The human immunodeficiency virus epidemic has remained a global public health challenge for over 40 years. The use of effective antiretroviral therapy has significantly reduced mortality and morbidity. The reduction of human immunodeficiency virus viremia greatly improves the health status of infected individuals. However, widespread use of effective antiretroviral therapy has not resulted in a sufficiently low mortality rate. The profile of causes of death has shifted – among patients on therapy, there has been an increase in fatal cardiovascular events and non-acquired immunodeficiency syndrome related cancers, while acquired immunodeficiency syndrome related deaths still occur among those who have never started treatment or have poor adherence and drug resistance. Most studies have focused on acquired immunodeficiency syndrome related mortality. Few studies address other causes of human immunodeficiency virus -related death, highlighting preventable mortality among people living with human immunodeficiency virus. Cohort studies reveal a significant and persistent gap in life expectancy between people living with human immunodeficiency viru and the uninfected population, especially in key affected groups. Thus, human immunodeficiency virus infection management is a dynamic process influenced by multiple factors. The ultimate goal of this process for infected individuals is to increase both life expectancy and quality of life. Analyzing causes of death can provide essential insights for optimizing human immunodeficiency virus infection control strategies.

Purpose – to analyse current scientific data on Human pegivirus type 1 (HPgV-1) infection. The review examines virus structure, epidemiology, transmission routes, pathogenesis features, impact on various human diseases, modern diagnostic methods, and therapeutic approaches for HPgV infection. A search of scientific publications was conducted in PubMed, Elibrary, CyberLeninka, and Scopus using keywords «Human pegivirus», «HPgV», «GBV-C», «Hepatitis G virus» for 1990-November 2024. Inclusion criteria were original research articles, reviews, and meta-analyses on HPgV-1 in Russian and English. Article selection was two-staged: initial screening by titles and abstracts, then full-text analysis of articles meeting criteria.

HPgV-1 is a lymphotropic RNA virus of the Flaviviridae family, globally distributed with an overall infection prevalence of approximately 3,1%, varying regionally. Main transmission routes are parenteral, vertical, and sexual. Diagnostic methods are PCR and ELISA. No specific antiviral treatment is currently developed. A significant clinical aspect is HPgV-1’s modulating effect on HIV infection, slowing disease progression and increasing CD4+ lymphocyte counts. A possible association with increased risk of non-Hodgkin’s lymphoma and neuroinfections is discussed, but these data need further confirmation.

Conclusion: HPgV-1 infection is a significant public health and biomedical research problem due to its wide prevalence and potential impact on various diseases, especially HIV. The protective effect of HPgV-1 against HIV offers new perspectives for therapeutic strategies. Further in-depth studies are needed to understand HPgV-1 pathogenesis mechanisms and clinical role in various pathologies.

Immune dysregulation is one of the main causes of severe coronavirus infection COVID-19. The immune response in COVID-19 is characterized by the activation of innate immune cells and elevated levels of pro-inflammatory cytokines in the blood (tumor necrosis factor alpha, interleukins-1, -6, -8), neutrophils, C-reactive protein and ferritin. Organ dysfunction, including acute respiratory distress syndrome, is associated with cytokine storm. Another important sign of immune dysregulation is lymphopenia, one of the key predictor of the development of severe COVID-19 and poor outcome. One of the main causes of lymphopenia in patients with severe COVID-19 is apoptosis of lymphocytes. The increased proinflammatory cytokines play a critical role in the induction of lymphocytes apoptosis and lymphopenia. The clinical role of lymphocytes apoptosis in COVID-19 is associated with the immunosupression and the opportunistic and secondary infectious diseases. The immunosupression in severe COVID-19 is confirmed by the results of morphological studies demonstrating the depletion of lymphocytes in lymphoid tissue. Next important cause of lymphopenia is lymphocyte sequestration in the lungs. Postmortem studies of the lungs of patients died from COVID-19 show the lymphocytic infiltration. Additionally, lymphopenia may result from impaired lymphopoiesis due to virus-induced damage to lymphocyte precursors in the bone marrow and thymus. In COVID-19 patients, there is a significant reduction in the production of T-cells in the thymus. The decreased thymic function may exacerbate lymphopenia in patients during the acute phase of COVID-19 and prolong the time required for the recovery of circulating T-cell counts.

