In December 2023, Rospotrebnadzor (Federal Service for Surveillance on Consumer Rights Protection and Human Wellbeing) announced an increase in the incidence of acute infections of the upper and lower respiratory tract caused by Mycoplasma pneumoniae. An increase in the incidence of respiratory mycoplasmosis, which lasts several months, is recorded every 5–7 years, which lasts several months, mainly in the autumn-winter period. Mycoplasma pneumonias, according to WHO, account for 10–20% of the total number of pneumonias.

BACKGROUND: This study was conducted to determine the characteristics of various viral respiratory pathogens spreading during the epidemic season 20212022 and the frequency of co-infection with SARS-CoV-2 and influenza. AIM: To assess the development of the influenza epidemic and frequency of cases of co-infection with respiratory pathogens in patients with acute respiratory viral infections between 2021 and 2022. MATERIALS AND METHODS: Traditional and hospital epidemiological surveillance methods for acute respiratory viral infections were used. RESULTS: The epidemic season of 20212022 was characterized by the early activity of the influenza A(H3N2) virus and the emergence and rapid spread of the omicron variant of SARS-CoV-2. The distribution of different respiratory pathogens during the epidemic season 20212022 was clearly traced: SARS-CoV-2 (18.8%) was predominant, followed by influenza viruses (10.6%) and pathogens of other acute respiratory viral infections (0.43.7%). With respect to influenza A (H3N2) and B viruses, the heterogeneity of their populations and drift variability in relation to vaccine strains were noted. DISCUSSION: The frequency of co-infection with various respiratory pathogens was low, i.e., it was no more than 0.1%according to traditional surveillance, and no more than 9.2% in the hospital surveillance. The rationale for updating the composition of influenza vaccines for the countries in the Northern Hemisphere for 20222023 season was identified. CONCLUSION: At present, early diagnosis of influenza is important given the availability of effective drugs with a direct mechanism of action for the prevention and treatment of this pathogen. Timely use of anti-influenza drugs will reduce the risks of a severe course, complications, and death, including co-infection with SARS-CoV-2.

Relevance. The long-term leadership of ARVI pathogens determines their significance in the damage caused to both health and the economy of the country. Aim. To identify the features of the structure of ARVI during the emergence and widespread spread of SARS-CoV-2. Materials and methods. The article uses methods used in epidemiological surveillance of acute respiratory viral infections. Results and discussion. The results of the diagnostic available ARVI pathogens monitoring during epidemic seasons 2018-2021 are presented. The tendency of greater engagement of aged group 15 y.o. and older in epidemic process by morbidity and hospitalization due to SARI was shown. 49 818 nasal swabs from patients with influenza infection, 36 044 – with ARVI and 59 062 – with SARS-CoV-2 were tested. The top three in the structure of ARVI were INF, HEV-D and HRSV (in the 2018–2019 season); INF, SARS-CoV-2 and HEV-D (2019–2020); SARS-CoV-2, HEV-D and HPIV/HCoV (2020–2021). The activity of viral pathogens also differed: for HPIV, HAdV, HEV-D, HMPV, a decrease in activity was noted during the appearance of SARS-CoV-2 (2019–2020) and some of its growth in the following season; in relation to HRSV and INF - a decrease in activity during the last two seasons, and for INF – extremely low activity in the 2020-2021 season; the activity of seasonal HCoV even increased slightly. The data of genetic analyses of SARS-CoV-2 positive samples showed the heterogeneity of its population with a representative of variants (Alfa, Delta) as well as endemic for Russia and Moscow variants only. The recommended composition of influenza virus vaccines for use in the 2021–2022 northern hemisphere influenza season and in the 2022 southern hemisphere influenza season are presented due to their drift changeability. Conclusions. SARS-CoV-2 was influenced by the activity of ARVI pathogens with the almost complete displacement of influenza viruses from the circulation in the period 2020–2021.

