ABSTRACT
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. © Burtseva EI, et al.
ABSTRACT
Background: The effectiveness of barrier function of the respiratory mucosa largely depends on interferons type I (IFNs-α/β) and type III (IFNs-λ). The IFNs-λ forms the first level of innate immune protection. The single-nucleotide polymorphisms (SNPs) affecting IFN- λ3 production were found previously. The study aimed to investigate a putative association of SNPs rs8099917 T/G located upstream IFNL3 gene and rs12979860 C/T within IFNL4 gene with a risk of pneumonia developing after infection with respiratory viruses. Methods: The nasopharyngeal swabs, lavages, and blood samples from 318 patients infected with respiratory viruses were analyzed. Of these, 168 participants were shown to have community-acquired pneumonia, while the rest patients were diagnosed with bronchitis. The respiratory virus genomes were detected by real-time polymerase chain reaction (PCR) using commercially available kits. The DNA samples from all patients were used to detect SNPs rs8099917 T/G and rs12979860 C/T by real-time PCR using a commercially available kit. COVID-19 morbidity and mortality data were obtained from the WHO website. Results: No association was found between different rs8099917 allelic variants and the development of pneumonia. The rs12979860 TT genotype was significantly more often detected in patients with pneumonia (p = 0.039;OR = 2.400;95% CI 1.310 - 3.706). IFN-λ3 production has been early found to be maximal with rs12979860 TT genotype. An association was established between rs12979860 T allele frequency and COVID-19 mortality rate in 13 countries. Conclusions: The rs12979860 TT genotype is a genetic marker of increased risk of pneumonia after infection with respiratory viruses. High T allele frequency may be an indicator of a higher COVID-19 mortality rate. Patients with rs12979860 TT genotype have an increased risk of developing COVID-19 pneumonia.