A system of practical medicine. By American authors. Vol. 2

by Unknown

As illustrating the conjoined operation of all these various causes, together with filth and foul effluvia, more especially exposure to cold, the story of dysentery was never better told than by Sir James MacGrigor, who, in speaking of the Peninsular campaign, remarks that "the army during June as well as July was traversing Castile, where it was exposed to the direct influence of a burning sun darting its rays through a sky without a single cloud, the troops marching and fighting during the day, and bivouacking during the night on arid, unsheltered plains. They felt at times every vicissitude of heat and cold. In the rapid advance they could not be regularly supplied with food or had not time to cook it, and not unfrequently indulged in bad wine and unripe fruit." ... The thousands of sick (chiefly from diarrhoea, dysentery, and remittent fever) were hurried off to Ciudad Rodrigo, the nearest hospital-station to the frontier of Portugal, a town "composed chiefly of ruins with very narrow streets," ... and from having been "so much the object of contest, and alternately the site of the hospitals of all the contending armies, nearly twenty thousand bodies were calculated to have been put into the earth either in the town or under its walls in the course of a few months." ... "It may easily be conceived," the author adds, "in what state cases of dysentery must have arrived after having sustained a journey in extent from four to twenty days, conveyed chiefly in bullock-carts or on the backs of mules, sometimes under incessant rain for several days together."

It is really quite superfluous to cite further opinions or examples in illustration of a fact which is so universally conceded as to be exaggerated in its general significance. Taking cold is the common idea of the cause of dysentery, and is always a satisfactory explanation in a case of obscure origin in this or any disease, even though the patient may be able to recall no possible exposure. The physician himself contents himself only too easily with resort to this refuge, and with further appeal to the locus minoris resistentiæ, as the explanation of the seat of the disease, which he hopes to cure with the aid of the vis medicatrix naturæ. But taking cold is only a popular paraphrase for contracting a disease, and will bear no scientific analysis of its meaning. Mere reduction of temperature will certainly not produce a disease whose habitat is the hottest zone, nor will a sudden chill of the surface be accepted as a sufficient cause so long as men daily remain exempt after a sudden plunge into cold water. Some other factor must be invoked to account for the outbreak of specific (epidemic) dysentery.

The influence of the nervous system, the mechanical and chemical or specific action of the ingesta and dejecta, remain to be especially considered in the etiology of the disease.

The influence of the nervous system is more directly seen in the production of diarrhoeas than dysenteries, but that sustained disturbances of the emotions play an important part in the production of dysentery is shown by the greater frequency of the disease among prisoners of war. In the Franco-Prussian war the French prisoners suffered more than the Germans, and the records of prison-life in our own war, at Andersonville, Libby, and Salisbury, furnish ghastly chapters in the history of this disease. Many other factors contribute to the development of the disease under such circumstances—in fact, all the cruelties of man's inhumanity to man—but the influence of the nervous system is too plain to be mistaken. The communication between the cervical ganglia and the sympathetic nerve-fibres which preside over the cerebral circulation and regulate intestinal peristalsis has been invoked (Glax) in explanation of the direct action of the brain upon the intestinal canal. Curious in this connection is the claim of Savignac, who considered dysentery a disease of the nervous system because in two cases he found spots of softening in the spinal cord.

The noxious action of irritating articles of diet has been recognized in the production of dysentery from the earliest times. Aretæus mentions acrid foods, and Aëtius crudities, as directly causing the disease; and unripe fruits have been especially stigmatized from the days of Galen down. Decomposing, fermenting food and drink cause diarrhoea much more frequently than dysentery, but if the irritation be severe or prolonged, or be superimposed upon a catarrhal state, a diarrhoea, it is claimed, may pass over into dysentery. Impurities in drinking-water were charged with causing dysentery by Hippocrates himself, with whom Avicenna fully coincided; and the view that epidemics of the disease are caused in this way has been abundantly advocated ever since. So far as running water is concerned, the researches of Pettenkofer have shown that all impurities are speedily destroyed, for even at the distance of a few rods from the reception of sewage the water is perfectly safe. Nor does standing water lack the means of purification, provided it be sufficiently exposed to the air. The observations of Roth and Lex have shown that the water of the wells of fifteen churchyards in Berlin contained nitrates in less quantity than the average wells in the city; and Fleck made a similar statement with regard to the wells of Dresden. But no one in our day would rely upon a mere chemical analysis in the detection of the organic poisons or particles of disease. It is the physiological test which remains the most conclusive, and the evidence in favor of the production of dysentery by the ingestion of drinking-water poisoned by the reception of excrementitious matter, especially the dejecta of disease, is as positive as in the case of typhoid fever. Thus, De Renzy found that the number of cases of dysentery "immediately decreased at Sibsagor (India) so soon as better drinking-water was obtained from wells deeply sunk and lined with earthenware glazed pipes;" and Payne found that the cases of dysentery (as well as diarrhoea and lumbrici) almost disappeared from the asylum at Calcutta as soon as the habit of drinking water from the latrines was stopped. In face of such facts, which might be infinitely multiplied, one would hesitate to subscribe to the statement of Fergusson that "true dysentery is the offspring of heat and moisture, of moist cold in any shape after excessive heat; but nothing that a man could put into him would ever give him a true dysentery."

The relation of the action of the dejecta must be studied from the double standpoint of the development and the dissemination of the disease, as originating the catarrhal form by mechanical or chemical irritation of the intestinal mucosa, and as spreading the specific form by direct or indirect infection.

By the time the contents of the alimentary canal have reached the colon they have become, through absorption of their fluids, more or less inspissated, and hence as hard, globular masses fill the sacculi of the large intestine. Mechanical irritations by crude, indigestible residue of any kind of food, more especially of vegetable food, or chemical irritations, as by fermenting food, accumulate in this region, fret the mucous membrane into a state of inflammation, even ulceration, and produce the anatomical picture and the clinical signs of dysentery. If there be a superadded or pre-existent catarrhal condition of the mucosa or a defective peristalsis of the muscular coat, which is sluggish enough at best, the development of a pathological state is much facilitated. And there is no doubt that the dysentery of the tropics is increased by the bulky, indigestible, feces-producing character of the food.

The anatomical construction of the colon may also favor these processes by its mere abnormal length or size or by duplicatures in its course. The protracted constipation of the insane, in whom the transverse colon is often found elongated or displaced—to assume the well-known M-form, for instance—may partially account for the frequency of dysentery in these cases (Virchow), though the neglect which comes of preoccupation of the mind, with the general inhibition of peristalsis, is a more frequent cause of the constipation.

Wernich (1879) sums up the action of the feces, independently of a specific cause, in attributing the dysentery of the tropics, aside from the great changes of temperature, to (1) bad aborts, the dejecta being deposited in all parts of the towns or into an opening made in the floor of the hut, with which is associated total lack of personal cleanliness; (2) to the diet, which causes a large amount of feces; and (3) to the relaxation of the intestine in general, permitting accumulations of infecting matter.

Upon the question of the propagation of the disease by the dejecta rest in great measure the all-important problems of a specific virus and of the contagiousness of the disease.