Part 143

The anthrax poison expends its fatal energy especially on the blood and blood-vessels. The bacilli in the blood use up the available oxygen, so that the circulating liquid becomes venous, dark, and unfitted for the maintenance of the normal functions of life. What is even worse, the ability of the blood to absorb oxygen is greatly impaired. In men and dogs suffering from anthrax the consumption of oxygen was found to be reduced in one instance even by two-thirds, probably in part by reason of the action of the chemical products of the bacillus. A third condition constantly found is embolism of the capillaries by the bacillus and the occurrence of local gangrene.

SYMPTOMS.--Anthrax shows itself in three principal forms: 1st, the apoplectiform; 2d, anthrax fever without local external lesions; and 3d, external localized anthrax. The two last forms correspond in the main to the acute and subacute forms.

The period of incubation varies according to the dose of the poison and the receptivity of the animal. In some cases infection is at once followed by illness. In these it is probably the chemical products that produce the first effect, while the disease caused by the propagation of the bacillus appears later should the animal survive. Such incubation is shortest for the smaller animals (mice, rabbits, guinea-pigs, cats), in which illness usually sets in in from twenty-four to forty-eight hours. In sheep and goats incubation may be extended to three or four days, while in horses and cattle it may last a day longer.

The apoplectiform type attacks animals which a few minutes before seemed in fine health, appetite, and spirits, striking them down as if by lightning, and the victims struggle convulsively for some minutes, expel blood perhaps by the nose or anus, and expire. In the less suddenly fatal cases there may be muscular trembling, unsteady gait, excited breathing, accelerated pulse, tumultuous heart's action, bleeding from some natural orifice, and death in from one to several hours. Occurring as these cases often do in summer, the sudden death is probably hastened by insolation.

In anthrax fever or acute internal anthrax there is loss of appetite, and, in ruminants, of rumination, suppression of milk, dulness, languor, staring coat, or even a rigor, and thirst. Then follows the hot stage, in which the temperature may rise to 106° or 107° F.; there are acceleration of pulse and breathing, petechiæ or a brown or yellowish tinge of the mucous membranes and white parts of the skin, tenderness of the spine, often jerking or clonic spasms of the muscles of the extremities, and much prostration and weakness, the patient hanging back on the halter, leaning against a wall, or swaying when made to move. The feces are usually more or less mingled with blood-clots, or may be at once liquid and bloody. Bloody urine and the discharge of blood from other natural channels are frequent. Some cases are manifestly delirious, and in others the skin crackles on being handled. Remissions are not uncommon, {935} during which the animal remains dull and prostrate. As the disease advances and the blood is robbed of its oxygen, the temperature descends below the natural standard, great weakness and stupor set in, the pupils are widely dilated, and death from asphyxia occurs in one or two days from the onset.

In localized external anthrax the local swellings may be first seen. There are usually some tenderness of the skin, erection of the hair, and the formation of a little nodule, like a hazel-nut or walnut, adherent to the deeper parts of the skin, firm and comparatively painless even when cut. Sometimes the swelling is diffuse, with a dropsical or erysipelatoid aspect, and crackles like parchment when handled. Whether the affection attacks the tongue, the throat, or some part of the head, body, or limbs, the tendency is to gangrene of the part, and, if the subject survives long enough, to an extensive sloughing and unhealthy sore. The sloughs and sores have either a black sanguineous appearance or they are lardaceous and intermixed with streaks of dark red. If fever is not present at the outset, it sets in early, and passes through the same stages as in the acute internal anthrax, the animals being suddenly plunged in prostration and stupor, with dusky yellow or blood-stained mucous membranes, dyspnoea, dilated pupils, convulsions, and death. On the mucous membranes (gloss-anthrax, anthrax angina) the engorgement is usually complicated with bullæ with red or yellow contents, and which on bursting leave unsightly gangrenous ulcers. In all such cases the morbid liquids of the swellings teem with bacilli.

MORBID ANATOMY.--The most characteristic changes are usually met with in the blood. This is black, thick, tarry, uncoagulable or coagulates only in loose diffluent clots, which are redissolved before squeezing out the serum; the fibrin is diminished (often by two-thirds), the red globules are not adherent in rouleaux, and are crenated and broken down and the hæmatin diffused through the liquid, so that it stains the hands or paper deeply; the white globules are increased, probably by reason of the early irritation of the lymphatic glands and spleen by the poison; and it reddens slowly and but slightly on exposure to the air, and speedily passes into decomposition. The blood can scarcely be made to flow in a full stream, but often trickles down the hair and skin by reason of its thick, consistent character. The microphytes above described are usually found in the blood, and always in the affected tissues if examined just after death.

