At present, at least two postulates are axiomatic in relation to the peculiarities of the course of foodborne botulism: botulism is an acute disease and does not turn into a chronic form, and that botulism does not cause persistent residual effects, and its clinical manifestations are reversible and do not lead to disability. However, if the first postulate does not raise objections, then the data of recent decades show that foodborne botulism, at least type A, being a disease of toxic genesis with almost single and simultaneous exposure to botulinum neurotoxin (BnT), can manifest itself for a long-term, up to 7 months or more, persistence of neurological symptoms with a natural decrease in working capacity. This state of affairs is due to the escape of the Type A light chain BcT from the influence of the ubiquitin-proteasome system, designed to destroy foreign proteins in the cell that enter the cytosol.
We analyzed in detail the dynamics of the reverse development of the clinical picture of botulism type A in 97 patients from the moment of their hospitalization to the 7^th month from the onset of the disease, among whom there were 59 patients with the initially severe course of botulism. There were 38 patients with a moderate course of the process. Patients received conventional therapy for botulism, including mandatory administration of 1 dose of intravenous antibotulinum serum. In 56 patients, for the purpose of nonspecific detoxification and restoration of intestinal propulsion function, the administration of saline enteral solution was added to the complex therapy at the hospital stage of treatment.
After 7 months, 34 out of 59 patients with severe forms of botulism (55.9%) and 27 out of 38 patients with a moderate course of the disease (77.1%) considered themselves fully recovered. Residual effects (persistent weakness, near vision impairment and other complaints that the patients associated with the hospital stage of the disease) occurred in 25 patients with severe forms of botulism and in 11 patients with moderate-severe forms of the disease.
It is concluded that the use of saline enteral solution (SAS) significantly reduces the time of repair, but it is not a panacea – the situation urgently requires not only the development of radically new approaches to treatment (including at the molecular level), but also the streamlining of the corresponding stages of dispensary observation and rehabilitation measures.

Despite almost universal detection of human herpesvirus 6 in general population (up to 90% of individuals are considered seropositive), human herpesvirus 6-associated diseases remain poorly explored. Knowledge of this microorganism has greatly increased over the recent 10 years. The review presents modern data on the biological properties of the human herpesvirus 6, highlights the epidemiology, variety of clinical forms and variants of the course of the disease, pathogenesis of the infection. Specific features of the human herpesvirus 6 were described. They determine difficulties of laboratory diagnostics of the infection and create problems in choosing treatment tactics.

The article presents modern views on the causes of the formation of drug-resistant HIV strains. The main reasons for the ineffectiveness of antiretroviral therapy are low patient adherence to treatment, lack of combination therapy, and high rate of viral recombination, which leads to the emergence of HIV drug resistance mutations. The data on HIV drug resistance mutations and their prevalence in different populations and in different age groups were analyzed. The most common HIV drug resistance mutations M184V and K103N are found in both acquired and transmitted HIV drug resistance, these mutations cause drug resistance to nucleoside and non-nucleoside reverse transcriptase inhibitors and are found in people living with HIV. Due to the high prevalence of drug-resistant strains, testing of people with HIV infection for HIV drug resistance mutations is necessary in cases of treatment failure and in patients in areas where the percentage of transmitted drug resistance is high.

The review is devoted to a challenging problem of modern infectology – viral gastroenteritis. The improvement of laboratory diagnostic methods has made it possible to identify a significant number of viral pathogens for which gastroenteritis has been established or is considered possible. The main pathogens are rotaviruses, noroviruses, sapoviruses, astroviruses, etc., while norovirus is the primary cause of sporadic cases and outbreaks of gastroenteritis.
Adults experience a predominantly mild and short-term self-limiting course of the disease. The main risk factor for severe course and unfavorable outcome of viral gastroenteritis in adults is any immunodeficiency condition, and therefore the patient’s age, concomitant diseases, and the use of immunosuppressive therapy should be taken into account.
Cancer patients and recipients of solid organ and blood stem cell transplantation are a particularly vulnerable group. In these patients, viral gastroenteritis often becomes chronic with a long period of viral shedding, which is frequently accompanied by the virus mutation. In turn, a viral infection can affect the course of non-infectious diseases and therapeutic approach, resulting in the need to discontinue immunosuppressive agents and causing post-transplant complications.

