Bovine tuberculosis. Detection of bovine tuberculosis culture. Folk remedies for tuberculosis

is a chronic disease with localized lesions in most internal organs. Both animals and humans are susceptible to it. Historical reference. Very old evidence confirms the presence of tuberculous lesions in Egyptian mummies. Hippocrates describes hemoptysis, pulmonary hemorrhage associated with consumption (tuberculosis), and suggests its contagiousness. Even before the discovery of the causative agent of tuberculosis, Villemin pointed out in 1865 that the disease was contagious and discovered the routes of its transmission from animals to humans and from one animal to another.

Tuberculosis is one of the most dangerous infections on the ground. The danger of this infection lies in the high percentage of deaths and disability, which in turn are a consequence of the high resistance of the tuberculosis pathogen to medicines, the presence of multidrug resistance and the lack of effective means of prevention.
In the overall structure of mortality from all infectious diseases, tuberculosis is one of the leading causes. In Russia, about 68 people die from tuberculosis every day. In Moscow in 2012, 169 people were registered. died from tuberculosis.
Due to high disability, large economic damage and mortality, tuberculosis is considered a socially significant infection.
Most often, tuberculosis affects organs respiratory system(lungs, bronchi, pleura), but other organs may also be affected. In view of this, based on localization, a distinction is made between pulmonary tuberculosis and extrapulmonary tuberculosis (intestines, bones, skin, etc.).

Pathogen, pathogen reservoir, transmission routes and excretion. The disease is caused by the tuberculosis pathogen Mycobacterium tuberculosis. There are the following main types of pathogens, pathogenic for humans and animals. Modern scientific data have established that the causative agent of tuberculosis can infect animals not only of the species to which it has adapted, but also of many other species.

Thus, a pathogen of the human type, in addition to humans, can infect dogs, cats, pigs, monkeys, parrots, and among laboratory animals, guinea pigs. The causative agent of bovine tuberculosis, in turn, in addition to cattle, can also infect humans, cats, pigs, goats, sheep, dogs and hares. The causative agent of avian tuberculosis affects pigs, horses, cats, and, as proven in Lately, quite often a person.

Tuberculosis incidence
All sick animals (regardless of the type of pathogen) pose a danger to human health. IN in turn, a person with tuberculosis is a source of infectious agents for animals, from which other, healthy people can become infected. Tomescu (1942) described many cases of human-type tuberculosis in monkeys from one of the menageries. All of the above indicates the need for a comprehensive fight against tuberculosis in both humans and all animal species susceptible to tuberculosis.

Soon after the discovery of the causative agent of tuberculosis by Robert Koch, it was established that the incidence of bovine type tuberculosis poses a danger to humans and especially to children. So, in 1933 Gervois (France) determined that of the 17,045 cases of tuberculosis described in the literature, 11.2% were caused by bovine pathogens. In Poland, the frequency of cases of bovine tuberculosis in humans is, according to Mulak (1962), 17.5-19.2%. It is interesting to note that the proportion of cases of bovine tuberculosis is associated with the age of the patients. The frequency of such cases, for example in children, fluctuates, according to various statistics, between 16 and 36%, reaching even 41%. As Wilson points out, in England, bovine tuberculosis most often affects preschool children. In general, the most dangerous age is considered to be from 2 to 4 years. According to Park and Krumwied, up to 5 years of age, the proportion of bovine-type tuberculosis cases is 26.5%, at the age of 5-15 years - 25%, and at the age of over 15 years - 1.5%.

It has long been noted that in rural areas the incidence of bovine tuberculosis is more common than in cities. Sigurdson (1945) found a bovine type pathogen in 3.6% of patients in major cities Denmark, 27.5% in other cities and 40% in villages of this country. For rural areas, Gertler also indicates a figure of 40%. As special studies have shown, the prevailing idea that tuberculosis caused by bovine mycobacteria is rarely localized in the lungs should be reconsidered; Lindau found that in Sweden 60% of patients with tuberculosis caused by bovine mycobacteria had a pulmonary form, and Christiansen estimates that the pulmonary form in rural areas is 60.8% in women and 76.9% in men. Having examined 607 cultures of Koch's bacillus isolated from people, Al. Pop (1969) found that 9.06% of them were of the bull type. As Meissner showed, in Germany, out of 4784 studied cultures, 10% belonged to the bovine type, including 5% in the pulmonary form, and 19% in other localizations, especially in children.

The causative agent of tuberculosis
The causative agent of bovine tuberculosis causes disease mainly among workers on livestock farms living near where animals are kept, and in children who consume milk from cows with tuberculosis. Slaughterhouse workers can also become infected with tuberculosis. Most often, bovine tuberculosis pathogens enter the human body through digestive tract, however, the possibility of their entry through Airways(aerogenic infection); In this second way, livestock farm staff become infected by inhaling tuberculosis pathogens in the air of the barnyard. Milk is a food product that plays a significant role in the distribution pathogenic microbes. The content of the tuberculosis pathogen in milk is proportional to the degree of infection of the animal from which it was obtained. Mixing milk yields from several cows leads to infection of a large amount of milk.

Dairy products for the preparation of which use unboiled milk are equally, if not more dangerous to human health. Some of them, such as cream and sour cream, contain more tuberculosis bacteria than milk due to the phenomenon of flotation. In dairy products the pathogen remains viable for a long time: in butter-21 days, in peasant cheese 50-60 days, in Swiss and other slowly ripening cheeses 30-240 days. Since dairy products are not consumed locally, but enter the retail chain, they become a factor in the spread of the pathogen over long distances. According to some authors, tuberculosis caused by a bovine type pathogen is more severe and is more often accompanied by generalization than tuberculosis caused by a human type pathogen (Bundetseanu and Ionica, 1967).
The number of recovered people is 2 times higher among patients with human type tuberculosis than among patients with bovine type tuberculosis. Of the 35 cases of pulmonary tuberculosis caused by a bovine pathogen, in 15 cases other organs were also affected. 9 times during treatment the disease was unexpectedly discovered meninges, 7 times - chronic kidney tuberculosis, and, in addition, one case of tuberculosis of the knee joint, intestines and larynx was noted. In a similar group of patients with human type tuberculosis, kidney lesions were found in only two cases. The mentioned authors claim that with the pulmonary form of bovine tuberculosis, the number of deaths was greater (almost 3 times), although in terms of the stages of disease development both groups were similar and all patients lived in rural areas.
Spread of tuberculosis occurs mainly among workers on livestock farms living near places where animals are kept, and among children who consume milk from cows with tuberculosis. Slaughterhouse workers can also become infected with some types of tuberculosis. Most often, bovine tuberculosis pathogens enter the human body through the digestive tract, but the possibility of tuberculosis spreading through the respiratory tract (aerogenic infection) cannot be ruled out; In this second way, livestock farm staff become infected by inhaling pathogens in the air of the barnyard.

Milk is a food product that plays a significant role in the spread of tuberculosis and other types of infections. The content of the pathogen in milk is proportional to the degree of infection of the animal from which it was obtained. Mixing milk yields from several cows leads to infection of a large amount of milk. Dairy products for the preparation of which use unboiled milk are equally, if not more dangerous to human health.

Some of them, such as cream and sour cream, contain more tuberculosis bacteria than milk due to the phenomenon of flotation. In dairy products, the pathogen remains viable for a long time: in butter - 21 days, in peasant cheese - 50-60 days, in Swiss and other slowly ripening cheeses - 30-240 days. Since dairy products are not consumed locally, but end up in the trade network, they become a factor in the spread of tuberculosis over long distances.

According to some authors, tuberculosis caused by a bovine type pathogen is more severe and is more often accompanied by generalization than tuberculosis caused by a human type pathogen (Bundetseanu and Ionica, 1967). The number of recovered people is 2 times higher among patients with human type tuberculosis than among patients with bovine type tuberculosis. Of the 35 cases of pulmonary tuberculosis caused by a bovine pathogen, 15 cases involved other organs. 9 times during treatment, a disease of the meninges was unexpectedly discovered, 7 times - chronic tuberculosis of the kidneys, and, in addition, one case each of tuberculosis of the knee joint, intestines and larynx was noted.

