ANTHRAX (Syn.: splenic fever, malignant pustule, wool sorters' disease). An acute, specific, infectious, virulent disease, caused by the Bacillus anthracis, in animals, chiefly cattle, sheep and horses, and sometimes occurring in workers in the wool or hair, as well as in those handling the hides or carcasses, of beasts, which have been affected. During the World War numbers of the British troops were infected by way of shaving brushes imported from Japan.
Animals.—Anthrax affects wild and domesticated animals over the world, and published writings on its nature, its peculiar characteristics and the injury it inflicts are innumerable. Regions notorious for its prevalence, are the marshes of Sologne, Dombes, and Bresse in France ; certain parts of Germany, Hungary and Poland; in Spain the half-submerged valleys and the maritime coasts of Catalonia; the Romagna and other marshy districts of Italy ; while it is epizootic, and even panzootic, in the swampy regions of Estonia, Livonia, Courland, and especially of Siberia. The records of anthrax go back to a very ancient date. Classical writers allude to anthrax as if it were the only cattle disease worthy of mention (see Virgil, Georg. iii.). The oldest Anglo Saxon manuscripts contain many fantastic recipes, charms and incantations for its prevention or cure. In the 18th and 19th cen turies it sometimes spread like an epizootic, over the whole of Europe, from Siberia to France. It was in anthrax that disease producing germs (bacteria) were first discovered, in 1849, by Pollender of Wipperf firth, and their real character afterwards verified by Davaine of Alfort in 1863 ; and it was in this disease that Toussaint, Pasteur and Chauveau first showed how to make the bacilli their own antidote. (See ANIMALS, EXPERIMENTS ON.) The symptoms vary with the species of animal, the mode of infection, and the seat of the primary lesion, internal or external. Cattle, sheep and horses nearly always owe their infection to spores or bacilli ingested with their food or water, and pigs usually contract the disease by eating the flesh of animals dead of anthrax. Internal anthrax, of cattle and sheep, exhibits no premonitory symptoms that can be relied on. Generally the first indication of an outbreak is the sudden death of one or more of the herd or flock. Animals which do not die at once stagger and tremble; the breathing becomes hurried and the pulse very rapid ; the internal temperature rises to 104° or 106° F. ; blood oozes from the nose, mouth and anus, the visible mucous membranes are dusky or almost black. The animal becomes weak and listless, the temper ature falls and death supervenes in a few hours, being immediately preceded by delirium, convulsions or coma. In some cases the animal rallies from a first attack and gradually recovers.
In the external or localized form, death may not occur for sev eral days. Swellings may appear in any part of the body, being preceded or accompanied by fever. They are developed in the subcutaneous connective tissue where this is loose and plentiful, in the interstices of the muscles, lymphatic glands, in the mucous membranes of the mouth and tongue (cattle), pharynx and larynx (horses and pigs), and the rectum. At first they are small, circum scribed, warm, slightly painful and oedematous. In from two to eight hours they are large, cold, painless and gangrenous, and when incised a blood-stained gelatinous exudate escapes. General infec tion occurs and death ensues in a few hours. Anthrax of the horse usually begins as an affection of the throat or bowel. In the former there is rapid obstructive oedema of the mucous membrane of the pharynx and larynx with swelling, fever, salivation, difficulty in swallowing, noisy breathing, frothy discharge from the nose and threatening suffocation. General invasion soon ensues, and the horse may die in from four to 16 hours. The intestinal form is marked by high temperature, great prostration, small thready pulse, tumultuous action of the heart, laboured breathing and symptoms of abdominal pain with straining and diarrhoea. When moved the horse staggers and trembles. Profuse sweating, a fall ing temperature and cyanotic mucous membranes indicate the approach of death. The appearances after death are those of blood-poisoning and rapid putrefaction. The most notable feature, however, in the majority of cases is the enormous enlargement of the spleen, which often ruptures, while its tissue is changed into a violet or black fluid mass.
Man.—Two well-marked forms of this disease in man are recognized, "external" and "internal." In external anthrax the infecting agent is accidentally inoculated into some portion of skin, often the hand, arm or face. A minute swelling soon appears locally, and develops into a vesicle containing serum or bloody matter, seldom larger than a shilling. This vesicle speedily bursts and leaves an ulcerated or sloughing surface round which are numerous smaller vesicles which undergo similar changes, and the whole affected part becomes hard and tender, while the sur rounding surface and the neighbouring lymphatic glands are also inflamed. This condition, termed "malignant pustule," is fre quently accompanied by fever, delirium, sweating, great prostra tion and a tendency to death from septicaemia.
In internal anthrax, the spores or bacilli gain access to the system from the air, as in rooms where the contaminated wool or hair is unpacked or sorted. The symptoms usually observed are those of severe prostration, with inflammation of the lungs and pleura. Death from collapse may occur in a few hours or from blood poisoning in three or four days. Sometimes the symptoms are intestinal, and consist in severe exhausting diarrhoea, with vomit ing and rapid sinking.
In all cases the course run by the disease depends upon inocu lation of a susceptible animal with a bacillus capable of living and multiplying in the tissues. If the powers of resistance on the part of the patient are sufficient to localize the disease and deal with the bacilli the patient has a chance of recovery; otherwise the bacilli invade the bloodstream directly or indirectly and death is probable as in any case of septicaemia. Treatment in animals is preventive, attenuated bacilli being inoculated as indicated by Pasteur. In man excision while the condition is local and external offers the best chance and administration of the specific anti serum may be of use. When the disease is internal or generalized no known treatment is of any avail. As preventive measures in manufactories disinfection of materials before handling and han dling in a wet condition are indicated.