The problem of the control of syphilis as a contagious disease is the least appreciated and the most important one in the whole field. It should be the key to our whole attitude toward the disease, and once given its rightful place in our minds, will revolutionize our situation with regard to it. For that reason, while some repetition of what has gone before may be unavoidable, it will be worth while to gather in one chapter the details relating to the question of how the disease is spread about.

Two bed-rock facts stand out as the basis for the whole discussion. First, for practical purposes syphilis is contagious only in the primary and secondary stages. Second, syphilis is transmitted only by open sores or lesions whose discharges contain the germs, or by objects which are contaminated by those discharges. Infection with syphilis by such fluids as the blood, milk, or spermatic fluid uncontaminated by contact with active lesions is at least unusual.

Contagiousness in the Primary Stage.—The chancre is always contagious. If it is covered with a dry crust, it is, of course, less so, but as soon as the crust is rubbed off, the germ-infested surface is exposed and the thin, watery discharge contains immense numbers of the organisms, especially in the first two or three weeks. This is just as true of a chancre on the lip or chin as on the genitals. Chancres which are in moist places, as in the mouth, or on the neck of the womb, or under the foreskin, are especially dangerous, because the moisture keeps the germs on the surface.

Contagiousness in the Secondary Stage.—In the secondary period, when the body is simply filled with germs, one would expect the risk to be even greater than in the primary stage. As a matter of fact, however, no matter how many germs there are in the body, the only ones that are dangerous to others are those that are able to get to the surface. A syphilitic nodule or hard pimple on the hand or face is not contagious so long as the skin is dry and unbroken over it. The sores which occur in the moist, warm, protected places, like the mouth, on the lips, about the genitals, and in the folds of the body, such as the thighs, groins, armpits, and under the breasts in women, are, like the chancre, the real sources of danger in the spread of the disease.

Relatively Non-contagious Character of Late Syphilis.—The older a syphilis is, the less dangerous it becomes. It is the fresh infection and the early years which are a menace to others. It will be recalled that the germs die out in the body in immense numbers after the active secondary period is over, so that when the tertiary stage is reached, there is only a handful left, so to speak. The germs in a tertiary sore are so few in number that for practical purposes it is safe to say they may be disregarded, and that for that reason late syphilis is practically harmless for others. Just as every syphilitic runs a gradual course to a tertiary period, so every syphilitic in time becomes non-contagious, almost regardless of treatment.

The Time Element in Contagiousness.—It is the time that it takes an untreated case to reach a non-infectious stage and the events or conditions which can occur in the interval, that perpetuate syphilis among us. The chancre is contagious for several weeks, and few syphilitics escape having some contagious secondary lesions the first year. These are often inconspicuous and misunderstood. They may be mistaken for cold sores or the lesions about the opening of the rectum may be mistaken for hemorrhoids, or piles. The recurrence of these same kinds of sores may make the patient dangerous from time to time to those about him, without his knowledge. It is an unfortunate thing that the most contagious lesions of syphilis often give the patient least warning of their presence in the form of pain or discomfort. While they can often be recognized on sight by a physician, it is sometimes necessary to examine them with a dark-field microscope to prove their character by finding the germs. It is a safer rule to regard every open sore or suspicious patch in a syphilitic as infectious until it is proved not to be so.

Contagious Recurrences or Relapses.—The duration of the infectious period in untreated cases and the proportion of infectious lesions in a given case vary a good deal and both may be matters of the utmost importance. Some persons with syphilis may have almost no recognizable lesions after the chancre has disappeared. Others under the same conditions may have crop after crop of them. There is a kind of case in which recurrences are especially common on the mucous or moist surfaces of the mouth and throat, and such patients may hardly be free from them or from warty and moist growths about the genitals during the first five years of the disease, unless they are continuously and thoroughly treated. Irritation about the genitals and the use of tobacco in the mouth encourage the appearance of contagious patches. Smokers, chewers, persons with foul mouths and bad teeth, and prostitutes are especially dangerous for these reasons.

Average Contagious Period.—It is a safe general rule, the product of long experience, to consider a person with an untreated[10] syphilis as decidedly infectious for the first three years of his disease, and somewhat so the next two years. The duration of infectiousness may be longer, although it is not the rule. It must be said, however, that more exact study of this matter since the germ of syphilis was discovered has tended to show that the contagious period is apt to be longer than was at first supposed, and has taught us the importance of hidden sores in such places as the throat and vagina.

