Acute norovirus gastroenteritis: epidemiology, clinical features, treatment and prevention

Achievements in the coverage of the child population with rotavirus vaccination in many countries have led to the fact that norovirus infection (NVI) is rapidly leading to the incidence of acute intestinal infections. NVI affects not only children but also the elderly, as well as patients with reduced immunity. NVI leads to a large number of hospitalizations and deaths, even though, in general, outbreaks of norovirus gastroenteritis are not severe and self-limited. Nevertheless, NVI's social and economic burden cannot be underestimated due to its ability to spread quickly and involve many patients, causing outbreaks in social institutions, schools, hospitals, and nursing homes. Thus 2023, 269 foci of group incidence of NVI were registered in the Russian Federation. The article presents the latest data on the epidemiology of NVI and the prevalence of norovirus genotypes; in particular, a sharp increase in the GII.17 genotype is noted. It is emphasized that the constant change in the genetic diversity of noroviruses and the emergence of new recombinant variants is a global trend that significantly complicates the creation of effective vaccines. Up-to-date information on the diagnosis and differential diagnosis of NVI is presented. The treatment section is devoted to all aspects of therapy and is based on the latest international and national clinical guidelines. The lack of causal therapy for NVI and the importance of timely administration of pathogenetic treatment, including probiotics, are emphasized. Data from experimental and clinical studies have shown that some probiotic strains, such as Saccharomyces boulardii CNCM I-745, which have an indirect antiviral effect, can significantly reduce the duration of diarrhea in children with acute gastroenteritis and the duration of hospitalization. The prospects for the development of various types of vaccines against norovirus are discussed, including vaccines based on non-replicating virus-like particles (VLP), vaccines based on recombinant adenoviruses, vaccines based on P-particles, and mRNA vaccines that form VLP. Prospects in the ongoing fight against NVI are associated with the development of specific methods of prevention (polyvalent vaccines) and treatment (antiviral drugs, microbiomemodulating therapy), the introduction of effective test systems for rapid diagnostics of NVI into routine practice, as well as genetic and immunological studies that will help to establish the subtle mechanisms of susceptibility to norovirus and the characteristics of the immune response to it. Key words: acute norovirus gastroenteritis, norovirus infection, dehydration, rehydration therapy, intestinal microbiome, probiotics, Saccharomyces boulardii CNCM I-745, children