Tuberculosis in children and adolescents

The collapse of the USSR led to a sharp change in the socio-economic situation, a rapid deterioration in the standard of living of the population in almost all former republics. These changes led to an equally rapid deterioration in the epidemiological situation of tuberculosis. The incidence of tuberculosis among migrants has grown catastrophically, it was practically not controlled. Preventive measures to combat tuberculosis in a number of "hot spots" not only among adults, but also among children were practically not carried out. Speaking about tuberculosis, one cannot ignore the fact that in the last decade, the manifestations of tuberculosis in the adult population have changed significantly. Thus, according to a number of authors, more than half of patients have an acute course with hectic body temperature and pronounced changes in the peripheral blood. Cases of complications of pulmonary tuberculosis in children have become more frequent. The massiveness of bacterial excretion and drug resistance of Mycobacterium tuberculosis to the main anti-tuberculosis drugs have sharply increased. All this leads to a decrease in the effectiveness of treatment and disability of patients.

Due to untimely detection of tuberculosis in adults, the risk of infection of children has increased. The infection rate of children living together with sick people is several times higher than that of children from a healthy environment. Since 1990, an increase in the incidence of children has been noted. The incidence of children in foci has increased in Russia more than 3 times (from 0.16 to 0.6%), exceeding the overall incidence of children by 50 times. In the structure of children newly infected in Russia, tuberculosis of the respiratory organs predominates (78%). The main form is tuberculosis of the intrathoracic lymph nodes. In children, the frequency of bacterial excretion in respiratory pathology is 3.0%. Against this background, in adolescents, the tendency for the spread of the tuberculosis process is close to that in adults, with predominant damage to the lung tissue in the form of its infiltrative forms with bacterial excretion in 80% of cases. Prevention and early detection of the disease are of primary importance in the fight against tuberculosis in children. Immediately after diagnosis, it is necessary to start treatment in a timely manner, its basis is antibacterial therapy.

By now, phthisiologists in the country have accumulated significant experience in the prevention, timely detection and treatment of tuberculosis. Monographs and scientific articles reflect the successes of the fight against tuberculosis among the adult population with sufficient completeness. At the same time, it is known that the first encounter with tuberculosis infection, ending in infection, and in some cases, disease, occurs in childhood and adolescence. Therefore, the main measures to prevent tuberculosis must be carried out in these age groups. More than 50 years of specific tuberculosis prevention have caused significant changes in the clinical course of tuberculosis in children and adolescents, affecting the pathomorphosis of the disease. Damage to the lymphatic system, severe bronchoadenitis developed both in the pre-antibacterial period and in the first years of antibacterial treatment. However, due to various reasons, the lymphatic system could not serve as a barrier and delay the spread of infection, and the lungs and other organs were affected. The spread of the process in the lungs, developing complications became the leading ones in the picture of the disease. Now, in the conditions of systematic anti-tuberculosis vaccination, increasing the general resistance of the body of children, the protective role of the lymphatic system is more clearly revealed, the infection in it lingers for a long time. In some cases, local forms of the disease do not develop, in others, lesions of the lymph nodes of varying degrees are detected, while in recent years, minor forms of bronchoadenitis have been increasingly encountered. Despite great success, there are still a number of unresolved issues in the problem of childhood tuberculosis. In particular, the percentage of irreversible residual changes is still significant, complicating the complete cure of the patient. Against this background, a decrease in the prevalence of tuberculosis among the population in the 70-80s of the last century, especially among children and adolescents, led to a decrease in alertness towards this infection among doctors, especially young ones.

Causes, pathogenesis and morphology of primary tuberculosis

The causative agent of tuberculosis is Mycobacterium tuberculosis. Although "consumption" as a disease was known in ancient times, there was a long and persistent struggle of opinions among various scientists on the etiology of the disease before the causative agent of tuberculosis was discovered. The infectious nature of tuberculosis was experimentally proven long before the causative agent of the disease was discovered. In 1865, the French scientist Villemin infected rabbits with tuberculosis by subcutaneously injecting them with tissues of affected organs and by inhaling sprayed sputum from tuberculosis patients.

In 1882, Robert Koch managed to detect a bacillus in tuberculosis foci when staining the preparation with methylene blue and obtain a pure culture of the pathogen. Scientists have established that tuberculosis mycobacteria are highly resistant to the effects of any physical, chemical and biological agents. Once in favorable conditions for their development, tuberculosis mycobacteria can maintain viability and virulence for a long time. They tolerate prolonged cooling and drying.

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Features of tuberculosis in children and adolescents

Due to the changed situation with tuberculosis in Russia and a number of other countries, the risk of infection of children has increased. The infection rate of children living with sick people is 2 times higher than that of children from a healthy environment. Since 1990, an increase in childhood morbidity has been noted in Russia: in foci, it has increased more than 3 times (from 0.16 to 0.56%), exceeding the overall morbidity of children by 50 times. Among children with tuberculosis who are in contact with sick people in the family, a significant number of young children with disseminated forms of tuberculosis are noted. In the structure of children newly infected with the disease in Russia, tuberculosis of the respiratory organs predominates (78%). The main form is tuberculosis of the intrathoracic lymph nodes. In children, the frequency of bacterial excretion in respiratory pathology is 3.0%. In adolescents, the tendency for the spread of the tuberculosis process is similar to that in adults; predominantly, the lung tissue is affected in the form of infiltrative forms with bacterial excretion in 80% of cases.