Next to the blood, the spleen presents the most constant lesions, being enlarged (by one-third, one-half, or to double, triple or quadruple its normal size) and gorged with blood (sometimes even to rupture). The lymphatic glands, and especially those adjoining the local anthrax swellings of the tissues, are always enlarged, marked with petechiæ, friable, easily reduced to a pulp, and swarming with bacilli and micrococci. Next to the glands of the affected parts the central ones, the axillary, prepectoral, thoracic, sublumbar, and abdominal, are the most constantly affected. The lymph is reddish and opaque.

Decomposition sets in early, and the resulting gases cause a puffy, emphysematous condition of the connective tissue. The fat and other white tissues are dusky brown or yellow, and petechiated; the muscles are soft, flabby, and dark red or brown, with occasional blood {936} extravasations; the blood-vessels, especially the veins, and the right heart are gorged with black, uncoagulable blood, and have their inner coats blood-stained. The serous membranes present numerous petechiæ, and contain more or less of a reddish serum. The intestines, and sometimes the stomach, are dark red throughout, marked by petechiæ, and are often the seat of thickening from sanguineous or transparent colloid infiltration. The lesions are especially extensive on the small intestines and rectum. The vagina and womb are also the frequent seats of sanguineous infiltration. The liver and kidneys are enlarged, congested, softened, and friable, and the ganglia of the sympathetic are enlarged, congested, and softened. The swellings are of two kinds, sanguineous and colloid. The former, when cut into, present one or more loose clots of black blood or a grumous mass of blood-elements, separating the tissues and often mixed with fetid gases. The colloid exudations are glairy, semi-solid, jelly-like masses, infiltrating the tissues. The tissues affected and the skin covering them are the seat of bacterial embolism and gangrene, and there is no tendency to suppuration. These products swarm with the specific microphytæ.

DIAGNOSIS.--The differential diagnosis of anthrax from other affections due to the propagation of microzymes in the system is not always easy--so much so that a variety of bacteridian and allied diseases (septicæmia in its various forms, erysipelas, swine plague, chicken cholera, poisoning by the micrococci of fungi, black quarter from bacteria, milk sickness, and Texas fever) have been erroneously confounded with this affection. These all show the same dusky or cyanosed mucous membranes, disintegrating blood-globules, loose blood-clots, petechiæ, blood-extravasations, sudden and great prostration, and enlargement and congestion of the lymphatic glands or spleen. In some of these the duration of incubation (in swine plague six to fourteen days and in Texas fever one month) serves to distinguish, while in the majority the microzyme is globular (Texas fever, micrococcus of fungi-poisoning, chicken cholera); in swine plague the cocci are arranged in pairs; in black quarter the microbe is a refrangent ovoid, single or in chains of two or three and a motile linear body with a refrangent nucleus in one end; and in milk sickness the germ is a spirillum. The germs are far more likely to be detected in the local lesions and lymphatic glands than in the blood. The specific nature of the symptoms and lesions can usually be relied on, but in cases of doubt the inoculation of a small animal (rabbit, guinea-pig, sheep) will be a material guide.

PROGNOSIS.--True anthrax leads to a very high mortality. The apoplectiform cases are fatal almost without exception; the acute cases of anthrax fever in many outbreaks perish to the extent of 75 or 80 per cent., and the more tardy ones to the number of 50 per cent. In a general outbreak the earlier cases are usually the most fatal, while later, when the less susceptible animals are attacked, the mortality is often decreased. Again, the mortality is often at once arrested by the emigration of the herd to a more healthy soil, a large proportion of those already attacked recovering.

PROPHYLAXIS.--In prophylaxis the soil demands the first attention. If this is damp and calcareous or rich in organic matter, the remainder of the herd should be at once removed to a drier and more porous soil, where the germ is less likely to be preserved and increased. In an {937} enzoötic in Livingston County, N.Y., in 1875, 40 bullocks out of 200 had perished in ten days, yet after removal to an adjacent dry pasture and the use of antiseptics with the food and water the attacks abruptly ceased and 48 out of 50 head already sick recovered. The drainage of anthrax soils leads to a steady reduction of the poison, favoring as it does the germination of the spores and the destruction or modification of the germ. When drainage is impossible, the mortality may be reduced by driving the stock to drier grounds during the hot, dry season, by stabling them morning and night when the dews are on the grass, also in wet times, when they are likely to pull up the plants by the roots, or, better still, by cutting the fodder and soiling the stock in stables or yards. Yet in all these cases the germs will at intervals find access to the animals in the green food or hay, so that badly infected soils must be secluded from live-stock, and either be abandoned or devoted to other cultures. A point of the very first importance is the safe disposal of the products and carcases of the sick. These should be thoroughly burned, or, failing this, deeply buried (4 feet) and the graves covered with coal tar and fenced in from all other stock for from five to ten years. Contaminated litter and fodder should share the same fate. Stables and yards where the sick have been, and all vehicles and implements used for them or their products, should be thoroughly disinfected. In the epizoötic in Livingston County, above referred to, these measures seem to have eradicated the disease in the course of six years, though the land was neither drained nor subjected to cultivation, and the dangerous meadows are now again pastured with impunity.