The epidemiological situation of rabies in the world remains very difficult. The problem of rabies does not lose its relevance due to the severity of the course and the lethality of the consequences. Rabies is a zoonosis, that is, an infection transmitted from diseased animals (both wild and domestic) to humans, accompanied by the development of encephalitis. The breadth of the range of susceptible species, which includes all warm-blooded vertebrates and birds, requires the attention of both veterinarians and infectious disease specialists. The main route of human infection is through bites or contamination of damaged skin with the saliva of infected animals. The classic variant of the disease includes successive stages of prodromal development, arousal and paralytic phase. Diseases caused by new, previously unknown lissaviruses carried by bats are becoming increasingly important. Modern immunotherapeutic methods of infection control are focused on the early, asymptomatic stage of the disease and are aimed at peripheral neutralization of the virus to prevent infection of the central nervous system and further development of pathology. In this work, the authors systematize modern data on the epidemiology, prevalence, pathogenesis, clinical features and approaches to the diagnosis and therapy of rabies.

Since the beginning of the COVID-19 pandemic, a large amount of data has been accumulated indicating a connection between this new coronavirus infection and the development of autoimmune manifestations in various organs and systems.

The review includes data from foreign and domestic articles published in PubMed over the past 6 years, which are devoted to the role of COVID-19 as a trigger for the occurrence of systemic and organ-specific autoimmune diseases, including hematologic diseases.

The development of autoimmune diseases (AID) after COVID-19 can be triggered by the infection itself, as well as vaccination. The emergence of AID is due to both molecular mimicry and immune dysregulation caused by the SARS-CoV-2 virus. The review provides a description of individual cases of development of different AIDs, as well as the results of a number of cohort observational studies covering a period of 1-2 years, which analyzed large data sets of patients with COVID-19 infection. A unique aspect of AIDs following SARS-CoV-2 infection compared to other previously known viral pathogens is the extremely broad spectrum of conditions observed. The timing of AID manifestation after COVID-19 is characterized by marked variability (from 1 to 15 months). Among the autoimmune blood system diseases, the most common are autoimmune hemolytic anemia (AIH) and immune thrombocytopenic purpura (ITP), which can develop within a few days after infection with the SARS-CoV-2 virus.

To date, COVID-19 remains a challenge for modern medicine. The prognosis of the disease is often associated with the development of complications caused by SARS-CoV-2 virus. Hemorrhagic complications of COVID-19 account for the highest incidence, ranging from 3.0% to 31.1%. Air leak syndrome has been observed from the respiratory system side. Surgical complications in COVID-19 constitute from 1% to 2.4%, with mortality rates varying from 7.9% to 78.5%.

The aim of the study was to determine the optimal approaches to the diagnosis and treatment of patients with air leak and hemorrhagic complications of COVID-19, taking into account the data of clinical laboratory, instrumental, pathomorphological and immunohistochemical studies. clinical-laboratory, instrumental, pathomorphological, and immunohistochemical data.

Materials and methods: The study included 213 patients who developed air leak syndrome, 332 patients with gastrointestinal bleeding, and 39 patients with spontaneous soft tissue hematomas.

Results: It was established that surgical complications most frequently occurred in patients with a burdened premorbid background during the late stages of COVID-19 progression.

Based on correlation analysis of clinical-laboratory and instrumental indicators, predictors for the development of air leak syndrome and gastrointestinal bleeding were identified with a significance level p<0.05. A prognostic model was constructed using logistic regression with Wald’s criterion calculation. The model’s quality was assessed using ROC curves: for air leak syndrome (AUC=0.97) and for gastrointestinal bleeding (AUC=0.78).

