Epidemiology and Infectious Diseases. Current Items

Objective. The analysis of some epidemic index of rises of COVID-19 morbidity in Russia in March 2020 – November 2023.

Materials and methods. Date from Internet resources Stopcoronavirus.rf, Yandex DataLens [Yandex DataLensс, Gogov.ru portal], and data of research, published in foreign and domestic scientist publication is used for conducting analyses.

Results. The cause of existing of rises of COVID-19 morbidity in Russia are or season’s factor (second, forth, seventh, and ninth rises) or spreading of new variants of SARS-CoV-2 virus. The genovariants of SARS-CoV-2 virus may essentially difference on epidemic characteristics of caused disease. The genovariant «Delta» is the most pathogenicity from all known variants of SARS-CoV-2 virus. the genovariant «Omicron» is the most transmissive. The maximum number of COVID-19 cases per day (203949 certificated cases) was registered during fifth rise of morbidity (dominant agent-BA.2 line of «Omicron» genovariant). The most highly index of lethality were registered during third (3,45%) and fourth (3,51%) rises of morbidity (dominant agent – the «Delta» genovariant).

Conclusion. The nine rises of morbidity were registered from the beginning of COVID-19 epidemic in Russia (March 2020). The epidemic characteristics of next rise of morbidity depend mainly on from dominant agent of SARS-CoV-2 virus and herd immunity. The main direction of natural evolution of SARS-CoV-2 virus during COVID-19 pandemic is the existing of virus genovariants with high transmissivity level, but lower pathogenicity. From beginning of 2022 the most wide spread variant of SARS-CoV-2 virus was omicron genovariant (B1.1.529) and their sublines BA.2, BA.2.75, («Centaur»), BA.5 («Czerber»), XBB.1.5 («Kraken»), XBB 1.16 («Arktur»), BA.2.86, («Pirola»). The reduction for every new rise of morbidity (began with sixth) the index of mean day number of cases in common with countermand of mass vaccination define continuous reduction of herd immunity against COVID-19 аnd this disease will be endemic in Russia.

Objective. Assessment of the epidemiological and epizootological situation of tick-borne infections (TBI) in the Tula Region over a 10-year period.

Materials and methods. The forms of federal statistical observation, accounting materials of the Center for Hygiene and Epidemiology in the Tula Region, Russian Federal Service for Supervision of Consumer Rights Protection and Human Well-Being, and reporting materials of the Office of the Russian Federal Service for Supervision of Consumer Rights Protection and Human Well-Being for the Tula Region for 2013–2022 were used.

Results. In recent years, there has been an increase in the registration of cases of population appeals regarding the bite of Ixodes ricinus and Dermacentor reticulatus ticks in the Tula Region, the number of which exceeded the average for the Russian Federation in 2021–2022. A third of the victims are minors. Among the TBI in the Tula Region, mainly cases of erythematous form of ixodid tick-borne borreliosis (ITBB) are registered in 18 municipalities out of 26. Tick bites occurred both in natural biotopes and in anthropurgic foci. ITTB was more often registered in the adult urban population aged 50–69 years. Infection with borrelia in I. ricinus ticks collected in natural biotopes and removed from people in the Tula region was noted in most areas. Every year, ticks of this species are found to contain agents of granulocytic anaplasmosis and monocytic ehrlichiosis, although there are no confirmed cases of human infection. There is evidence of the involvement of D. reticulatus ticks in the circulation of TBI pathogens.

Conclusion. Ixodid ticks provide circulation of pathogens in natural foci of TBI over a large area of the region and are the main source of these pathogens for humans. The results of the work indicate the relevance and need for in-depth clinical and epidemiological studies of tick-borne infections in the Tula Region.

Objective. Evaluation of the frequency of detection of Epstein–Barr virus (EBV) DNA and its quantitative assessment in biological material samples using real-time PCR; description of the clinical and radiological picture of pulmonary pathology with high concentrations of EBV DNA in respiratory substrates and establishment of the relationship between the concentration of EBV DNA in biological materials and EBV-related lung damage in HIV-infected patients.

Materials and methods. The article presents the results of clinical follow-up and analysis of case histories of 5485 hospitalized HIV-infected patients, 1954 of whom had lung damage. Samples of whole blood (510), sputum (35), bronchoalveolar lavage fluid (BALF) (1026), pleural fluid (PF) (38), bronchial biopsy (BB) (133), lymph nodes (LN) (57) were examined by the RT-PCR method with the determination of EBV DNA, M. tuberculosis, Pn. jirovecii, Candida fungi, cytomegalovirus (CMV), human herpes virus 6a/b in qualitative and quantitative formats. The search for associations between the number of EBV DNA copies in biomaterials and EBV-related organ damage (in particular, lungs) was performed using ROC analysis.