Individual Resistance to Infection.—The contagiousness of untreated syphilis is influenced by two other factors besides the mere lapse of time. The first of these is the resistance or opposition offered to the germ by the person to whom the infection is carried. The second is the feebleness of the germ itself, and the ease with which it dies when removed from the body. In regard to the first of these factors, while natural resistance to the disease in uninfected persons is an uncertain quantity, it is very probable that it exists. It is certain that the absence of any break in the skin on which the germs are deposited makes a decided difference if it does not entirely remove the risk of infection. A favorable place for the germ to get a foothold is a matter of the greatest importance. When, however, it is remembered that such a break may exist and not be visible, it is evident that little reliance should be placed on this factor in estimating the risk or possibility of infection.

Transmission by Infected Articles.—The feebleness of the germ and the ease with which it is destroyed are its redeeming qualities. This is of special importance in considering transmission by contact with infected articles. Nothing which is absolutely dry will transmit syphilis. Moisture is necessary to infection with it, and only articles which have been moistened, such as dressings containing the discharges, and objects, such as cups, eating utensils, pipes, common towels, and instruments which come in contact with open sores or their discharges, are likely to be dangerous. Moreover, even though these objects remain moist, the spirochetes are likely to die out within six or seven hours, and may lose their infectiousness before this. Smooth, non-absorbent surfaces, especially of metal, are unfavorable for the germ. Wash-basins, dishes, silverware, and toilet articles are usually satisfactorily disinfected by hot soapsuds, followed by drying. Barbers, dentists, nurses, and physicians who take care at least to disinfect instruments and other objects brought into contact with patients with carbolic acid and alcohol will never transmit syphilitic infection to others. Toilet-seats, bath-tubs, and door-knobs, although theoretically dangerous, are practically never so, and syphilitic infection transmitted by them can be dismissed as all but unknown. This is in marked contrast to gonorrhea, which in the case of little girls can be transmitted apparently by toilet-seats. Much depends, as has been said, on placing the germ on a favorable ground for inoculation, and the bare skin, unless the virus is massaged or rubbed in, is certainly not a favorable situation. Many experts do not hesitate to handle infectious lesions with the fingers provided the skin is not broken, relying simply on the immediate use of soap and water, and perhaps alcohol, to remove the germ. While this may be a risk, it should, none the less, reassure those who are inclined to an unreasoning terror of infection whenever they encounter the disease.

Transmission Under the Conditions of Every-day Life.—The question of just how dangerous the worker with foodstuffs may be to others when he has active contagious lesions is unsettled. Recent surveys of various types of workers have tended to show that syphilis in transmissible form is not especially prevalent among them. The same general principle applies here as elsewhere. The risk of infection with syphilis increases with dirty and unsanitary conditions, and becomes serious when there is opportunity for moist materials to be transferred to sensitive surfaces, like the mouth, sufficiently soon after they have left the syphilitic person for the germs to be still alive. That the real extent of the risk is not known does not make it any the less important that persons who have opportunity to handle materials in which this may occur should be subject to frequent sanitary inspection. Restaurants in which the silverware is not properly cleaned, and is used over and over at frequent intervals, and in which there is a careless and unsanitary type of personal service, can hardly be regarded as safe. While there is no need for hysterical alarm over such possibilities, it is just as well to provide for them. Crowding, close quarters, and insufficient sanitary conveniences in stores and offices, in restaurants or tenements, provide just the conditions in which accidental infection may occur. A gang of men with a common bucket and drinking cup may be at the mercy of syphilis if one member is in a contagious condition. A syphilitic might cough into the air with little risk, since the germs would die before they could find a favorable place to infect. But a syphilitic who coughs directly into one's face with a mouth full of spirochetes multiplies the risk considerably. The public towel is certainly dangerous—almost as much so as the common drinking cup. The possibility of syphilitic infection by cutting the knuckle of the hand against the teeth of an opponent in striking a blow upon his mouth should not be overlooked, and the occurrence is common enough for this type of chancre to have received the special name of brawl, or fist, chancre.

Accidental Syphilis in Physicians and Nurses.—Another type of infection ought not to go unmentioned—that to which physicians and nurses are exposed in operating on or handling patients with active syphilis. Before the day of rubber gloves such things were much more common perhaps than they are now, yet they are common enough at the present time. Most of the risk occurs in exploring or working in cavities of the body containing infected discharges. The blood may become infected in passing over active sores. The risk from all these sources is so considerable that it is justifiable as a measure of protection to a hospital staff to take a blood test on every patient who applies for treatment in a hospital, to say nothing of the advantage which this would be to the patient.

