by far the most fatal of the class, has of late years been shorn of its terrors by the beneficent discovery of Jenner. Thus, during the sixteenth and seventeenth centuries, it is estimated that from seven to twelve per cent of all deaths were caused by small-pox; while since the general introduction of vaccination the proportion has been reduced to less than one per cent.
The next most dreaded and at present the most fatal of these diseases is scarlet fever. In England, during the period already named, 6·7 per cent of all deaths under five were due to this cause; while an analysis of the registration reports of Massachusetts shows that two thirds of the deaths from this cause occur under five years of age.
Diphtheria is especially a filth-disease as well as a contagious disease; while the prevalence of each member of the class varies greatly in different localities and different years, being largely dependent upon certain unknown epidemic influences, which as yet have not been brought under the control of man.