Novel recombinant GII.P16_GII.13 and GII.P16_GII.3 norovirus strains in Italy

• Recombinant GII.P16 noroviruses were detected in children with enteritis in Italy.
• GII.P16_GII.3 recombinants had never been reported previously in Europe.
• GII.P16_GII.13 recombinants were detected in Italy 2 years before a large German outbreak.
• The study highlights the need for improved surveillance programs for noroviruses.

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.