Croup causes a life-threatening condition in children.

Objective: to study the etiological structure of acute obstructive laryngitis and to identify the clinical and immunological features of croup syndrome in children with COVID-19.

Materials and methods. The article presents an analysis of the etiological structure of acute obstructive laryngitis in 897 children aged 6 months to 5 years. Etiological decoding was carried out by the PCR method, the cytokine status (the content of IFN-á and -ã, IL-1â, -8 and -17) was determined by the ELISA method in the material from the nasopharynx of patients. Patients with croup in coronavirus infection were divided into groups: Group I — children with seasonal coronaviruses (n = 39), Group II — children with COVID-19 (n = 30). Results. The proportion of viral acute obstructive laryngitis is 86.0%. The leading provocateurs of laryngeal stenosis are parainfluenza viruses (26.9%). Children with COVID-19 more often suffered from grade II laryngeal stenosis (60.0%) with dyspnea of mixed nature (26.7%) against the background of severe intoxication (63.3%) and moderate catarrhal syndrome (70.0%) with the addition of croup syndrome more often on the second (43.3%) and third (40.0%) days of the disease. Activation of local immunity and clinical symptoms of catarrhal-respiratory syndrome were due to an increase in the content of proinflammatory cytokines IL-1â, -8, -17 and the IL-17/IL-8 ratio in the pharyngeal secretion in children of group II with COVID-19, which correlated with low levels of IFN-á and -ã.

Conclusion. Croup in COVID-19 in children is typical. Children with a complicated premorbid background are most susceptible, which correlated with low interferon levels and increased interleukins. Acute obstructive laryngitis in COVID-19 should be considered as one of the clinical manifestations of coronavirus infection.

The problem of treatment and prevention of acute respiratory viral infections in children with functional and morphofunctional health conditions has not been sufficiently studied.

Objective: to study the pharmacological properties of recombinant interferon-alpha-2b with antioxidants (VIFERON^®, rectal suppositories) in the complex therapy of influenza and other acute respiratory viral infections (ARVI) in children of II—IV health groups.

Materials and methods: 66 children of II— IV health groups with moderate acute respiratory viral infections aged from 1 month to 18 years, randomized into two groups: group 1 — children who received in complex therapy VIFERON^®, rectal suppositories (new modified regimen, dosage according to age: 1 month — 3 years — 500,000 IU 2 times a day for 5 days, then 150,000 IU 2 times daily for 5 days; 3—7 years — 500,000 IU 2 times a day for 5 days, then 500,000 IU 1 time a day in the morning and 150,000 IU 1 time a day in the evening for 5 days; 7—18 years old — 1,000,000 IU 1 time a day in the morning and 500,000 IU 1 time a day in the evening for 5 days, then 500,000 IU 2 times a day for 5 days); group 2 — children who received symptomatic therapy and a placebo drug. The therapy was carried out for 10 days, and patients were monitored 1, 3, and 6 months after the end of treatment.

Results: recombinant interferon-alpha-2b with antioxidants in the complex therapy of acute respiratory viral infections significantly reduces the level of malonic dialdehyde (0.92 nmol/ml compared with placebo — 1.10 nmol/ml (p = 0.026)) and significantly increases the levels of the antioxidant enzyme glucose-6-phosphate dehydrogenase (GP) in red blood cells (8118.38 and 6973.43 Units/l, respectively, p = 0.003) and non-enzymatic antioxidant glutathione — 1403.63 and 1291.04 mmol/l, respectively, p = 0.005. There was also a significant increase in serum total antioxidant activity (AOA) levels (1.73 and 1.64 mmol/L, respectively, p = 0.017) against the background of a significant reduction in recovery time (5.38 and 8.06 days, respectively, p < 0.001).

Conclusion: the inclusion of recombinant interferon-alpha-2b with antioxidants (VIFERON^®, rectal suppositories) in a modified dosage regimen in the complex therapy of moderate acute respiratory viral infections significantly increases the functioning of the antioxidant defense system and reduces the content of malonic dialdehyde, the end product of cell membrane degradation, in the blood serum of children of II—IV health groups in a double-blind, placebo-controlled trial.

The aim of the study was to identify the main microorganisms colonizing the mucous membrane of the nasal cavity and pharynx in children of different age groups, and their antibiotic sensitivity.

