ANTHRAX IN MAN.
Causes: infection from animals and their products, from soil, by flies, by dust. An industrial disease, of workers among animals and animal products. Wounds as infection atria, ingestion anthrax, inhalation. Lesions: malignant vesicle, anthrax œdema, intestinal anthrax: pulmonary anthrax. Symptoms: malignant vesicle, œdematous anthrax, intestinal, pulmonary. Prevention. Treatment: caustics: antiseptics, excision of nodule and subsidiary glands, mercurial ointment, iodine, sodium bicarbonate. For intestinal anthrax: emetic, oleaginous purgatives, potassium iodide, sodium salicylate, iron muriate, heart stimulants. For pulmonary anthrax: inhale chlorine, iodine, bromine, phenic acid, eucalyptol, oil of cinnamon, sterilized cultures of prodigiosus, pneumococcus of Friedländer, bacillus pyocyaneus, staphylococcus aureus, or streptococcus: blood serum of immune animals: blood serum (sterilized) of anthrax cattle.
Causes. Anthrax in man is usually the result of contamination by infected animals or their products. It is quite possible that man, like animals, may be infected directly from the soil or water, or from the same source through the medium of flies or windblown dust, yet undoubted cases of this kind are rare or unrecognized. The animal origin of the disease, as regards man, makes this largely an industrial affection, attacking shepherds, cattlemen, horsemen, farmers, drovers, butchers, veterinarians, tanners, and workers in hides, wool, hair, bristles, furs, hoofs, bones, rags, felt, glue, and even leather. The sound skin is sufficient protection, but the slightest abrasion may form an infection atrium. Workers in tanneries and those who live near them are notoriously subject to anthrax. The hides must of course be drawn from an anthrax region. Russian, Armenian, South American, Australian and African hides have an especially bad reputation. The British Medical Journal, May 21st, 1898, records cases occurring in postal clerks who had to handle foreign parcels bound with strips of hide. Proust records cases from handling Chinese goat skins (Bull. de l’Acad. de Med. 1894). Infection may also occur through leather made from infected hides as proved experimentally on Guinea pigs.
Hair has long been recognized as a frequent medium of infection and outbreaks among brushmakers have been recently recorded by Gerode, Sarmont and Chauveau. (Compt. Rend. de l’Acad. des Sc. 1893). Trousseau reports twenty cases in Paris, all contracted from South American horse hair. Wool from infected countries is often dangerous and has given rise to special names for the disease (wool-sorter’s, rag-picker’s) which may be developed in the lungs from inhalation of the dust. In the same way those who handle bones about fertilizer, glue and rendering works, are particularly exposed. The agency of insects in man is undoubted. In sixty cases recorded by Dr. Bell, fifty-four were on the face, two on the hands, one on the wrist and one on the forearm. This is mainly due to blood-sucking flies, yet Heim incriminates the coleoptera as well (Compt. Rend. de Soc. de Biol. 1894). Wounds of all kinds contribute to inoculation, hence, the presence of burdocks, thorns, thistles and the like in the matted wool or hair is often a direct cause of infection.
The infection may be transferred on surgical instruments, and in these days of hypodermic medication the greatest care is necessary to prevent infection through the needle.
As in animals man suffers from ingestion and inhalation of the bacillus; and sometimes widespread mortality comes in this way. Meat just killed may be thoroughly disinfected by the secretions of a healthy stomach, yet the bacillus may pass through in an envelope of fat, in an undigested mass or during an attack of dyspepsia, and infect the intestines. The spores are proof against the gastric juice, and as they are produced in a few hours after death the meat of an anthrax animal must always be considered as exceedingly dangerous.
Man is much less susceptible than some other animals and the disease wherever inoculated tends to remain for a time localized, in the skin, the lungs or the bowels. The forms of the disease are malignant carbuncle (pustule), malignant œdema, intestinal anthrax, and pulmonary anthrax.
Lesions. The morbid histology is in the main the same as described in animals. In the protracted cases there is the same dark nonærated blood, forming a loose coagulum, the crenated or distorted blood globules aggregated in irregular masses, the escape and solution of the hæmoglobin so as to stain the white tissues, the enlargement of the spleen which is gorged with dark blood, and the hyperæmia of the liver and lymph glands. There is in the affected tissues and usually in the blood the characteristic large bacillus anthracis.
In the malignant vesicle there is first a minute, firm central, dark nodule like an insect bite with a lighter colored areola, and showing not only hyperæmia, but blocking of the capillaries, and minute areas of extravasation. Somewhat later the dark centre is surmounted by a small vesicle, beneath which the tissues are becoming necrotic, and the area of congestion and extravasation has extended and thus the local disease advances by a constant invasion of new tissue which in its turn becomes the seat of coagulation necrosis. On microscopic section the central necrotic part shows the cells of the rete Malpighi separated by a finely granular coagulum, and the papillæ are greatly swollen by serous and hæmorrhagic exudate. The cell nuclei are necrotic and no longer take a stain. The capillaries are gorged with red globules and bacilli. In the surrounding tissues there is much congestion and exudation, with numerous points of extravasation, but the abundant multinuclear cells retain their staining power.
In Anthrax Œdema, which appears in parts like the eyelids, neck and forearm where there is an abundance of loose connective tissue and a scanty blood supply, there is no firm central nodule, but a diffuse soft infiltration, with points or patches of a yellow or reddish color. The capillaries are congested, with minute emboli and extravasations and there is an excessive and rapidly spreading exudation. It shows a great tendency to early general infection and may end in vesication and local gangrene or in favorable cases in resolution.
In Intestinal anthrax (intestinal mycosis) the lesions are usually concentrated on the small intestines, while the stomach and large intestines in the main escape. The walls of the bowel are of a dark red, and greatly thickened by exudation and extravasation which also mixes with the ingesta giving it a dark bloody tinge. At intervals on the mucosa are nodular hæmorrhagic swellings, from the size of a linseed to a pea, with commencing necrotic changes or the formation of sores. The mesenteric glands are swollen, infiltrated and hæmorrhagic, and like the other lesions abound in bacilli. Hyperæmia and engorgement of the liver and above all of the spleen are the rule.
In pulmonary anthrax (wool-sorter’s disease) a sanguineous liquid is found in the lower trachea and bronchia, and not infrequently in the pleuræ and pericardium. The bronchial glands are swollen, hyperæmic and often hæmorrhagic, and exudations and extravasations may be found in the mediastinum and lungs. Lesions of the intestines and spleen are common, and in all alike the bacilli are found.
In certain cases the anthrax lesions may be found in the brain, or any part of the body but in all they show the same general characters and the same specific microbe.