The combined course of the COVID-19 and the human immunodeficiency virus infection (HIV) has attracted the attention of researchers since the advent of COVID-19 due to the unpredictable course of the new disease in patients with immunosuppression.
Objective: To study the clinical and laboratory profile of patients with co-infection of HIV and COVID-19 based on disease outcomes.
Materials and methods: A retrospective analysis was conducted on the medical records of 310 HIV-infected patients admitted for COVID-19 treatment at the S.P. Botkin Clinical Infectious Diseases Hospital between 2020 and 2021. The first patients admitted to the hospital, whose hospitalization ended in death (n=147, 48%) and the first patients discharged after recovery from COVID-19 (n=163, 52%) were selected.
Results: At the onset of the pandemic, the infectious disease hospital admitted predominantly young patients (median (Q25; Q75) – 41 (37; 46) years), male (66%), with advanced stages of HIV infection (2B – 0.4%, 3 – 4.8%, 4A – 17.9%, 4B – 7.7%, 4C – 69.2%), not on antiretroviral therapy (73%), with low CD4+ T-lymphocyte counts (median (Q25; Q75) – 34 (7; 130) cells/mL), high HIV viremia (median(Q25; Q75) – 127,516 (1,568; 593,661) copies/mL), and the presence of current opportunistic infections (88%) and viral hepatitis (58%). Deceased patients were more frequently male (72% vs. 62%, χ2=4.935, p=0.026), admitted at later stages of COVID-19 (median (Q25; Q75) – 9 (2; 22) vs. 2 (1; 8) days, p<0.001), with predominantly severe disease progression (mild – 2%, moderate – 37%, severe – 53%, critical – 8% vs. mild – 21%, moderate – 79%, p<0.001), and died at a median of 12 days (median (Q25; Q75) – 12 (6; 25) days).
Among deceased patients, substance dependence (35% vs. 16%, p<0.001) and alcohol abuse (23% vs. 10%, p=0.003) were more common, as were complications such as pneumonia (62% vs. 43%, p=0.001), along with neurological, respiratory, cardiovascular, digestive, and genitourinary system involvement. Deceased patients exhibited more pronounced immunological abnormalities, higher HIV viremia, worse liver and kidney function markers, and more severe inflammatory changes in laboratory tests. The severity of COVID-19 was inversely correlated with absolute CD4+ T-lymphocyte counts (Spearman’s r = -0.278, p<0.001).
Conclusion: HIV-infected patients with COVID-19 who died during hospitalization were primarily admitted in severe or critical condition and were characterized by uncontrolled HIV progression due to lack of antiretroviral therapy, as well as substance and alcohol dependence.

Purpose of the study. To analyze the influence of comorbid pathology and age on the duration of inpatient treatment of adult patients with respiratory syncytial virus infection.
Materials and methods. An observational retrospective cross-sectional study was conducted of 3821 patients who were treated at the St. Petersburg State Budgetary Institution “Clinical Infectious Diseases Hospital named after. S.P. Botkin” with the main diagnosis B97.4 “Respiratory syncytial virus infection” for the period from January to December 20023. The influence of comorbid pathology and patient age on the duration of hospitalization was analyzed.
Results. A significant increase in the length of hospitalization in patients with respiratory syncytial virus was observed when combined with the following comorbid conditions: J12 “Viral pneumonia, not elsewhere classified”; J15 “Bacterial pneumonia, not elsewhere classified”; G40 “Epilepsy”; K75 “Other inflammatory diseases of the liver”; G62 “Other polyneuropathies”; B27 “Infectious mononucleosis.” In all cases p < 0.001. A relationship was found between the duration of hospitalization and the age of the patients – an increase in age by 2.718 times was accompanied by an increase in the duration of hospitalization by 10.60%.
Conclusion. The results obtained indicate age and comorbid pathology as significant predictors of increasing the duration of hospital treatment for respiratory syncytial infection.