Prevention and early detection of the disease are of primary importance in the fight against tuberculosis in children. Immediately after diagnosis, it is necessary to start treatment in a timely manner, the basis of which is antibacterial therapy.

Specific tuberculosis prevention for a long time (more than 50 years) has caused significant changes in the clinical course of tuberculosis in children and adolescents, affecting the pathomorphosis of the disease. In conditions of systematic anti-tuberculosis vaccination, increasing the general resistance of the body of children, the protective role of the lymphatic system is more clearly manifested. Infection in it is delayed for a long time; in some cases, local forms of the disease do not develop, in others - varying degrees of damage to the lymph nodes are observed, while in recent years, minor forms of bronchoadenitis have been increasingly diagnosed. Despite great success, a number of unresolved issues in the problem of childhood tuberculosis remain. In particular, the percentage of irreversible residual changes is still significant, complicating the complete cure of the patient. Against this background, the decrease in the prevalence of tuberculosis among the population, especially among children and adolescents, in the 70s and 80s of the last century led to a decrease in alertness towards this infection among doctors, especially among young people.

In early childhood, primary forms of tuberculosis are predominantly detected. In older children and adolescents, secondary tuberculosis is detected in more than 50% of cases.

Tuberculosis in different age categories has certain characteristics, which contributes to the formation of residual changes after the disease of varying severity.

In newborns and young children, tuberculosis proceeds less favorably than in older children, and is characterized by a tendency to generalization of the infection, its spread mainly by lymphohematogenous route with the formation of extrapulmonary foci, to damage to the lymphatic apparatus, which sometimes determines the severity of the disease. At this age, such forms as primary tuberculosis complex, tuberculous meningitis and miliary tuberculosis predominate. In preschool and school age, tuberculosis proceeds favorably, generalization of the process is rarely observed, and the so-called mild forms of tuberculosis in the form of tuberculosis of the intrathoracic or peripheral lymph nodes come to the fore, especially at present.

Adolescence is also critical, when infiltrative changes in the lungs are relatively common, hematogenous dissemination of infection occurs, and serous membranes are affected. The predominant forms are infiltrative and disseminated pulmonary tuberculosis. In adolescents, there is a significant restructuring of the neuroendocrine apparatus, which has a particularly negative effect on the course of tuberculosis in massive superinfection.

The peculiarities of the development of the disease in different age periods are determined by the anatomical, physiological and immunobiological properties of the body.

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Tuberculosis in young children

Anatomical and physiological characteristics of young children:

• immaturity of cellular and humoral immunity;
• the migration of blood cells to the site of inflammation is slowed down and reduced:
• incomplete phagocytosis (the absorption phase is developed, the digestion phase is reduced);
• deficiency of essential complement components;
• the upper respiratory tract and trachea are short and wide, the remaining respiratory tracts are narrow and long (impaired ventilation of the lungs);
• relative dryness of the bronchial mucosa due to an insufficient number of mucous glands, low viscosity of secretions;
• acini are poor in elastic fibers;
• insufficient amount of surfactant leads to easy occurrence of atelectasis;
• the intersegmental pleura is practically not developed, the interlobar pleura is poorly developed; not all layers of the pleura are formed;
• poorly developed cough reflex;
• there is little lymphoid tissue in the lymph nodes, a weak valve apparatus, and lymph backflow is possible;
• many anastomoses between the lymph nodes of the mediastinum:
• many anastomoses between blood and lymphatic vessels;
• immaturity of the thermoregulatory center.

Tuberculosis in young children is detected mainly by referral (the most common diagnosis is pneumonia, the ineffectiveness of non-specific antibacterial therapy forces differential diagnostics with tuberculosis). In children under 1 year of age with tuberculosis, tuberculosis contact is detected in 100% of cases, from 1 to 3 years - in 70-80% of cases (the old saying is well known: "Little children do not get infected, they just get sick"); 2/3 of young children with tuberculosis are not vaccinated with BCG or do not have a post-vaccination sign.

The most common complications are: bronchopulmonary lesions, hematogenous dissemination to the lungs and meninges, and the disintegration of lung tissue.

Late diagnosis and progressive course lead to death.

Clinical forms of tuberculosis in children and adolescents

Clinical forms of tuberculosis in children and adolescents

Tuberculosis infection, penetrating the child's body, can affect all organs and systems of the body, the tuberculosis bacillus does not penetrate only the hair, nails and teeth. Therefore, there are various forms of tuberculosis. In childhood, primary forms of tuberculosis mainly develop. In older children and adolescents, secondary tuberculosis occurs in more than 50% of cases. According to the international classification, tuberculosis is divided into tuberculosis of the respiratory organs, tuberculosis of the nervous system, tuberculosis of other organs and systems and miliary tuberculosis.