Results. The frequency of EBV DNA detection in biomaterials exceeded 55%, the sensitivity was 84.6–100% with a specificity of 5.3–35.4%. Diagnostically significant concentrations of EBV DNA in blood leukocytes, EBV DNA concentrations in BALF, BB, PZ, LN samples with 95% and 99% probability confirming the EBV nature of pulmonary pathology, as well as low quantitative values of EBV DNA in biosamples with 95–99% probability excluding the EBV etiology of lung damage in patients with HIV infection were determined. EBV-related organ damage was detected in 379 patients. Clinical manifestations and radiographic data of 172 patients with EBV-related pulmonary pathology are described.

Conclusion. Quantitative determination of EBV DNA in biomaterials is of crucial importance for confirming the EBV nature of lung damage. Along with the «classical» pathogens of secondary diseases in HIV-infected patients, EBV can be the cause of severe organ pathology.

Objective. Evaluation of approaches to the prevention of varicella in newborns at risk of perinatal infection.

Materials and methods. The study included 27 pregnant and postpartum women with varicella, 18 newborns born to mothers with confirmed varicella. In venous/umbilical cord blood samples, specific antibodies (Ig) of M and G classes to antigens of human herpes virus type 3 (HHV-3) were determined by ELISA and quantitative determination of HHV-3 DNA by RT-PCR. HHV-3 DNA in a smear sample from the oropharyngeal mucosa of newborns was also determined by RT-PCR. An examination of 27 pregnant and postpartum women and 18 newborns was conducted at the time of birth. All newborns were followed-up.

Results. Specific anti-HHV-3 IgM and IgG in pregnant and postpartum women were determined by the 6th–7th day of the disease. Transplacental transmission of IgG occurred by the 9th day of the mother’s illness. Of the 29 newborns, 1 was diagnosed with neonatal varicella, and 2 with postnatal varicella. Mothers of all newborns with varicella were not prescribed antiviral therapy with acyclovir in a timely manner. Anti-HHV-3 IgM was detected in a child born on the 17th day of the mother’s illness, which allowed diagnosing an asymptomatic form of variella. HHV-3 DNA was detected in a smear sample from the oropharyngeal mucosa at birth in 5 of 13 healthy children born through the natural birth canal. This group of newborns was breastfed from the 3rd day of life and received normal human immunoglobulin (NHI) for intravenous administration for prophylactic purposes.

Conclusion. The importance of antiviral therapy for pregnant women with varicella, the administration of NHI to newborns, and the advisability of breastfeeding in order to enhance passive immunity were determined.

Objective. Determination of the features of the NKT cell phenotype in patients with chronic hepatitis C (CHC) with varying fibrosis degrees before and after treatment with direct-acting antiviral drugs (DAAs).

Materials and methods. A total of 112 patients with CHC aged 44.2 ± 7.4 years were examined. The diagnosis was confirmed by PCR-RNA of the hepatitis C virus (HCV). To diagnose liver fibrosis, the shear wave transient elastometry method was used. Patients with CHC were treated with DAAs, Sofosbuvir 400 mg/day and Velpatasvir 100 mg/day, for 12 weeks. Depending on the liver fibrosis degree before the start of DAA treatment, patients with CHC were divided into 3 groups: with fibrosis F0-F1, with fibrosis F2 and with fibrosis F3–F4. All patients were examined before and after DAA treatment. As a control, 23 healthy people of the same age range were examined. The study of the phenotypic composition of NKT cells was performed by flow cytometry.

Results. The features of the NKT cell phenotype which characterize the functional activity of this fraction of lymphocytes were established. Changes in the NKT cell phenotype in patients with CHC depended on the examination period (before or after DAA treatment). Before treatment, against the background of a high viral load and ALT activity in the blood, the NKT cell phenotype slightly depended on the fibrosis degree and was characterized by a high level of expression of the CD57 receptor on the membranes of total NKT cells, as well as lymphocytes of this fraction expressing CD8, CD62L and CD94 markers. After treatment, patients achieved complete HCV clearance. Against this background, the features of the NKT cell phenotype began to depend more significantly on the fibrosis degree, while characterizing the preservation of inflammatory imprinting in the immune system. The most significant changes in the NKT cell phenotype were found in patients with fibrosis F3–F4, which were expressed in a reduced number of CD62L⁺NKT cells, the maximum level of CD73⁺NKT cells, and the preservation of a high level of CD57 expression on the surface of CD8⁺ and CD94⁺NKT cells.