Coronavirus infection caused by the SARS-CoV-2 virus is becoming one of the seasonal respiratory infections, which requires a decision on the continuation of vaccination for certain groups of people.
The purpose: To study the relationship between the clinical and immunological efficacy of vaccination and revaccination against COVID-19 in people of different ages, health conditions and occupational risk.
Research methods: Clinical observation of 258 adults who were vaccinated and revaccinated, as well as those with hybrid immunity, in a catamnesis for 2 years after vaccination with an assessment of the frequency and severity of confirmed coronavirus infection; laboratory examination of antibody titers (IgG to RBD fragment of S – protein) in blood serum over time by enzyme immunoassay; statistical data processing.
Results: The average antibody levels after vaccination were 353.1±35.9 BAU/ml, after the first revaccination 481.6±30.1 BAU/ml, and 2471.1±811.9 BAU/ml after the second revaccination (p<0.01 Student’s criterion). In individuals with hybrid immunity, after vaccination, 424.7±15.9 BAU/ml, after revaccination, 457±99.9 BAU/ml, respectively. The incidence among those vaccinated was 32.9% after primary vaccination and 21.9% after revaccination. The level of antibodies before the disease in patients was significantly lower than in those who did not get sick (pt<0.005). After revaccination, there were no significant differences in the level of antibodies before the disease in those who were ill and those who were not. Among people with hybrid immunity, 27.1% became ill after vaccination, also without significant differences in antibody levels before the disease in those who were ill and those who were not. Medical workers were significantly less likely to get sick than non-medical workers (16.7% and 66.7%, p<0.05). A relatively strong correlation (Pearson coefficient) of disease risk was confirmed, despite the presence of revaccination, in people over 60 years of age, compared with the young (k=0.418) and middle (k=0.432) age groups.
Conclusion: People with hybrid immunity have the same patterns in disease prevention as vaccinated and revaccinated people. The age over 60 determines the need for routine revaccinations. Medical workers are not at increased risk of infection if they have been vaccinated, revaccinated, or have developed hybrid immunity.

Study objective. To identify features of endobronchial symptoms, includingincluding whether there is a relationship between the characteristics of endobronchial findings and the predominance of a particular COVID-19 viral strain during specific time intervals.
Materials and methods. This study analyzed the results of 668 (100%) initial bronchoscopies performed in patients with COVID-19. All procedures were carried out in an endoscopy unit or intensive care setting. To assess the frequency of various events, the chi-square (χ2) test was used to evaluate the equality of proportions, with a significance level of p = 0.05.
Results. Two distinct time periods were provisionally identified, differing in endobronchial symptomatology. During the first period, the predominant circulating strains of COVID-19 were Alpha, Beta, Gamma and Delta. The onset of the second period approximately coincided with the dominance of the Omicron variant. In the first time period (278 primary bronchoscopies, 41.617%), inflammatory changes of the bronchial mucosa were mild, and hemorrhagic endobronchial syndrome was frequently observed. There were 4 cases (0.599%) of endobronchial ulcers requiring morphological and bacteriological verification. A purulent component of endobronchial inflammation was rare (14 cases, 2.096%) and occurred only in the presence of pre-existing bronchial obstructive disease. In the second time period, purulent inflammation became widespread, while hemorrhagic endobronchial syndrome nearly completely resolved. In most cases, bronchial obstruction during this period was directly attributable to COVID-19. All observed differences were statistically significant.
Conclusion. Endobronchial findings in patients with COVID-19 are nonspecific, lack pathognomonic features and generally align with the typical presentation of endobronchitis. Prior to the emergence of the Omicron variant, the endobronchial picture was characterized by mild inflammatory changes and hemorrhagic endobronchial syndrome. During the Omicron-dominant period, inflammatory changes intensified against the backdrop of an almost complete resolution of hemorrhagic endobronchial syndrome.

Purpose: comparative study of the informativeness of tumor markers GP-73 and AFP in the early diagnosis of hepatocellular carcinoma associated with liver cirrhosis of HCV etiology.
Materials and methods: In the study, 71 people were divided into 4 groups. The groups included patients with hepatocarcinoma, liver cirrhosis, chronic viral hepatitis C and healthy people. Healthy people made up the comparison group. In all patients, the study included the study of AFP and GP-7 protein values. Fibrotic changes in the liver tissue were studied based on the results of ultrasound and fibroscanning of the liver using the Fibroscan apparatus (France).
Results. In the verification of fibrosis (cirrhosis) and tumor lesions of the liver, the threshold values for GP-73 and alpha-fetoprotein (AFP) were 529.9 ng/l and 29 ng/ml, respectively. At the same time, the level of specificity of the GP-73 marker was equal to 86%, and sensitivity – 87%. In this case, the sensitivity and specificity rates of AFP were 71% and 79%, respectively. The level of negative diagnostic value of the GP-73 marker was 86.5%, and the level of positive prognostic value of GP-73 was 85.2%, while these AFP indicators were 72.6% and 76%, respectively.
Conclusion: The marker – serum protein Golgi-73 can be used as a reliable diagnostic marker for early verification of hepatocellular carcinoma associated with liver cirrhosis of HCV etiology.