Materials and methods: 311 children aged 0 to 17 years who applied for outpatient care of St. Petersburg State Medical Establishment «City Polyclinic No. 63» for the period from March to December 2023 were examined. 511 samples were examined — 241 from the nasal mucosa and 270 from the pharyngeal mucosa. Antibiotic sensitivity has been determined. The frequency of colonization in children who sought outpatient care for upper respiratory tract infections (n = 186) and for other reasons (n = 103) was calculated.

Results. Clinically significant microorganisms were isolated from 176 (61.3% ± 2.87) children: S. aureus 30.0 ± 2.7, S. pyogenes 19.9 ± 2.3, M. cataralis 11.1 ± 1.9, S. pneumoniae 8.4 ± 1.6, H. influenzae 5.6 ± 1.3, others 3.8 ± 1.1. 41 (14.3%). The risk group for colonization of S. aureus are boys RR = 1.47 (95% CI: 1.02—2.12) p = 0.02. The risk group for colonization of M. cataralis and S. pneumoniae are children from 0 to 9 years old: RR = 9.45 (95% CI: 2.29—38.93); p (Fisher) = 0.00002 and RR = 4.9 (95% CI: 1.49—16.06); p (Fisher) = 0.0018, respectively. 59.8% of S. aureus strains were resistant to benzylppenicillin, 14% to roxithromycin and clindamycin, 13% to azithromycin and erythromycin, 18.7% of H. influenzae strains to ampicillin and amoxicillin, 87.5% of S. pneumoniae strains had intermediate resistance to cefaclor, 90.8% of S. aureus strains to clarithromycin. 99% of S. aureus strains, 98.4% of S. pyogenes and 97.4% of S. pneumoniae had intermediate resistance to levofloxacin.

Objective: A survey of 464 primary care pediatricians was conducted to determine the choice of therapy for a group of frequently ill children depending on their length of service: from 3 to 10 years or more.

Results: Recurrent acute respiratory infections are a complex problem for treating physicians. There is no consensus on the tactics of managing a group of frequently ill children among practicing pediatricians with different lengths of service. Preventive strategies come to the forefront to minimize the frequency of acute respiratory infections.

The relevance of the problem of whooping cough in newborns is due to the severity of clinical manifestations and high mortality.

The aim of the work is to present the data available in the literature on the causes of the unfavorable course of whooping cough in newborns, illustrated by our own clinical examples, as well as to summarize the ways to solve this problem.

Materials and methods: a review of domestic and foreign literature over the past 10 years, including Internet resources, was conducted and our own clinical observations of newborns with whooping cough are presented.

Conclusion. Whooping cough in newborns and children of the first months of life develops due to the absence of maternal anti-whooping cough antibodies. The disease is often severe, ending in death. Prevention of whooping cough in newborns and infants should include mandatory vaccination of pregnant women in the 2nd or 3rd trimester of pregnancy.

Human papillomavirus infection is an infectious disease caused by the human papillomavirus (HPV). Some types of HPV, especially high oncogenic risk types, can lead to cervical cancer, vaginal and vulvar cancer, anal cancer, and oropharyngeal cancer. HPV of low oncogenic risk, in turn, can cause anogenital warts or juvenile recurrent respiratory papillomatosis in childhood. Human papillomavirus infection is the most common sexually transmitted infection in the world. However, there are other important ways of transmission: vertical (from mother to child), horizontal, including infection through inoculated objects and surfaces (fomites), heteroinoculation and autoinoculation (self-infection is the way of virus transmission from one part of the body to another).

In this literature review we analysed data from basic research and clinical studies that show that HPV can survive far beyond its host and potentially can be transmitted not only in sexual contact.

Disorders of sex formation are congenital conditions characterized by a mismatch between chromosomal, gonadal and anatomical sex. Currently, genetic factors affecting the development of sex during gonad differentiation, biosynthesis and the action of sex hormones have been identified. The incidence of the disease is 1 case per 4,500—5,000 newborns, for this reason, every pediatrician will face the problem of managing a newborn with atypical genitalia. The improvement of prenatal diagnostic methods, in particular, the use of non-invasive prenatal testing, allows the identification of genetic mutations of the Y chromosome as early as 7 weeks of pregnancy. This work reflects the etiological structure of disorders of sex formation — genetic mutations, diagnostic and therapeutic features of the management of patients with impaired sex formation are noted.

The aim of the work is to collect and summarize modern scientific data on gender formation disorders with the identification of the main causes of development, methods of diagnosis and therapy of the disease in different countries.

