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.
[11] Schamberg, J. F.: "An Epidemic of Chancres of the Lip from Kissing," Jour. Amer. Med. Assoc., 1911, lvii, 783.
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.