**2. Purpose of the study**

*Molecular Epidemiology Study of Mycobacterium Tuberculosis Complex*

such dangerous diseases as tuberculosis.

adolescents, well-being

**1. Introduction**

posing factors.

participation in its base of the interdepartmental approach. All of this allows newly taking a look at problem of the latent tuberculous infection at preschool age children and role general practitioner in preventive maintenance of the development

**Keywords:** quality of life, latent tuberculosis infection, treatment, children and

Tuberculosis is a main infectious reason of deaths in the world and one of 10 leading reasons of deaths in the world. From tuberculosis in 2020 have all over the world died 1,85 million people (including four hundred thousand people with HIV), but had suffered 10,4 million people. In 2020 1,3 million children had ill of tuberculosis, and 250 000 children have died from it (including children with HIV-associated by tuberculosis). Tuberculosis is one of the main reasons to deaths of the people with HIV. Serious problem became the tuberculosis with multi drug resistance. However, in global scale number of patients with tuberculosis falls approximately on 2% per annum [1]. Latent tuberculosis infection (LTI) is a state of persistent immune response to stimulation by *Mycobacterium tuberculosis* antigens without evidence of clinically manifested active TB. A direct measurement tool for M. tuberculosis infection in humans is currently unavailable. One-third of the world's population is estimated to have LTI: they do not have active TB disease but may develop it in the near or remote future, a process called "TB reactivation". The lifetime risk of reactivation for a person with documented LTI is estimated to be 5–10%, with the majority developing TB disease within the first five years after initial infection. However, the risk is considerably higher in the presence of predis-

At present statistics data persuasively show that in some country of the world number of children, for the first time infected with tuberculosis mycobacterium, continues to grow. For instance, in some region to Russia amount such children forms more than 2% whole baby population of the country. Most often primary infecting children of the preschool age, diseases range in this age group on 52%

TST (Tuberculin Skin Test) and IGRAs (Interferon-Gamma Release Assays) are the main tests currently available for the diagnosis of LTI. Persons with LTI have negative bacteriological tests: the diagnosis is based on a positive result of either a TST or IGRA test indicating an immune response to Persons with LTI have negative bacteriological tests: the diagnosis is based on a positive result of either a skin (tuberculin skin test, TST) or blood (Interferon-gamma release assay, IGRA) test indicating an immune response to M. tuberculosis. However these tests have limitations as they cannot distinguish between latent infection with viable microorganisms and healed/treated infections; they also poorly predict who will progress to

Either TST or IGRAs can be used to identify candidates to LTI treatment in high and upper-middle-income countries with estimated TB incidence less than 100 per 100,000. IGRAs should not replace TST in low and other middle-income

Who should be tested and treated for LTI? The risk of progression to active disease is considerably higher in infected individuals who belong to specific high risk populations. Major risk factors for TB activation include: HIV infection, recent contact with an infectious patient, initiation of an anti-tumor necrosis factor (TNF)

exceeds the general range of diseases amongst baby population [2, 3].

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active TB.

countries.

Study health condition of children preschool age with latent tuberculous infection for development of organizing measures on improvement of the preventive maintenance of the tuberculosis and dispensary observation in primary public health care.

### **3. Problems of the study**


### **4. Scientific novelty**

For the first time children of preschool age with latent tuberculous infection will are elaborated physician-biological and social factors, which can be reasons low resistivity and infecting with mycobacteria of tuberculosis.

Deflections of health preschool age children will revealed on base clinic-functional complex study with latent tuberculous infection. Will revealed and portioned on groups anamnestic, clinical and laboratory markers of latent tuberculous infection beside of preschool age children.

Will installed influence of latent tuberculous infection on parameters preschool age children's quality of life.

Will scientifically motivated measures of the preventive maintenance of the tuberculosis and dispensary observation for infected children in primary public health care.

## **5. Materials and methods of study**

During 2017–2019 was examined 100 children 4–7 years age on the base of Samarkand state antituberculous sanatorium, kindergarten № 84 of Samarkand. For including children in conducted study obligatory condition was presence

BCG vaccination at birth, attendance by children educational institution.

In study were excluded children, which parents were not agree to participate in study, children with delay psychomotor developments, having chronic diseases with symptoms of intoxication, children, have had sharp disease before 1 month back.

Children were divided in 3 groups. First group (n = 40) - a children with LTI, which were engulfed by dispensary observation and got the chemoprophylaxis in sanatorium. "Sharp turn" of tuberculin skin tests was noted at 3 (7,5%) children, increase of test result on 6 mm and more for one year - at 19 (47,5%), hyperergic result of test – at 12 (30%); annual increase test results with papule size on 12 mm and more - at 3 (7,5%), unchangeable sizes of the test in more than 3 years - at 3 (7,5%) children. Group of the comparison (n = 40) has comprised preschool age children, treated in Samarkand state tuberculosis hospital. Group of the checking (n = 20) have constituted the preschool age children from 1 groups of health with presence correct scar of BCG vaccination. In all group distribution children on sex and age had not a reliable difference.

