Zmienność genetyczna i rekombinacje norowirusów

The epidemic human gastroenteritis can be caused by different factors, including viruses. The World Health Organization reports the increase of foodborne and waterborne disease outbreaks as a result of the contamination of food and water by viruses, especially noroviruses. Norovirus (NoV) are classified in the Caliciviridae family, Norovirus genus. The genome contains a linear positive-sense, single-stranded RNA. Noroviruses are classified into 5 genogroups (GI-GV), and 31 genotypes: 8 GI, 19 GII, 2 GIII, 1 GIV and 1GV. The human noroviruses belong to GI, GII and GIV. Genetic analysis of norovirus strains has revealed nucleotide and amino acid mutations as well as the existence of recombination between strains. The intragenotype and intragenogroup recombination was recognized most frequently, but intergenogroup recombination was also identified in the last years. Recombination between human and animal strains has not yet been identified. The variants of NoVs GII.4 emerged to be the predominant strains in human populations as a result of norovirus evolution.