Malignant anthrax

Description:

Malignant anthrax - the acute zoonotic infection proceeding with the expressed intoxication, formation of an anthrax on skin (a skin form) or in the form of sepsis.

Short historical data.

The disease is known from antiquity under various names: "sacred fire", "the Persian fire", "углевик", etc. Russia called it "malignant anthrax" in connection with preferential distribution in Siberia. Now the disease meets in isolated cases. Identity of an infection at animals and the person and a possibility of its transfer from sick animals are proved to people by S. S. Andreevsky in experience of autoinfection (1788). The infestant is described by F. Pollender, F. Brauell and K. Daven (1849-1850); the true culture was marked out by R. Koch (1876). The outstanding role in studying of a malignant anthrax belongs to domestic scientists - to I. I. Mechnikov, G. N. Minkh, N. F. Gamaley, to A. A. Vladimirov, L. S. Tsenkovsky, etc.

Symptoms of the Malignant anthrax:

Incubation interval. Proceeds within several days, but it can be extended up to 8-14 days or be reduced till several o'clock. Allocate the skin (localized) and generalized forms of a disease.

Skin form. Meets most often (more than 95% of cases). Can proceed in the form of several versions - karbunkulyozny, edematozny and violent. Most often the karbunkulyozny kind of a skin form develops. In these cases on skin in the place of entrance infection atriums the painless reddish spot with a diameter up to several millimeters appears. It very quickly turns into a papule of copper-colored color, sometimes with a crimson shade, raised over skin level. Formation stain papules accompany a local itch and easy burning. In several hours the papule turns into the vesicle with a diameter of 2-4 mm filled with serous contents. Vesicle contents quickly become bloody, gain dark, and sometimes crimson-violet color (pustula maligna). When combing or (less often) spontaneously the vesicle bursts, and the ulcer with the edges raised over skin level, a bottom of dark brown color and serous and hemorrhagic separated is formed. On its edges there are secondary vesicles ("necklace") that is considered typical for a disease. Further "affiliated" vesicles pass the same stages of development, as primary element. At their opening and merge the sizes of an ulcer increase.

In several days, sometimes in 1-2 weeks, owing to a necrosis in the center of an ulcer the black scab which quickly increases in sizes is formed, closing all bottom of an ulcer, and bears a strong resemblance to a burned crust. Painful sensitivity in the field of a scab is lost (local anesthesia) that is an important differential diagnostic character. Around a scab the inflammatory roller of crimson color towering over the level of healthy skin forms. The scab with the roller resembles the fading piece of coal superficially, as defined the old Russian name ("углевик") and the modern Latin name of a disease (from Greek anthrax - coal). In general skin changes received the name of an anthrax. Its sizes vary from several millimeters to 5-10 cm.

On the periphery of an anthrax expressed develops swelled fabrics, occupying sometimes big sites, especially in places with friable hypodermic cellulose (for example, on a face). The nature of hypostasis student invisible, at blow by a percussion hammer in its area arises trembling of fabrics (Stefansky's symptom). Localization of an anthrax and hypostasis on a face is very dangerous as it can extend to upper respiratory tracts, and lead to asphyxia and death. Formation of an anthrax accompanies regional lymphadenitis (and at heavy disease and a lymphangitis).

From the very beginning of a disease observe the expressed intoxication with high temperature of a body, a headache, an adynamia, an ache in a waist. Fever remains within 5-6 days then body temperature critically decreases. Its normalization is accompanied by involution of the general and local symptoms. By the end of the 2-3rd week the scab is torn away, the ulcer gradually heals with formation of a hem.

More often one anthrax forms, at the same time the disease in most cases proceeds in an easy or medium-weight form. In rare instances the number of an anthrax can reach to 10 and more. At their development on the head, a neck, mucous membranes of a mouth and a nose the disease proceeds especially hard and can be complicated by development of anthracic sepsis.

Edematozny kind of a skin form. At the beginning the disease is shown only by the expressed hypostasis, development of a necrosis and formation of an anthrax of the big sizes observe in later terms of a disease.

Violent kind of a skin form. Differs in formation of bubbles with hemorrhagic contents on site of entrance infection atriums. After opening of bubbles extensive ulcers are formed; the subsequent necrosis in the field of their bottom leads to development of an anthrax.