In a similar group of patients with human type tuberculosis, lesions in the kidneys were found in only two cases in one natural focus of the disease. The mentioned authors claim that with the pulmonary form of bovine tuberculosis, the number of deaths was greater (almost 3 times), although in terms of the stages of disease development both groups were similar and all patients lived in rural areas.

Forms of tuberculosis
Pigs can become infected with bovine, avian, and human tuberculosis. The incidence of disease in pigs is associated with the spread of tuberculosis among cattle and poultry. The source of the infectious agent is sick animals kept near pigsties, as well as infected food waste used for feeding. This is the milk of sick cows or waste from its processing, food waste from tuberculosis hospitals and sanatoriums that have not undergone heat treatment. Thus, the main route of entry of the pathogen into the pig’s body is the digestive tract.

The disease manifests itself in different ways, depending on the form of tuberculosis. In the pulmonary form of tuberculosis, the disease occurs against the background of a feverish state and is accompanied by cough, respiratory failure, and weight loss. If the lymph nodes are infected, they increase in size, and after slaughter tuberculous changes are found in them. When localized in the intestines, the disease develops as chronic inflammation intestines. This case is described in more detail when considering avian tuberculosis.

Avian tuberculosis. Tuberculosis in poultry is caused by the avian form of tuberculosis, but they are also susceptible to other types of microbacteria. Birds kept in the apartment of a person with tuberculosis may develop human or bovine tuberculosis. Infection occurs less frequently by aerogenic means and more often through the digestive tract, since the pathogen comes with grain, which can be grown in a natural focus on soil fertilized with the droppings of sick birds. In birds, tuberculosis occurs in a generalized form; the lesions are represented by miliary nodules in all organs (very small in size), which is a consequence of bacteremia. Waterfowl are very resistant to these types of infections and get sick extremely rarely, but the lungs of sick individuals are much more affected than those of chickens. Tuberculosis of sheep and goats. In sheep and goats, the disease takes on a pulmonary form of tuberculosis, characterized by a long, progressive course. Animals lose weight and lose appetite due to fever, shortness of breath and cough. There are usually no tuberculosis bacteria cells in the mammary gland.
Tuberculosis of dogs and cats. The disease occurs in pulmonary or intestinal form. Animals are depressed, refuse food, lose weight, cough, and their secretions are rich in pathogens. Dogs tend to contract the human form of tuberculosis and, in turn, become dangerous to humans. Tuberculosis was detected in 41 (11.6%) of 354 examined people who had contact with 41 dogs that died from tuberculosis. Since tuberculosis in cats often affects the intestines and lungs, and sometimes skin, they can also serve as a source of pathogenic disease for humans, sometimes very severe. Thus, Lewis-Johnson observed a 3-year-old boy who was bitten by a cat; a primary complex arose at the site of the bite, followed by generalization, meningitis and death.

Tuberculosis in humans. Symptoms
Human tuberculosis transmitted from animals has been studied for a long time. Repeated attempts have been made to classify the forms of tuberculosis in humans infected from animals in various natural foci by manifestation and course. And in these cases, two stages can be distinguished in the development of the disease: primary disease and secondary, or tuberculosis of any organ. Regardless of how the pathogen entered the body - with air or food, primary tuberculosis is characterized by the formation of a primary complex. If infection with this type of infection occurs through an aerogenic route, then the primary complex includes one or more alveolar tuberculous nodules and inflamed regional lymph nodes.

The primary complex in pulmonary localization develops simultaneously with a violation of the general condition. The patient has low-grade fever, mild cough, weight loss, asthenia, and lack of appetite. Intestinal primary human tuberculosis, which occurs as a result of the entry of a large number of pathogens into the digestive tract (most often in children with milk from sick cows), develops slowly and is accompanied by mild fever, asthenia, mild abdominal pain, and diarrhea. In small and infant children, intestinal primary tuberculosis can manifest itself in the form of inflammation of the peritoneum, tuberculous peritonitis with a very severe course. Sometimes, depending on the type of immunity, the primary complex is localized in the tonsils.

The focus of primary tuberculosis either develops favorably until it is cured by resorption and calcification, or, conversely, spreads until secondary tuberculosis or a localized process appears in any organ. The clinical manifestation of secondary tuberculosis depends on the location infectious process. In the pulmonary form, a disturbance in the general condition, weight loss, lack of appetite, normal or subfebrile temperature, heavy breathing, shortness of breath, cough with copious sputum saturated with pathogens, sometimes with blood, are noted; With large blood losses, this form of the disease is called hemophthisia.

Lung damage is characterized by the formation of nodules and cavities. Tuberculosis of the digestive tract appears as an intestinal form, characterized by disturbed general condition by diffuse abdominal pain, bloating, nausea, and diarrhea. Changes in the intestine lead to stenosis. In persons exposed to occupational diseases If tuberculosis in humans is caused by a bovine type pathogen, extrapulmonary forms, such as meningitis, arthritis or ganglion tuberculosis, are often observed, especially in children.

Prevention of tuberculosis
Prevention of tuberculosis involves identifying and removing animal sources of pathogens, which reduces the incidence of human tuberculosis by approximately 10%. In some countries where animal tuberculosis has been eliminated, the danger of infection for humans has decreased, but sick people have begun to pose a danger as a source of infectious agents for animals. Animal farms unaffected by tuberculosis are dangerous due to the numerous sources of these types of infections for humans (cattle, pigs, poultry, cats, dogs).

Human infection can occur in a natural focus of the disease through direct contact with animals and through consumed products of animal origin, therefore, the prevention of tuberculosis should be aimed at identifying sick animals through periodic examination of livestock for reaction to tuberculin. Sick animals must be sent to slaughter. Their meat is sent for technical disposal, and for fresh consumption - only after heat treatment in autoclaves and provided that the general condition of the animals before slaughter was good. Livestock premises, equipment and machines used for feeding animals are disinfected with 20% bleach or 2% caustic soda. Manure, straw and excrement are burned. In poultry houses, disinfection is carried out repeatedly, especially on soil where the avian pathogen persists.

Disinfection team workers must be provided with protective clothing. People who keep dogs and cats at home should avoid too close contact with these animals, and if this happens, take serious hygiene measures. Prevention of tuberculosis also includes veterinary examination of all food products of animal origin. Livestock is also checked for the presence of infectious animal diseases in order to exclude them from the general herd. Milk is suitable for consumption after proper pasteurization, and eggs obtained from sick birds must be boiled in boiling water for 20 minutes. Animal care workers and veterinary personnel periodically undergo medical examinations for tuberculosis. In the prevention of tuberculosis, sanitary and educational work among persons who may be infected is of great importance.

Tuberculosis is an infectious, chronic disease of all species of animals and humans, characterized by the formation of various organs specific nodules undergoing caseous necrosis and calcification.

Historical reference. Tuberculosis has been known to mankind since ancient times. Hippocrates (4th century BC) described the clinical signs of tuberculosis in humans and recommended treatment methods. The term “tuberculosis” was first used by the French physician Lenek (1819) in 1869. Villemin established the infectiousness of tuberculosis.
The causative agent of the disease was discovered by R. Koch in 1882. In 1890, he produced the diagnostic drug tuberculin.

In 1924 And Calmette and S. Guerin produced the BCG vaccine for the specific prevention of tuberculosis in humans.
Tuberculosis is registered in many countries of the world. In Russia, the prevalence of tuberculosis among animals is insignificant.
Eradication of tuberculosis is a serious problem and is especially urgent because the disease is zoonotic and anthropozoonotic.

Economic damage. Tuberculosis causes great economic damage to livestock production, which is associated with a decrease in productivity, premature culling and delivery of animals for slaughter, lengthy and expensive anti-epizootic measures and other material costs.