In the case of sick animals the greatest care is requisite to keep them from common drinking- or feeding-troughs; to exclude all other animals, even the smaller quadrupeds and birds, which may become the bearers of the poison; to avoid the chance of the drainage of infected excreta into other yards and pastures, and to carefully disinfect and guard the human attendants against contamination. The sale of animals out of an infected herd, and, above all, for the meat-market, and the use of the milk or other products of such animals, until attested sound, are highly reprehensible.

Finally, there are the different methods of protecting the system by inoculation with modified virus. The first of these is that of Burdon-Sanderson, Dugnid, and Greenfield, who in 1878 and 1879 inoculated six cattle with the blood of guinea-pigs dead of anthrax, all of which survived except an old, emaciated, worn-out, and pregnant cow, and all the survivors would only afterward contract anthrax in a mild form. The anthrax blood of the guinea-pig inoculated on the sheep proved fatal. The second mode is that of Pasteur, who cultivated the anthrax-germ artificially in flasks of meat-infusion, and after the nourishment in the latter had been used up left the bacilli to degenerate until their virulence had been so far decreased that the liquid could be safely inoculated on animals, so as to produce a mild anthrax infection and thereafter secure immunity from this poison. For all the larger domestic animals he found that the eighth day of the culture sufficed, provided there had been no formation of spores; and the method has now been applied on many scores of thousands of domestic animals. Klein, however, has found that cultures in pork-broth of the same age are invariably fatal to rodents, {938} and that a guinea-pig which survived inoculation with culture a month old did not possess immunity against fresh virus. The third method, that of Toussaint, consists in heating the fresh virus, so as to lessen its activity, and then inoculating it on the animals to be protected. He found that a temperature of 55° C. (131° F.) maintained for one hour rendered the virus non-fatal, without impairing its prophylactic powers on animals inoculated. In spite of a partial failure at Alfort from insufficient heating of the virus, the method has now been firmly established as at once easy and effective.

The great value of these discoveries can hardly be overestimated, yet it is to be feared that the éclat of their reception has led to a far too general adoption of the methods. No one of the methods professes to destroy the life of the bacillus nor to impair its power of self-propagation. The bacillus, therefore, is likely to be planted in the localities where it is being employed, and, if the soil is favorable, to be perpetuated there. It follows also, from the susceptibility of the bacillus to change under varying conditions of life, that the modification impressed on it by the methods of Pasteur and Toussaint may be reversed under a reverse state of the environment, and that the harmless virus sown by our inoculators may in favorable soils produce the more deadly types. The methods secure the safety of the individual herd inoculated, at the expense of planting in the pasture a seed most perilous to all future uninoculated herds that may roam there. The only place for such protective inoculations is on pastures already charged with the anthrax bacillus, and from which that cannot be eradicated. On the dry, healthful soils where the bacillus cannot survive the inoculation is useless, while on the dense, damp, rich soils favorable to its preservation, but as yet uninfected or nearly so, this inoculation is but sowing deadly seed to secure a very temporary and questionable advantage.

TREATMENT.--Bloodletting and laxatives have been largely used in the treatment of anthrax, though both are mostly useless in acute cases, their possible good effects being anticipated by the early death. When of service at all, it is probably mainly in reducing that plethora which serves often to enhance the virulence and severity of the malady. Apart from these, the agents resorted to are more or less of an antiseptic nature, and probably exert their action mainly on the bacilli undergoing development near the surface of the skin or intestinal mucous membrane. In extensive outbreaks I have had the best results with the administration thrice daily of carbolic acid, nitro-muriatic acid, or bichromate of potassium, and hypodermically of iodide of potassium and sulphate of quinia. Alcoholic stimulants, chlorate of potassium, and muriate of iron are equally indicated, especially when the period of prostration has set in. If the local anthrax can be detected when there is as yet but a hard nodule, there should be no hesitation in cauterizing it to its depth and treating the resulting sore and surrounding parts with tincture of iodine or iodized phenol. After crucial incision the nodule may be treated with powerful caustics (potassa, nitric acid, chloride of zinc), to be followed by iodized phenol, with or without poultices or fomentations.

