The Effects of Physical Distancing and Lockdown to Restrain SARS-CoV-2 Outbreak in the Italian Municipality of Cogne

Abstract

The outbreak of SARS-CoV-2 started in Wuhan, China, and is now a pandemic. An understanding of the prevalence and contagiousness of the disease, and of whether the strategies used to curb it to date have been successful, is important to implement future containment measures. A widely used way to break down the spread of SARS-CoV-2, as part of the non-pharmaceutical interventions (NPIs), is to adopt strong social distancing policies. Cogne (Italy) is an isolated alpine village served by a single access road: a rare and ideal socio-geographic framework for studying the dynamics of viral shedding. The Municipality of Cogne imposed strict lockdown rules from March 4, 2020 up to May 18, 2020. This first wave of the pandemic impressed by the extremely low impact of the SARS-CoV-2 on the inhabitants. Starting from October 2020 up to the end of December, when the second wave hit Italy and Cogne territory, heavier effects were observed. In order to cast light on the effectiveness of the adopted strategy 74,5% of the local population underwent a blood screening to detect IgM and IgG antibodies and after six months all the people tested positive were again investigated to establish the longitudinal changes in antibodies level. The main topic of the present observational study is the comparison of the SARS-CoV-2 outbreak in the March 2020 lockdown vs the October 2020 lockdown. Emphasis is put on the usefulness of the early and strict lockdown tool to contain the pandemic. Moreover a rare and interesting case of secondary infection has been identified and here reported.Funding Statement: The project was budgeted under the contract COGNE-COVID by the Municipality of Cogne. The funder granted access at acquisition of the results of serological tests and nasopharyngeal swabs carried out in Cogne between March and December 2020, but played no part in the design, data analysis and writing. The two authors are responsible for the decision to submit for publication.Declaration of Interests: Both authors have no conflict of interest to disclose.Ethics Approval Statement: The study was approved by the Ethics Committee of Aosta Valley (I). All experimental and sensible data treatment were performed in agreement with the relevant guidelines and regulations issued by the International Committee of Medical Journal Editors (ICMJE Recommendations).