Identification of the novel Kawasaki 2014 GII.17 human norovirus strain in Italy, 2015
Surveillance of noroviruses in Italy identified the novel GII.17 human norovirus strain, Kawasaki 2014, in February 2015. This novel strain emerged as a major cause of gastroenteritis in Asia during 2014/15, replacing the pandemic GII.4 norovirus strain Sydney 2012, but being reported only sporadically elsewhere. This novel strain is undergoing fast diversification and continuous monitoring is important to understand the evolution of noroviruses and to implement the future strategies on norovirus vaccines.
Sentinel hospital-based surveillance for norovirus infection in children with gastroenteritis between 2015 and 2016 in Italy
Noroviruses are one of the leading causes of gastro-enteric diseases worldwide in all age groups. Novel epidemic noroviruses with GII.P16 polymerase and GII.2 or GII.4 capsid type have emerged worldwide in late 2015 and in 2016. We performed a molecular epidemiological study of the noroviruses circulating in Italy to investigate the emergence of new norovirus strains. Sentinel hospital-based surveillance, in three different Italian regions, revealed increased prevalence of norovirus infection in children (<15 years) in 2016 (14.4% versus 9.8% in 2015) and the emergence of GII.P16 strains in late 2016, which accounted for 23.0% of norovirus infections. The majority of the strains with a GII.…
Novel recombinant GII.P16_GII.13 and GII.P16_GII.3 norovirus strains in Italy.
Novel norovirus strains are continuously emerging worldwide. Molecular investigation and phylogenetic analysis identified GII.P16 recombinant noroviruses from the stools of four Italian children with gastroenteritis. The capsid gene was characterized as either GII.13 or GII.3. The GII.P16_GII.13 Italian strains were closely related to German strains involved in a large outbreak in the second half of 2012 and the Italian strains are the first recorded occurrence of GII.P16_GII.13 in Europe.
Epidemiological dynamics of norovirus GII.4 variant New Orleans 2009.
Norovirus (NoV) is one of the major causes of diarrhoeal disease with epidemic, outbreak and sporadic patterns in humans of all ages worldwide. NoVs of genotype GII.4 cause nearly 80–90 % of all NoV infections in humans. Periodically, some GII.4 strains become predominant, generating major pandemic variants. Retrospective analysis of the GII.4 NoV strains detected in Italy between 2007 and 2013 indicated that the pandemic variant New Orleans 2009 emerged in Italy in the late 2009, became predominant in 2010–2011 and continued to circulate in a sporadic fashion until April 2013. Upon phylogenetic analysis based on the small diagnostic regions A and C, the late New Orleans 2009 NoVs circulati…
MLB1 Astrovirus in Children with Gastroenteritis, Italy
To the Editor: Astroviruses are notable agents of gastroenteritis in many mammalian and avian hosts. Astroviruses are nonenveloped RNA small, round, viruses (SRVs) with a single-stranded, positive sense RNA of 6.1 to 7.9 kb (1). The genome contains 2 nonstructural genes, open reading frame (ORF) 1a and 1b, and a capsid gene, ORF2, with short 5′ and 3′ untranslated regions. Human astroviruses, a major cause of gastroenteritis, are classified in the human astrovirus species, comprising 8 serotypes (1). Recently, astroviruses genetically unrelated to canonical human astroviruses have been identified in human stools in several countries. These unusual astroviruses form 2 main genetic clades. On…
Analysis of GII.P7 and GII.6 noroviruses circulating in Italy during 2011-2016 reveals a replacement of lineages and complex recombination history.
Noroviruses are important human enteric pathogens and monitoring their genetic diversity is important for epidemiological surveillance, vaccine development, and understanding of RNA viruses evolution. Epidemiological investigations have revealed that genogroup II, genotype 6 noroviruses (GII.6) are common agents of gastroenteritis. Upon sequencing of the ORF2 (encoding the viral capsid), GII.6 viruses have been distinguished into three variants. Sentinel hospital-based surveillance in Italy revealed that GII.6 noroviruses were the second most common capsid genotype in 2015, mostly in association with a GII.P7 ORF1 (encoding the viral polymerase). Upon molecular characterization of the ORF1 …