Immunohistochemical studies using monoclonal antibodies against the SARS-CoV-2 spike S-protein (COVID-19 spike antibody) revealed SARS-CoV-2 viral particles in endothelial cells. Expression of CD31, CD34, CD68, and vWF receptors reflected SARS-CoV-2-associated systemic endothelial changes considering coagulopathy factors and proinflammatory responses. In cases of air leak syndrome, one key factor was the formation of endothelial microthrombi; in hemorrhagic events, degenerative changes in the endothelium were prominent.

Conclusion: The cytopathic effect of SARS-CoV-2 led to degradation of the endothelial monolayer, contributing to vascular wall destruction and the development of clinically significant hemorrhagic events. Implementing predictive methods for assessing the risk of air leak syndrome and bleeding in COVID-19 patients in clinical practice allowed some patients to be prophylactically protected against complications. The preferred treatment algorithm for spontaneous soft tissue hematomas in COVID-19 patients involves a sequential transition from non-invasive to minimally invasive methods for hemostasis.

Objective: To identify clinical and instrumental characteristics of the cardiovascular system in COVID-19 convalescents, with the aim of optimizing follow-up monitoring strategies for this patient population.

Materials and Methods: The study enrolled 100 young and middle-aged patients at 6 months post-COVID-19 infection (44 severe cases, 56 moderate cases). Evaluations included: symptom assessment, physical examination, electrocardiography, and transthoracic echocardiography. Additionally, transthoracic echocardiography was performed in 20 randomly selected patients from this cohort at 12 months post-infection, along with 30 control subjects.

Results: Echocardiography revealed persistent, stable, and unidirectional parameter alterations in post-COVID patients compared to controls. The most significant findings involved diastolic dysfunction: a pseudonormal left ventricular dysfunction pattern was observed in 40% of patients at both 6- and 12-month follow-ups, while right ventricular dysfunction was present in 62% and 60% of patients, respectively. Pericardial effusion was detected in 50% of examined patients at both time points. Persistent pulmonary artery changes were documented: median diameters measured 27.5 mm (IQR 25.0–30.0) at 6 months and 28.0 mm (26.0–30.0) at 12 months for the main artery, with right branch diameters of 20.0 mm (18.0–22.0) and 19.0 mm (18.0–20.0), respectively. Pulmonary artery pressure remained higher than in the control group, with median values of 25.0 mmHg (17.0-28.0) at 6 months and 23.0 mmHg (18.0–25.0) at 12 months post-infection.

Conclusion: The study identified persistent cardiovascular sequelae in COVID-19 convalescents lasting ≥1 year, including biventricular diastolic dysfunction and pericardial effusion without evidence of regression. These findings support the need for modified clinical follow-up protocols for this patient population.

The aim of the study is to assess the relationship between low parental compliance with child immunization and individual socio-demographic factors.

Materials and methods. An anonymous online questionary was sent to people whose children attend preschool educational institutions. 890 respondents from 5 cities of the Russian Federation and 2 cities of the Republic of Belarus took part in the survey. To assess the relationship with such potential risk factors as city of residence, age of respondents, number of children in the family, level of education of parents, level of family income, binary logistic regression analysis was performed. Odds ratio (OR) and 95% confidence intervals (95%CI) were calculated. R 4.3.1 (RStudio) environment was used for statistical analysis.

Results. 78.5% of all respondents stated a positive attitude towards vaccination. After receiving the survey results, respondents were divided into two groups: group 1 (180 people): parents with a low level of compliance with child immunization (they do not vaccinate their children or vaccinate them partially, not with all the vaccines from the vaccination schedule); group 2 (710 people): parents with a high level of compliance with child immunization (they vaccinate their children with all vaccines on time or with a delay in the schedule due to episodes of acute illnesses of the child). According to the results of logistic regression analysis, the factors statistically significantly associated with a lower level of adherence were: parent’s age over 45 years compared to 18-24 years (OR 3,32; 95% CI 1,11–10,35), professional but not higher education (compared to higher education) (OR 1,55; 95% CI 1,01–2,39), moderate level of income (compared to high level) (OR 1.97; 95% CI 1,12–3,54). Respondents from Makhachkala were found to have the lowest probability of being adherent to vaccination (OR 4,90; 95% CI 2,29–10,85 compared to the reference city – Almetyevsk).