The causative agent of the disease-Mycobacterium tuberculosis, a rod from 0.5 to 8µ long, often bent at an angle, sometimes appears in the form of grains located in one line. The microbe is a strict aerobe, non-motile, does not form spores, acid-resistant, and also alcohol- and antimorphine-resistant. The acid-fastness of the tuberculosis bacillus is used to differentiate it from other non-acid-fast bacteria. The tuberculosis bacillus contains fatty wax and therefore does not accept paint well, but, being colored with carbolfuchsin when heated, it retains this paint better than other microorganisms. When processing smears weak solution With sulfuric acid, tuberculosis bacteria are not discolored (they are stained magenta red), but other microbes are discolored (Ziehl-Neelsen method). In smears they are located singly or in groups.

There are three known types of tuberculosis bacillus: human (humanus), bovine (bovines), avian (avium), which are varieties of the same species. Under certain conditions, they can sometimes change, turning into other types. Most often there is a transition from the bull type to the human type. In 1937, Wales isolated a special type of bacteria from the field mouse, called the Oxford strain. This strain is close to the bovine type. Other scientists consider it the fourth type of tuberculosis bacillus - mouse.

The main difference between the types is their unequal virulence for individual species of animals and humans.

Mycobacterium tuberculosis (human species) causes tuberculosis in humans. TO this species Pigs, cats, dogs, cattle, and fur-bearing animals are also susceptible to mycobacteria, but birds (with the exception of parrots) are not susceptible.

Micobacterium bovis (bovine species) causes tuberculosis in all types of agricultural and wild animals, including fur-bearing animals, as well as humans. Birds are not susceptible to this type of mycobacteria.

Mycobacterium avium (avian species) causes tuberculosis in domestic and wild birds; pigs are susceptible to this type of mycobacterium; Animals of other species and humans are rarely infected.
In nature (in peat and soil) there are opportunistic atypical and saprophytic mycobacteria, which in their morphological and cultural properties are close to avian mycobacteria.

Animals infected with such mycobacteria can react to tuberculin for mammals, which is used by practical veterinarians when carrying out planned anti-epizootic measures, which causes certain difficulties when carrying out allergic diagnosis of tuberculosis.

The tuberculosis bacillus, due to the content of fatty wax elements, is very resistant to external environment and exposure to disinfectants. In air-dried pieces of affected lungs, microbes remain virulent for 200 days, and in soil and manure they remain viable for up to 4 years, and in birds for up to 10 years. sunlight disinfects bacteria in sputum only after 72 hours. In products obtained from sick animals, the tuberculosis pathogen persists: in milk for up to 19 days, in butter for up to 300 days, in cheese for 145-200 days, in frozen meat for up to 1 year, in salted meat for 60 days. In the carcasses of cattle and birds, mycobacteria persist from 3 to 12 months.
Heat has a detrimental effect on tuberculosis bacteria. Heating milk to 55° kills them after 4 hours, to 85° kills them after 30 minutes; when milk is boiled, mycobacteria die after 3-5 minutes.

Chemicals have a detrimental effect on bacteria over relatively long periods of time: a 5% solution of carbolic acid - after 24 hours, a 5% formaldehyde solution - after 12 hours, a solution containing 5% active chlorine - after 3 hours.
The best disinfectants are a 3% alkaline solution of formaldehyde (exposure 1 hour), a suspension of bleach containing 5% active chlorine, a 10% solution of iodine monochloride, a 20% suspension of freshly slaked lime, a 5% solution of calcium hypochloride, 1 % solution of glutaraldehyde and other preparations.

Epizootological data. More than 55 species of domestic and wild animals and about 25 species of birds are susceptible to tuberculosis. The most susceptible are cattle and pigs, fur-bearing animals are minks, and chickens are among birds. Less commonly, goats, dogs, birds, ducks and geese get sick with tuberculosis. Sheep, horses, and cats very rarely get sick.
The main source of infectious agents for tuberculosis are sick animals. They excrete bacteria in feces, sputum, milk, and, if the genitourinary tract is affected, in semen. In cattle with pulmonary tuberculosis, there may be up to 100,000 tuberculosis bacteria in 1 g of sputum. When coughing, part of the sputum is sprayed into the air, and part is swallowed by animals and comes out with feces. A cow with tuberculosis is capable of excreting an average of 37 million tuberculosis bacteria per day in feces. The excretions of animals sick with tuberculosis contaminate the environment: premises, walking yards, pastures, watering places.

Factors of transmission of the infectious agent can be feed, water, bedding, manure, etc.

Infection with tuberculosis occurs more often during the stall period when animals are kept in crowded conditions. Young animals become infected mainly through milk and skimmed milk obtained from sick animals. Intrauterine infection of calves is possible. Animals can become infected through contact with people with tuberculosis, especially milkmaids and calves who do not undergo annual medical examinations. On the pasture, infection is less common, since the bacteria die under the influence of sunlight, but if the summer is rainy and cold, then mass reinfection of animals is possible on the pasture. During the stall period, adult cattle are infected mainly by aerogenous means, while on pasture they become infected through nutritional means; pigs become infected by feeding them undisinfected kitchen waste from hospitals, tuberculosis dispensaries, or by contact with sick birds. Dogs and cats - from people suffering from an open form of tuberculosis or from eating milk and meat from sick cows.

Poor living conditions, inadequate feeding, and excessive exploitation reduce the resistance of animals to tuberculosis. Abrupt transitions from one living conditions to another, replacement of feed, lack of regular exercise in the fresh air, crowded and damp rooms and other unsanitary conditions for keeping animals also have a negative impact.

In beef cattle kept in the steppes, the incidence of tuberculosis is insignificant. However, as soon as cattle are deprived of the conditions to which they are accustomed, resistance to tuberculosis drops and the cattle get sick.

In herds, tuberculosis usually spreads slowly, with massive re-infection of livestock occurring over several months. The comparatively slow spread of tuberculosis is explained, on the one hand, by the duration incubation period, and on the other hand, by the fact that not all sick animals are active bacteria excretors.

Most often, a certain number (sometimes significant) of sick animals is detected in the spring, when the veterinary service carries out routine tuberculinization on farms, but sometimes livestock is re-infected on pasture, especially if the summer is damp and cold.

Pathogenesis. Having penetrated the animal's body with inhaled air or through the digestive tract, tuberculosis bacteria enter the lungs or other organs through the lymphogenous and hematogenous routes. At the site of localization of tuberculosis bacteria, it develops inflammatory process with the subsequent formation of tuberculous nodules - tubercles the size of a lentil grain, grayish in color, round in shape. In the center of the tubercle, dead cells are converted into a curdled mass under the influence of mycobacterial toxins.
Depending on the resistance of the organism and the virulence of the bacteria, the tuberculosis process can be benign or malignant.

In a resistant organism, tuberculosis bacteria are surrounded by epithelioid cells, from which giant cells are subsequently formed. This entire group of cells is surrounded by a ring of lymphocytes. Exudate is deposited between the cells and fibrin coagulates. The developing avascular tuberculous tubercle (granuloma) is encapsulated. Tissue cells in the tubercle die due to the lack of influx of nutrients, and under the influence of bacterial toxins, a curdled mass is formed, impregnated with lime salts. With such a benign course of the disease, in such an encapsulated focus, tuberculosis bacteria can ultimately die and further development of the infectious process stops.

In cattle, tuberculosis of the serous membranes (pleura, peritoneum) - “pearl oyster” - is quite often observed. In this form of the disease, inflammation from the very beginning is productive. Tuberculous tubercles undergo fibrinous degeneration and turn into dense shiny growths.

In an organism with reduced resistance, the process of delimitation and localization of the tuberculosis pathogen is weakly expressed. Due to insufficient encapsulation, melting of the walls of tuberculous nodules occurs. Mycobacteria enter healthy tissue, which leads to the formation of new small (miliary) nodules. The latter merge with each other and form large tuberculous foci. If the cheesy mass is released from these foci, for example in the lungs through the bronchi, then cavities are formed. The pathogen spreads through the lymphatic vessels; When it enters the circulatory system, bacteremia occurs in the animal’s body. Bacteria are spread throughout the body, the process generalizes, and many organs are affected (liver, kidneys, spleen, etc.).