Objective: The main objective of our work is to forecast the daily Infection Fatality Rate (IFR) index for Mpox, a disease that has posed significant challenges, particularly in African countries. Mpox has become a major public health concern due to its rapid spread and the strain it places on healthcare systems
Methods: In this paper, we use a hybrid approach to enhance the performance of traditional models. First, we apply the ARIMA model, which is more suitable for the task, and then we implement a noise reduction technique to further improve the results.
Results and discussions: We utilize four performance measures RMSE, MSE, MAE, and MAPE to evaluate the efficiency of our approach. By combining a denoising technique with ARIMA and integrating Singular Spectrum Analysis (SSA) with the ARIMA model, the SSA-ARIMA model demonstrates the best performance.
Conclusion: Forecasting the Infection Fatality Rate with an appropriate model provides a deeper understanding of this phenomenon, enabling authorities to effectively control and manage the risks associated with Mpox.

The hepatitis B virus (HBV) and the disease it causes have been actively studied for over 50 years. Recent estimates provided by the World Health Organization indicate that approximately 1 in 22 (4.5%) individuals with chronic hepatitis B have antibodies to the hepatitis D virus (HDV). The exact global prevalence of hepatitis D remains unclear due to differences in the sensitivity and specificity of diagnostic tests and the lack of standardized testing systems. In Russia, patients with hepatitis D are not subject to mandatory registration, and the routes of transmission are similar to those of hepatitis B. The disease is often diagnosed at a late stage (e.g., liver cirrhosis) due to the lack of widespread targeted screening for HDV antibodies among HBsAg-positive patients; about two-thirds of patients are unaware of their infection status. The study of socio-epidemiological and clinical-laboratory characteristics of HIV-positive patients co-infected with chronic hepatitis B and delta agent is of significant scientific and practical interest.
The aim of this study was to conduct a comparative analysis of socio-epidemiological and clinical-laboratory features of HIV-positive patients with chronic hepatitis B and delta agent compared to patients without HIV infection.
Materials and Methods. The study included 50 patients under observation at the city AIDS center, of whom 24 were diagnosed with HIV infection and chronic hepatitis B+D (Group 1), and 26 had chronic hepatitis B+D without HIV infection (Group 2). The mean age of the patients was 46.7±0.5 years, with 34 males (68.0%) and 16 females (32.0%).
Results and Discussion. The “social profile” of HIV-positive patients with chronic hepatitis B+D is characterized as follows: these individuals are typically intravenous drug users, lack higher education, are unemployed, not in formal marriages, and have an HIV infection duration of more than 8 years, often with stage 4A HIV infection according to the Russian classification. All patients in this group were receiving antiretroviral therapy, and the vast majority were also on antiviral therapy for chronic hepatitis.
Conclusion. Thus, HIV-positive patients with chronic hepatitis B+D significantly differ from those with chronic hepatitis B+D alone in terms of infection routes, education level, marital status, disease duration, aminotransferase levels, and hematological abnormalities. In both groups, severe liver fibrosis (F3-F4) predominated, accounting for a total of 70%. Antiviral therapy for chronic hepatitis B+D using bulevirtide represents a promising direction for the elimination of HBV and HDV and requires further study and analysis.

