Analysis of genetic diversity among noroviruses (Caliciviridae, Norovirus) across specific municipalities in the Sverdlovsk region during the period from 2022 to 2024

Human noroviruses are highly contagious pathogens that cause acute infectious gastroenteritis. The high frequency of mutational variability of noroviruses causes the formation of a wide range of new genovariants. In the Russian Federation, the incidence rate of norovirus infection in 2023 was 34.5, while the Sverdlovsk region is one of the subjects of the Russian Federation with the highest incidence rate. The objective of the study is to investigate the genetic diversity and conduct a phylogenetic analysis of norovirus isolates in the Sverdlovsk region for the period 2022–2024. Materials and methods. Biological samples of native fecal material from sick children with norovirus gastroenteritis (n = 719) were collected in individual municipalities of the Sverdlovsk region. All samples were analyzed by PCR of the genome region containing the ORF1/ORF2 region. Results. Analysis of the obtained data allowed us to identify 312 NVI pathogens. Molecular genetic study of the norovirus population of the Sverdlovsk region was conducted in two genetic groups GII and GI, with the GII genogroup detected 10 times more often than GI. Conclusion. For the first time in the Sverdlovsk region, a genetic analysis of the causative agents of human norovirus infection was carried out. It is known that in the countries of Europe, Asia, Africa, and in the islands of Oceania, GII is the prevailing genogroup, occurring 10 times more often than GI, which was confirmed by us during the analysis of norovirus populations in the Sverdlovsk region. The genotypic profile is mainly represented by norovirus genotypes GII.4 and GII.17, GII.7; rare genotypes GI.3, GI.5, GI.6, GI.2 were also identified. The organization of surveillance activities for the circulation of the norovirus population, using sequencing and phylogenetic analysis of data will provide an opportunity to test hypotheses about the common source of the infectious agent, as well as to determine transmission factors in foci of group morbidity with acute norovirus gastroenteritis. Key words: GI.3 genovariant, noroviruses, GII, sequencing, phylogenetic analysis