The resistance of an animal's body depends not only on its initial state, but also on the conditions in which it is located. If there are favorable feeding and housing conditions on the farm that increase the body's resistance, the onset of development of the tuberculosis process can be delayed at a certain stage. Even large tuberculosis foci can undergo encapsulation and calcification in the body of animals. Immuring the causative agent of tuberculosis either leads to the suppression of its reproduction, or ends in the death of the pathogen, and then the body of the sick animal recovers.

In the case of generalization of the tuberculosis process and extensive lung damage, gas exchange is disrupted, toxins of tuberculosis bacteria reduce erythropoiesis, which causes anemia. If this is accompanied by intestinal lesions, accompanied by impaired absorption of nutrients, then the animal suffers exhaustion and death.

Course and symptoms of the disease. The duration of the incubation period for tuberculosis ranges from two to six weeks. Tuberculosis in animals is chronic or latent, so clinical signs of the disease may appear several months or even years after infection.

The onset of tuberculosis in animals in private household plots, peasant farms and agricultural enterprises is determined during routine diagnostic tests for tuberculosis (tuberculinization) by veterinary specialists based on the presence of positive allergic reactions.
When animals that react positively are sent for diagnostic slaughter, and during post-mortem examination of organs and lymph nodes, signs characteristic of tuberculosis are found.

Conventionally, a distinction is made between active, or open, tuberculosis, when tuberculosis bacteria are released with bronchial mucus, feces or milk, and latent tuberculosis, when the bacteria are so isolated in the tuberculosis focus that they are not released outside.

When the intestines, udder and uterus are affected, the tuberculosis process is always open; when the lungs are affected - not always, but very often. Based on the location of the pathological process, pulmonary and intestinal forms of tuberculosis are distinguished; In addition, animals also have lesions of the udder, serous integument (pearl mussel), genital form and generalized tuberculosis. The course of the disease in individual animals is generally similar, but there are some peculiarities.

In cattle Tuberculosis is mostly chronic or latent. In young animals - acute and subacute. Clinical signs of the disease are: increased body temperature (39.5-40°C), moist cough, especially in the morning. The mucus released when you cough sometimes contains pieces of dead tissue. Sick animals experience shortness of breath. On auscultation chest We detect wet or dry wheezing in the lung area. If an animal's pleura is affected by the tuberculosis process, the animal will experience pain when pressing between the ribs. A sick animal loses weight. The skin becomes dry and loses elasticity.

With generalized tuberculosis, the lymph nodes (submandibular, retropharyngeal, parotid, cervical, prescapular, inguinal, knee fold, suprauterine) become enlarged. When palpated, the affected lymph nodes are dense, sometimes lumpy, and painful. An enlargement of the mediastinal nodes leads to compression of the esophagus, and this disrupts the belching process and causes chronic swelling of the rumen.

If the udder of animals with tuberculosis is affected, then part of it, usually the back, swells, becomes painful and hard. Milk mixed with blood or curdled mass is squeezed out of the nipples.

When the intestines are affected, intermittent diarrhea is initially observed, which then becomes constant. A sick animal develops cachexia. Damage to the uterus and vagina is accompanied by abortion, nymphomania, barrenness. A glassy discharge mixed with pus is released from the vagina. Damage to the genital organs in bulls is complicated by orchitis. A pearl oyster on the pleura can be identified by auscultation.

The tuberculosis process, as a rule, progresses slowly. The disease can last for many years. Some sick animals recover, and in cases where the primary complex becomes sterile, the animal loses sensitivity to tuberculin. Most animals with tuberculosis appearance And general condition no different from healthy people. Tuberculosis lesions are found only at slaughter.

Horses suffer from tuberculosis relatively rarely, mainly on farms where cattle suffer from tuberculosis, and the disease most often occurs latently. If the tuberculosis process is severe, severe emaciation of the animal is noted, although the appetite may persist for a long time. When the lungs are affected, a weak cough appears, and the horse quickly gets tired of working. In some cases, there have been cases of damage to the nasal mucosa with the presence of nodules and ulcers.

Young horses have tuberculosis of the intestines and mesenteric lymph nodes. In this case, we notice poor appetite and colic appears. Constipation alternates severe diarrhea. Equine tuberculosis is characterized by polyuria, the amount of urine excreted increases 3-4 times.

Porcine tuberculosis observed in farms where there are cattle or poultry with tuberculosis. The disease in pigs is predominantly asymptomatic. The most characteristic clinical signs are enlargement of the submandibular, retropharyngeal and cervical lymph nodes. Sometimes abscesses form in these nodes, after opening which fistulas remain, from which a purulent-curdled mass is released. If the lungs are affected, coughing and vomiting, difficulty breathing are observed, and if the intestines are affected, diarrhea occurs. Sick pigs lose weight quickly.

In sheep and goats Tuberculosis basically proceeds in the same way as in cattle. More often the disease is asymptomatic. With a highly expressed tuberculosis process, patients experience coughing, nasal discharge, and emaciation. In goats, udder damage is characterized by the formation of hard, lumpy swellings, sometimes reaching a significant size.

Avian tuberculosis. Chickens get sick more often, geese and turkey ducks much less often. The disease is chronic with very unclear clinical signs. Sick chickens become lethargic and lose weight while maintaining their appetite. The crest becomes pale and wrinkled, the bird is inactive, egg production decreases, and the pectoral muscles atrophy. Generalization of the tuberculosis process is accompanied by damage intestinal tract. Vomiting and diarrhea are observed, causing severe exhaustion of the bird. Sometimes bones and joints are affected, and lameness is noted. A sick bird develops anemia: the number of red blood cells drops to 1 million, the hemoglobin content to 35%.

Canine tuberculosis. In dogs, tuberculosis is characterized by low-grade fever, decreased appetite, lethargy, and gradual emaciation of the animal. There is a cough and nasal discharge. If the intestines are affected, diarrhea occurs. Due to tuberculosis, dogs may develop synovitis and deforming osteoarthritis. Death occurs from complete exhaustion.

Camel tuberculosis. The cervical and submandibular lymph nodes are affected; There is a cough, increased sweating, and rapid fatigue.

From fur-bearing animals Silver-black foxes, minks and nutria are susceptible to tuberculosis. Young animals get sick more often. The disease is predominantly chronic; weakness, lethargy, and progressive emaciation are noted. When the lungs are affected, coughing, difficulty and rapid breathing are observed. If the intestines are affected, diarrhea and, less commonly, constipation appear. Liver damage may be accompanied by jaundice. Foxes sometimes develop non-healing ulcers on the skin of their necks.

Pathological changes. In large and small cattle, tuberculosis most often affects the lungs and bronchial-mediastinal lymph nodes.

According to P.I. Kokurichev (1950), lymph nodes in a cattle patient with tuberculosis chest cavity affected in 100%, lungs in 99% of cases; other organs - rarely: liver - 8%, spleen - 5%, udder - 3%, intestines - 1%.

When opening the lungs, dense foci of reddish-gray or yellowish color. The contents of the lesions are cheesy or calcareous. Sometimes the lesions look like purulent foci surrounded by a thin connective tissue capsule. Around such foci are scattered nodules of various sizes, from a pinhead to a millet grain. The presence of cavities surrounded by a dense capsule is also characteristic. Tuberculosis foci can be detected, although much less frequently, also in other parenchymal organs, V bone marrow and bones. The pleura is also affected, and sometimes fusion of its leaves is observed. The so-called pearl mussel is characterized by the formation on the serous membranes of the thoracic and abdominal cavities small tuberculous nodules with simultaneous proliferation of connective tissue. A cluster of dense nodes looks like cauliflower. On a section of the lymph nodes affected by tuberculosis, a curdled degeneration is detected. On the mucous membrane of the pharynx, small intestine and cecum, individual tubercles and ulcers of various sizes are observed, having a hard bottom, they are covered with a dry cheesy mass.

When autopsying the corpses of adult horses that died from tuberculosis, changes are found mainly in the lungs, often in the form of a miliary process. In foals, damage to the mesenteric lymph nodes is noted. The latter are enlarged, and numerous cheesy-purulent foci are found in them. Nodes and ulcers are found on the intestinal mucosa. If the liver and spleen are affected by the tuberculosis process, they can be enlarged several times. In horses, damage to the serous membranes (pearl oyster) is also observed.