Conclusion. A low level of parental compliance to child vaccination (79.8%) was found, which is insufficient to prevent epidemics. Low compliance to vaccination was associated with older parental age, lower education level and family income. No connection with the number of children in the family was found.

Chronic hepatitis B (CHB) remains a global health challenge with over 296 million virus carriers and high mortality from complications. In Uzbekistan, HBsAg prevalence reaches 3.7%, highlighting the need for improved diagnostic approaches. Traditional markers (HBV DNA, HBeAg) have limitations, particularly in cases of viral persistence through covalently closed circular DNA (cccDNA) and integrated DNA (iDNA). The study aimed to investigate the relationship between HBV DNA, HBV RNA, and quantitative HBsAg (qH-BsAg) in treatment-naive patients, with emphasis on paradoxical marker dissociation.

Methods. This prospective study included 116 adult patients with chronic HBV infection without prior antiviral therapy. Exclusion criteria comprised cirrhosis, hepatocellular carcinoma, and autoimmune diseases. HBV DNA was determined by PCR, HBV RNA by RT-PCR, and qHBsAg by enzyme immunoassay (EIA). Patients were stratified into three groups: DNA+/RNA+ (48 patients – 41.4%), DNA-/ RNA+ (24 patients – 20.7%), and DNA-/RNA- (44 patients – 37.9%).

Results. The median qHBsAg levels in DNA+/RNA+ and DNA-/RNA- groups were comparable (4,300 vs 1,840 IU/ mL, p=0.12), but significantly higher in the DNA-/RNA+ group (8,300 IU/mL, p<0.003). In HBeAg-positive patients, a correlation was observed between HBV RNA and qHB-sAg (r=0.592, p<0.001), while no association was found in HBeAg-negative patients. The DNA-/RNA+ group was characterized by elevated ALT levels (34.8 vs 27.8 U/L, p=0.01) and lymphocytosis, indicating immune activation.

Conclusion. The paradoxical dissociation of HBV markers in treatment-naive patients demonstrates that the DNA-/ RNA+ phenotype is associated with active cccDNA transcription without DNA replication, accompanied by elevated qHBsAg levels and subclinical hepatitis. Integration of HBV RNA and qHBsAg analysis into clinical practice will improve patient stratification, particularly in regions where HBeAgnegative forms predominate. These findings underscore the necessity for revising diagnostic algorithms to optimize chronic HBV management.

The purpose of this study was to study the influence of social and living conditions on the formation of a microbial and immunological background in children with recurrent respiratory diseases.

Materials and methods. 407 children aged 7–16 years were examined. Depending on the living conditions of the children, 3 groups were identified: Group I – institutionalized families; group II – children living in unfavorable social conditions, with a lack of parental attention, and group III – from complete, prosperous families. The presence of specific IgM and IgG antibodies in serum to CMV, HSV 1/2, EBV, as well as Mycoplasma pneumoniae and Chlamydophila pneumoniae was investigated. When antibodies were detected, a study was conducted for the presence of DNA in an oropharyngeal smear by PCR analysis. All children were in clinical remission for at least 10 days at the time of the study.

Results. The registration of the category of «frequently ill children» was most often determined among children from single-parent families living in unfavorable social conditions, with a deficit of parental attention 38,16% higher than in the group of institutionalized children and 2 times compared with children from complete well-off families. Infection with persistent intracellular infections was most often recorded among children from single-parent families living in unfavorable social conditions, with a lack of parental attention, which exceeded the indicators of institutionalized children by 33,33% and was 64,29% higher when compared with children from full, prosperous families.

