The new coronavirus infection (COVID-1 9) is a socially significant problem around the world. According to available statistics, complications are less common among children, asymptomatic or mild forms of the disease prevail more often.

This article presents the features of the viral landscape of the upper respiratory tract in children with ARVI in a pandemic, the clinical and laboratory features of the course of COVID-1 9 in children of different ages.

It was found that SARS-CoV-2 is detected only in a third (32.9%) of hospitalized patients with respiratory symptoms, in 4.3% of cases — in combination with seasonal CoV-OC43 / CoV-229E, in 1 1.6% — with other respiratory viruses. The most frequent source of infection with the SARS-Cov-2 were family members. Children with a moderate form of the disease predominated among the patients. The leading symptoms of COVID-19 were fever, catarrhal symptoms, as well as gastrointestinal manifestations and anosmia. A feature of the new coronavirus infection in newborns and children of the first month of life was the absence of fever and intoxication, the lack of expression of catarrhal manifestations when the colon is involved in the pathological process (colitis, rarely — hemocolitis). In the compete blood test in children under the age of one year, monocytosis prevailed, in children over 7 years old — leukopenia and accelerated ESR. Among the changes in the biochemical analysis of blood, the most common was an increased C-reactive protein.

Objective: Determine the role of infectious diseases in the development of strokes in children and to identify risk groups for its progression.

Materials and Methods: A retrospective analysis of 660 case histories of children aged 1 months to 1 8 years old, hospitalized in Morozov Children's City Clinical Hospital with stroke in the period from 201 6 to July 2020 was carried out.

Results. An infectious disease or fever 4 weeks before stroke is diagnosed in 78 (1 2%) cases. Infections more often act as a stroke trigger in children under 7 years old (28% in children under one year old). The incidence of strokes against a background of a bacterial infection is higher than against a background of a viral infection (47% versus 35%). Among bacterial infections, meningitis (35%), otitis media (24%), pneumonia (1 8%) prevailed. With a viral infection, viruses of Herpes are more common (44%), as well as respiratory viruses (37%). Two cases of cerebrovascular accident were revealed in children who have undergone a new coro-navirus infection SARS-CoV-2 (7%). Among the types of stroke, with bacterial infection, sinus thrombosis was more common (50%), among viral infection, the most common was ischemic stroke (60%). The presence of an additional risk factor was revealed in 72%, most often these were prothrombotic conditions (35%).

Acute respiratory viral infections remain the most common diseases in the world, accounting for about 90% of all infectious diseases. The possibilities of etiological decoding of ARVI using modern examination methods made it possible to establish an increase in the proportion of rhinovirus infection in the structure of ARVI.

The aim of the study in this regard was to study the features of the clinical course of rhinovirus infection in children of different ages in modern conditions. The study included 50 patients with rhinovirus infection of children, among whom 1 2 children (24%) were under 1 year old; 34 children (68%) — 1—3 years old, 4 children (8%) — 3—7 years old. To confirm rhinovirus infection, a study of mucus from the nasopharynx by PCR was carried out.

A thorough analysis of the symptom complex of the infection showed that in 1 3 (26%) patients the infectious process was limited to lesions of the upper respiratory tract, in 14 (28%) there were symptoms of acute stenosinglaryngotracheitis, in 1 1 (22%) children developed pneumonia, in 1 2 (24%) — bronchitis, with obstructive syndrome in 1 0 (83.3%) patients in this group.

The article deals the possibilities of using early clinical and anamnestic data for the diagnosis of severe bronchial obstruction in children.

The aim of the study was to search for informative indicators that affect the severity of bronchial obstruction against the background of acute respiratory viral infections, and to develop a mathematical predictive model for use at the stages of hospitalization.

Materials and methods. The study was based on the examination and observation of 386 children aged 1 month to 5 years who were treated in the respiratory department and the intensive care unit with a diagnosis of bronchial obstruction syndrome. To search for informative indicators, 34 anamnestic signs were studied, including those in mother-child pairs. Comparison of indicators was carried out according to Student's t-test for independent samples and у 2 test to assess categorical differences. To assess the effect of each independent variable on the outcomes of interest, variables reaching P ≤ 0.25 in bivariate analysis were included in a multivariate logistic regression model.

Results. Mathematical processing showed that only 1 9 factors were identified as significantly influencing the severity of the disease (p < 0.001), while others were not potential determinants of severity. For the main ones, diagnostic values were calculated and a mathematical forecasting model was built with a high level of reliability — 95%.