When autopsying birds that have died from tuberculosis, specific lesions are often found in the liver and spleen in chickens, and in the lungs in geese and ducks.
The liver and spleen are usually sharply enlarged, have a flabby consistency and contain numerous tubercles located both in the depths and along the periphery of the organ. Tuberculosis foci of various sizes are sometimes found in large numbers in the small and large intestines, where they are located in the mucous membrane and submucosal layer. There may be ulcers of various sizes on the mucous membrane. The lymph nodes of the mesentery are enlarged and contain caseous masses. In rare cases, tuberculous lesions are found in the kidneys and bones.

Diagnosis Tuberculosis is diagnosed comprehensively, taking into account epizootic data, clinical signs and the results of allergic, pathological, histological, bacteriological and biological studies.

The clinical diagnostic method is of limited value, since in relation to large species Animals using this method manage to isolate very few patients with tuberculosis.

The main method of intravital diagnosis of tuberculosis is allergic. Allows you to identify patients with any form of tuberculosis, regardless of whether the animal has clinical signs of the disease or not.

To diagnose tuberculosis in cattle, buffaloes, pigs, goats, sheep, horses, camels, dogs, monkeys and fur-bearing animals, tuberculin is used - a sterile filtrate of killed cultures of the tuberculosis pathogen of two types: dry purified (PPD) tuberculin for mammals and PPD - tuberculin for birds. Tuberculin PPD for birds is prepared from the causative agent of tuberculosis bird-like and is used to diagnose tuberculosis in birds and pigs.

The main intravital method for diagnosing tuberculosis in animals is an allergic intradermal tuberculin test. In horses, camels, buffaloes, diagnostics are carried out by eye method(ophthalmic test). If necessary, an ophthalmic test is also carried out in cattle simultaneously with an intradermal test.

Tuberculinization is subjected to:

cattle (buffaloes) twice a year: in the spring, before pasture, and in the fall, before placing livestock for winter maintenance, and young cattle from 2 months of age, cattle of fattening groups - once a year;
horses, mules, donkeys, sheep and goats - depending on the epizootic situation;
all adult sows, as well as young animals after weaning in all breeding farms - once a year, and on other pig farms - depending on the epizootic situation;
adult birds (over two years old) of original lines and ancestral flocks at breeding factories and breeding poultry stations - once a year.

Animals belonging to citizens living on the territory of farms or in separate populated areas, are examined for tuberculosis simultaneously with tuberculinization on the farm.

With the intradermal method of tuberculinization, tuberculin is injected into the middle of the neck of cattle, buffalo, zebu, deer (deer) in the middle of the neck, in bulls - under the tail fold, in camels - in the area of the outer surface of the ear 2 cm from its base, in goats - in the thickness lower eyelid; dogs, monkeys and fur-bearing animals (except minks) - to the region inner surface thigh or elbow crease; mink - intrapalpebrally in upper eyelid; for cats - in the area of the inner surface of the ear; for chickens - in the beard; for turkeys - in the submandibular earring; for geese, ducks - in the submandibular fold; pheasants - males - in cavernous bodies heads; peacocks, parrots, pigeons, cranes, herons, storks, flamingos - in the area of the outer side of the lower leg 1...2 cm above the ankle joint.

Before tuberculin is administered, the fur (hair) at the injection site is trimmed (feathers are plucked), and the skin is treated with 70% ethyl alcohol.

Reading of the reaction to intradermal injection of tuberculin is carried out in cattle, buffaloes, zebu cattle, camels and deer in 72 hours; in goats, sheep, pigs, dogs, cats, monkeys, fur-bearing animals in 48 hours; in a bird in 30-36 hours. In areas unaffected by tuberculosis, cattle and camels are allowed to re-inject tuberculin 72 hours after the first administration in the same dose and in the same place. The response to repeated administration is recorded and assessed after 24 hours.

When taking into account the intradermal reaction, the site of tuberculin injection is palpated in each animal under study; in minks, the eyelids of the left and right eyes are visually compared.

If, during reading, thickening of the skin is detected at the site of tuberculin injection in cattle, buffalos, zebu cattle, camels, deer, we take a cutimeter and measure the thickness of the fold in millimeters and determine the magnitude of its thickening, comparing it with the thickness of the fold of unchanged skin near the site of tuberculin injection.

Animals are considered tuberculin responsive:

cattle (except bulls), buffalo, zebu, camels, deer, deer, antelope - with thickening of the skin fold by 3mm or more regardless of the nature of the swelling (swelling, pain, increased local temperature);
bulls, sheep, goats, elephants, rhinoceroses, hippopotamuses, pigs, dogs, wolves and other representatives of carnivores, birds, dolphins, cats – when swelling forms at the site of tuberculin injection.

Intradermal tuberculin test - a highly specific reaction to tuberculosis. At the same time, it depends on the general immunoreactivity of the body. In old, deep-pregnant animals, in animals with low fatness, as well as in generalized tuberculosis, the reaction to tuberculosis may be weakly expressed or absent altogether (anergy).

Veterinary specialists conducting tuberculinization should keep in mind that sometimes nonspecific (para- and pseudo-allergic) reactions to tuberculin for mammals are possible, due to sensitization of the body by avian mycobacteria, pathogens of paratuberculosis and atypical mycobacteria, as well as other reasons. To differentiate nonspecific reactions, a simultaneous allergy test is used, which is carried out simultaneously with tuberculin for mammals and a complex allergen from atypical bacteria (CAM). If, when reading the reaction, the intradermal reaction to the administration of CAM is more intense than to tuberculin for mammals, veterinary specialists consider the reaction to be nonspecific; material from such animals is examined for tuberculosis using laboratory methods.
Tuberculinization by the eye method (ophthalmic test) is used to diagnose tuberculosis in horses and other representatives of equids.

In cattle, this method can only be used simultaneously with an intradermal tuberculin test for additional identification of infected animals in farms unaffected by tuberculosis or when selecting animals for diagnostic slaughter. The diagnosis of tuberculosis during pathological examination is most often confirmed in animals that react simultaneously when examined in each of the samples.

Ocular tuberculinization is carried out twice with an interval of 5-6 days between administrations. Tuberculin in an amount of 3-5 drops is applied with a pipette or syringe without a needle to the conjunctiva of the lower eyelid or to the surface of the cornea with the lower eyelid retracted.

Animals that responded to the first injection of tuberculin are not given the drug again.

The results of the ophthalmic test are recorded after 6,9,12, and 24 hours after the first and 3,6,9 and 12 hours after repeated administration of tuberculin. A positive reaction is characterized by the formation of a mucopurulent or purulent secretion that accumulates in the conjunctival sac or flows in the form of a cord from the inner corner of the eye, hyperemia and swelling of the conjunctiva. When taking into account the reaction, it is necessary to retract the lower eyelid and inspect the conjunctival sac, since the reaction may be limited to the short-term formation of purulent secretion in the form of grains.

Short-term hyperemia and lacrimation with the formation of a small amount of mucous secretion, as well as the absence of any changes, are assessed as a negative reaction.

If, during routine tuberculinization in a prosperous farm, animals that react to tuberculin are identified for the first time, then in order to clarify the diagnosis, under the supervision of specialists from the state veterinary network, a commission diagnostic slaughter of 3-5 animals with the most pronounced reactions to tuberculin is carried out and the internal organs and lymph nodes are examined. If pathological changes typical of tuberculosis are detected in at least one of the killed animals, the diagnosis is considered established.

If changes in organs and tissues characteristic of tuberculosis are not found in killed animals, material is taken for bacteriological examination with a bioassay. When mycobacterium tuberculosis of bovine or human species is isolated from material from killed animals or with a positive bioassay, the diagnosis is also considered established;

Immunity and specific prevention.

