title: Recombinant norovirus GII.g/GII.12 gastroenteritis in children.
abstract: Recombinant GII.g/GII.12 norovirus (NoV) strains emerged in 2008 in Australia and subsequently have been associated with gastroenteritis outbreaks worldwide. In the winter season 2009-2010 GII.12 strains caused 16% of the NoV outbreaks in the United States. During 2009-2010 we also identified GII.g/GII.12 strains during surveillance of sporadic cases of gastroenteritis in Italian children. Severity scores were calculated for the GII.g/GII.12 NoV infections using the Vesikari scale and in two out of three paediatric cases they exceeded the median value calculated for concomitant GII.4 infections. Upon sequence analysis, the Italian strains were found to be recombinant viruses and displayed different patterns of nucleotide polymorphisms. Phylodynamic analysis with other GII.g/GII.12 recombinants showed a high rate of evolution, comparable to the rates observed for GII.4 viruses. The mechanisms leading to worldwide emergence of GII.12 NoV strains in 2008-2010 are not clear. Monitoring of GII.12 NoV circulation is necessary to understand these mechanisms of evolution.
authors: Dipartimento di Scienze per la Promozione della Salute, G. D'Alessandro, Sezione di Microbiologia, Università di Palermo, via del Vespro 133, 90127 Palermo, Italy. giovanni.giammanco@unipa.it
authors: Giovanni M
authors: GM
authors: Giammanco
authors: Valentina
authors: V
authors: Rotolo
authors: Maria C
authors: MC
authors: Medici
authors: Fabio
authors: F
authors: Tummolo
authors: Floriana
authors: F
authors: Bonura
authors: Carlo
authors: C
authors: Chezzi
authors: Vito
authors: V
authors: Martella
authors: Simona
authors: S
authors: De Grazia
mesh_terms: D036022:Capsid Proteins / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks; D005759:Gastroenteritis / Q000453:epidemiology* / Q000821:virology*; D005838:Genotype; D006801:Humans; D007223:Infant; D007558:Italy / Q000453:epidemiology; D029322:Norovirus / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D010802:Phylogeny; D058974:Phylogeography; D011110:Polymorphism, Genetic; D012367:RNA, Viral / Q000235:genetics; D011995:Recombination, Genetic; D017422:Sequence Analysis, DNA
chemical_list: D036022:Capsid Proteins; D012367:RNA, Viral