Infectiousness

“ We have endeavoured to illustrate the great obscurity of its operation by an allusion to generation, digestion, and other animal functions, with which it is equally obscure and inexplicable. It is similar to generation in this, that its influence does not pass from one species of animal to another; for the poison of the plague, that of the small pox, that of fever, and the venereal disease, do not affect brutes47, nor do the infectious diseases of brutes affect different species of them, nor the human species. ”

“ One half of the sickness in our land is catching sickness. That is, it is sickness which passes from one person to another and is caused by tiny germs or microbes. A catching sickness is called a contagious disease. Some of the common catching diseases are sore throat, colds, diphtheria, pneumonia, typhoid fever, measles, grippe, and whooping cough.
How we get a Catching Sickness.—We get a catching sickness by taking into our bodies the germs from some other person. The germs of the sick do not pass off in the breath, but in the spit or anything else which comes from their bodies. ”

“ This enormous mass of disease furnishes ample material for infection on every side. A most infinitesimal germ, invisible, impalpable, would suffice to infect a single human body, and that body might suffice to infect very many others. ”

“ Many infections begin acutely and later change to the chronic type. Syphilis in man is a good illustration.
The differences between acute and chronic infections are partly due to the nature of the organism, partly to the number of organisms introduced and the point of their introduction and partly to the resistance of the animal infected.
An infectious disease is said to be specific when one kind of organism is responsible for its manifestations—as diphtheria due to the Corynebacterium diphtheriæ, lockjaw due to Clostridium tetani, Texas fever due to the Piroplasma bigeminum, etc. ”

“ Nothing is more important for us to recognize than that our diseases are contracted from neighboring subjects just in proportion as we are closely associated with them. From our fellowmen we contract, as everyone knows, a large number of diseases, either by direct contact or by means of the air that surrounds us. From the earth we get hook-worms and other animal parasites, either by coming directly in contact with it or through eating uncooked fruits and vegetables. From water we get typhoid fever, dysentery, cholera, and many other parasitic diseases. ”

“ I have said that our knowledge in this direction has, even in the last two or three years, made enormous strides, and it is now almost a matter of certainty that all contagious or infectious disorders, as well as many others, are but the expression of the fact that minute living bodies have made a resting-place for themselves in or upon other living tissues; and that the development of the phenomena of these morbid states is but an indication of their presence and reproductive activity—either as cause, or as an accompaniment of these disease manifestations. ”

“ When the germs of the virus mature in the living being, ready for reproduction in another person, they produce the acute contagious diseases, including small-pox, chicken-pox, scarlet fever, typhns fever, relapsing fever; measles, miliary fever, influenza, whooping-cough, and hydrophobia. ”

“ The small quantity of diseased organic matter originally introduced into the system by absorption, acts as a ferment and reproduces itself in the mass of the blood, until this becomes unfitted for the performance of its functions and the animal is killed; the active principle being thus copiously present, is exuded from the skin and lungs and gives a contagious character to the disease, or it remains only in the blood, or is secreted in pustules, constituting infection, by which the disease may be communicated to some other person. ”

“ For the extension of infection from one individual to another the infecting organisms must in some way be transferred. The most important of the conditions influencing this are the localization of the disease and the character of the infectious organisms, particularly with regard to their resistance to the conditions met with outside of the body. The seat of disease influences the discharge of organisms; thus, if the disease involve any of the surfaces the organisms become mingled with the secretions of the surface and are discharged with these. ”

“ Which should be endeavour'd, as well by purifying the Air we breathe, as also by fortifying our selves against taking the Infection at our Nostrils, Mouth, or Pores of the Body, which are the chiefest, if not the only parts the Poison creeps in at. ”

“ I say, I must be allowed to believe, that no one in this whole Nation ever sreceiv’d the Sickness or Infection, but who receiv’d it in the ordinary Way of Infection from some Body, or the Cloaths, or touch, or stench of some Body that was infected before. ”

“ The most important congenital infections are syphilis, gonorrhœa, tuberculosis, variola, typhoid, pyogenic infection, tetanus, measles, scarlatina, influenza, meningitis, malaria, recurrent fever, pneumococcus, colon bacillus and others, mostly very rare. ”

“ Occupation.—During one epidemic, water-carriers, or those who used much water, or who dealt in oil and fats were found comparatively free; but this observation cannot be relied upon. Those whose business requires them to come much in contact with the sick, and also those who are engaged in cleaning are naturally more exposed to infection. 16 It has been said that one attack generally protects from a second, which, if it occurs, usually runs a mild course.
Sanitation and Personal Hygiene.—Plague, germs thrive in filth. ”

“ If not infectious unto all, but unto some particular persons only, I say then it ought not to be deemed or esteemed infectious at all, at least not any more infectious than are all other diseases, viz. small-pox, scurvy, pleurisy, ague, gout, &c. since (though the notion of infection be laid aside) there is not a person born into the world that hath not at some time of his life (as his nativity shall truly show) some one disease or other. ”

“ The 'Germ Theory,' briefly stated, is this. There are all around us millions of micro-organisms, parasites which thrive and grow by feeding upon the animal world. In proportion as these parasities infest, and thrive upon a given individual, so will that individual become diseased, and it has been shown that in many cases a special germ will cause a special disease. I could deliver you a lecture, hours long, upon the classification, morphology, and pathogenic action of bacteria, but I wish at present to lead your mind into a different channel. ”

