Settings
We included 22 NHs of the Montpellier area (France), each with at least
five residents with a previous diagnosis of COVID-19 confirmed by RT-PCR
on a nasopharyngeal swab test between March and December 2020
(PCR-positive residents). This study follows previous studies conducted
in the same NHs with a COVID-19 outbreak between March and June 202016,19,20.