The purpose. To study the structure and evaluate the role of isolated and combined opportunistic infections in the formation of lethal outcomes in patients with HIV-associated tuberculosis.

Materials and methods. Comparative clinical and morphological analysis of deaths in patients with HIV-associated tuberculosis (group No. 1) and in patients with HIV infection without tuberculosis (group No. 2).

Results. The study included 87 cases, including 57 in group 1 and 30 in group 2. There were no significant differences in the groups by sex, age, duration of HIV infection and underlying comorbid pathology. In group No. 1, diseases of the cardiovascular system were more often detected (78.9 and 46.7%, p=0.002). CD4 lymphocyte levels were 23.0 (8.2; 73.4) cells/ml in group 1 and 10.3 (3.7;21.5) cells/ ml in group 2. In group 1, generalized tuberculosis was diagnosed in 45 patients (78.9%), including tuberculosis of the central nervous system in 20 patients. 33 (57.9%) patients in group 1 did not receive antiretroviral therapy. The main causes are death before the start of TB therapy (16 patients) and in the first weeks of therapy (14 patients), treatment of opportunistic infections (3 patients). In group 1, tuberculosis as the only as a single opportunistic infection was detected in 17 patients (29.8%); combined opportunistic infections were diagnosed in 40 (70.2%) patients, including two infections in 20 (35.1%), three in 14 (24.6%), four in 6 (10.5%) patients. Esophageal candidiasis (26 cases) and pneumocystis pneumonia (15 cases) were most often opportunistic infections detected together with tuberculosis. Distribution by causes of deaths among patients in group 1: HIV-associated tuberculosis – 39 (68.4%) patients, a combination of opportunistic infections, including tuberculosis – 7 (12.3%) patients, opportunistic infections in the background of tuberculosis – 9 (15.8%) patients, progression of other diseases without a significant role of tuberculosis – 2 (3.5%) of patients.

Conclusion. A combination of several opportunistic diseases has been found in the majority of deceased patients with HIV-associated tuberculosis, which has an negative effect on the prognosis, timing of appointment and the likelihood of temporary discontinuation of antiretroviral therapy.

Timely immunoprophylaxis of respiratory syncytial virus (RSV) infection aimed at reducing the risks of severe disease during infancy may influence the incidence of subsequent respiratory diseases in this cohort of children at an early age.

Objective: to evaluate the impact of immunoprophylaxis of RSV infection carried out in the first year of life in children at risk of severe course, and its completion on the frequency of repeated episodes (≥3 times a year) of bronchial obstruction, community-acquired pneumonia at an early age.

Materials and methods. A prospective case-control study was conducted from 2020 to 2024. 247 children aged 1–3 years were observed: the case group consisted of 150 children who received immunization courses against RSV infection, the control group – 97 children who did not receive immunoprophylaxis. The passive immunization course included 3–5 injections of the monoclonal antibody to the RSV F protein palivizumab from October 1 to April 1 at a dose of 15 mg/kg of body weight. The frequency of respiratory infections was also compared in children who received 1–2 (n=75, “incomplete immunization course” group) and 3–5 (n=150, “cases” group, “completed immunization course”) injections of the drug. The mean value and standard deviation (M) were calculated, as well as odds ratio (OR) indicators with 95% confidence interval (CI).

Results: Children immunized in the first year of life, compared with children without immunization, had a lower risk of recurrent (≥3 times per year) episodes of bronchial obstruction (OR = 4,33 95% CI [2,44–7,70]) and community-acquired pneumonia (OR = 3,38 95% CI [1,86–6,14]) in early life. A completed course of immunization (3-5 injections of monoclonal antibodies) compared with an incomplete course (1–2 injections) significantly reduced the risk of repeated (≥3 times a year) episodes of bronchial obstruction (OR=2,2 95% CI [1,27–5,00]).

Conclusion: Immunoprophylaxis of RSV infection in children at risk significantly reduces the risk of episodes of bronchial obstruction and community-acquired pneumonia at the age of 1-3 years.

