Noroviruses (NoVs) cause sporadic acute nonbacterial gastroenteritis in all age groups [12, 13] . NoVs are divided into five genogroups, GI to GV, of which GI and GII strains mostly affect humans [21] . Recently, NoV genotype GII-4 has been responsible for the majority of sporadic gastroenteritis cases and outbreaks [13] . The NoV genome consists of a single-stranded RNA of about 7.6 kb, organized into open reading frames (ORF 1-3). ORF-1 codes for the RNA-dependent RNA polymerase, and ORF-2 and -3 encode the two structural proteins VP1 and VP2 [10] .