Coronaviruses can cause damage to various parts of the respiratory system, gastrointestinal tract, and other organs and systems.The aim of the study: to monitor the circulation of seasonal coronaviruses in hospitalized children in the pre-pandemic period.

Materials and methods: real-time multiplex PCR was used to test samples of nasopharyngeal mucus from 2188 patients aged 1 monthto 17 years, hospitalized with acute respiratory infection in 2014—2018. The results are presented with the indication of the fractions (%) and the calculation of the 95% confidence interval according to Klopper-Pearson. The differences between the groups were evaluated using the Pearson χ2 test. The differences in the groups were considered statistically significant at the level of the criterion p< 0.05.

Results: monitoring of the circulation of pathogens of acute respiratory viral infection (ARVI) during 5 epidemic seasons showed that the appearance of a new subtype of coronavirus in 2019 was preceded by a gradual displacement of influenza, RS-and bocavirus infections from the circulation due to a statistically significant increase in the proportion of seasonal coronaviruses from 3.6% in 2014—2015 to 10.8% in the prepandemic season 2018—2019 (p= 0.007). The circulation of seasonal coronaviruses had a distinct seasonality (november-april)with the peak of registration in february (28.4%) and march (36.7%). Seasonal coronaviruses were detected in 7.3% of hospitalized children with ARVI, with a predominance in the age groups under 2 years (58.2%) and 3—6 years (25.4%). Hospitalization was more often required for patients with lower respiratory tract lesions (58.2%), a fifth of which was pneumonia (21.8%). In most children, ARVI caused by coronaviruses occurred as a monoinfection (79.9%), combined infection with other pathogens was observed in 20.1% of cases with fluctuations from 18.2% to 28.6% in different epidemic seasons. Viral associations are most common in young children (85.2%).

The paper presents data on the detection and role of cytomegalovirus infection (CMVI) in 146 children of certain groups aged from 3 months to 15 years who were hospitalized — frequently ill children with respiratory pathology, patients with shiga-toxin-associated hemolytic uremic syndrome (STEC-HUS) and schoolchildren with somatic diseases during rehabilitation in a sanatorium.

The aim of the study was to determine the frequency of detection of CMVI in the presented groups, the originality of the main clinical manifestations in correlation with the markers of activity of herpesvirus type V infection. Clinical monitoring was carried out, oropharyngeal swabs, saliva,blood samples (serum and blood cells) were studied using a set of laboratory diagnostic methods:RCM (rapid culture method) on Vero- and M-19 cells, IIR (reaction of indirect immunofluorescence), ELISA to detect specific antigens and antibodies (IgM, IgG).

The detection rate of CMV IgG in diagnostic values ranged from 6.4% in the group of frequently ill children with respiratory pathology to 31.7% in schoolchildren of the sanatorium, the acute course of infection was detected in3.2% and 6.4%, respectively, based on markers of acute infection (CMV IgM and cytomegalovirus antigen). In patients with STEC-HUS CMV IgG in diagnostic titers were recorded with the highest frequency — in 74.4% of patients.

There is a close relationship between intestine and liver, so-called ‘gut liver’ axis, especially in patients suffered from chronic liver diseases with significant degree of fibrosis. Small intestinal bacterial overgrowth and disturbance in the microbiota composition lead to an increase in the permeability of the intestinal epithelium, the development of endotoxinemia, the activation of pro-inflammatory cytokines and, as a consequence, an additional damage to hepatocytes.

Objective. To estimate the incidence of bacterial overgrowth syndrome (BOS) in the small intestine in adolescents with chronic hepatitis C (CHC), to identify the interaction between this syndrome and cytolytic activity, the degree of fibrosis.

Materials and methods. There is a group of 33 patients aged 12—17 years old with CHC. All children underwent a hydrogen breath test with lactulose. The degree of fibrosis was assessed by the results of liver elastography (Fibroscan), cytolytic activity was determined by the level of alanine transaminase in serum.

Results. The frequency of BOS was 81.8% in the study group. As a result of the correlation analysis, no relationship was found between the development of BOS and the degree of cytolytic activity of chronic hepatitis C (criterion χ2= 0.914, p > 0.05). Also, there was no correlation between excessive bacterial contamination and the degree of fibrosis in the liver tissue (criterion χ2= 0.914,p> 0.05).

Conclusion. BOS in children with CHC occurs much more often than in adults. However, no relationship was found between this syndrome and the severity of cytolytic activity, the degree of fibrotic changes in the liver.

Insulin-like growth factor 1 (IGF-1) plays an important role in the energy balance of the newborn baby's body, is associated with protein stores, which allows us to consider its level as an indicator of nutritional status.

Objective: to study the value of insulin-like growth factor 1 and basic nutrients in the blood in premature infants in the process of neonatal adaptation.

Materials and methods. Dynamics blood levels of insulin-like growth factor 1 in premature newborns included two trends: decrease (1 group) and increase (2 group). During a pregnancy most mothers of newborns from 1 group had been nonspecific respiratory and urinary-sexual organs’sinfectious diseases, in mothers of newborns from 2 group prevailed disorders which carried high risk of fetal hypoxia. During a neonatal period blood levels of albumen of newborns from 1 group decreased and blood levels of glucose increased; blood levels of nutrients in newborns from 2 group did not change.

Conclusions. Dynamics blood levels of insulin-like growth factor 1 in premature newborns are markers of metabolism’s processes which were originated in fetal stage and continue in the neonatal period.

Purpose: to evaluate the effectiveness of post-vaccination immunity against whooping cough in children aged 1 to 17 years with connective tissue dysplasia syndrome in Stavropol.