Objective: to evaluate the incidence of Betapolyomavirus hominis in individuals at risk of developing infectious complications associated with virus reactivation.

Materials and methods. The prospective study included 601 patients in 6 groups: hematopoietic stem cell recipients with and without established hemorrhagic cystitis, allogeneic kidney recipients, HIV-infected persons, pregnant women and a control group. Quantification of B. hominis DNA by RT PCR was performed for 1202 samples of whole venous blood and urine. The results were statistically processed using the STATTECH program.

Results. The prevalence of B. hominis among people at risk of developing infectious complications ranged from 6.0% to 89.2%, depending on the study group. Allo-HSCT recipients had the highest incidence of the viral DNA presence in urine samples – 89.2% with hemorrhagic cystitis and 26.3% without it, at concentrations up to 9.3×10¹¹ IU/ml. In the remaining groups, the viral load in urine was lower (up to 1.1×10⁸ IU/ ml), and the detection rate was: pregnant women – 14.3%, HIV-infected persons – 10.6%, allogeneic kidney recipients – 6.0%, control group – 5.8%. The chance of detecting viral DNA in urine samples of allo-HSCT recipients with hemorrhagic cystitis is 134.7 times higher than in the control group (p<0.001). B. hominis DNA was found in whole venous blood samples: 8.4% and 21.1% of allo-HSCT recipients with and without hemorrhagic cystitis, respectively (р=0,051), HIV– infected persons – 1.4%, control group – 0.4%. Simultaneous detection of viral DNA in blood and urine presented in patients after allo-HSCT, regardless of the presence of hemorrhagic cystitis and HIV–infected persons.

Conclusion. Reactivation of B. hominis continues to pose a threat to human health and life, causing various complications in patients with weakened immune systems. The obtained data on the prevalence of B. hominis are necessary for studying the diseases associated with the virus and generating an algorithm for examining patients at risk of developing infectious complications.

Objective: To identify the features of the epidemic process of measles in Saint Petersburg and the Leningrad region during the period of increased morbidity.

Materials and Methods: A retrospective epidemiological analysis based on data from the accounting and registration database of infectious and parasitic diseases of the Federal Budgetary Institution «Center for Hygiene and Epidemiology in Saint Petersburg and the Leningrad Region» for the period from January 1, 2023, to August 1, 2024.

Results: A total of 1,044 confirmed cases of measles were recorded, with an incidence rate of 13,80 (95% CI 11.71–15.89) per 100,000 population (13,31 in St. Petersburg and 13,41 in the Leningrad region). The incidence among children was 6,95 times higher thanthatamong adults (p<<0,01): 8,57 times in the Leningrad region and 6,84 in St. Petersburg. The highest incidence was observed among children aged 1–2 years (110,82 per 100,000, 95% CI from 3,95 to 12,1 per 100,000). In 2024, there was a sharp increase in incidence from January to April. In the age structure, children under one year old accounted for 1.08%, 1–2 years – 14,08%, 3–6 years – 13,10%, 7–14 years – 24,54%, 15–17 years – 5,28%, 18–35 years – 18,57%, 36–55 years – 20,04%, and 55 years and older – 3,32%. Unorganized children made up 25%, organized children 13%, school students 22%, university students 2%, working adults 23%, and non-working adults 15%. A late appeal for medical assistance was identified among the sick (50.9% on the fourth day or later from the onset of symptoms). Contact with a measles-infected individual was observed in 34.10% of cases: 41,82% among children and 23,46% among adults. 82,47% of those infected were unvaccinated, 11,87% were vaccinated according to the schedule, 4,31% were vaccinated for epidemiological reasons, 1,15% received measles immunoglobulin, and 0.19% had previously had measles.

Conclusion: During the activation of the epidemic process, manifestations of the epidemic process take on characteristics typical of the pre-vaccination period, namely: pronounced winter-spring seasonality, high incidence among young children, including those under one year old, and significant focality. The high level of morbidity is sustained by unvaccinated individuals, and the late appeal for medical assistance contributes to the spread of measles.

