Occupational Exposure in the Lombardy Region (Italy) to SARS-CoV-2 Infection: Results from the MUSTANG-OCCUPATION-COVID-19 Study

• Published in: International journal of environmental research and public health 2021-03, Vol.18 (5), p.2567
• Main Authors: Della Valle, Paola, Fabbri, Marco, Madotto, Fabiana, Ferrara, Pietro, Cozzolino, Paolo, Calabretto, Elisabetta, D'Orso, Marco Italo, Longhi, Ermanno, Polosa, Riccardo, Riva, Michele Augusto, Mazzaglia, Giampiero, Sommese, Carmen, Mantovani, Lorenzo Giovanni, The Mustang-Occupation-Covid-Study Group
• Format: Article
• Language: English
• Subjects: Antibodies; Antibodies, Viral; Antibody response; Consent; Coronaviruses; COVID-19; Epidemics; Epidemiology; Health surveillance; Humans; IgG antibody; Immunoglobulin G; Immunoglobulin M; Infections; Italy - epidemiology; Medical personnel; Occupational Exposure; Occupational health; Occupations; Risk groups; Sample size; SARS-CoV-2; Serology; Severe acute respiratory syndrome; Severe acute respiratory syndrome coronavirus 2; Viruses; Workers
• ISSN: 1660-4601; 1661-7827; 1660-4601
• DOI: 10.3390/ijerph18052567

Sero-epidemiological surveys are valuable attempts to estimate the circulation of SARS-CoV-2 in general or selected populations. Within this context, a prospective observational study was conducted to estimate the prevalence and persistence of SARS-CoV-2 antibodies in different categories of workers and factors associated with positivity, through the detection of virus-specific immunoglobulin G and M (IgG/IgM) in serum samples. Enrollees were divided in low exposure and medium-high groups on the basis of their work activity. Antibody responders were re-contacted after 3 months for the follow-up. Of 2255 sampled workers, 4.8% tested positive for SARS-CoV-2 IgG/IgM antibodies, with 81.7% to IgG only. Workers who continued to go to their place of work, were healthcare workers, or experienced at least one COVID-19-related symptom were more likely to test positive for SARS-CoV-2 antibodies. SARS-CoV-2 antibodies prevalence was significantly higher in the medium-high risk vs. low-risk group (7.2% vs. 3.0%, < 0.0001). At 3-month follow-up, 81.3% of subjects still had antibody response. This study provided important information of SARS-CoV-2 infection prevalence among workers in northern Italy, where the impact of COVID-19 was particularly intense. The presented surveillance data give a contribution to refine current estimates of the disease burden expected from the SARS-CoV-2.