2019 – Surveillance for norovirus in Italy 2015-16 reveals the spread of GII.P16_GII.2 and GII.P16_GII.4 strains

Noroviruses are important gastro-enteric pathogens of humans. Novel epidemic noroviruses with GII.P16 polymerase and either GII.4 or GII.2 capsid types emerged worldwide in the late 2015 and in 2016. Hospital-based surveillance in Italy revealed increased prevalence of norovirus infection in children in 2016 (14.4% versus 9.8% in 2015) and the emergence of GII.P16 strains in the late 2016, with an overall yearly prevalence of 23.0%. The majority of the strains with a GII.P16 ORF1 showed a GII.2 capsid genotype (79.5%). The emergence and global spread of non-GII.4 noroviruses poses challenges for the development of vaccine strategies. A detailed overview of the 2015-2016 report is available on Plos ONE.