Identification of a novel intra-genotype reassortant G1P[8] rotavirus in Italy, 2021.

Rotaviruses G1P[8] are epidemiologically relevant and are targeted by vaccines. The introduction of vaccines has altered rotavirus epidemiology. Hospital-based surveillance conducted in Sicily, Italy, showed a progressive decline in rotavirus prevalence since 2014, along with an increasing vaccine coverage (63.8% in 2020), and a marked decrease in circulation of G1P[8] strains. Surprisingly in 2021, G1P[8] viruses accounted for 90.5% (19/21) of rotavirus infections. This study aimed to understand if the increased activity of G1P[8]s was related to virus-related peculiarities. In 2021, 266 patients <15 years of age were hospitalized with acute gastro-enteritis (AGE) and included in rotavirus surveillance. VP7/VP4 genotyping and sequence data were generated from all rotavirus-positive samples. The genetic make- up of G1P[8] rotaviruses was investigated by full-genome sequencing. Peculiar G1P[8] rotaviruses, with VP7 and VP4 belonging to novel sub-lineages, circulated in 2021, accounting for 76.2% (16/21) of all rotavirus infections. On full-genome analysis, the novel G1P[8] variant displayed an intra-genotype (Wa-like) reassortant constellation, involving G12 and G1 strains, into a unique arrangement never observed before. The novel G1P[8] variant showed peculiar aa substitutions in 8-1 and 8-3 epitopes of the VP4 with respect to the Rotarix strain. Prompt identification of virus variants circulating in human population is pivotal to understanding epidemiological trends and assessing vaccine efficacy.

Informations de copyright

Copyright © 2024. Published by Elsevier Ltd.

Déclaration de conflit d'intérêts

Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.