# Popular Science Monthly/Volume 44/January 1894/Emotions and Infection

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* EMOTIONS AND INFECTION.
By M. CH. FÉRÉ.
THE relation that exists between the activity of the nervous system and resistance to causes of destruction may be illustrated by facts of different sorts. It has been often remarked, and the registers of the academies confirm it, that we find many old men among scientific and literary people. Whether the resistance in question is attributable to the habitual exercise of the mental functions, or vital resistance and mental power are conjointly attributable to a good natural organization, the relation is no less certain. The same relation is found, susceptible of like interpretations, among persons without cultivation, whose existence has been, as we might say, all organic, and who are more exposed to the action of atmospheric inclemencies and to all the chances of mortality. The remark is attributed to Baillon by Cabanis that porters and laboring men offer only a feeble resistance to blood-letting and purgatives. Nothing is more remarkable than the facility with which weak-minded persons succumb to acute diseases of every kind.
Many violent maladies have been supposed to have been produced under the operation of moral influences. Sennert believed that fear was capable of provoking erysipelas, Hoffmann also made fear and the adynamy resulting from it play an important part as the predisposing cause of contagious diseases. Dr. H. Tuke believed, in particular, in the influence of fear upon the contagion of rabies. The breaking out of rabies has been sometimes observed after psychic emotion. Bouley cites the case of a dog which went mad after having been immersed in water. Gamléia cites a similar case in a man, and another in a woman who was frightened by a drunken man. In order to avoid the influence of fear, Desgenettes concealed the name and the nature of the plague; and it is to be remarked further that the Turks died less rapidly of it than the Christians. Cullen supposed that sad emotions favor contagious diseases, and particularly the plague. This disposition to contagion after violent emotions which determine discharge of the secretions may be partly explained by the fact that the conditions that diminish the proportion of the liquids of the blood favor absorption. It, however, seems at least probable that the nervous discharge is accompanied by alterations of the blood and modifications of the interior medium which justify the popular expressions concerning having bad blood and turning the blood. It is admitted that ​violent emotion is capable of causing and of curing intermittent fever. In the latter part of June, 1889, M. Jullien, a surgeon of Saint-Lazare, called me in consultation over a neurasthenic and hypochondriac patient who thought he was suffering from ataxy. He was a vigorous man, without any stigmatic marks of degenerescence, but very emotional. He had had some attacks of marsh fever in Poland about twelve years before, but had not suffered from it since. At St. Petersburg, when near the place where Czar Alexander II tragically perished, he experienced a violent emotion, after which he suffered for three days attacks of well-characterized fever. A new attack came on at Paris a few months before my visit, corresponding with the emotion he experienced on finding a friend dead in the Hopital Beaujon.
The old authors give the moral emotions a part in most eruptive fevers. "We meet them in the etiology of cholera. Pneumonia sometimes appears on the occasion of a strong moral emotion. Rostan relates the story of a woman who was suddenly struck with a very severe pneumonia on receiving news of the death of her son. Grisalle observed it in a woman who, learning that she had been robbed, experienced instantly a violent attack, which was followed promptly by a chill, a stitch in the side, and spitting of blood.
Depressing emotions often seem to have an action on the development of tuberculosis. Laënnec believed that griefs and nnoyances were important constituents in the frequency of phthisis in large cities.
Puerperal infection is also favored by depressing moral emotions. "I have often in my practice," says M. Hervieux, "seen young women in childbed, in a fair way toward recovery, take a chill and become mortally ill after a visit or untimely reproaches from their mother or relatives; or after the agitation or perplexity occasioned by their resolving to abandon their child, unfortunate girls, till then doing well, falling ill on carrying out the resolution and succumbing in a short time." Rivière, Willis, Denman, Delaroche, Paul Dubois, Alexis Moreau, Tonnelé, and others attribute an important part in the etiology of diseases of women in childbed to the moral affections; and this opinion is supported by more recent observations.