The forecast at a skin form of a malignant anthrax usually favorable.

Generalized form. Meets seldom in the form of pulmonary, intestinal or septic versions.

Pulmonary kind of a generalized form. Symptoms of defeat of a respiratory organs are typical that it is connected with the fact that lungs are the first fabric filter on a lymph outflow tract in blood. The first phase of a disease is shown by grippopodobny symptoms: indisposition, headache, mialgiya, dacryagogue, cold, cough. Already from the very beginning note the expressed tachycardia, a tachypnea and an asthma. Duration of this phase makes from several hours to 2 days. In the second phase observe rough increase of intoxication, and body temperature increases to 39-41 °C, being followed by a strong fever. Quite often there are pains and constraint in breasts, cough with plentiful allocation of a bloody phlegm which is curtailed in the form of "cherry jelly". In lungs listen to a large number of rattles; formation of extensive zones of a dullness over lungs is possible. On the roentgenogram reveal symptoms of pneumonia or pleurisy (a serous and hemorrhagic exudate in a pleura). The third phase is characterized by bystry increase of cardiovascular insufficiency, edematization of lungs and an oliguria. Consciousness of patients is kept. Duration of the third phase is no more than 12 h.

Intestinal kind of a generalized form. Differs in the heaviest current and a failure in most cases. For the first short-term phase of a disease (no more than 1,5 days) the headache, dizziness, pains and burning in a throat, a fever, high fever are inherent. In the second phase the strong cutting abdominal pains, nausea, a hematemesis, a liquid chair join the listed symptoms. In fecal masses visually find blood. In the third phase of a disease the decompensation of cordial activity catastrophically accrues. Patients are alarmed, fear. The person of pink and cyanotic color or crimson, scleras are injected. In certain cases on skin papular or hemorrhagic rashes can develop.

Septic kind of a generalized form. Can proceed in the form of primary sepsis or secondary, arising as a complication of any forms of a disease. This version is distinguished by rapid increase of intoxication, abundance of skin and internal hemorrhages, involvement in process of a meninx. A frequent outcome of this version is infectious and toxic shock.

Reasons of the Malignant anthrax:

The activator - the optional and anaerobic motionless gram-positive spore-forming encapsulated V.'s bacterium of anthracis of the family Bacillus of the Bacillaceae family. Morphologically looks as a large stick with the chopped-off ends. In smears is located odinochno, couples or chains. In the presence of oxygen forms disputes. Well grows on beef-extract environments. The antigenic structure of the activator is presented by a capsular and somatic antigen, antibodies to them have no protective properties. Pathogenicity of the activator is defined by existence of the capsule and synthesis of exotoxin. The anthracic stick is capable to emit the strong exotoxin of the proteinaceous nature rendering both inflammatory, and lethal action. It consists of three components, or factors: edematous, protective antigen (it is not toxic, shows immunogene properties) and actually lethal factor. Its combined action on a human body is shown by hypostasis of fabrics, disturbances of processes of tissue respiration, oppression of activity of phagocytes. Anthracic exotoxin extremely лабилен: it completely collapses after half-hour heating at 60 °C.

Temperature optimum for height of 35-37 °C, an optimum рН 7,2-7,6. Vegetative forms are unstable in external environment, quickly perish during the heating and boiling, under the influence of usual disinfectants. Disputes are very steady, can remain long under the most unfavorable conditions in water several years, in the soil - decades. After 5-minute boiling disputes keep ability to vegetirovat. Under the influence of fluid steam perish only in 12-15 min., at 110 °C - in 5-10 min. Dry heat (140 °C) kills disputes in 3 h. Under the influence of 1% of solution of formalin and 10% of NaOH solution perish in 2 h. In the soil disputes of the activator of a malignant anthrax not only have a long time, but under certain conditions can burgeon and again form disputes, supporting existence of the soil center.