The purpose is to characterize the clinical and laboratory parameters in children with different rates of congenital HIV infection progression and, based on the data obtained, to develop independent predictors of forecasting the course of the disease.

Research methods. The comparison of clinical, immunological and virological parameters in 91 children with HIV infection with rapid (26%) and slow progression of the disease (74%) was carried out. The criterion for the rapid progression of HIV infection was considered the development of the AIDS clinic in the first two years of life.

Results. Testing of clinical, immunological and virological parameters in a multivariate logistic regression model revealed independent predictors of rapid progression in children aged 6 months — HIV blood viral load more than 1 00 000 cop./ml (odds ratio OR 23.9; 95% confidence interval 95% CI 4.6—71.8; P < 0.001) and a decrease of blood CD4-lymphocytes less than 25% (OR 6.3; 95% CI 1.2—33.4; P = 0.029). The predictor «HIV blood viral load more than 100 000 cop./ml» was characterized by a higher sensitivity (91.3%), specificity (97.1 %) compared to the indicator «CD4 lymphocyte count less than 25%» (88.2% and 86.9%).

Conclusion. In 26% of children with HIV infection, there is a rapid progression of the disease with the development of AIDS clinic during the first two years of life. The independent predictors of forecasting an unfavorable course of the disease are HIV blood viral load of more than 1 00 000 cop./ml and a decrease in CD4 lymphocytes in the blood of less than 25% at the age of 6 months. The level of viremia seems to be more preferable for predicting the course of HIV infection in children due to its high sensitivity and specificity.

The aim of this study was to determine whether there is an association between antenatal antibi-otic exposure and the incidence of necrotizing enterocolitis (NEC) in low birth weight infants.

Study design: A retrospective case-control study was conducted on all infants with NEC who were born between 201 0 and 2020. Medical histories of all infants diagnosed with NEC ≥ Bella IIA stage and corresponding controls without NEC were examined. Maternal and newborn char-acteristics were compared using the Cochran-Mantel-Haenszel method, and logistic regression models were constructed to account for bias.

Results. Clinical data were analyzed for 97 matched pairs. The adjusted odds ratio (OR) for pre-natal ampicillin exposure was significantly higher for infants who developed NEC (OR 2.3, 95% CI 1.1,4.8, P = 0.003) than for children in the control group. Infants who developed NEC were more likely to have a history of intrauterine exposure to ampicillin in the immediate prenatal period than infants who did not develop NEC.

Aim: to determine the relationship between of levels»protoxic» metabolites and «profibrotic» metabolites in the blood serum in children with chronic viral hepatitis C (HCV).

Material and methods: the authors examined 54 children 14.0[6,0] years old with HCV. The blood serum levels of Molecules of average mass, Oligopeptides, Alcohol dehydrogenase, Glutathione-S-transferase, Ammonia, Arginase and Collagen IV have been studied.

Results: A high level of «protoxic» metabolites in the blood serum was associated with a disorder of their elimination. The relationship with viral replication and biochemical hepatitis activity has not been identified. The collagen IV blood serum level was correlated with the accumulation and elimination of «protoxic» metabolites: R = 0.63, F = 5.19, p = 0.018.

Conclusion: The level of collagen IV in the children's blood serum was associated with the accumulation and the elimination of «protoxic» metabolites.

The aim of the research is to study the features of the intestinal microbiota in children with parasitic invasions.

Clinical and microbiological examination of 40 children aged from 9 months to 1 0 years with functional disorders of the intestine was carried out, in 20 of whom intestinal parasitoses were detected (15 of them — ascariasis, 5 — intestinal lambliosis) — the main group. The comparison group consisted of 20 other children with functional disorders of the intestine without intestinal parasitosis.

All children underwent: assessment of the course of the ante-neonatal periods, the nature of feeding and clinical symptoms of intestinal parasitosis; triple study of feces for eggs of worms and protozoa in the enrichment environment of Turdyev, coprocytogram, biochemical analysis of feces, ultrasound of internal organs. To identify the quantitative content of the main groups of normobiota, species composition and spectrum of opportunistic bacteria and viruses, the method of gas chromatography-mass spectrometry of intestinal microbial markers was used.

It was found that in children with intestinal parasitosis, already at the prenatal stage of the formation of the intestinal microbiota, risk factors were recorded that negatively affect the composition of the forming microbiota, associated with functional disorders of the digestive tract from the first days of life.