The aim of this study was to provide an epidemiological characteristics of HIV infection spread among female population of the Siberian Federal District (SFD).

Materials and methods. The study was conducted on the territory of the constituent entities of the Siberian Federal District for the observation period from 2009 to 2023. The material for the study was the data from federal statistical observation forms No. 2, No. 61, No. 4 from all ten constituent entities of the SFD. The traditional algorithm of descriptive and evaluative observational epidemiological study was used.

Results. A total of 105,110 women (the average long-term rate was 75.4 cases per 100 thousand female population) were diagnosed with HIV in the Siberian Federal District from 2009 to 2023. A change in the trend of the epidemic process of HIV infection in the female population was observed – the period of growth and stabilization of incidence at a high level was followed by a trend towards a decrease in incidence since 2019. A 1.3-fold increase (from 34,8% in 2009 to 46,0% in 2023) in the proportion of women among new cases of HIV infection was noted alongside the decrease of the incidence of HIV infection in women in the Siberian Federal District. The share of heterosexual route of transmission of HIV among females increased to 81,6% cases. The age structure of newly diagnosed cases of HIV in women was characterized by an increase in the proportion of the age group over 35 years. The proportion of women of reproductive age among HIV cases decreased from 95,6% in 2009 to 80,9% in 2023. The decrease in the number of HIV-infected pregnant women and HIV detection rate in pregnant women to 1,16 cases per 1000 examined were noted.

Conclusion. The Siberian Federal District was characterized by a complicated epidemiological situation. Feminization of the HIV epidemic in modern conditions requires the revision of approaches to the implementation of the strategy of counteracting HIV infection at the regional level along with strengthening of preventive programs and measures that could prevent the spread of infection.

Aim. The aim of the study was to investigate molecular genetic diversity of Epstein-Barr virus (EBV) and human herpes virus 6B (HHV6B) and its influence on viral load in children of Nizhny Novgorod region during co-infection.

Materials and methods. 246 children with mononucleosis-like syndrome (MLS) and 118 healthy virus-carriers were examined. Based on serological and PCR studies, etiological agent in children with MLS and EBV and/or HHV6B carriage in healthy children were established, EBV and/or HHV6V DNA content in blood leukocytes was determined. EBV and HHV6B genotyping was performed based upon amino acid sequence of EBV LMP-1 protein fragment and nucleotide sequence of HHV6B U90 gene fragment.

Results. EBV + HHV6B manifest coinfection or healthy carriage was detected in 31% of children with MLS and 34% of healthy children, respectively. Circulation of 4 EBV genovariants (B95-8, NC, China-1, and MEDneg) and 4 HHV6B genovariants (GV1a, GV2a, GV2b, and GV2e) was detected under monoinfection, 11 combinations of virus genovariants – under coinfection. Under monoinfection and coinfection, EBV/B95-8, EBV/NC, HHV6B/GV2b and HHV6B/GV2e genovariats dominated. In children with MLS, EBV DNA content decreased by 230-276 copies/10⁵ cells under EBV/ B95-8 coinfection compared to monoinfection regardless of HHV6B genovariants. Under EBV/B95-8 + HHV6B/GV2b or EBV/B95-8 + HHV6B/GV2e coinfection HHV6B viral load decreased by 1.3 copies/10⁵ cells. Under EBV/B95-8 + HHV6B/GV1a and EBV/B95-8 + HHV6B/GV2e coinfection HHV6B and EBV DNA content interconnected in linear-logarithmic manner.

Conclusion. Molecular genetic polymorphism of EBV and HHV6B influenced on viral DNA content in blood leukocytes of children with MLS during coinfection.

Purpose: to analysis of mortality with pertussis in the Russian Federation during the rise in the incidence of 2023-2024.