The level of vaccination of current and future health workers (students) is insufficient. Influenza vaccination is a measure aimed at preventing the disease itself, reducing the likelihood of adverse public health consequences, and minimizing the risk of involvement in a pandemic. Immunized health care workers interrupt the pathways of infection, are less susceptible to infection and further transmission to their immediate environment. In some cases, a health worker’s personal belief in the low effectiveness of the influenza vaccine may be reflected in low adherence to immunization among patients and like-minded colleagues. During the training phase, medical students should be motivated and convinced of the importance, efficacy and safety of vaccination.
Aim of the study: to analyze the current level of knowledge about influenza and influenza vaccination among undergraduate medical college students
Materials and methods. A sociological survey of undergraduate students of medical college conducted to analyze the current level of knowledge about influenza, attitudes towards influenza vaccination and to assess the respondents’ opinion about the effectiveness of vaccine prevention.
Results. More than 60% of students consider influenza vaccination to be a professional obligation. Five% of respondents believe that vaccination is more dangerous than the disease and is associated with side effects. The majority of respondents (36%) indicate that the post-vaccination period is not a cause for concern. 312 students (64.19%) vaccinated in the last 5 years. The multiplicity of vaccination among medical students amounted to: five cases – 175 (36.01%), 4 – 38 (7.82%), 3 – 37 (7.61%), 2 – 36 (7.41%), 1 – 26 (5.35%), not vaccinated – 24 (4.94%). It is also important to note this result of the survey: 269 students believe that they infected with influenza (55, 35%). Regarding the issues of influenza epidemiology, students demonstrated an average level of knowledge.
Conclusion. A sociological survey shows an average level of knowledge about influenza and vaccination among medical college students.

In recent years, there has been an increase in the incidence of scarlet fever in the world, especially in urban areas with higher population density and more developed transport infrastructure.
Objective: to study the clinical and epidemiological features of modern scarlet fever in children in St. Petersburg to assess the development trends of the epidemic process and the effectiveness of anti-epidemic measures.
Materials and methods: a retrospective analysis of the medical records of a children’s clinic for 2015-2023 was carried out. The diagnosis was established on the basis of clinical data and laboratory examination results: sowing of discharge from the pharynx for group A streptococcus (GAS), determination of group-specific antigens of GAS in discharge from the pharynx using a commercial test system.
Results: until 2018, the situation with the incidence of scarlet fever in the observed children remained stable with a downward trend. In 2019, another increase in the incidence began. The COVID-19 pandemic interrupted the negative trend, but after the lifting of restrictive measures in 2023, the incidence rate continued to increase. Over the entire multiyear period, the number of cases in foci was limited to 1-3 cases, and the duration of outbreaks did not exceed 1-2 months. Even during the lockdown, the characteristic winter-spring seasonality of scarlet fever remained. However, in 2023, an off-season peak in incidence was noted (March-May) with the formation of 23 foci in the service area of the children’s clinic, 18 of which were observed in preschool organizations. 91.2% of outpatient children suffered from mild scarlet fever, 8.8% – in a moderate form.
Conclusion: the epidemiology of scarlet fever has not changed significantly in the last decade. However, as the experience of the COVID-19 pandemic has shown, strict restrictive measures can significantly affect the incidence rate.

Aim of the study is to analyze the effect of remdesivir on the outcome of hospitalization in patients with COVID-19 during the period of the SARS-CoV-2 Delta predominance.
Material and methods. Among 11203 patients hospitalized from the pandemics start until June 2023 in the Minsk City Clinical Hospital for Infectious Diseases (Republic of Belarus), 3085 patients admitted during SARS-CoV-2 Delta variant predominance (June 2021 – January 2022). After applying exclusion criteria, the final cohort included 2940 patients, of whom 27,7% (813/2940) received remdesivir. Survival analysis was performed using Cox proportional hazards model, stratified by respiratory failure status at admission. The model included remdesivir and dexamethasone administration, symptom duration, comorbidities, sex, and age as covariates. P-values < 0,05 were considered to be statistically significant. Statistical analysis was performed in R v.4.4.1 with libraries: dplyr, tidyr, survival, survminer, matchit, gtsummary, forplo.
Results. The 28-day survival among patients with remdesivir use and respiratory failure at baseline was 86,5 (79,9-93,6)%, and 91,3 (85,6-97,4)% in patients without respiratory failure. In patients without remdesivir use, the 28-day survival in those with respiratory failure at baseline was 77,9 (69,4-87,5)%, and 85,6 (77,3-94,8)% in patients without respiratory failure. In the Cox proportional hazards model stratified by baseline respiratory failure status, remdesivir use was associated with significantly lower mortality (adjusted HR 0,58, 95% CI 0,39-0,88; p=0,01) after adjustment for sex, age, comorbidities, and dexamethasone administration.
Conclusion. Remdesivir was effective in decreasing inhospital mortality during the predominance of the SARSCoV-2 Delta variant.