Conclusion. It is necessary to develop a differentiated approach to the treatment of liver fibrosis and methods for predicting the development of hepatocellular carcinoma in patients with a high degree of fibrosis after successful antiviral therapy.

Objective. Determination of the causes and conditions for the spread of leptospirosis and the emergence of human diseases in 2022–2023 in the non-endemic Khanty-Mansi Autonomous Okrug (Yugra).

Materials and methods. A retrospective analysis of the incidence of leptospirosis in humans and animals, a comprehensive survey of the population (n = 66), argicultural and domestic animals (n = 50), small mammals and birds (n = 1292) was conducted, operational information on patients with leptospirosis and contacts at risk of infection was obtained.

Results. Over the past 10 years, the Yugra Veterinary Service reported five farms with unfavorable conditions for leptospirosis in cattle. Isolated cases of human disease were registered in 1995 and 2008-2010. After a long period of epidemiological well-being, an imported case of leptospirosis was detected in 2021. Since 2019, there has been a significant increase in the epizootic activity of natural foci of leptospirosis in Yugra; in the summer-autumn season of 2022, the infection rate of carriers according to PCR results was 13.2 ± 3.3%. Specific antibodies were detected in 86.5 ± 5.6% of cases in deer, which, during nomadic grazing, could be infected in several natural foci at once. Circulation of leptospira of the Australis, Autumnalis, Bataviae, Canicola, Grippotyphosa, Hebdomadis, Icterohaemorrhagiae, Sejroe, Tarassovi serogroups was detected.

Conclusion. The season of detection of sick people (Novemb–March) indicates infection in anthropurgic foci. The results of the studies indicate a wide distribution of leptospirosis among deer. The seroscape of specific anti-leptospirosis antibodies in animals in anthropurgic and natural foci confirms possible cross-infection.

The article analyzes descriptions of rare clinical observations of various diseases published in periodical medical literature, where the etiological role of various infections is presented in a presumptive or evidentiary form. Criteria for orphan pathology of infectious genesis are proposed. The role of infectious pathology in the formation of orphan diseases is substantiated. It is proposed to develop an additional list of orphan diseases of a new format with its submission to the Ministry of Healthcare of the Russian Federation. The need to develop educational programs for additional training of doctors of various profiles on these diseases is substantiated.

Acute respiratory viral infections (ARVI) are among the most common infectious diseases in the world. A promising direction of pathogenetic therapy is the modulation of the immune response and anti-inflammatory action. In this aspect, sodium aminodihydrophthalazinedione (Galavit^®) is of interest.

Objective. Evaluation of the effectiveness of «Galavit^®», sublingual tablets, in the complex therapy of ARVI, including influenza, in adult patients by the effect on the duration and severity of the main symptoms of the disease.

Material and methods. A multicenter, randomized, double-blind, placebo-controlled study in parallel groups was conducted. 218 adult patients with a diagnosis of mild-to-moderate ARVI (including influenza) were included. Two groups of 109 patients who received Galavit^® (main group) or placebo (control group) as part of combination therapy for 10 days were randomly formed. By the 5th day of treatment, the proportion of patients whose body temperature had returned to normal ≤ 36.9 °C was determined. Secondary efficacy endpoints were the proportion of patients who achieved resolution of the main symptoms; duration of fever nd cough; time of disappearance of intoxication symptoms; change in patients’ assessment of their condition.

Results. In the main group, statistically significant improvement in the primary and secondary efficacy endpoints was achieved. By the 5th day of treatment, the temperature had returned to normal in 75.2% of patients (according to assessment data during the visit and diary) in the main group, compared with 25.7% of patients (according to data recorded during a visit to the center) and 31.2% (according to the patient’s diary) in the control group (р < 0.001). A significant reduction in the duration of fever, the time for intoxication symptoms dissolution, and the reverse development of catarrhal symptoms was noted in patients of the main group. The drug was characterized by good tolerability, comparable to placebo.

Conclusion. The results of the study confirmed the efficacy and safety of Galavit^® for the treatment of acute respiratory viral infections and influenza when used in combination therapy in adult patients.