Material and methods. Medical documents of 15 children who died in 2023-2024. with a posthumous diagnosis of pertussis from 11 regions of the Russian Federation, provided to the Reference Center for Pertussis Monitoring of the FBUN MNIEM named after G.N. Gabrichevsky Rospotrebnadzor. In the reference center, all samples of the sectional material were tested for the presence of B. pertussis DNA using the AmpliPrime ® Bordetella reagent kit and AmpliSenso ® Bordetella multi-FL reagent kit.

Results and discussion. Results and discussion. Among the causes of death, the main one is the severe course of pertussis in young children who have morphofunctional immaturity and lack of innate immunological protection against pertussis toxin. The immediate cause of death is damage to the bronchopulmonary system, complicated by the development of a septic process, which led to death.

Conclusion. In order to form immunological protection against pertussis in children aged 0-3 months, it is necessary to vaccinate pregnant women who do not have anti-pertussis IgG antibodies. In the early stages of the disease, when respiratory failure appears, it is advisable to use antitoxic methods of therapy.

The COVID-19 pandemic has led to global consequences, including Long-COVID. This term is used to refer to the symptoms of a new coronavirus infection that last more than 4 weeks, but less than 12 weeks from the onset of the disease. The most common symptoms are shortness of breath, cough, and general weakness. The risk group for the long-term course of COVID-19 includes patients with immunodeficiency. One of the reasons for the long-term persistence of symptoms is the persistence of the virus in the body. However, in 30–40% of cases, the results of the SARS-CoV-2 test turn out to be negative, which makes it difficult to make a diagnosis. In addition, patients with immunodeficiency against Long-COVID may develop opportunistic infections caused by reactivated opportunistic microflora against the background of lymphopenia. The presented clinical example demonstrates a case of Long-COVID infection complicated by the development of pneumocystis pneumonia in a patient with follicular lymphoma. Timely diagnosis and initiation of specific treatment made it possible to stabilize the patient’s condition and prevent the fulminant course of pneumocystis infection.

Meningococcal infection is characterized by an unpredictable course and a high mortality rate. Currently, doctors often have no previous experience of encountering and being wary of the disease. Missed opportunities due to late diagnosis and inadequate treatment significantly increase the likelihood of an unfavorable outcome. The objective of the study was to identify the most typical defects in providing medical care for generalized meningococcal infection based on the analysis of a clinical case of the disease in a young child. As a result of errors at the prehospital stage (ignorance of the peculiarities of the course of infection in children with a typical clinical picture, incorrect diagnosis, underestimation of the severity of the condition, transportation without monitoring vital signs and infusion support) and the initial stage in the hospital (delayed examination in the emergency room, lumbar puncture in the presence of contraindications, late initiation of respiratory support, incorrect tactics of anti-shock therapy), the chance for recovery could have been missed. The child developed critical complications (refractory septic shock, DIC syndrome, multiple organ failure), which led to a fatal outcome within the first day from the onset of the disease. The presented clinical case will help to increase the alertness of doctors to meningococcal infection and improve the quality of medical care. Following clinical recommendations will ensure adequate medical care at all stages, including the development of life-threatening conditions.

Herpes Zoster is a manifest disease caused by the reactivation of the type 3 herpes virus Varicella Zoster as a result of immunological or hormonal stress. Since 2021, the Russian Federation has a stable tendency to increase of Varicella incidence due to the beginning of a new long-term epidemic cycle. Since Herpes Zoster is secondary to Varicella, the recurrent form of infection has been subject to statistical monitoring in the Russian Federation since 2019. The analysis of the data obtained shows that Herpes Zoster is present in all age groups, including infants, and its incidence increases with age. The increase of Herpes Zoster incidence is caused not merely by the rise of Varicella, but also with the recent Covid-19 pandemia, since adults who have experienced a new coronaviral infection are more likely to catch Herpes Zoster. The article provides a clinical case of Herpes Zoster that developed in a 5-year-old child as a result of maternal Varicella at 30 weeks pregnant.