Suppression of a SARS-CoV-2 outbreak in the Italian municipality of Vo’
2020; Nature Portfolio; Volume: 584; Issue: 7821 Linguagem: Inglês
10.1038/s41586-020-2488-1
ISSN1476-4687
AutoresEnrico Lavezzo, Elisa Franchin, Constanze Ciavarella, Gina Cuomo-Dannenburg, Luisa Barzon, Claudia Del Vecchio, Lucía Rossi, Riccardo Manganelli, Arianna Loregian, Nicolò Navarin, Davide Abate, Manuela Sciro, Stefano Merigliano, Ettore De Canale, Maria Cristina Vanuzzo, Valeria Besutti, Francesca Saluzzo, Francesco Onelia, Monia Pacenti, Saverio Giuseppe Parisi, Giovanni Carretta, Daniele Donato, Luciano Flor, Silvia Cocchio, Giulia Masi, Alessandro Sperduti, Lorenzo Cattarino, Renato Salvador, Michele Nicoletti, Federico Caldart, G. Castelli, Eleonora Nieddu, Beatrice Labella, Ludovico Fava, Matteo Drigo, Katy A. M. Gaythorpe, Alessandra Rosalba Brazzale, Stefano Toppo, Marta Trevisan, Vincenzo Baldo, Christl A. Donnelly, Neil M. Ferguson, Ilaria Dorigatti, Andrea Crisanti, Kylie E. C. Ainslie, Marc Baguelin, Samir Bhatt, Adhiratha Boonyasiri, Olivia Boyd, Lorenzo Cattarino, Constanze Ciavarella, Helen Coupland, Zulma M. Cucunubá, Gina Cuomo-Dannenburg, Bimandra A. Djafaara, Christl A. Donnelly, Ilaria Dorigatti, Sabine van Elsland, Richard G. FitzJohn, Seth Flaxman, Katy A. M. Gaythorpe, Will D. Green, Timothy B. Hallett, Arran Hamlet, David Haw, Natsuko Imai, Benjamin Jeffrey, Edward Knock, Daniel J. Laydon, Thomas A. Mellan, Swapnil Mishra, Gemma Nedjati‐Gilani, Pierre Nouvellet, Lucy Okell, Kris V. Parag, Steven Riley, Hayley A Thompson, H. Juliette T. Unwin, Robert Verity, Michaela Vollmer, Patrick Walker, Caroline E. Walters, Haowei Wang, Yuanrong Wang, Oliver J. Watson, Charles Whittaker, Lilith K. Whittles, Xiaoyue Xi, Neil M. Ferguson,
Tópico(s)COVID-19 Clinical Research Studies
ResumoOn 21 February 2020, a resident of the municipality of Vo', a small town near Padua (Italy), died of pneumonia due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection1. This was the first coronavirus disease 19 (COVID-19)-related death detected in Italy since the detection of SARS-CoV-2 in the Chinese city of Wuhan, Hubei province2. In response, the regional authorities imposed the lockdown of the whole municipality for 14 days3. Here we collected information on the demography, clinical presentation, hospitalization, contact network and the presence of SARS-CoV-2 infection in nasopharyngeal swabs for 85.9% and 71.5% of the population of Vo' at two consecutive time points. From the first survey, which was conducted around the time the town lockdown started, we found a prevalence of infection of 2.6% (95% confidence interval (CI): 2.1–3.3%). From the second survey, which was conducted at the end of the lockdown, we found a prevalence of 1.2% (95% CI: 0.8–1.8%). Notably, 42.5% (95% CI: 31.5–54.6%) of the confirmed SARS-CoV-2 infections detected across the two surveys were asymptomatic (that is, did not have symptoms at the time of swab testing and did not develop symptoms afterwards). The mean serial interval was 7.2 days (95% CI: 5.9–9.6). We found no statistically significant difference in the viral load of symptomatic versus asymptomatic infections (P = 0.62 and 0.74 for E and RdRp genes, respectively, exact Wilcoxon–Mann–Whitney test). This study sheds light on the frequency of asymptomatic SARS-CoV-2 infection, their infectivity (as measured by the viral load) and provides insights into its transmission dynamics and the efficacy of the implemented control measures. The authors describe the prevalence of SARS-CoV-2 infection, viral load and the frequency of symptomatic versus asymptomatic and presymptomatic infection in an Italian town, before and after a strict 14-day lockdown.
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