{939} Anthrax in Man (Malignant Pustule or Vesicle, Anthrax Intestinalis, Mycosis Intestinalis).

Fournier in 1769 first traced the communicated anthrax of man to the consumption of the flesh of diseased animals and the handling of their wool. Until quite recently, however, the form which originated as a local external affection was the only type recognized, while internal anthrax was confounded with a multitude of other affections.

ETIOLOGY.--That anthrax in man is almost invariably derived from the lower animals by infection is now undoubted, while for the direct infection of man, as of animals, by the germs propagated in the soil, there is no absolute proof. The latter mode of propagation has only been recognized in the Herbivora, which are so much more exposed to contamination from the soil; yet, abstractly, there is no reason to suppose that man is less susceptible to the earth-grown bacillus than to that produced in the animal, if only he were as frequently exposed to its infection. The spontaneous development of anthrax apart from the pre-existent bacillus in animals or soil is a chimera. The principal modes of infection may be considered as direct and mediate. Among the direct are included infection from handling the sick animals, their carcases, their wool, hair, bristles, hides, fat, and guts; the inoculation of physicians, surgeons, and nurses from their patients; and the infection of men by the meat, milk, and cheese eaten. As attested modes of mediate infection may be cited the inoculation by insects (mosquitoes, bluebottles, and other bloodsuckers), and the introduction by water into which anthrax products have drained or been washed; there are also hypothetical cases in which anthrax-germs from the earth have entered the system in the air, drink, or food (raw vegetables). The direct inoculations are especially common in certain classes (shepherds, farmers, butchers, knackers, tanners, veterinarians, and workers in hides, hoofs, glue-factories, fat-rendering works, in hair, wool, bristles, and catgut, and in felting and paper-making). In such cases the disease usually begins as a local one, and occurs on uncovered portions of the body. Three such cases occurred in 1875 on one farm at Avon, N.Y., where the victims had assisted in burying forty dead cattle, and a number of other similar instances can be adduced in different parts of the same State, in one of which a physician was accidentally inoculated in dressing a farmer's hand. Physicians whose practice includes large tanneries become very familiar with the disease and recognize it very readily.

Infection through food is much less frequent in men than in animals, the process of cooking combining with the action of the gastric juice in destroying the poison. Yet it is by no means unknown. The records above given of infection in St. Domingo, Naples, and the Russian steppes can be easily supplemented. Dr. Keith of Aberdeen, Scotland, records the case of a family that suffered, two of them fatally, after partaking of broth and meat which had been boiled for hours, one member of the family (a vegetarian) having alone escaped. Infection through milk, butter, and cheese is less common, the gravity of the disease in animals leading to an early suppression of the mammary secretion. In all such cases the infection enters through sores in the mouth or from the bowels.

Those cases in which the bacillus enters the system with the inspired {940} air are probably the least numerous. Yet the germ may reach the lungs in fine dust, and then find in the delicate respiratory mucous membrane the most accessible of all channels into the system.

The proportion of men affected is much greater than that of women and children, doubtless by reason of their greater exposure to infection, and, as in the lower animals, the summer months are most productive of anthrax. The susceptibility of the human race appears to be less than that of the Herbivora, and doubtless varies, as in these animals, with the nature of the food. It is at least temporarily exhausted by a first attack, though in exceptional cases and under a strong dose of the poison a man may be affected a second time.

SYMPTOMS.--Symptoms usually set in within twenty-four hours after inoculation of the poison, though it is alleged that the incubation may be extended to twelve or fourteen days. Itching draws attention to a small red spot like a mosquito bite, but with a black central point. This speedily increases to a small rounded swelling (papule), and in fifteen hours is surmounted by a minute vesicle with dark-red or bluish contents. From the size of a millet-seed this increases to that of a pea, and in thirty hours bursts spontaneously or under friction and forms a dark-red, indurated, comparatively painless nodule (parent nucleus, Virchow). The adjacent skin shows a swollen areola livid and red, on which there appear vesicles similar to the first, which pass through the same stages, burst, and leave a livid, hard, or doughy gangrenous surface. By this time the surrounding skin is red, shining, and puffy, and the disease continues to spread by the same method of extension. The diseased part now becomes the centre of an oedematous swelling which may invade the entire arm, face, or neck, and is attended with more or less constitutional symptoms. The affected part may be cold or hot, and it may show the red lines of lymphangitis and the swelling of the adjacent lymphatic glands.

