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.