The emergence and development of the tuberculosis process is accompanied by irritation of the central nervous system. This causes an increase in the body's specific sensitivity to tuberculosis bacteria and their toxins. Hypersensitivity, or allergy, is detected several days or weeks after bacteria enter the body and marks not only the onset of an infectious process, but also the beginning of the formation of a certain degree of non-sterile immunity.
In tuberculosis, phagocytosis is rarely complete; bacteria multiply in neutrophils and macrophages. Agglutinins, precipitins and complement-fixing antibodies also play a minor role in immunity. In the process of evolution, the body has developed the ability to isolate (immine) the pathogen in granulomas-tubercules. The degree of this ability, depending on many factors, including the virulence of the pathogen, can be different, and this determines the outcome of the disease. Infectious (non-sterile immunity) continues as long as tuberculosis bacteria are in the body; with their release or death, immunity also ceases.

For specific prevention of tuberculosis in medical practice The BCG vaccine, made by Calmette and Guerin (1924) from a culture of bovine mycobacteria, is widely used.

Specific prevention of tuberculosis using BCG vaccines is possible, but in most countries farm animals are not vaccinated against tuberculosis.

Prevention. Prevention and control measures against tuberculosis are carried out in accordance with current sanitary (SP 3.1 093-96) and veterinary rules (VP 13.3 1325-96).

Animal owners, farm managers, regardless of their form of ownership, peasant farm owners and others are obliged to:

if you have or purchase animals, register them at a veterinary institution, obtain a registration number in the form of a tag and monitor its safety;
purchase, sale, slaughter, pasture, placement on pastures and all other movements and regroupings of animals, sale of livestock products must be carried out only with the knowledge and permission of the state veterinary service authorities;
equip the necessary veterinary and sanitary facilities;
take precautions when preparing feed to prevent infection;
quarantine newly arrived animals for 30 days for veterinary research and treatment;
promptly inform the veterinary service about all cases of illness in animals with suspected tuberculosis (loss of fatness, signs of pneumonia, enlarged superficial lymph nodes);
provide, at the request of veterinary specialists, all necessary information about purchased animals and create conditions for their examination, research and treatment;
comply with zoohygienic and veterinary requirements when transporting, keeping and feeding animals, and constructing livestock facilities;
carry out timely delivery of sick animals or complete elimination of all unfavorable livestock as directed by veterinary specialists;
ensure the implementation of restrictive, organizational, economic, special and sanitary measures provided for in these rules to prevent tuberculosis in animals, as well as to eliminate an epizootic outbreak in the event of its occurrence, with the allocation of the necessary material, technical and financial resources.

Treatment. Animals with tuberculosis are sent for slaughter. In herds, on farms, in populated areas where the disease has already been established, animals that react to tuberculin are recognized as having tuberculosis and sent for slaughter within 2 weeks.

Currently, it is necessary to distinguish 5 types of tuberculosis pathogen: human (typus humanum), bovine (typus bovinum), avian (typus avium s. gallinaceum), cold-blooded animal type, or fish (typus piscium), and mouse (typus murium). The mutual infectivity of humans and animals with human, bovine and avian types of pathogens is recognized by many researchers. But the possibility of transformation is excluded various types in the body of animals and humans with the acquisition of morphological and physiological characteristics of one type or another, depending on the type of organism in which the tuberculosis pathogen is located.

The significant spread of pulmonary tuberculosis among people caused by the bovine type of pathogen is beyond doubt. In patients in rural areas, the bovine type pathogen occurs several times more often than in sick city dwellers. According to N. Lellhuber (cited from M.K. Yuskovets, 1963), it was found in 60.8% of women and 76.9% of men suffering from pulmonary tuberculosis.

Vigorous measures to combat tuberculosis in animals have undoubtedly had their impact positive results. At the same time, in areas with almost eliminated tuberculosis among cattle, there is an incidence of tuberculosis in people caused by bovine mycobacteria. The reason is that humans become infected with this type of pathogen from goats and pigs. The role of domestic animals (cats, dogs) in infecting people with mycobacteria of the bovine type has also been proven.

The problem of tuberculosis caused by mycobacteria of the avian type, which are pathogenic not only to birds and humans, but also to pigs and cattle, has not lost its practical significance (A.I. Kagramanov, 1968; Ya.A. Blagodarny, 1972). Consequently, the source of this type of infection can be birds, pigs and cattle (M.K. Yuskovets, 1963).

Tuberculosis caused by bovine and avian types of mycobacteria, in most cases has extrapulmonary localization. The first two places are occupied by skin lesions (29.2%) and lymph nodes (18.7%), meningitis and osteoarticular lesions are found. Many authors pay attention to the slow development of tuberculosis, asymptomatic onset and the predominance of productive phenomena. Mycobacteria of bovine and avian types differ from humans in significant resistance to tuberculostatic drugs, especially the first series (streptomycin, tubazid, ftivazid, PAS, etc.).

The problem of combating bovine and avian tuberculosis in humans has significant features and difficulties. Unfortunately, identification of mycobacterium types is not carried out in livestock farmers with tuberculosis and resistance to treatment. For this reason, it is impossible to determine not only the connection between the disease and the profession, but also to prescribe effective treatment.

In connection with the above, determining the type of causative agent of pulmonary tuberculosis in rural residents, especially livestock breeders, becomes of great practical importance. By determining the type, the question of the connection of the disease with the profession can be resolved. For this, the epidemiological situation in livestock farms is of no small importance. As noted above, with a long course of the disease, the type of pathogen can change and acquire features characteristic of humans. Often there is a combination of two types of pathogen - human and bovine. The combination of the bovine type of pulmonary tuberculosis pathogen in livestock breeders with an unfavorable epizootological situation is undoubted evidence of the occupational nature of the infection (disease). Identification of the animal type of pathogen (bovine, avian) without obvious indications of the presence of tuberculosis in livestock farming requires a more thorough investigation of the primary source of infection (domestic animals). Contact with sick animals in the absence of contact with people sick with tuberculosis indicates occupational infection and in cases where the type of pathogen of pulmonary tuberculosis is human (apparently, a transformation of the type of pathogen has occurred).

The type of pathogen is determined by its morphological and biological properties. Mycobacteria of human type blue medium with bromocresolurpur is changed to greenish color, mycobacteria of the bovine type do not change the color of the medium. Guinea pigs are most sensitive to the human type, while rabbits are most sensitive to the bovine and avian types. In addition, there is the greatest sensitivity to tuberculin of the type that is the cause of the disease in this case (mixed infection is also possible).

Several factors play a role in increasing the proportion of bovine and avian mycobacteria in human tuberculosis pathology. Among them, the first place should be given to the fairly high effectiveness of anti-tuberculosis drugs in relation to the human type and low – to bovine and avian ones.

Skin tuberculosis is typical example exogenous tuberculosis infection, developing most often in livestock breeders. Mycobacteria can penetrate the skin through a damaged surface, adapt there and cause tuberculous lesions. This route of penetration into the body almost always causes the development of warty skin tuberculosis. The main localization of occupational tuberculosis is the dorsum of the hands and fingers, interdigital folds, and much less frequently, the forearms, palms and backside stop. The possibility of localization on the skin of the buttocks, neck, face and other areas cannot be excluded. However, there are cases where there is no reliable information about the infection being introduced from the outside. Therefore, in the etiology of this type of tuberculosis, the endogenous route of penetration of the pathogen into the skin cannot be excluded.

For clinical picture Warty skin tuberculosis is characterized by a plaque, in the center of which dense cracked papillary growths are noticeable, elements of purulent inflammation are closer to the periphery, then gray dense scales on a dark red background and a zone of hyperemia with circular and polycyclic edges. After the papillae and scales are rejected during the healing process, the skin surface appears uneven. Healing is accompanied by scar formation or atrophy. Concomitant signs of warty skin tuberculosis may include lesions characteristic of colliquative skin tuberculosis. This form of skin tuberculosis is relatively benign and treatable.

The occupational etiology of skin tuberculosis can be established when the characteristics of working conditions confirm contact with tuberculous material and the presence of factors damaging the epidermis.

