tetano
Editor, Senior Moderator
PLoS One
. 2021 Feb 24;16(2):e0246513.
doi: 10.1371/journal.pone.0246513. eCollection 2021.
Prevalence of SARS-CoV-2 in an area of unrestricted viral circulation: Mass seroepidemiological screening in Castiglione d'Adda, Italy
Gabriele Pagani[SUP] 1 2 [/SUP], Andrea Giacomelli[SUP] 1 2 [/SUP], Federico Conti[SUP] 1 2 [/SUP], Dario Bernacchia[SUP] 1 2 [/SUP], Rossana Rondanin[SUP] 3 [/SUP], Andrea Prina[SUP] 3 [/SUP], Vittore Scolari[SUP] 4 [/SUP], Arianna Rizzo[SUP] 1 [/SUP], Martina Beltrami[SUP] 1 [/SUP], Camilla Caimi[SUP] 1 [/SUP], Cecilia Eugenia Gandolfi[SUP] 5 6 [/SUP], Silvana Castaldi[SUP] 5 6 [/SUP], Bruno Alessandro Rivieccio[SUP] 7 [/SUP], Giacomo Buonanno[SUP] 8 [/SUP], Giuseppe Marano[SUP] 9 [/SUP], Cosimo Ottomano[SUP] 10 [/SUP], Patrizia Boracchi[SUP] 9 [/SUP], Elia Biganzoli[SUP] 9 [/SUP], Massimo Galli[SUP] 1 2 [/SUP]
Affiliations
Abstract
Castiglione D'Adda is one of the municipalities more precociously and severely affected by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) epidemic in Lombardy. With our study we aimed to understand the diffusion of the infection by mass serological screening. We searched for SARS-CoV-2 IgGs in the entire population on a voluntary basis using lateral flow immunochromatographic tests (RICT) on capillary blood (rapid tests). We then performed chemioluminescent serological assays (CLIA) and naso-pharyngeal swabs (NPS) in a randomized representative sample and in each subject with a positive rapid test. Factors associated with RICT IgG positivity were assessed by uni- and multivariate logistic regression models. Out of the 4143 participants, 918 (22?2%) showed RICT IgG positivity. In multivariable analysis, IgG positivity increases with age, with a significant non-linear effect (p = 0?0404). We found 22 positive NPSs out of the 1330 performed. Albeit relevant, the IgG prevalence is lower than expected and suggests that a large part of the population remains susceptible to the infection. The observed differences in prevalence might reflect a different infection susceptibility by age group. A limited persistence of active infections could be found after several weeks after the epidemic peak in the area.
. 2021 Feb 24;16(2):e0246513.
doi: 10.1371/journal.pone.0246513. eCollection 2021.
Prevalence of SARS-CoV-2 in an area of unrestricted viral circulation: Mass seroepidemiological screening in Castiglione d'Adda, Italy
Gabriele Pagani[SUP] 1 2 [/SUP], Andrea Giacomelli[SUP] 1 2 [/SUP], Federico Conti[SUP] 1 2 [/SUP], Dario Bernacchia[SUP] 1 2 [/SUP], Rossana Rondanin[SUP] 3 [/SUP], Andrea Prina[SUP] 3 [/SUP], Vittore Scolari[SUP] 4 [/SUP], Arianna Rizzo[SUP] 1 [/SUP], Martina Beltrami[SUP] 1 [/SUP], Camilla Caimi[SUP] 1 [/SUP], Cecilia Eugenia Gandolfi[SUP] 5 6 [/SUP], Silvana Castaldi[SUP] 5 6 [/SUP], Bruno Alessandro Rivieccio[SUP] 7 [/SUP], Giacomo Buonanno[SUP] 8 [/SUP], Giuseppe Marano[SUP] 9 [/SUP], Cosimo Ottomano[SUP] 10 [/SUP], Patrizia Boracchi[SUP] 9 [/SUP], Elia Biganzoli[SUP] 9 [/SUP], Massimo Galli[SUP] 1 2 [/SUP]
Affiliations
- PMID: 33626045
- DOI: 10.1371/journal.pone.0246513
Abstract
Castiglione D'Adda is one of the municipalities more precociously and severely affected by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) epidemic in Lombardy. With our study we aimed to understand the diffusion of the infection by mass serological screening. We searched for SARS-CoV-2 IgGs in the entire population on a voluntary basis using lateral flow immunochromatographic tests (RICT) on capillary blood (rapid tests). We then performed chemioluminescent serological assays (CLIA) and naso-pharyngeal swabs (NPS) in a randomized representative sample and in each subject with a positive rapid test. Factors associated with RICT IgG positivity were assessed by uni- and multivariate logistic regression models. Out of the 4143 participants, 918 (22?2%) showed RICT IgG positivity. In multivariable analysis, IgG positivity increases with age, with a significant non-linear effect (p = 0?0404). We found 22 positive NPSs out of the 1330 performed. Albeit relevant, the IgG prevalence is lower than expected and suggests that a large part of the population remains susceptible to the infection. The observed differences in prevalence might reflect a different infection susceptibility by age group. A limited persistence of active infections could be found after several weeks after the epidemic peak in the area.