The emotions, likewise, have a part in the evolution of surgical diseases, and particularly in their infectious complications. The theories recently put forth to explain contagion and immunity from infectious diseases may agree with the facts we have learned relative to the influence of the emotions. Among these theories is one to which the facts lend an important support. In this theory the mesodermic cells, and particularly the white globules, are charged with the protection of the organism against the ​invasion of microbes. We know that the leucocytes have the property of moving and putting out prolongations, by means of which they surround foreign bodies and force them into the mass of their protoplasm. They behave in a similar way toward microbes, which, once surrounded, are destroyed by a real intracellular digestion, and we give the name of phagocytism to the whole of these operations. Now, dilatation of the peripheric vessels occurs in sthenic emotions, in which it is manifested by ruddiness, increase of volume, and functional exaltation. In asthenic emotions, on the contrary, inverse phenomena betray a diminution of circulation and a decrease in the caliber of the vessels, and consequently a condition unfavorable to the sally of the white globules and to phagoyctism. Asthenic emotions, from this point of view, lead to the same conditions as traumatisms, fatigue (Charrin and Bogen), chill (Pasteur, Wagner, Platania, Charrin), inanition (Canalis and Morpurgo), loss of blood (Serafini), and nervous sections (Charrin and Ruffer, Roger and Herman).
Not only do the conditions of the vessels change, but the phagocytes and the white globules especially are modified as to their vitality and their chimiotaxy, and their property of being attracted or repelled by the microbes or their products of secretion vary under the same circumstances. Under the influence of cold the white globules tend to become paralyzed. MM. Massert and Bordet, whose experiments seem to demonstrate the absence of a relation between the chimiotaxic action of the leucocytes and the condition of the vessels, admit that under defective conditions of nutrition the whole organism is more easily impregnated by a poison which provokes at every point the chimiotactic activity of the leucocytes, which then have no occasion to direct themselves toward any particular point. The modifications in the composition of the blood after nervous excitements and under emotions which we have mentioned can also be adapted to this theory. Experimental data show that in all conditions in which nutrition is deficient—and painful emotion is one of these conditions—infection is caught more easily. Evidence of this is not only derived from animals; I have had occasion to observe on man several facts which give support to results obtained in the laboratory.
Having to revaccinate patients in my practice, I inoculated a dozen hemiplegic persons symmetrically in both arms in order to see whether the paralyzed side would offer a different resistance to the virus. Real vaccine was not developed in any of these patients, all of them having been vaccinated not more than three or four years before. Upon three of them only were developed pustules of false vaccine, exclusively on the hemiplegic side of one, and with a marked predominence of volume and duration on the other two.
​In the case of a little girl eighteen months old, afflicted with infantile spinal paralysis of the left leg, with considerable chill, I made four punctures on the outer side of each arm with a lancet carefully charged with vaccine matter; the inoculation was successful only on the diseased side. Some more recent experiments bear in the same direction. On the other hand, certain medicines quieting to the nervous system, like opium, morphine, chloral, and bromide of potassium, seem also to favor infection.
The influence of the emotions on infection is further susceptible of a direct experimental demonstration. Having under my care a number of weak-minded persons susceptible of taking interest in a monotonous exercise, I profited by the opportunity to try upon a considerable number of animals—pigeons, rabbits, and white mice—the effect of fear, which was excited by means of noise or threatening motions, through several consecutive hours. The experiments may be divided into three groups: 1. The blood of frightened animals and of witnessing animals was sown. While the blood of the latter animals was sterile, that of the former gave in half the cases more or less numerous colonies of microbes. 2. Animals, some of which had been left at rest, and others had been disturbed, were inoculated with cultivations of pathogenic microbes—of carbuncle, hen cholera, pneumo-enteritis of swine, and Fraenkel's pneumococcus. In all the experiments, without exception, the frightened animals died first, if the cultivations were virulent; while if the cultivations were attenuated they alone died or were ill. We have seen animals little susceptible to an infection succumb to it under the influence of fear; frightened pigeons yielded to pneumo-enteritis of swine, while mere witnesses did not appear to be affected at all. 3. On introducing under the skin of the ear or of the brow of rabbits, or under the skin of the wing of pigeons, capillary tubes closed at the end and filled with cultivations of pathogenic microbes or of saprophytes, we discovered considerable differences in the chimiotactic properties of the white globules, according to the condition of the animals. With frightened animals the tubes were often found at the end of thirty-four hours entirely filled with transparent liquid, while with witness animals the tubes containing whitish trails through their whole length were choked at the ends with a compact wad of leucocytes two or three millimetres long. Most of the microbes had disappeared in the case of healthy animals, while a very large number of them remained in the fluid of the other animals, in which the microscope could discover only a very few leucocytes. We are therefore able to show experimentally in frightened animals that one of the conditions of resistance to infection is absent. The study of these facts deserves to be pursued in detail.
We know the influence local traumatisms have on the location ​of the accidents of infection and of diseases of nutrition. Moral shock is in reality equivalent to a cerebral commotion; and, without forcing analogies too far, we are able to understand that it all the more readily can provoke cerebral lesions.—Translated for The Popular Science Monthly from the Revue Scientifique.