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 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 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.

MORBID ANATOMY.—The lesions closely agree with those already described for animals in general. The blood presents the same dark-red or black, tarry, incoagulable, or only slightly coagulable condition in the worst cases, yet this is less constant in man, as the bacteria are less constant or numerous in the blood, in keeping with the more prolonged localization of the external anthrax in man, and the more pronounced antagonism between the blood and the bacillus which results from feeding exclusively or largely on flesh. The red globules do not tend to adhere together, and the white globules are in excess and very granular. The spleen is less extensively enlarged than in animals, but is highly charged with blood, bacilli, and micrococci. The lymphatic glands too are enlarged, hyperæmic, cloudy, hemorrhagic at points, of a dark grayish, deep red, or blackish color, and highly charged with the bacillus. The surface of the skin and mucous membranes (mouth) presents hemorrhagic spots and patches, with serous vesicles and eschars. The malignant pustule when cut into presents a central slough and a surrounding hard indurated mass, both of a dark blood-red, with similar prolongations downward into the adipose tissue, and around all the characteristic oedematous infiltration, often streaked with blood. The bacillus is found in tufts or dense groups at intervals in the rete mucosum, the dermis, and the subcutaneous connective tissue. The serous membranes present the same general lesions as in animals. The walls of the stomach and bowels are the seat of cloudy red infiltration, with at intervals small hemorrhagic foci, and on the mucous surface distinct sloughs. Jelly-like exudations are also found in these membranes in the mesentery and in the retro-peritoneal tissue. The liver and kidneys are usually congested or are infiltrated with an oedematous exudate, and in these, as in all the local anthrax lesions, the characteristic bacilli are found.

DIAGNOSIS.—Malignant pustule is distinguished by its commencing from a minute red point with dark centre, and by its progressive extension from this point by a dark-red, puffy, and vesicular areola, with steadily advancing induration and gangrene. The bites of insects have a yellowish central point with red areola. A boil lacks the dark centre and the rapidly rising elevated red areola. Carbuncles and plague-boils tend to appear on clothed parts of the body, respectively on the back of the neck and shoulders and on the trunk and extremities. In carbuncle several boils rise and burst simultaneously, though they may finally slough into one sore, while in anthrax the extension is from one point. The plague-boil is usually multiple and much more painful than anthrax. The glanderous nodule is usually multiple, situated at intervals on the course of a lymphatic, the intervening portion of which is inflamed, hard, and cord-like. It is also usually associated with the specific glairy discharge from the nose, the nasal ulcers and nodules, and the enlarged painless, nodular, and indolent submaxillary lymphatic glands. As a last resort the detection of the bacillus in the indurated nucleus and the inoculability of the disease on the lower animals (rabbit, guinea-pig), may be appealed to.

Malignant anthrax oedema is less easily recognized, but may be inferred from the sudden swelling with a dusky yellow or greenish hue and a tendency to vesiculation and gangrene, the whole preceded and attended by the constitutional symptoms of anthrax, and, above all, from the presence of the bacillus in the exudate.

In both of these forms much may be deduced from the known liability of the district to anthrax, from the occupation of the subject as being exposed to infection (worker in hair, wool, bristles, hides, catgut, etc.), or from his having eaten meat which was open to suspicion.

Internal anthrax is less certainly diagnosed because of the absence of local symptoms until the constitutional disorder is well advanced. Yet the reasonable suspicion of infection and the sudden and violent eruption of the disease (headache, nausea, vomiting, bloody diarrhoea, extreme anxiety, debility, dyspnoea, cyanosis, convulsions, collapse, with petechiæ, and local discharges of diffluent blood) serve to identify it. The bacillus is not always to be detected in the blood under the microscope, but its presence can usually be demonstrated by inoculation.

PROGNOSIS.—The prognosis of malignant pustule energetically treated in its early stages is good. The disease is as yet a local one, and the germs can be extinguished by local treatment. In anthrax districts, where the disease is feared and early recognized, the mortality may be from 5 per cent. (Nicolai) to 9 per cent. (Lengyel, Koranyi). Even this mortality is mainly due to delay in treatment. In districts, on the other hand, where the malady is infrequent, and where efficient measures are applied too late, the mortality is often 30, 40, or even 50 per cent. After internal infection, and where local symptoms only appear after general infection, the case is very hopeless.

PROPHYLAXIS AND TREATMENT.—The prophylaxis of anthrax in man is to a large extent identical with that for animals. All considerations as regards soil, culture, drainage, sick and dead stock, cremation, burial, disinfection, etc. have a most important if only a secondary bearing on the protection of man. Still more important is the free use of carbolic acid, chloride of lime, or tincture of iodine for the hands of those dressing unhealthy sores in animals or handling suspicious cases of sickness or cadavers, and of those working in hides, wool, hair, horns, hoofs, guts, etc. Similarly, all products of animals with anthrax should be withheld from general use.

In external anthrax of man, before the system has been contaminated, the thorough destruction by caustic of the diseased part with its contained poison is most effectual. Where there is as yet but the preliminary papule it may be incised and thoroughly destroyed by a stick of chloride of zinc, caustic potassa, or nitrate of silver, or, if more convenient, by fuming nitric acid, muriatic or sulphuric acid, or, perhaps preferably to all others, iodized phenol. Should the parent nucleus have already formed, it should be excised with the knife or deeply incised in a crucial direction, and then thoroughly cauterized with one of the more potent escharotics (caustic potassa, strong nitric acid) or with the iodized phenol. The latter agent may be further applied on the sound skin adjacent, especially if there is the slightest swelling or redness. Should the peripheral oedema persist or reappear after the cauterization, the latter should be repeated until this tendency is overcome. Hypodermic injections of a solution of iodine and iodide of potassium may be made into the entire swelling. After the caustic has done its work the eschar may be softened and its separation favored by a warm poultice containing a small amount of carbolic acid or iodized phenol. This treatment is often highly beneficial, even after constitutional symptoms have set in, by arresting the propagation of the bacillus and checking its introduction and that of its chemical products into the circulation.

Constitutional treatment is not to be forgotten. Carbolic acid may be profitably given to the extent of fifteen drops daily, iodide of potassium ten to twenty grains thrice a day, and sulphate of quinia ten grains at the same intervals. The strength should be sustained by iron (tincture of the chloride) and wine or other alcoholic beverage, both being, like the agents already named, calculated to retard if not to limit the propagation of the bacillus. The diet throughout should be nutritious and easily digested.

When a person is known to have eaten anthrax meat an emetic will be indicated, followed by a smart oleaginous purgative combined with five drops of carbolic acid, and subsequently by the constitutional treatment above recommended. In case of extensive anthrax oedema, incisions may be made into the part as far as the yellow exudate extends, and a poultice containing carbolic acid may be applied. Or, preferably, the swelling may be freely injected with a weak solution of iodized phenol (1:100 water), and then painted with the same agent or with tincture of iodine.