The pyrexia, at first slight, often reaches a high grade, attended with occasional chilliness, pains in the back and loins, great prostration, languor, dulness, and even delirium, with cold sweats, anxiety, dyspnoea, and at times muscular spasms. As in beasts, there are the dusky skin and mucous membranes, petechiæ, and cyanosis, and in bad cases there may be sudden collapse and death. The symptoms vary much, however, according to the extent of the local lesion, to the amount of poisonous chemical products thrown into the blood, to the degree of the invasion of the blood by the bacillus, and to the complication (not infrequent) of the affection with septicæmia. In the very mildest cases the affection never proceeds beyond a local slough, the size of a quarter or half dollar, the germs do not enter the blood in sufficient numbers to survive, the constitutional symptoms are few or absent, and the sore heals by granulation.

The disease usually lasts from six to ten days, and for the first forty-eight hours the symptoms are generally purely local.

Malignant anthrax oedema (oedeme maligne) was first observed by Bourgeois as occurring in the eyelid, and has since been recognized in other parts of the body (arm, forearm, head). It differs mainly from malignant pustule in the absence of the preliminary vesicle, of the hard nodule (parent nucleus), and of the early circumscribed gangrene. It has this further peculiarity, that the local disease often appears as a {941} sequel rather than a precursor of the constitutional disturbance. It corresponds in the main to the diffuse erysipelatoid anthrax of the lower animals, and has been attributed to the anthrax poison introduced by inhalation. It has been observed to follow eating of anthrax flesh (Leube, Müller). Inasmuch as the active disease is often delayed a week or ten days after exposure to infection, it may reasonably be supposed that the bacillus has been imprisoned on the mucous membrane, or, entering the blood in small quantity only, has been held in check by the antagonism of the blood-globules until some elements, escaping into the connective tissue, have started the local disease. The symptoms are usually first languor, sleeplessness, restlessness, with some sense of chill, debility, and headache, and finally, after a few days, the formation of the specific oedema at one point or more. This has a pale, semi-translucent, slightly yellowish or greenish aspect, pits on pressure nearly equally at all points, and tends to a rapid extension, with concomitant aggravation of the constitutional symptoms, and in many cases nausea and vomiting. Gangrene sets in--not progressively, as in malignant pustule, but simultaneously over a more extensive surface--and is followed by great prostration, stupor, dyspnoea, cyanosis, collapse, and death.

Anthrax intestinalis may be looked upon as the counterpart of the internal anthrax or anthrax fever of animals, described above. As in animals, the constitutional symptoms may result early in a fatal issue, with scarcely any local lesion save in the blood and spleen (Carganico, Leube, Müller, Winkler, Lorinser). As in animals too, the sanguineous engorgement of the spleen and the intestinal anthrax are often complicated by external anthrax oedema or malignant pustule (Heussinger, Virchow, Buhl, Waldeyer, etc.). In this form pyrexia and other constitutional disturbances are first seen. There is a general feeling of languor and depression, with some chilliness, fever, pains in the limbs, back, and head, vertigo, and ringing in the ears. Even at this early stage there is noticed a dusky hue of the skin and visible mucous membranes, which goes on increasing to a brown or yellow tinge, to petechiæ, or, with the supervention of dyspnoea, to cyanosis. Digestive derangement is early shown in abdominal pain, nausea, vomiting, tenderness, some swelling, and finally diarrhoea, often bloody and sometimes profuse and exhausting. In acute cases the symptoms become rapidly worse, and then follow discharge from the mouth and nose of uncoagulable blood, dyspnoea, cyanosis, small pulse, dilated pupils, great anxiety or drowsiness, and stupor, or there may be tonic spasms of the trunk or extremities. Death usually results from asphyxia or collapse, as in animals. These cases are almost invariably fatal within a period of thirty-six hours, though some linger six or seven days.

Allied to the intestinal anthrax is anthrax angina, a not unknown occurrence in man. This begins as a bad sore throat, with an especially dark-red hue of the pharyngeal mucous membrane. As it advances the shade becomes increasingly darker, the power of deglutition is lost, serous phlyctenæ with gangrene and deep ulceration set in, but without any tendency to the formation of false membrane as in diphtheria. There are early superadded the constitutional symptoms above described, and the patient dies in a state of collapse or asphyxia.