The form of warty tuberculosis of the skin also includes the cadaveric tubercle, or anatomist tubercle (verruca necrogenica). It is a local manifestation at the site of any damage to the epidermis by infected material. Occurs in people who have professional attitude to sources of tuberculosis infection (animal corpses). These may be veterinarians, workers of bacteriological and pathological laboratories. Cadaveric tubercles are usually localized on the fingers, in the area of the interphalangeal joints. Although the cadaveric tubercle is clinically no different from warty tuberculosis of the skin, however morphological feature it is a pronounced hyperkeratosis, which predominates over the tubercular infiltrate. The diagnosis is based on the typical clinical picture of the disease, taking into account information about professional activity sick. The results of tuberculin tests can serve as a diagnostic aid, although they are less pronounced than with lupus vulgaris. Verrucous tuberculosis of the skin is faster and easier to treat than other types of this disease.

Prevention comes down to increasing the body's resistance to tuberculosis infection, eliminating damage to the epidermis when working with infected material, lubricating abrasions and scratches with Novikov's liquid.

Helpful information:

Tuberculosis (from Latin tuberculum - tubercle) - infection, affecting the human lungs with the development of general inflammation.

The disease is caused by three types of mycobacteria - human, bovine and intermediate.

Tuberculosis is a disease that affects not only people, but also animals - livestock (cows and other cattle), pigs, and chickens.
Historically, tuberculosis had a different name - in the Russian-speaking environment it was called consumption. This disease was incurable until the beginning of the twentieth century, and patients died for a long time, gradually “wasted away”, their condition constantly worsened.

Those at risk for tuberculosis today are people with weakened or insufficiently developed immunity - children, elderly people, and women. According to the World Health Organization, more than 35% of the world's inhabitants are carriers of mycobacteria.

Today, tuberculosis is curable, but up to two million people die from this disease every year. As a rule, death occurs in cases where the patient does not know about his disease, refuses treatment, lives in a region where medicine is not sufficiently developed, or is inaccessible to patients for economic reasons.

Causes of tuberculosis development

The main cause of the development of tuberculosis is identified - mycobacteria, as well as secondary ones (environmental conditions and the state of medicine).

So, most often tuberculosis is caused by:

mycobacteria of human type;
bovine mycobacteria;
mycobacteria of intermediate type;
mycobacteria of other types living in the environment (there are more than 70 types, and for the most part they have no epidemiological significance, and become aggressive towards humans only in cases where the body itself is weakened, and environmental conditions contribute to the active development microbe).

For rural residents, the most common cause of infection is M. Avium, a bovine mycobacterium. As a rule, tuberculosis affects patients suffering from immunodeficiency conditions.

The causative agent of tuberculosis is Koch's bacillus, named after the researcher who first described the bacterium and its effect on humans. The cell wall of Koch's bacillus consists of polysaccharides, thanks to which the mycobacterium is able to tolerate even the most unfavorable external conditions, as well as maintain a stable size. Mycobacteria are not able to move independently because they lack flagella.

Koch's bacillus contains tuberculin (tuberculoproteins, specific proteins with antigenic function). It is the antigenic function that provides increased sensitivity to the effects of this protein, and the lipid fraction adds resistance to acidic and alkaline environments.

Routes of infection with tuberculosis

Main paths:

aerogenic (airborne);
contact (by direct contact);
nutritional (for disorders of absorption function digestive system in general and, in particular, the intestines);
transplacental.

If the human body is healthy, then the elements of the respiratory system provide protection from the effects of any infections, including Koch’s bacilli. However, the slightest diseases of the respiratory system or a decrease in their protective function (for example, as a result of toxic effects) leads to infection. Mycobacteria infect bronchioles, alveoli, etc., overcoming the natural protective barriers of the mucous membrane of the respiratory system.

Stages of development of tuberculosis

The first stage, thus, received the definition of latent microbiism. A person can remain at this stage for quite a long time – sometimes years. At the same time, if at this stage immune responses to the effects of mycobacteria are not formed, this leads to a sharp increase in the number of mycobacteria.

The second stage is determined by the spread of Koch bacilli in lymphatic vessels, from them - into the lymph nodes, spreading throughout the body. This stage is called primary mycobacteremia. At this stage, the target organs are the lungs, adrenal glands, organs of the reproductive system, lymph nodes, epiphyses and metaphyses of bones, that is, all organs and tissues with developed system microcirculation of lymph and blood. Phagocytosis develops at the affected sites.

Polynuclear leukocytes are the first to suffer, macrophages are the second. The former die due to weak bactericidal protection, the latter lose viability due to virulence factors. After the defeat of macrophages, the stage of incomplete phagocytosis begins - Koch's bacillus enters the space between the cells, increasing the number of proteolytic enzymes there.

If phagocytosis is ineffective, mycobacteria begin to multiply intensively and in an unlimited manner. In turn, this leads to a decrease in density, tissue liquefaction and, as a consequence, the progression of the disease. At this stage, tuberculous granulomas are already formed, growing from foci of caseous necrosis. This is already - specific signs tuberculosis.

Symptoms of tuberculosis

At the first stages, the disease may not manifest itself in any way; a long period may pass in the absence of specific symptoms. Or the symptoms may turn out to be “blurred” and it is almost impossible to make a correct diagnosis without closer diagnostics.

Most common nonspecific symptoms tuberculosis:

signs of general intoxication of the body:
- a rise in temperature while maintaining it for a long time at a slightly elevated level (usually about 37 degrees Celsius);
- increased sweating, especially during night rest;
- various asthenic manifestations.
gradual weight loss;
lymphadenopathy (limited or generalized), that is, enlarged lymph nodes, pain in enlarged lymph nodes.

At further development diseases, the list of symptoms is replenished with cough with sputum production, pain in the chest area (sometimes pain accompanies coughing), and catarrhal symptoms.

Risk groups, such as experts include:

by professional basis:
- medical workers;
- food industry workers;
on the basis of chronic diseases, patients with confirmed:
- diabetes;
- immunodeficiency states;
- as well as those who are being treated with immunosuppressants (cytostatics and glucocorticoids).

Diagnosis of tuberculosis

Diagnosis of tuberculosis is the results of a comprehensive examination: first of all, assessment of the clinical picture, laboratory and instrumental studies. The first to be examined are biological fluids, primarily sputum released when coughing.

The following methods for examining sputum are used:

bacteriological;
molecular biology;
serological.

During laboratory microbiological research Mycobacteria are identified and their sensitivity to drugs that are usually used to treat tuberculosis is determined. The latter is especially important for those patients who have been engaged in symptomatic self-medication for some time, and therefore are resistant to a number of drugs, including antibiotics.

In addition to sputum, water from the bronchi and stomach (obtained by washing the latter), smears from the larynx, and pleural fluid are used for analysis. Bronchial lavage is an extremely unpleasant procedure, therefore it is performed under local (and in some cases, general) anesthesia. During this procedure, saline solution is injected into the bronchi.

PCR diagnostics have also become quite widespread in large medical centers today. This kind laboratory research is based on the identification of mycobacterial DNA that is isolated from samples biological fluids. The polymerase chain reaction method allows you to quickly obtain results - after five to six hours, and at the same time - at minimal cost. However, this method has not yet received widespread use due to its innovative nature.

The following hardware tests are used to diagnose tuberculosis:

fluorographic examination (the main method of primary diagnosis of tuberculosis);
X-ray examination;
lung biopsy;
pleural biopsy;
bronchoscopy;
CT scan.

If changes in the lungs are detected during a fluorographic examination, the patient is sent for additional examination, during which the localization of the changed tissues is revealed, and the diagnosis of tuberculosis is confirmed or refuted. As a rule, the second stage of a hardware diagnostic examination is a chest x-ray.

Using X-rays, both pathological elements themselves and pulmonary fibrosis, pulmonary emphysema, and bronchiectasis can be detected. In addition, calcified foci of previously suffered or inactive tuberculosis are detected. Computer and magnetic resonance imaging will provide more detailed information about the patient.