The degree of deficiency of normobiota, as well as the spectrum of opportunistic bacteria in children with parasitic invasions, was greater: 14 types of bacteria in combination with herpes viruses versus 9 in the comparison group. Association Clostridium spp. — Herpes virus against the background of a deficiency of bifidobacteria and lactobacilli acts as a dominant association in the relationship with intestinal parasitosis.

Invasive meningococcal infection is a significant cause of death, reaching 80% in septic shock. The Pediatric Research and Clinical Center for Infectious Diseases (PRCCID) has developed an algorithm for the treatment of children with invasive meningococcal infection with refractory septic shock and multiple organ failure syndrome, which includes basic drug therapy with polymyxin hemoperfusion in combination with extended methods of extracorporeal hemocorrection.

Purpose: to evaluate the effectiveness of extracorporeal hemocorrection operations in children with invasive meningococcal infection with refractory septic shock and multiple organ failure syndrome.

Materials and research methods: to the intensive care unit of the PRCCID for the analyzed period 2006—2020 34 children were hospitalized with invasive meningococcal infection with refractory septic shock and multiple organ failure syndrome. Two groups were formed: Group 1 — children admitted to the PRCCID in the period 2014—2020 (n = 23), who underwent polymyxin hemoperfusion simultaneously with extended methods of extracorporeal hemocorrection, group 2 — children hospitalized in 2006—201 3 (n = 1 1), methods of extracorporeal hemocorrection were not performed. The Mann-Whitney U-test and ANOVA were used to evaluate the results.

Results and discussion: the use of extracorporeal hemocorrection operations in the complex therapy of invasive forms of meningococcal infection with refractory septic shock and multiple organ failure syndrome in children provides stabilization of central hemodynamics, reduces clinical and laboratory inflammatory reactions, helps to reduce the dose of vasopressor drugs and parameters of respiratory support, and also increases patient survival rate by 82.6%.

Aim: To compare the features of clinical-anamnestic and laboratory-instrumental data and treatment of children with typical and atypical (Mycoplasma) forms of pneumonia.

Materials and methods. A comparative analysis was carried out of 1 70 case histories of children in hospital with a verified diagnosis of pneumonia in 2020. The basis for the diagnosis of Mycoplasma pneumonia was a positive PCR result of a smear of the posterior pharyngeal wall. The resulting data was constructed using Microsoft Excel 2007.

Results. Mycoplasma pneumonia is specific for older schoolchildren; characterized by: prolonged course (73.5%), long-term preservation of an unproductive cough (75.7%), mild intoxication (68.6%) and catarrhal syndromes (54.3%), gradual onset (76.6%), severe lymphocytosis up to 55%, segmental or polysegmental damage to the lung tissue (92.7%).

Objective: The article deals with a clinical case of new coronavirus infection in a 1 5-year-old child who was receiving treatment in an infectious diseases hospital of City Children's Clinical Hospital №3 during the period from 1 0 October to 1 December 2020.

Materials and methods. The diagnosis was confirmed through nasal swabs examination for the presence of SARS-CoV-2 RNA using PCR and SARS-CoV-2 IgM detection through ELISA.

Results. The main feature of the infection course in the present patient was multisystem inflammatory syndrome development with long-term fever, maculopapular rash and multisystemic lesions including bilateral pneumonia, acute carditis and polyserositis.

The new coronavirus infection COVID-1 9 in children generally proceeds favorably, but in combination with other acute infectious diseases and in persons with background pathology and impaired immune reactivity may pose a particular threat.

The article presents a clinical case of chickenpox, complicated by meningoencephalitis and cerebral edema, in combination with COVID-1 9 in a 5-year-old child. Chickenpox was not quite typical: against the background of febrile temperature, there was a scanty spot-papular rash with single vesicles that appeared later, the absence of elements on the mucous membranes and the development of neurological symptoms in the first day of the disease. CОVID-1 9 was characterized by a wave-like course with fever up to 39,1 °C, tonsillitis phenomena and inflammatory changes in the blood test.

The article presents a case of an unusual course of chickenpox in a young child (1.5 months). The development of acute hepatitis against the background of the course of the disease is described.

This clinical observation clearly demonstrates that the varicella zoster virus, like other viruses from the herpes family, is secondary hepatotropic and is capable of causing acute hepatitis. This experience allows us to recommend assessing liver function in patients with chickenpox, and, if abnormalities are found, supplement the standard therapy with the appointment of hepatoprotectors.