Objective. To identify the drift variability of influenza viruses during the period of epidemic rise in the incidence of acute respiratory viral infections in the period 2018-2019. The biological and molecular-genetic properties of epidemic strains isolated in certain territories of the Russian Federation were studied and compared with data from the countries of the Northern Hemisphere. Materials and methods. A range of laboratory diagnostic methods has been applied, including immune fluorescence, RT-PCR, sequencing, methods for determining sensitivity to influenza drugs and receptor specificity. Results and discussion. The proportion of influenza viruses was as follows: A (H1N1) pdm09 - 53 %, A (H3N2) - 46 %, B - about 1 %. Cases of severe acute respiratory infections have most often been associated with influenza A(H1N1) pdm09 virus. According to antigenic properties, isolated strains corresponded to the properties of vaccine viruses (A/Michigan/45/2015 - by 99.6 % and A/Singapore INFIMH-16-0019/2016 - by 86 %). The heterogeneity of influenza A virus strains population was revealed as regards individual mutations in hemaglutinin. The influenza B virus population was equally represented by both evolutionary lines (B/Victoria and B/Yamagata-like). Receptor specificity was favorable for the course and outcome of the disease. Among 70 studied epidemic strains, no strains resistant to anti-neuraminidase drugs, oseltamivir and zanamivir, were detected. The article presents WHO recommendations on the composition of influenza vaccines for the countries of the Northern Hemisphere for 2019-2020, provides data on cases of human infection with avian influenza viruses A(H5N1), A(H5N6), A(H7N9) and A(H9N2).

Relevance. Influenza viruses, having an extremely high variability of the genome and significant environmental plasticity, continue to maintain a potential threat to the biological safety of mankind. The purpose Aims of the work is to analyze the features of the epidemic season of2017-2018. Materials and methods . The collection of data on the incidence and laboratory diagnosis of influenza and ARVI was carried out in the framework of the epidemiological surveillance of the circulation of influenza viruses in the Russian Federation. The observation period was from 40 weeks (october) 2017 to 25 weeks (june) 2018. The typing of the isolates was performed in the reaction of inhibition of hemagglutination activity (HI) according to the standard technique with diagnostic sera to reference and epidemic influenza viruses. Results and discussion . The article presents the features of the influenza virus circulation n for the period from october 2017 to may 2018 in some territories of Russia, collaborating with D. I. Ivanovsky Institute of Virology. The epidemic season had its own peculiarities: delayed and long-term activity of three influenza viruses, the share participation of which was almost equal, with some dominance of the influenza A(H1N1)pdm09 virus by the end of the season. Morbidity rates for the total population were comparable with the last epidemic season, meantime the morbidity among schoolchildren was higher. The number of hospitalizations and lethal outcomes was lower and mostly was found in patients of 65 years and older. In patients with severe acute respiratory infection (SARI) influenza A(H1N1)pdm09 was detected more frequently (58%). The influenza A(H1N1)pdm09 and A(H3N2) viruses were antigenically similar to strains included in influenza vaccines, at the same time, 96% of the isolated strains of influenza B virus belonged to a different evolutionary line. Epidemic strains were sensitive to neuraminidase inhibitors, except for 5 strains of influenza A(H1N1)pdm09 virus, isolated from pregnant women. Conclusions. The activity of non- influenza ARI viruses was similar to preliminary epidemic seasons. Recommendations on the influenza vaccines composition for the Northern hemisphere for 2019-2020 season are presented as well.

The article presents the features of the influenza virus circulation for the period from October 2016 to May 2017 in some territories of Russia collaborating with the D.I. Ivanovsky Institute of Virology, Federal State Budgetary Institution "N.F. Gamaleya Federal Research Centre for Epidemiology and Microbiology", Ministry of Health of the Russian Federation. One of the 2016-2017 season's peculiarities in Russia and countries of the Northern hemisphere was the earlier start of an increase in ARD morbidity with peak indexes reached towards the end of December 2016 - January 2017. First, influenza A(H3N2) virus was predominant; then, it was followed by influenza B virus activity observed until the end of the season. The indexes of morbidity were higher than in the previous season, while the rates of hospitalization and mortality were lower, lethal cases being detected in persons 65 years old and older. Epidemic strains of influenza A(H3N2) virus belonged to 3c.2a genetic group, reference strain A/Hong Hong/4408/2014, and its subgroup 3c.2a1, reference A/Bolzano/7/2016, that are antigenically similar. Strains of influenza B virus were antigenically similar to the B/Brisbane/60/2008 vaccine virus. Strains were sensitive to oseltamivir and zanamivir. The share participation of non-influenza ARI viruses was similar to preliminary epidemic seasons. WHO has issued recommendations for influenza virus vaccines composition for 2017-2018 for the Northern hemisphere.