Transmission by Intimate Contacts—Kissing.—As we pass from the less to the more intimate means of contact between the syphilitic person and others, the risk of transmitting syphilis may be said to increase enormously. The fundamental conditions of moisture, a susceptible surface, protection of the germ from drying and from air, and possibly also massage or rubbing, are here better satisfied than in the risks thus far considered. Kissing, caresses, and sexual relations make up the origin of an overwhelming proportion of syphilitic infection. Infections are, of course, traceable to the nursing of syphilitic infants. It is through these sources of contact that syphilis invades the family especially. Many a syphilitic who realizes that he should not have sexual relations with his wife while he has the disease in active form will thoughtlessly infect her or his children by kissing. Kissing games are potentially dangerous, and a classical example of this danger is that of a reported case[11] in which a young man in Philadelphia infected seven young girls in one game, all of whom developed chancres on the lips or cheeks. It is no great rarity to find a syphilis dating from a sore on the lip that developed while a young couple were engaged. Certainly the indiscriminate kissing of strangers is as dangerous an indulgence as can be imagined. Syphilis does not by any means invariably follow a syphilitic's kiss, but the risk, although not computable in figures, is large enough to make even the impulsive pause. The combination of a cold sore or a small crack on the lip of the one and a mucous patch inside the lip of the other brings disaster very near. Children are sometimes the unhappy victims of this sort of thing, and it should be resented as an insult for a stranger to attempt to kiss another's child, no matter on what part of the body. It would be easy to multiply instances of the ways in which syphilis may be spread by the careless or ignorant in the close associations of family life, but little would be accomplished by such elaboration that would not occur to one who took the trouble to acquaint himself with the principles already discussed.

The Sexual Transmission of Syphilis.—The sexual transmission of syphilis is beyond question the most important factor in the spread of the disease. Here all the essential conditions for giving the germ a foothold on the body are satisfied. The genitals are especially fitted to keep the germs in an active condition because of the ease with which air is excluded from the numerous folds about these parts. It is remarkable what trifling lesions can harbor them by the million, and how completely, especially in the case of women, syphilitic persons may be ignorant of the danger for others. Sexual transmission of syphilis is simply a physiologic fact, and in no sense to be confounded with questions of innocence and guilt in relation to the acquiring of the disease. A chancre acquired from a drinking cup or pipe may be transmitted to husband or wife through a mucous patch on the genitals and to children through an infected mother, without the question of innocence or guilt ever having arisen. On the other hand, chancres on parts other than the genitals may be acquired in any but innocent ways. It is impossible to be fair or to think clearly so long as we allow the question of innocence or guilt to color our thought about the genital transmission of syphilis. That syphilis is so largely a sexually transmitted disease is an incidental rather than the essential fact from the broadly social point of view. We should recognize it only to the extent that is necessary to give us control over it—not allow it to hold us helplessly in its grip because we cannot separate it from the idea of sexual indiscretion. There is a form of narrow-minded self-righteousness about these things that sets the stamp of vice on innocent and guilty alike simply on the strength of the sexual transmission of syphilis. In the effort to avoid so mistaken and heartless a view, we cannot remind ourselves too often that syphilis is a disease and not a crime, and as such must be approached with the impulse to heal and make whole, and not to heap further misfortune on its victim or take vengeance on him.

Extragenital and Marital Syphilis.—Estimates of the ratio of genital to non-genital or so-called extra-genital infection in syphilis vary a good deal, and are largely the products of the clinical period in the history of the disease before the days of more exact methods of detecting its presence. The older statistics estimate from 5 to 10 per cent of all syphilitic infections to be of non-genital origin, while the remaining 90 per cent are genital. As we become better able to recognize hidden syphilis, we shall probably find that the percentage of non-genital infections will increase.

The physician's suspicions are easily aroused by a genital sore, less so by one on the lip or the tonsil, for example. The same thing is true of the layman. Syphilis which starts from a chancre elsewhere than on the genitals runs the same course and may conceal itself quite as effectively as syphilis from the usual sources, and for that reason may even more easily escape notice because misinterpreted at the start. It is my personal impression that careful study of patients with syphilis, and of those who live with them, would bring to light many overlooked extragenital infections, especially among those who are the victims of crowding, poor living conditions, and ignorance. Estimates on the amount of syphilis which is contracted in marriage are apt to be largely guesswork in the absence of reliable vital statistics on the disease. Fournier believed that 20 per cent of syphilis in women was contracted in marriage. So much syphilis in married women is unsuspected, and so little of what is recognized is traceable to outside sources, that 50 per cent seems a nearer estimate than twenty.