Keywords
The small Italian municipality of Vò, located in the Veneto region, northeast of Italy, with a population of nearly 3200 inhabitants, suffered the first COVID-19-related death of the country on February 21, 2020. Immediately, the small town was strictly quarantined for 14 days and all population underwent a two-round testing for SARS-CoV-2 by nasopharyngeal swab, becoming a unique epidemiological experiment for studying COVID-19 infection.
Recently, Lavezzo et al. [
[1]
] reported the epidemiological and clinical data of the Vò population at the two time points, demonstrating that the prevalence of the infection dropped from 2.6 to 1.2% at the second screening. Unexpectedly, 42.5% of the confirmed SARS-CoV-2 infections were asymptomatic and did not develop any clinical signs of the disease afterwards. Furthermore, the authors did not find any statistical differences between the viral load of symptomatic and asymptomatic subjects, proving the pivotal role of asymptomatic individuals in spreading the pathogen.- Lavezzo E.
- Franchin E.
- Ciavarella C.
- Cuomo-Dannenburg G.
- Barzon L.
- Del Vecchio C.
- Rossi L.
- Manganelli R.
- Loregian A.
- Navarin N.
- Abate D.
- Sciro M.
- Merigliano S.
- De Canale E.
- Vanuzzo M.C.
- Besutti V.
- Saluzzo F.
- Onelia F.
- Pacenti M.
- Parisi S.
- Carretta G.
- Donato D.
- Flor L.
- Cocchio S.
- Masi G.
- Sperduti A.
- Cattarino L.
- Salvador R.
- Nicoletti M.
- Caldart F.
- Castelli G.
- Nieddu E.
- Labella B.
- Fava L.
- Drigo M.
- Gaythorpe K.A.M.
- Brazzale A.R.
- Toppo S.
- Trevisan M.
- Baldo V.
- Donnelly C.A.
- Ferguson N.M.
- Dorigatti I.
- Crisanti A.
Imperial College COVID-19 Response Team
Suppression of a SARS-CoV-2 outbreak in the Italian municipality of Vo'.
Suppression of a SARS-CoV-2 outbreak in the Italian municipality of Vo'.
Nature. 2020; ([Epub ahead of print])https://doi.org/10.1038/s41586-020-2488-1
Although in a different scenario, the Vò investigation resembles the famous and well-known “Framingham” study (FHS), which was performed in the middle of the past century in the town of Framingham, Massachusetts [
[2]
]. The FHS was designed to characterize the epidemiology, prevention and treatment of cardiovascular disease (CVD) and even now, it represents the most comprehensive cohort study investigating the aetiology of the CVD.Both FHS and Vò investigation are prospective observational cohort studies, which represent the most appropriate method to investigate diseases with a subclinical phase and a significant impact on public health.
The FHS was aimed to identify determinants of CVD to guide public health prevention, as well as to identify their natural history. Similarly, the “Vò study”, by its methodology, has clearly demonstrated that the extensive testing, independently from the presence of COVID-19-related symptoms, together with the accurate and prompt isolation of the SARS-CoV-2 positive subjects represent the most effective measures to limit the widespread diffusion of the infection and to contain new outbreaks of the virus.
Analogously to the FHS, the “Vò study” researchers will set further investigations to better characterize the epidemiological features of the SARS-COv-2 infection, by evaluation of gene variants at the population level, and their potential implications in susceptibility or resistance to the infection []. These results will surely help the development of novel therapeutic approaches and of effective vaccine.
The FHS extended its observations to the second and third generation of the original sample population, in order to integrate the natural course of the CVD and of the cardiovascular risk factors with social and economic issues. Similarly, the Vò community should undergo a continuous, repetitive and extensive nasopharyngeal swab testing to monitor the post-pandemic incidence of new cases and to understand how to prevent further outbreaks. Indeed, considering the worldwide impact of the COVID-19 pandemic and the burden of SARS-CoV-2 infection on world economy, the results of the “Vò study” and their subsequent implications make this study the Framingham study of the 21st century.
Declaration of Competing Interest
The authors have no conflicts of interest to declare.
References
- Suppression of a SARS-CoV-2 outbreak in the Italian municipality of Vo'.Nature. 2020; ([Epub ahead of print])https://doi.org/10.1038/s41586-020-2488-1
- Cohort profile: the Framingham Heart Study (FHS): overview of milestones in cardiovascular epidemiology.Int J Epidemiol. 2015; 44: 1800-1813
https://ilbolive.unipd.it/it/news/studio-crisanti-coronavirus-vo.
Article info
Publication history
Published online: July 21, 2020
Accepted:
July 19,
2020
Received:
July 11,
2020
Identification
Copyright
© 2020 Published by Elsevier B.V. on behalf of European Federation of Internal Medicine.
