1. Epidemiological and Clinical Features of SARS-CoV-2 Variants Circulating between April–December 2021 in Italy
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Alessia Lai, Annalisa Bergna, Carla Della Ventura, Stefano Menzo, Bianca Bruzzone, Fabio Sagradi, Francesca Ceccherini-Silberstein, Alessandro Weisz, Nicola Clementi, Gaetano Brindicci, Ilaria Vicenti, Lolita Sasset, Sara Caucci, Benedetta Corvaro, Silvia Ippoliti, Carla Acciarri, Vanessa De Pace, Leonardo Lanfranchi, Maria C. Bellocchi, Giorgio Giurato, Roberto Ferrarese, Antonella Lagioia, Daniela Francisci, Martina L. Colombo, Samuel Lazzarin, Matilde Ogliastro, Maria R. Cappelletti, Marco Iannetta, Francesca Rizzo, Carlo Torti, Maurizio Fumi, Morena d’Avenia, Stefano Brusa, Francesca Greco, Angela Menchise, Vittoria Letizia, Emilia Vaccaro, Carmen R. Santoro, Chiara Fraccalvieri, Sophie Testa, Luca Carioti, Teresa Rocco, Annalisa Saracino, Annamaria Cattelan, Massimo Clementi, Loredana Sarmati, Agostino Riva, Massimo Galli, Spinello Antinori, Gianguglielmo Zehender, and SARS-CoV- ITALIAN RESEARCH ENTERPRISE–(SCIRE) Collaborative Group more...
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variants circulation ,SARS-CoV-2 ,Italy ,epidemiology ,Microbiology ,QR1-502 - Abstract
SARS-CoV-2 is constantly evolving, leading to new variants. We analysed data from 4400 SARS-CoV-2-positive samples in order to pursue epidemiological variant surveillance and to evaluate their impact on public health in Italy in the period of April–December 2021. The main circulating strain (76.2%) was the Delta variant, followed by the Alpha (13.3%), the Omicron (5.3%), and the Gamma variants (2.9%). The B.1.1 lineages, Eta, Beta, Iota, Mu, and Kappa variants, represented around 1% of cases. There were 48.2% of subjects who had not been vaccinated, and they had a lower median age compared to the vaccinated subjects (47 vs. 61 years). An increasing number of infections in the vaccinated subjects were observed over time, with the highest proportion in November (85.2%). The variants correlated with clinical status; the largest proportion of symptomatic patients (59.6%) was observed with the Delta variant, while subjects harbouring the Gamma variant showed the highest proportion of asymptomatic infection (21.6%), albeit also deaths (5.4%). The Omicron variant was only found in the vaccinated subjects, of which 47% had been hospitalised. The diffusivity and pathogenicity associated with the different SARS-CoV-2 variants are likely to have relevant public health implications, both at the national and international levels. Our study provides data on the rapid changes in the epidemiological landscape of the SARS-CoV-2 variants in Italy. more...
- Published
- 2022
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