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.
【초록키워드】 severe acute respiratory syndrome coronavirus 2, CLIA, SARS-CoV-2, IgG, coronavirus, susceptibility, Infection, severe acute respiratory syndrome Coronavirus, coronavirus 2, Prevalence, lateral flow, Randomized, Epidemic, Serological assay, Rapid test, persistence, age, respiratory, serological, SARS-CoV-2 IgG, Naso-pharyngeal swab, lombardy, Factor, Participants, acute respiratory syndrome coronavirus, subject, multivariate logistic regression, multivariable analysis, IgG positivity, epidemic peak, logistic regression models, positive, capillary blood, diffusion, naso-pharyngeal swabs, immunochromatographic test, active infections, NPs, susceptible, the epidemic, active infection, performed, affected, increase, searched, expected, were assessed, 【제목키워드】 SARS-CoV-2, Italy, mass,