Investigating SARS-CoV-2 transmission among co-workers in a University of Northern Italy during COVID-19 pandemic: an observational study

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Alfredo Montecucco
Guglielmo Dini
Alborz Rahmani
Bruno Kusznir Vitturi
Chiara Barletta
Luca Pellegrini
Alessia Manca
Andrea Orsi
Bianca Bruzzone
Valentina Ricucci
Vanessa De Pace
Giulia Guarona
Simona Boccotti
Alessio Signori
Giancarlo Icardi
Paolo Durando


COVID-19, SARS-CoV-2 infection, occupational setting, COVID-19 transmission, secondary attack rate, contact tracing, co-workers, preventive measures in workplace


Background: This study aimed to investigate SARS-CoV-2 transmission among co-workers at the University of Genoa, Italy, during the second COVID-19 pandemic wave. Methods: A cross-sectional study was carried out in October 2020 – March 2021: RT-PCR confirmed cases of COVID-19 notified to the Occupational Health Service were included in the analysis. Results: Among the n = 201 notified cases, contact tracing of n = 53 individuals identified n = 346 close contacts. The household setting (IRR = 36.8; 95% CI: 4.9-276.8; p < 0.001) and sharing eating areas (IRR = 19.5; 95% CI: 2.5-153.9; p = 0.005) showed the highest Secondary Attack Rates (SARs) compared to the office setting. Fatigue (IRR= 17.1; 95% CI: 5.2-55.8; p < 0.001), gastrointestinal symptoms (IRR= 6.6; 95% CI: 2.9-15.2; p< 0.001) and cough (IRR= 8.2; 95% CI: 3.7-18.2; p= p< 0.001) were associated with transmission of infection. Polysymptomatic cases (IRR= 23.1; 95% CI: 3.1-169.2; p = 0.02) were more likely to transmit the infection. Among COVID-19 index cases aged >60 years (OR = 7.7; 95% CI: 1.9-31.9; p = 0.0046) SARs were higher than in other age groups. Wearing respiratory protections by both the case and the close contact resulted an effective measure compared with no use (IRR = 0.08; 95% CI: 0.03-0.2; p = < 0.0001). Conclusions: Accurate infection monitoring and contact tracing was useful to identify the main situations Conclusions: Accurate infection monitoring and contact tracing was useful to identify the main situations of SARS-CoV-2 transmission in the workplace, and hence for risk assessment and prevention programs.


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