This paper presents the risk analysis of influenza virus infection in different age groups based on the prevalence and mortality rates. The epidemiological characteristics of the influenza virus circulation during postpandemic period are given. Main aspects of specific and non-specific influenza prevention are discussed. The efficacy of the interferon-based medication Grippferon in the prevention of influenza and acute respiratory viral infections (ARVI) is justified.

The aim of this study was to monitor in-hospital influenza virus infection during 2015 – 2016 epidemic flu season. Methods. Influenza virus was searched in patients hospitalized to a clinical infectious diseases hospital with acute respiratory viral infection during 2015 – 2016 influenza seasonal growth period using real-time RT-PCR method. Influenza virus was isolated from nasal swabs and autopsy material using canine kidney cell line. Other laboratory methods used included complete blood count, blood chemistry, blood gas analysis, urinalysis, and chest X-ray examination. Results. We examined 1,491 patients (375 adults, 546 children, 570 pregnant women with early gestational age). The proportion of hospitalized patients with confirmed A / H1N1pdm09 influenza in January – February, 2016, was 91.3%. A / H3N2 influenza virus was diagnosed in 5.7%, influenza B virus was isolated in 1.2% of patients. Totally, influenza virus was detected in 35.2% of samples, of which 30.1% of samples were obtained from adults, 33.7% of samples were obtained from children, and 39.8% of samples were obtained from pregnant women. The prevalent patient’s age was 15 to 60 years (76.1%) in adults and 3 to 6 years in children. Moderate course of influenza with a high rate of hospital admission was seen more often and was similar to that of 2009 – 2010 epidemic season. Proportion of patients with flu complicated by pneumonia was higher than that in 2014 – 2015 epidemic season. Bilateral lung injury was diagnosed in 48.4% of patients. High mortality in ICU (46.4%) was due to delayed start of antiviral treatment and late admission to a hospital. Conclusion. In 2015 – 2016 epidemic flu season, higher morbidity, complications and poor outcomes were related to predominant infection of A – H1N1pdm09 influenza virus. Risk factors of complications and death were delayed care seeking, lack of modern antiviral medications and comorbidity.

The aim of this study was to monitor in-hospital influenza virus infection during 2015 – 2016 epidemic flu season. Methods. Influenza virus was searched in patients hospitalized to a clinical infectious diseases hospital with acute respiratory viral infection during 2015 – 2016 influenza seasonal growth period using real-time RT-PCR method. Influenza virus was isolated from nasal swabs and autopsy material using canine kidney cell line. Other laboratory methods used included complete blood count, blood chemistry, blood gas analysis, urinalysis, and chest X-ray examination. Results. We examined 1,491 patients (375 adults, 546 children, 570 pregnant women with early gestational age). The proportion of hospitalized patients with confirmed A / H1N1pdm09 influenza in January – February, 2016, was 91.3%. A / H3N2 influenza virus was diagnosed in 5.7%, influenza B virus was isolated in 1.2% of patients. Totally, influenza virus was detected in 35.2% of samples, of which 30.1% of samples were obtained from adults, 33.7% of samples were obtained from children, and 39.8% of samples were obtained from pregnant women. The prevalent patient’s age was 15 to 60 years (76.1%) in adults and 3 to 6 years in children. Moderate course of influenza with a high rate of hospital admission was seen more often and was similar to that of 2009 – 2010 epidemic season. Proportion of patients with flu complicated by pneumonia was higher than that in 2014 – 2015 epidemic season. Bilateral lung injury was diagnosed in 48.4% of patients. High mortality in ICU (46.4%) was due to delayed start of antiviral treatment and late admission to a hospital. Conclusion. In 2015 – 2016 epidemic flu season, higher morbidity, complications and poor outcomes were related to predominant infection of A – H1N1pdm09 influenza virus. Risk factors of complications and death were delayed care seeking, lack of modern antiviral medications and comorbidity.