Objective: To evaluate the role of a person’s temperament type in the formation of infectious diseases based on the results of a comprehensive multicenter study in various groups of military personnel and patients of military medical organizations.
Materials and methods: The results of a retrospective epidemiological analysis of data on infectious diseases in the groups of cadets of military educational organizations of St.Petersburg from among contract servicemen of the Armed Forces of the Russian Federation and the Socialist Republic of Vietnam, conscripts of military units of the Leningrad Military District and patients of the hemodialysis department of the S.M. Kirov Military Medical Academy for the period from 2018 to 2024 were used. The results of determining the type of temperament of individuals included in the study (n = 1714) were also used, using the personality questionnaire of G. Eysenck (EPI temperament test, option A), assessment of situational and personal anxiety using the Spielberg-Khanin Anxiety Inventory (STAI) and a health self-assessment questionnaire. The inclusion criterion was the presence of voluntary informed consent to participate in the study, the exclusion criterion was the absence or withdrawal of voluntary informed consent to participate in the study. Results: The predictable prevailing average long-term share of acute respiratory infections of the upper respiratory tract (ARI URT) was shown for all groups in the study period. It was found that among military cadets (both the RF Armed Forces and the SRV Armed Forces), individuals with the “sanguine” and “choleric” temperament types predominated. It was shown that the increased average annual incidence of ARI URT diseases had a weak correlation with the “melancholic” temperament type with a high level of personal and situational anxiety in the groups of military cadets of the RF Armed Forces and the SRV Armed Forces. It was found that in most cases (67.7% ± 5.2% of cases), military personnel of all groups with the “melancholic” temperament type with a high level of personal and situational anxiety noted the presence of frequent colds (more than 3 times a year) in childhood and adolescence. Behavioral risk factors were identified, although they do not directly affect the occurrence of infectious diseases, but play a significant role in maintaining epidemiological distress. A comparative analysis of the registered incidence of COVID-19 with the results of determining the type of temperament, levels of personal and situational anxiety of individuals in this group showed that it had a weak correlation with the type of temperament “choleric” and “sanguine” and low levels of situational and personal anxiety.
Conclusion: Thus, the role of temperament type and levels of personal and situational anxiety in the formation of infectious diseases is supportive and consists of their specific complex influence on human behavioral preferences associated with the epidemic situation and awareness, or, conversely, denial of the need to implement preventive and treatment measures.

Aim: Analyse changes in the intensity of humoral immunity against hepatitis B depending on the duration of the post-vaccination period to assess the effectiveness of vaccination and factors affecting it.
Materials and methods. The study was conducted by questionnaire method, during which an epidemiological history was collected from 409 persons aged 18 to 36 years who were not infected with hepatitis B virus. Absence of data on vaccination or presence of HBV markers was an exclusion criterion. Information about hepatitis B vaccination was confirmed by medical documentation, including form No. 156/u-93. All volunteers underwent vaccine audit, including determination of HBV vaccination status, presence of irregularities in the vaccination regimen, dosage, determination of the series of the administered preparation and date of vaccine administration.
Epidemiological and statistical methods of research (software product ‘WinPepi’ (version 11.65)) were used in the work. When assessing the statistical significance of differences in the compared epidemiological indicators, the 95% confidence interval was taken into account.
Results. Among the subjects aged 18-36 years (21.8 ± 2.7), timely vaccination (within the first 24 hours of life) was performed in 3.4% (n=13) of cases, 7.9% (n=30) were vaccinated in the first year of life and 9.9% (n=38) between one and two years of age. The highest percentage of vaccinated (42.1%) were children aged 7–11 years. The lowest vaccination coverage was determined among adults – 1.8%. Longterm post-vaccination immunity (17 years) was established in the subjects whose age of vaccination coverage was the first three years of life. In those vaccinated with the full scheme, intense immunity is maintained for over 20 years in 100% of cases. After revaccination, a high protective antibody titer was observed in the first five years and amounted to 101-1000 mIU/ml in 55.56% of cases and more than 1000 mIU/ml in 11.11%. A decrease in the protective antibody titer in those who received revaccination was noted after 11-15 years, when the proportion of non-immune individuals was 33.3%.
Conclusion. Long-term post-vaccination immunity was formed with vaccination coverage in the first three years of life. In those vaccinated with the full scheme, intense immunity was maintained for over 20 years. If the vaccination scheme is violated, the immunological response weakens and revaccination is required. The need for a booster dose occurs after 11-15 years.

