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actinomycosis(ăk'tənōmīkō`sĭs), chronic suppurative infection that occurs around the face and neck. The disease is characterized by the formation of abscesses, or pus-filled cavities, below the surface of the skin. These abscesses spread rapidly and form channels that discharge a yellow granular pus on the surface of the skin. In humans these granules consist of Actinomyces israelii, a bacterium that used to be considered a fungus. Actinomycosis also sometimes affects the lungs, appendix, or the pelvic region, especially in women with certain kinds of intrauterine devices. Treatment consists of prolonged therapy with massive doses of penicillin and drainage by surgery. Actinomycosis also occurs in horses, cattle, swine, and dogs; it resembles human actinomycosis, but is caused by various other species of Actinomyces.
a chronic infectious disease of both humans and animals (cattle, and less frequently swine, sheep, goats, and horses), produced by anaerobic and aerobic ray fungi (the actinomycetes). The disease is distributed universally.
Human actinomycosis. Human actinomycosis comprises 6–8 percent of all chronic suppurative processes. The disease was first described by the German surgeon B. Langen beck in 1845. Ray fungi inhabit the human mouth cavity and intestinal tract; they are not usually harmful, but in some circumstances they become pathogenic. The principal infection route is the gastrointestinal tract, but the infecting fungi are airborne in some instances. Ray fungi which have entered tissue are surrounded by a cell barrier and a connective capsule; an actinomycoma is formed whose suppurative fusion leads to spread of the fungi into surrounding tissues. Actinomycosis is propagated within the organism either through direct contact or by way of the lymphatic system and blood stream. The disease follows an undulant course, with periodic fever and pains. It appears with the development of dense, elastic abscesses which become inflamed and suppurative and must be lanced; this in turn produces fistulas, accompanied by the discharge of bloody pus. Actinomycosis may affect any organ or tissue. Complications include contracture of the mastication muscles as a result of scar formation, contraction of the intestine and urinary tract, development of bronchiectasis and cystic cavities in the lungs, and pathological crises. The treatment may consist of actinolysate, actinomycetic polyvalent vaccine, antibiotics, sulfanilamide preparations, blood transfusions, and surgical intervention. Careful oral hygiene is the prophylaxis.
O. B. MINSKER
Animal actinomycosis. Animal actinomycosis may occur at any time of the year but appears most often during indoor periods when dry coarse fodder is used or during autumn pasturage on stubble. Actinomycetes most frequently enter the body tissues of animals through breaks in the mucous membrane. The general clinical sign of actinomycosis in all animal species is the formation of an actinomycoma, usually in the region of the head. The dense tumors, firmly accreted to the skin, are lanced from the outside or through the pharyngeal cavity. The fistulas thus formed exude pus which contains drusen of the irritating agent. The treatment consists mainly of antibiotics (penicillin, oxytetracycline). Surgery is used in cases where the tumors are circumscribed and separable. For prevention of animal actinomycosis in districts in which actinomycosis is endemic, animals should not be pastured on low-lying, swampy, or moist lands. Coarse fodder (hay, straw, or chaff) should be steamed before feeding. Sick animals should be isolated. The question of using meat from animals with actinomycosis is decided by specialists on the basis of the extent to which the carcass has been affected.
I. G. LEVENBERG
REFERENCESAsnin, D. I. Immunodiagnostika aktinomikoza. Moscow, 1956.
Ospovat, B. L. Aktinomikoz legkikh. Moscow, 1963.
Suteev, G. O. Aktinomikoz. Moscow, 1951.