Tuberculin diagnostics (Mantoux test)

The first tuberculin in history was prepared using an aqueous extract from mycobacteria artificially grown in vitro. It was made by Koch himself, from mycobacteria of human and bovine strains. Today, similar tuberculin is created in glycerin broth in concentrations from 0.00002 mg (PPD-S) to 0.00006 mg (PPD-L). This value represents 1 TU, that is, the international unit of tuberculin, which gives positive reactions in 80 percent or more of those infected with tuberculosis, without causing too strong reactions. As a rule, the Mantoux test includes 2TE, i.e., two international units of tuberculin, but other dosages are also used, as well as other methods of testing for tuberculin sensitivity.

In particular, these are:

subcutaneous Koch test;
graduated skin test;
protein-tuberculin test;
eosinophilic tuberculin test;
tuberculin titer analysis, etc.

Tuberculin diagnostics is essentially based on an analogue of an allergic reaction. Strictly speaking, the Mantoux test is a delayed allergic reaction caused by contact of an antigen (tuberculoprotein) with lymphocytes (cells immune system). After the introduction of tuberculin, lymphocytes are sent to the site of accumulation of the allergen, which, when interacting with tuberculin, create biologically active substances, or, more simply, form an inflammatory process in the reaction zone. Previously, it was believed that the inflammatory process that occurs with a positive mantoux test (resembling a papule in appearance) is similar to inflammation in the foci of tuberculosis, but in the vast majority of cases, specific tuberculosis inflammation does not occur with the mantoux test.

The Mantoux test is usually performed in the middle or upper third of the forearm, on the front surface. The development of a skin reaction to tuberculin is basically completed after 48 hours, and after 72 it is completely completed. Thus, if repeated diagnostics are not planned, it is best to carry out the examination three days after the test.

The development of the mantoux reaction occurs in this way. Already one and a half to two hours after the test, the appearance of a “lemon peel” is noted - resorption of the tuberculin subcutaneous sphere, and another half hour later a pink spot is formed - the first skin reaction. After four to eight hours, most patients develop watery, soft pink papules. After 12 hours they reach largest size. After 14-20 hours, the early papule differentiates, the main papule stands out in color and density (for now in the form of a small compaction in the center). It is based on the main one that it will subsequently be possible to evaluate the mantoux sample. A day later, the differentiation process is completely completed, and two days after the mantoux test, a bright hyperemic spot with a clearly visible papule in the center is easily visible in all diagnosed patients.

After three days, the process of reducing the size of the papule begins, after 96 hours it gradually shrinks. The papule itself completely disappears after a week, but the mark on the skin caused by pigmentation remains for several weeks (usually three to four), depending on the individual characteristics of the patient’s skin, as well as on the nature of the reaction itself.

If it is necessary to repeat the mantoux test, it is carried out in a different place, otherwise a pronounced reaction can lead to errors in diagnosis. In cases where the reaction occurs quickly and lasts for several weeks (“inflammation of the reaction”), we are most likely talking about the fact that the introduction of tuberculin occurred at the same place where tuberculin diagnostics had previously been carried out.

The diameter of the papule is estimated in millimeters. If the size is 5 millimeters or more, the sample is considered positive. If the diameter of the papule is on the border, ranging from three to four millimeters, a repeat test can be carried out on the other forearm, with a more concentrated solution (for example, if the primary sample included 1 TE, then the secondary one - 2 TE). Determining the threshold of skin sensitivity to tuberculin - titration - includes several mantoux samples alternately on different forearms to determine the minimum dosage at which a positive reaction is obtained, that is, a papule with a diameter of five or more millimeters.

If the sensitivity threshold for a sample with the amount of tuberculin 1TE is 19 millimeters or more, and for 2TE - more than 22 millimeters, not to mention such manifestations as lymphadenitis, lymphangitis, and vesicles indicate hyperergy, that is, increased tuberculin sensitivity . In adolescents, this is evidenced by papule sizes of more than 17 mm. In turn, papule sizes up to 19 mm on 1TE and from 8 to 22mm on 2TE are called normergic.

For mass diagnostics in domestic practice, solutions containing 2TE tuberculin are usually used.

The results of the mantoux test can also be affected by both external and internal factors. Thus, in women the result of the reaction is usually more pronounced (especially in the postpartum period, as well as in women who are overweight or prone to obesity), and with age this increased sensitivity to tuberculin decreases very slowly. But during menstruation and pregnancy, the Mantoux reaction is suppressed. In turn, when diagnosing men, it is necessary to keep in mind that their skin reactions are weaker and noticeably decrease with age. With age, skin reactivity decreases (more so in men), and the role of the supporting antigenic effect of infections decreases in them.

According to a number of researchers, sensitivity to tuberculin increases significantly in spring period and decreases in the autumn. Changes in sensitivity to tuberculin also have professional causes. Thus, chemists, textile workers, specialists dealing with synthetic rubber, lead and chromium show more pronounced reactions.

A decrease in the tuberculin reaction is caused by:

malnutrition;
chemical and thermal burns;
foci of inflammation on the skin;
skin manifestations (psoriasis, acne and etc.);
dry skin;
venous hyperemia;
hypothyroidism;
alcoholism;
measles;
vitamin deficiency (especially vitamin C deficiency);
long lasting heat bodies;
X-ray irradiation in medium and high doses;
use of a number of pharmaceuticals (norsulfazole, penicillin, iodine, antihistamines, pyridoxine, rutin, bromine, butadione, iron-ascorbic acid, glucocorticosteroids);

Treatment of tuberculosis

Treatment of tuberculosis is carried out only qualified doctors and in a specialized tubal hospital.

The treatment regimen, depending on the severity of the disease, includes to a greater or lesser extent the following blocks:

daily routine and motor mode (bed rest, gentle mode or training mode);
nutrition and diet;
drug therapy;
natural and instrumental physiotherapy;
especially severe cases- surgery.

Anti-tuberculosis drug therapy allows you to achieve a tuberculostatic effect, or, in other words, reduce the activity of mycobacteria and their virulence, and suppress their reproduction. It is especially important to carry out treatment comprehensively and rationally, eliminating not only the symptoms of the disease, but also curing it. An ill-conceived treatment policy, in turn, can lead to the transfer of tuberculosis to a chronic form.

The main anti-tuberculosis drugs (tuberculostatics):

isoniazid and its derivatives;

The duration of treatment depends on the age, weight and condition of the patient. The minimum effective daily dose of the drug – 0.3 g – is usually prescribed to elderly patients, as well as patients weighing less than 55 kilograms. As a rule, the daily dose of this drug is 0.6 g. Isoniazid (tubazid) is used in the vast majority of cases in combination with other drugs, the only exceptions being patients with allergies to other specialized anti-tuberculosis drugs.

streptomycin and its derivatives;

Complex antituberculosis drugs based on streptomycin are widely used to treat patients of any age and weight. The minimum effective daily dose of the drug is 0.5 g (for elderly patients and patients weighing less than 55 kilograms), for middle-aged and more impressively built people - from 1 g daily. It is used both as an intramuscular agent and as an aerosol for inhalation (based on saline solution).

Separately, it should be noted that Streptosaluside is a drug that is complex in itself and combines streptomycin and saluzide. As a rule, this drug does not require additional inclusion in the treatment regimen of other drugs.

PASK;

PAS drugs are not used for monotherapy - only in combination with isoniazid or streptomicides.
- combination drugs.

Additional anti-tuberculosis drugs:

kanamycin;
ethionamide;
cycloserine;
ethambutol;
rifampicin

This semi-synthetic antibiotic, which acts specifically on mycobacteria - reducing their activity, preventing their reproduction - is quite easily excreted in the patient’s urine, and therefore is used for both pulmonary and urogenital tuberculosis. The daily dose per 1 kilogram of patient weight is 10 mg.
Combination therapy, which includes drugs from different therapeutic groups, simultaneously solves several problems. This includes monitoring the patient’s medication intake (which is especially important for those patients who avoid treatment), reducing the drug resistance of mycobacteria, slowing down their development, and generally achieving a positive therapeutic effect.

The routes of administration of most drugs are intramuscular, intrapleural, inhalation, tracheobronchial.