The purpose of this study was to identify the genetic markers of Borrelia burgdorferi sensu lato, Rickettsia spp. SFG, Anaplasma phagocytophilum, Ehrlichia caffeensis/E. muris, Coxiella burnetii, and tick-borne encephalitis virus (TBE) in ixodes ticks and organs of wild small mammals collected and captured in 2020-2023 in the Kurortny district of St. Petersburg.
Materials and methods. Samples of ixodes ticks and organs of wild small mammals were examined by real-time PCR for the presence of genetic material of the causative agents of tick-borne infections. Ixodes ticks were collected and wild small mammals were captured in the Kurortny district of St.Petersburg in the period 2020-2023. The study was conducted using commercial test systems.
Results. The overall infection rates of ixodes ticks and wild small mammals in relation to B. burgdorferi s.l. were 23.7% and 5.2%, respectively; Rickettsia spp. SFG – 11.5% and 0.9%; E. chaffensis/ E. muris – 4.0% and 0.0%; A. phagocytophilum – 1.6% and 0.6%; C. burnetii – 3.3% and 5.2%; tick–borne encephalitis virus – 0.2% and 0.0%. The total infection rate of ticks with two or more pathogens was 6.6%, the most common combinations of mixed infections were: B. burgdorferi s.l. + Rickettsia spp. SFG, B. burgdorferi s.l. + C. burnetii and B. burgdorferi s.l. + E. chaffensis/ E. muris.
Conclusion. The results obtained indicate the existence of active natural foci of tick-borne infections in the Kurortny district of St. Petersburg and substantiate the expediency of continuous entomological and zoological monitoring and improvement of preventive measures against tick-borne infections.

The article presents a clinical case of successful application of high doses of normal human immunoglobulin in a patient with secondary hemophagocytic syndrome associated with adenovirus infection, who was in the clinic of infectious diseases of the Military Medical Academy (St. Petersburg). A 17-year-old patient with adenovirus type 55 infection developed multisegmental pneumonia accompanied by acute respiratory failure. Further progression of viral-bacterial pneumonia, prerenal renal damage, development of systemic inflammatory response syndrome was observed. The attending physician suspected secondary hemophagocytic lymphohistiocytosis. A decision was made to perform a sternal puncture. The results of bone marrow aspirate examination revealed characteristic signs of hemophagocytic lymphohistiocytosis: marked activation of macrophage-histiocytic system; 25.6% monocytes with vacuolized cytoplasm; macrophages with phagocytized platelets and normoblasts. The patient was diagnosed as “secondary hemophagocytic lymphohistiocytosis associated with viral infection” on the basis of HLH-2004 criteria (persistent fever, hyperferritinemia, morphologic picture of hemophagocytosis in the bone marrow, cytopenia, splenomegaly) and HScore (244 out of 337 points, 99% probability). Therapy with etoposide 100 mg once and intravenous immunoglobulin at a total dose of 3 g/kg was successful. At the control examination two months later, the patient had no complaints, clinical, laboratory and instrumental methods of examination revealed no abnormalities. No clinical cases of hemophagocytic lymphohistiocytosis associated with adenovirus type 55 have been previously described in the scientific literature.

Vaccination, as the most effective tool of preventive medicine, allows to control the epidemic process, thereby reducing morbidity, mortality and severe course of infections. The population’s refusal to undergo vaccination is often associated with fear of developing consequences after vaccination, for example, damage to the nervous system. A cause-and-effect relationship between neuropsychiatric disorders and vaccination still exists among specialists. n the presented clinical case, an assessment was made of the relationship between acutely developed neurological symptoms (hyperkinetic syndrome, motor tics) and the chickenpox vaccine administered the day before.