Tank and source of an infection - vegetarians (large and small cattle, horses, camels, pigs, etc.). The period of contageousness of a source is equal to the period of a disease of animals during which they allocate activators with urine, a stake, bloody allocations. Among animals important epizootological value has an alimentary way of transfer of the activator: during the eating of the forages or drink of water polluted by disputes of a malignant anthrax. The transmissible way of transfer is implemented through stings of flies stable-flies, the gadflies transferring the activator from sick animals, the infected corpses and objects of external environment to healthy animals. Not opened corpse of a sick animal is infectious within 7 days. The raw materials received from a sick animal (wool, a skin, etc.) and products of its processing constitute danger for many years. In the soil the activator can not only remain, but also under certain conditions (temperature is not below 12-15 °C, humidity of 29-85%, the neutral or alkalescent environment, etc.) to burgeon in a vegetative form. The soil centers of a malignant anthrax keep potential epizootic and epidemic danger within decades. When carrying out construction, hydromeliorative and other earthwork, and also with storm and flood waters disputes can be taken out on the surface of the soil, creating a possibility of infection of animals and people. Reliable cases of infection of the person from the person are unknown, however the person can become a source of infection of animals. The sick person does not constitute danger to healthy individuals that it is possible to explain with features of the mechanism of transmission of infection realized among animals or from an animal to the person and impossible among people.

The transfer mechanism - various, the most often contact. The activator gets into an organism through the damaged integuments, microtraumas of mucous membranes. Infection comes in the course of a nosotrophy an animal, a face, cutting of hulks, culinary processing of meat, work with animal raw materials and production of objects from it more often (short fur coats, shaving-brushes, etc.). Extremely exceptional cases of infection with a food way are known, and also at inhalation of the infected aerosol. As factors of transfer serve the infected livestock products, raw materials, processing products, kontaminirovanny objects of external environment and stock for care of animals. Infection with activator disputes through respiratory tracts in the past was repeatedly noted at the paper and shersteobrabatyvayushchy enterprises. "The disease of tryapichnik" was widespread in Russia among collectors of the landfill rags polluted by allocations and manure of animals.

Natural susceptibility of people rather low (about 20% of the persons put risk of infection get sick), but almost general at airborne (dust) infection. At had there is a strong immunity, repeated cases of diseases are extremely rare.

Main epidemiological signs. The malignant anthrax is widespread everywhere; the majority of cases register preferential in the developing countries of Asia, Africa and South America. Diseases are met in regions with the developed livestock production. Seasonality of incidence of people in a certain measure repeats the aestivo-autumnal nature of incidence of animals. Register sporadic cases and group diseases. The main reasons for developing of group diseases - non-compliance with veterinary health requirements regarding prevention of a malignant anthrax by private owners of the cattle, heads of farms, the trade and purchasing organizations and the enterprises of various forms of ownership which are engaged in preparation, processing and implementation of meat and meat products.

Diseases prevail in rural areas among persons of active age, is more often than a male. Distinguish household and professional incidence of a malignant anthrax. Infections in city conditions are connected with preparation, storage, processing of animal raw materials, with disturbances of the technological mode and safety regulations. Sometimes diseases are met when carrying out earthwork; cases of laboratory infection are known.

Disputes of the activator of a malignant anthrax can be applied as means of bioterrorism that visually showed events in the USA in the fall of 2001.

Treatment of the Malignant anthrax:

Penicillin remains effective etiotropic remedy. It is appointed intramusculary in a daily dose of 12-24 mln units before disappearance of clinical signs of intoxication, but not less than to 7-8 days. Appointment in doxycycline in usual doses and a levofloksatsina on 500 mg of 1 times a day, in hard cases - ciprofloxacin intravenously on 400 mg 2 times a day is possible.

Causal treatment is combined with intramuscular administration of antianthracic immunoglobulin: at an easy form of 20 ml, and at severe and medium-weight forms on 40-80 ml; at a severe disease the course dose can reach 400 ml. Drug is used in the warmed-up look in 30 min. after introduction 90-120 mg of Prednisolonum.

Active disintoxication therapy with intravenous infusions of colloidal and crystalloid solutions with addition of Prednisolonum and simultaneous carrying out an artificial diuresis is necessary. Treatment of heavy complications, including infectious and toxic shock, carry out by the standard techniques.

At a skin form of a malignant anthrax recommend imposing of aseptic bandages. Surgical interventions are contraindicated as they can provoke process generalization.