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Examination of children and adolescents with tuberculosis

Tuberculosis in children is characterized by pronounced polymorphism of clinical manifestations, the absence of strictly specific symptoms, which creates significant difficulties in diagnostics. There is not a single clinical sign characteristic only of tuberculosis. Often in children, the initial manifestations of tuberculosis infection are expressed only in behavioral changes, general symptoms of intoxication. Therefore, the main condition for timely and correct diagnostics is a comprehensive examination.

Examination of patients with tuberculosis

Semiotics of tuberculosis

When collecting anamnesis, it is necessary to identify all factors that contribute to infection and development of the disease. At the same time, general pediatricians should pay special attention to children and adolescents infected with MBT with factors that increase the risk of tuberculosis:

• frequently suffering from acute respiratory infections (flu, parainfluenza, adenovirus, rhinovirus, RS infection);
• children with chronic, frequently recurring diseases of various parts of the respiratory tract (chronic nasopharyngitis, sinusitis, chronic tonsillitis, chronic bronchitis and pneumonia);
• children and adolescents with other chronic non-specific diseases, including diabetes mellitus:
• children and adolescents receiving glucocorticoid treatment.

Symptoms of tuberculosis

Methods of detecting tuberculosis

Mass tuberculin diagnostics are carried out using a RM with 2 tuberculin units (RM with 2 TU) for children and adolescents vaccinated against tuberculosis, once a year, starting at 1 year of age; for children and adolescents not vaccinated against tuberculosis, once every 6 months, starting at 6 months of age until vaccination.

Fluorography is performed on teenagers, students (in schools, higher and secondary specialized educational institutions), workers, and unorganized people. The examination is performed at the place of work or study, for those working in small enterprises and unorganized people - in clinics and tuberculosis dispensaries.

Methods of detecting tuberculosis

Tuberculin diagnostics

Tuberculin diagnostics is a set of diagnostic tests for determining the specific sensitization of the body to MBT using tuberculin. Since the creation of tuberculin to this day, tuberculin diagnostics has not lost its significance and remains an important method for examining children, adolescents and young people. When encountering mycobacteria (infection or BCG vaccination), the body responds with a certain immunological reaction and becomes sensitive to the subsequent introduction of antigens from mycobacteria, that is, sensitized to them. This sensitivity, which is delayed in nature (that is, the specific reaction manifests itself after a certain time - 24-72 hours), is called delayed-type hypersensitivity. Tuberculin has high specificity, acting even in very large dilutions. Intradermal administration of tuberculin to a person whose body has been previously sensitized either by spontaneous infection or as a result of BCG vaccination causes a specific response that has diagnostic value.

Tuberculin diagnostics

Preventive (prophylactic) treatment of tuberculosis

Preventive treatment for the prevention of tuberculosis is prescribed by a phthisiopediatrician. This section of work should be a priority in the work of the phthisiopediatric service. Preventive treatment is carried out for children and adolescents infected with MBT for the first time (virage, early period of latent tuberculosis infection), as well as from high-risk groups for tuberculosis.

If a turn is established, the child is referred to a phthisiatrician who monitors the patient for 1 year. After the early period of primary tuberculosis infection, the child remains infected with MBT (in the absence of risk factors for tuberculosis, provided that timely chemoprophylaxis is carried out) or local tuberculosis develops at various times after the primary infection (depending on the massiveness, virulence of MBT and the state of the macroorganism).

Preventive treatment of tuberculosis

Vaccination against tuberculosis

In childhood, the main method of tuberculosis prevention is vaccination with BCG and BCG-M vaccines. According to the existing Russian calendar of vaccination against childhood infections, primary vaccination with BCG vaccine is carried out on all healthy newborns on the 3rd-7th day of life. Revaccination is subject to children aged 7 and 14 years who have a persistently negative RM with 2 TE, children infected with MBT are not subject to revaccination. Upon reaching the age of 15, regardless of the results of tuberculin diagnostics, vaccination against tuberculosis is not carried out. All vaccination activities are carried out according to the calendar of vaccination against childhood infections.

Vaccination aimed at forming artificial immunity to various infectious diseases has become the most widespread preventive measure in medicine in the 20th century. Depending on the virulence of microorganisms, the role of the immune system in the pathogenesis of infectious diseases caused by them and specificity, in some cases vaccination prevents the occurrence of the disease (smallpox, tetanus, poliomyelitis), in others it mainly affects its course. The main criterion in determining the method of mass immunization against any disease is its biological feasibility in specific epidemiological conditions. The lower the specific effectiveness of the vaccine, the more importance is attached to the negative consequences of its use (complications). As a result, the improvement of the epidemiological situation naturally leads to a revision of vaccination tactics.

Tuberculosis vaccine (BCG)