Background: Although the diagnosis of new coronavirus 2019 (COVID-19) is made through the identification of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in respiratory secretions by means of molecular methods, a more accurate estimation of SARS-CoV-2 circulation can be obtained by seroprevalence studies. The main aim of this study was to evaluate the true epidemiology of SARS-CoV-2 infection among workers in the metal-mechanical sector who never stopped working during the pandemic period in an area with a high incidence of COVID-19 and to define whether and how they could continue the work without appreciable risks during a second wave. Methods: A total of 815 metal-mechanical workers who had never stopped working even during the pandemic period in three different factories in the Emilia-Romagna Region, Italy, and who had always used face masks during working hours, underwent a capillary blood rapid test for the determination of IgM and IgG against SARS-CoV-2 (COVID-19 IgG/IgM Rapid test, PrimaLab, Modena, Italy). In the event of a positive test, a nasopharyngeal was performed and tested for the presence of SARS-CoV-2. Results: The detection of serum IgG/IgM against SARS-CoV-2 was significantly more common among workers employed in Parma (21/345, 6.1%) than among those employed in Calerno (7/242, 2.9%) or in Spilamberto (3/228, 1.3%) ( p <0.001). The analysis of the role of the different variables as predictors of seropositivity for IgG/IgM against SARS-CoV-2 revealed that the presence of specific antibodies was strictly associated with a previous history of COVID-19-like symptoms (odds ratio [OR] 3.95, 95% confidence interval [CI] 1.9–8.2) and household members with COVID-19-like symptoms (OR 2.20, 95% CI 1.04–4.82). Conclusion: This study shows that seropositivity to SARS-CoV-2 is low even among employees who did not interrupt their work during the lockdown phase in a region with a high incidence of COVID-19. The use of face masks appears effective in the avoidance of the transmission of SARS-CoV-2 in factories even in the presence of asymptomatic or mildly symptomatic workers, suggesting that work activities can continue if adequate infection control measures are used during a second wave.
【저자키워드】 COVID-19, public health, SARS-CoV-2, Epidemiology, occupational medicine, 【초록키워드】 infection control, coronavirus, pandemic, lockdown, SARS-COV-2 infection, Diagnosis, risk, Symptom, Italy, severe acute respiratory syndrome Coronavirus, activity, serum, Region, Asymptomatic, Rapid test, nasopharyngeal, symptomatic, Rapid, Face masks, Seropositivity, second wave, predictor, circulation, molecular, respiratory, specific antibodies, New coronavirus, Face mask, Analysis, Odds ratio, IgM and IgG, an area, acute respiratory syndrome, 95% CI, acute respiratory syndrome coronavirus, acute respiratory syndrome coronavirus 2, 95% confidence interval, secretion, avoidance, measure, Positive test, serum IgG, capillary blood, transmission of SARS-CoV-2, working hours, variable, Modena, effective, tested, evaluate, significantly more, specific antibody, was performed, appear, to define, Emilia-Romagna, incidence of COVID-19, 【제목키워드】 Mask, Testing, Rapid, IgM and IgG, an area, worker, sector, wearing, Area, Against, Determination,