“ Now we know that many diseases called infectious are caused by micro-organisms, and we group others under this class because we hold theoretically that they have their origin in microbes not yet isolated. Hence we define an infectious disease as one which is caused by a living pathogenic micro-organism, which enters the tissues from without, and is capable of multiplying therein. These micro-organisms have a time of incubation during which a poison is made in the tissues, and this brings about the intoxication we call the disease. ”

“ Remember that we and the disease germs are both cells; and that, if they are numbered by millions, we are by billions; and that we are made up of far the older and the tougher cells of the two. Except in a few of the most virulent and deadly of fevers, like the famous "Black Death," or bubonic plague, and lock-jaw, or tetanus, ninety-five times out of a hundred when disease germs get into our bodies, it is our bodies that eat up the germs instead of the germs our bodies. Keep away from disease germs all that you reasonably and possibly can ”

“ In this manner they cause the particular symptoms that are characteristic of a special infectious disease. Why is it that some persons, on exposure to an infectious disease, contract the malady while others similarly exposed do not? ”

“ Such affections chiefly comprise fevers par excellence—the epidemic, endemic, and contagious or infectious disorders—which suddenly attack masses of people, which spring from different sorts of malaria, or from specific communicable poisons ”

“ Moreover, the extirpation of one disease after another, the careful isolation of all infectious cases, and the destruction of every article that could preserve or convey the poisonous germs, has in the course of ages enabled us utterly to destroy them. ”

“ The Progress of an Epidemic That it is at least as difficult to stay a moral infection as a physical one; that such a disease will spread with the malignity and rapidity of the Plague; that the contagion, when it has once made head, will spare no pursuit or condition, but will lay hold on people in the soundest health, and become developed in the most unlikely constitutions: is a fact as firmly established by experience as that we human creatures breathe an atmosphere. ”

“ Infectious diseases, on the other hand, belong to the people, and not to the place. They are communicated from one person to another through the air, or by means of infected articles of clothing, etc., and they attack the strong and healthy, no less than the weak. Among such are smallpox, scarlet fever, measles, etc. ”

“ Definition.— Plague is a specific, inoculable, and otherwise communicable epidemic disease common to man and many of the lower animals. It is characterized by fever, adenitis, a rapid course, a very high mortality, and the presence of a specific bacterium, Bacillus pestis, in the lymphatic glands, viscera, and blood. In a large proportion of cases buboes form in the groins, armpits, or neck. ”

“ Loathsome contagious diseases include those whose presence excites abhorrence in others, and which are essentially chronic, such as favus, ringworm of the scalp, parasitic fungus diseases, Madura foot, leprosy and venereal disease. Dangerous contagious diseases are such as trachoma, filariasis, hookworm infection, amœbic dysentery, and endemic hematuria. ”

“ In the latter, the name of the man, date of admission, and nature of disease, is placed over the bed of each patient, which in any contagious disease gives timely warning to any one fearing infection. ”

“ While fortunately none of these disease germs can breed, or reproduce their kind, outside the human body, and while comparatively few of them live very long outside the human {304}body, they may, if mixed with food or caught upon clothing, hangings, walls, or floors, remain in a sort of torpid, but still infectious, condition for weeks or even months. ”

“ The Smoke continually oozed from All Parts of his Body.
"My dear fellow," he said impressively, "you must understand that all diseases are [Pg 107] caused by germs—microscopic bugs and plants, you know, many of them so small that they are invisible to an ordinary microscope, or, if seen at all, are not recognized. There are thousands and thousands of them, and each and every one has its mission in life, and preys upon and destroys other germs. Now, the human body is constantly getting a lot of germs inside of it which do not belong there. ”

“ The only important point to be ascertained is, whether there be in nature any substance which, applied to the internal parts of the body, or to a wound, will instantly disorder the whole in such a manner as to bring on a violent disease which may prove mortal in a short time. If any such there is, that substance, whether solid or fluid, visible or invisible, may with propriety be called contagion; and if any such proceeds222 from the body of a diseased person to one in health, the vapour so proceeding is infection. ”

“ Those which come through the mouth come with the food or drink which we swallow; those which enter through the nose must be traced to the air; and those which enter through the skin come in most cases through contact with some infected object, such as direct contact with the body of an infected person or his clothing or some objects he has handled, etc. Occasionally, perhaps, the bacteria may get into the skin from the air, but this is certainly uncommon and confined to a few diseases. ”

“ There are no epidemical nor contagious diseases that attack every person who breathes the same air, or that is in contact with the infection, else whole regions would be depopulated. The habit must be graduated, or adapted, for the reception of a disease. ”

“ Fevers were classed of old as putrid diseases, and any one who has witnessed the prompt decomposition and the foul emanations of fever stricken beings, whether human or brute, can readily understand that it was no very India rubber like stretch of the imagination that led our forefathers to confound contagion with putrescence. ”

“ The sources from which the infection is derived he believed to be—1st, from the dead body, regardless of age, sex, or disease, no matter whether the latter is of puerperal or non-puerperal origin, the virulence depending upon the stage of decomposition; 2d, diseased persons, whose malady is associated with decomposition of animal tissue, no matter whether the affected person suffers from childbed fever or not, the decomposing matter alone furnishing the product from which infection is derived ”

“ Every particle of animal or vegetable matter, even if only a single grain in weight, by exposure to the air, putrefies, breeds, and attracts to itself thousands of microbes, and becomes a center of infection. Thus, in a piece of street dirt containing organic matter, we may find upon examination, the germs of typhoid fever, diphtheria, scarlet fever, or consumption. ”