Estimation of children health was conducted by analysis health factors: social, genetic, biological. In addition were studied criteria of health: physical development, functional condition, level to resistivity, psychomotor development, sharp and chronic diseases in anamnesis, presence of congenital development defects.

It was used study anamnestic data, questioning, estimation quality of life, anthropometry, data of objective examination, laboratory data and parameters of functioning, electrocardiography, vegetative nervous system spectrography (VNSspectrography), manual ergometry. Information about each child is received information from history of disease and history of child development. Was conducted analysis factor risk of contamination with mycobacteria tuberculosis: physicianbiological, social, genetic. Efficiency of vaccination BCG valued on presence scar, size less 4 mm was indicate as faulty vaccination. Physical development valued with the help of specialized tables. Leukocyte intoxication index is calculated on formula Shemitova V.F. Children observed by other specialists.

In help of cluster method all data were generalized. Variety heart rhythm (VHR) was studied by method VNS-spectrography on vegetotester "VNS-Micro" with computer program "Polispectr" of company "Neyrosoft". Registered more than 500 cardiac cycles. Interpretation source vegetative tone and vegetative reactivity was realized according to recommendation N.A. Belokon. Vegetative provision of activity was valued on tolerance to steady-state load by method manual ergometry (MEM) in help of manual dynamometer.

Quality of life was defined with the help of questionnaire PedsQL version 4.0 (the Russian version), for 5–7 age children. Statistical processing was organized on PC Pentium 4. Made descriptive sample method, method one-factorial analysis of variance, Chi-square, U-criterion of Mann-Uitni, factor of Spearmen correlation, criterion of Fisher, reliable were considered differences p < 0,001.

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*Latent Tuberculous Infection: Influence on Patient's Quality of Life*

Our study is indicating that at preschool age children with LTI there are deflections of health condition and quality of life. Premorbid background complicated by risk factors of developing tuberculous infection. Amongst specific risk factor, in the main group priority value has a contact with the source of infection (45,0%), presence of the disease at close relatives (42,5%), faulty vaccination BCG - 1-4 mm, absence of the incidence with chemoprophylaxis children with "sharp turn" of tuberculin skin test (17,5%). Reliable difference at frequency specific factor risk with group children, who had treatment in Samarkand state antituberculous sanatorium, was not revealed. Factors, having importance, as at children with LTI, so at children with evident form of the disease, were contact with tuberculous patients

Important social risk factors at children with LTI were: not working parents (82,5%), asocial lifestyle of family (50,0%), unsatisfactory home conditions (77,5%), alcoholism of parents (72,5%), large families (55,0%). Nearly similar factors detected at children with evident form of tuberculosis. Biomedical risk factors at children with LTI in the first group were polydeficient anemia (35,0%), chronic nonspecific lungs disease (27,5%), preeclampsia and eclampsia during pregnancy in mother's anamnesis (45,0%) - realistically often, than at children with evident tuberculosis. During of cluster analysis are determined as significant factors - early begin artificial feeding (65,0% - on 55,0% often, than in checking group, p < 0,01), extensive tooth decay (32,5%, p < 0,001), presence to anemia light degree (27,5%, p < 0,01) - as at children with LTI, so and at children with evident forms of the tuberculosis. These risk factors promoted lowered resistivity of the children organism, and according to opinion O.B. Nechaeva, could become the reason infecting children with mycobacteria tuberculosis and it persisting in child organism, and speak about insufficiency of mechanism immunological protection. Low resistivity of organism was one of the important sign at group of

At preschool age children with LTI exist the subclinical signs of infecting MBT, basically manifestations of intoxication. Deflections in physical development (PhD) are discovered at 62,5% (p < 0,001) of the first group, at each third child from this groups it was connected with low mass of the body (30,0%, p < 0,01). Deficit of body mass is probably connected with reinforcement of the processes catabolism, which is called to provide the compensation and adaptation during chronic stressful situation. Intoxication phenomena in the first group children were also expressed as pale skin cover (47,5%, p < 0,001), anemia light degree (27,5%), fast heart rhythm (25,0%). These signs were importance as well as in group of the comparison. Intoxication was confirmed by leukocyte intoxication index by V.F. Shemitova. In the main group children this index was positive more than at half of examined

Condition of peripheral lymph elements in the first group and group of the comparison in principal did not differ, that is indicate of generalities in reactions lymphatic system of children in response to persistence MBT in child organism. However, by comparing these factors in the first group and group of healthy children, noted brightly expressed differences: lymphatic elements dense and elastic consistencies (77,5%), plural (85,0%), size more than 5 mms (85,0%), with perifocal inflammation phenomena (22,5%, p < 0,01), unrepresentative localization lymphadenopathy - an cubital (20,0%), parotid (42,5%), occipital (35,0%) in first

group was realistically often than in checking group (p < 0,01).

*DOI: http://dx.doi.org/10.5772/intechopen.96901*

**6. Results and their discussion**

and faulty vaccination of BCG.

children with LTI.

person (75,0%).