Materials and methods: the analysis of modern domestic and foreign literature on the topic of gender formation disorders in the period from 2016 to 2024 was carried out.

Results: the modern classification of disorders of sex formation, the main syndromes and diseases, clinical symptoms, and current diagnostic methods are presented. Approaches to therapy vary from country to country, which will allow domestic specialists to apply the most appropriate treatment.

Acute kidney injury (AKI) is one of the most serious complications of infectious diseases, occurring in 5% to 30—50% of hospitalized patients. Despite advances in the treatment of AKI, including renal replacement therapy, morbidity and mortality rates continue to rise. There is significant variability in the clinical manifestations of AKI among patients with identical pathology, highlighting the need to study additional factors that influence the severity and outcomes of the disease. Genetic variability, including gene polymorphisms that determine individual characteristics of regulatory mechanisms in kidney damage, may play an important role in this process. This article aims to analyze existing data on the impact of genetic factors on the development and outcomes of AKI, as well as gene polymorphisms that may serve as diagnostic criteria for early detection and risk of AKI. The focus is on genes associated with the inflammatory response, such as TNF-á, IL-1â, IL-6, IL-8, IFN-ã, TGF-â, and IL-10, and their potential role in predisposition to AKI and disease progression. The influence of genetic variations in vasomotor regulatory proteins, such as angiotensin-converting enzyme (ACE) and endothelial nitric oxide synthase (eNOS), on the development of AKI is also discussed. The relationship between polymorphisms in the BCL2 and SERPINA genes and AKI, as well as between polymorphisms in the SERPINA4 and SERPINA5 genes and the development of AKI in COVID-19 patients, is analyzed. Despite numerous studies and identified associations, data on genetic risk factors remain limited and contradictory, underscoring the need for further research. The identification of new genetic markers will help improve diagnosis and provide a personalized approach to the prevention and treatment of AKI, especially in children with a high predisposition to this condition.

Being a rather rare, but at the same time extremely important finding in the general blood test, the leukemoid reaction (LR) is a short-term sharp increase in the level of leukocytes above 30—50 x 10⁹/l with a shift of the leukocyte formula to the left. The development of this condition may be due to a number of factors, but in pediatric practice, LR is primarily associated with prematurity, the course of the infectious process (most often pneumonia), extremely low body weight, taking certain medications both by the mother during pregnancy and by the child, chromosomal abnormalities and others. Of particular importance to the study of LR is the fact that similar changes in peripheral blood are observed in a number of other diseases, including the course of malignant processes — leukemia, which requires a competent approach to differential diagnosis, the involvement of various specialists and makes LR an exception diagnosis.

Immune-mediated dermatoses develop as a result of an inadequate immune response to various triggers (medications, bacterial and viral infections). In 2020, a new term was proposed to combine various mucositis in combination with skin lesions on the background of respiratory infections — reactive infectious mucosal rash (reactive infectious mucosal eruptions, RIME). We present the case of a seventeen-year-old girl with reactive infectious mucocutaneous eruption associated with atypical respiratory pathogens — Chl. pneumoniae and M. pneumoniae. On the 5th day of the disease, against the backdrop of pneumonia, the patient developed an enanthem with lesions of the oral mucosa, conjunctivae, and polymorphic rashes. The diagnosis was confirmed by the detection of IgM and IgG antibodies to Chl. pneumoniae and M. pneumoniae using ELISA. Recovery occurred against the background of etiotropic antibacterial therapy, on the 14th day of the disease, the patient was discharged from the hospital in a satisfactory condition. The case demonstrates the difficulties in diagnosing a rare complication of respiratory infections and emphasizes the need for further research to clarify the tactics of managing patients with skin and mucous reactions.

For six decades, the Department of Pediatric Infectious Diseases of the Russian Medical Academy of Continuous Professional Education of the Ministry of Health of the Russian Federation has been a leader in one of the key areas of pediatrics — pediatric infectious diseases. Over the course of its work, significant teaching and research experience has been accumulated, which has earned the respect of not only infectious disease specialists, but also specialists in other pediatric fields. Since its inception and to this day, the department has prioritized postgraduate education, advanced training of doctors, training of specialists in clinical residency and postgraduate study. Scientific activity covers the most relevant topics, which ensures both scientific novelty and practical significance of the research. In addition, the department constantly improves the educational process in the specialty «Infectious diseases». The results of this activity are many published methodological recommendations and manuals, as well as the presentation of the results of the department's work at scientific conferences, congresses and conventions.