The principal component analysis was used to optimize the interpretation of immunograms in connective tissue dysplasia syndromedepending on protective titers for whooping cough. Analysis by the method of principal components showed that the links of cellular immunity predominate in children with connective tissue dysplasia syndrome with low titers of antibodies to whooping cough.The general variant of the response of the immune system was observed in children with protective titers of antibodies to whooping cough (1: 160—1: 320). In children with connective tissue dysplasia with titres of 1: 640or more antibodies to whooping cough, humoral and cellular immunities are closely interrelated, it is the presence of humoral and cellular immunity that makesit possible to develop a stable immunity to preventable infections.

Thus, the method of main components effectively provides accessible information on key immune processes and is promising.

The article presents a literature review, which provides data on the role of interferons in the immunopathogenesis of COVID-19 and the clinical efficacy of drugs based on recombinant interferon-alpha 2b in the treatment of children with new coronavirus infection. Shown the leading role ofinterferons as factors of the first line of defense against various viruses, including SARS-CoV-2. Numerous studies have proven the feasibility of including interferon preparations in COVID-19 therapyregimens in children, both as combinations with antiviral agents and as monotherapy.

The paper summarizes information on the etiology, life cycles, epidemiology, pathogenesis, pathomorphology, clinical manifestations, diagnostics, etiotropic therapy and prevention of digestive tract trematodiases caused by representatives of the Heterophyidaefamily: metagonimiasis, heterophyiasis, haplorchiasis, pygidiopsiasis, heterophyopsiasis, stellantchasmiasis, centrocestiasis, stictodoriasis, proceroviasis, acanthotremiasis, apophalliasis, ascocotyliasis, cryptocotyliasis.

The paper presents the indications and main differences of frequently used rectal suppositories containing interferon alpha-2b.The features and differences in the contained excipients are highlighted. A range of diseases in children's practice is presented, in which candles are shown VIFERON®, Kipferon®, Genferon light®

Introduction. Measles infection in recent years has become particularly relevant in connection with the registration of outbreaks of this disease in various territoriesof the Russian Federation and abroad.

The aim of the study is to characterize the epidemic process of measles in a large industrial city in the near and long term with the use of modern mathematical modeling technologies for making new management decisions on infection control at the elimination stage.

Materials and methods. The research materials were data from statistical reports of measles incidence in Yekaterinburg from 1950 to 2019 (70 years of follow-up), medical documentation of measles cases, population vaccination data (form No. 6 for 2000—2018 and outpatient maps of children under two years of age vaccinated against measles), results of screening for measles IgG ofmedical organizations, data of planned serological monitoringof population immunity to measles in «indicator» groups in the period from 2013 to 2017 and the results of mathematical modeling of measles incidence in different scenarios of its prevention.

Results. Under the influence of vaccination, the epidemic process of measles in Yekaterinburg — a city with a population of 1.5million inhabitants-has undergone significant changes. During the observation period, the incidence decreased to sporadic levels, there was no indigenous measles, drifts from endemic areas had no consequences, the epidemic process was under control. However, outbreaks of 72 cases in 2016 and 90 cases in 2019 have changed our view of measles as a eradicated infection.

Of the factors that led to the spread of infection in the foci, the most significant were the presence of measles-susceptible children and adults, including those previously vaccinated, mainly in the periods remote from vaccination and revaccination, defects in the clinical diagnosis of measlesin the first and subsequent cases, and violations in the organization and conduct of anti-epidemic measures. Conclusion. Based on the data of mathematical modeling of the epidemic process of measles with different combinations of its determinants, for the elimination of infection, it is necessary to ensure vaccination against measles at the age of 1 year and 6 years in 95—97.5%. In vulnerable groups for infection to discuss the introduction of routine revaccination among people up to 50 years of age with an interval of 10 years.

Toxocarosis is a widespread geohelminthiasis in the world. In the body of children, the eggs of the parasite usually fall with the soil. Larvae enter the bloodstream through the intestinal wall and are carried by blood to various organs, where they cause inflammation and necrosis. The diseaseis characterized by non-specific clinical manifestations, as a result of which the diagnosis is not always timely. In children, toxocarosis often occurs againstthe background of various diseases of the respiratory, cardiovascular and gastrointestinal systems.

The article presents a case of a combined course of gastric ulcer and visceral toxocarosis in a child of 2 years and 4 months. Taking into account the uncharacteristic disease for this age and the absence of risk factors for the development of stomach ulcers in this patient, it is suggested that toxocarosis may cause the development of stomach ulcers in children.

The variety of clinical manifestations and the absence of strictly specific features make tuberculosis and toxocariasis difficult to diagnose and treat. Doctors of various specialties are engaged in the diagnosis of toxocariasis, depending on which organ system is affected in a person and with whatsymptoms he turned to a medical institution.

Purpose: to describe the case of detecting toxocariasis in a child who was treated in a tuberculosis hospital from a bacillary family contact with pronounced indicators of immunological tests and revealed changes during CT scan of the chest organs.

A complex differential diagnostic path and constant medical supervision made it possible to establish a rather rare disease - toxocariasis in a child from family contact with a patient with tuberculosis.

Conclusion. In the differential diagnostic series in patients withtuberculosis, the presence of parasitic diseases with a similar clinical and radiological picture cannot be excluded.

Routine vaccination against viral hepatitis B (HBV) has significantly reduced morbidity and mortality from this infection. The development of acute HBV in children is currently a rarity, but there is still the possibility of developing a similar scenario in children from family foci of HBV, aswell as in children with no specific prophylaxis. A clinical observation of the development of acute HBV in aninfant is presented, and the difficulties of managing such patients are demonstrated.