Occupational risk of COVID-19 in the first versus second epidemic wave in Norway, 2020

Background: The occupational risk of COVID-19 may be different in the first versus second epidemic wave. Aim: To study whether employees in occupations that typically entail close contact with others were at higher risk of SARS-CoV-2 infection and COVID-19related hospitalisation during the first and second epidemic wave before and after 18 July 2020, in Norway. Methods: We included individuals in occupations working with patients, children, students, or customers using Standard Classification of Occupations (ISCO08) codes. We compared residents (3,559,694 on 1 January 2020) in such occupations aged 20-70 years (mean: 44.1; standard deviation: 14.3 years; 51% men) to age-matched individuals in other professions using logistic regression adjusted for age, sex, birth country and marital status. Results: Nurses, physicians, dentists and physiotherapists had 2-3.5 times the odds of COVID-19 during the first wave when compared with others of working age. In the second wave, bartenders, waiters, food counter attendants, transport conductors, travel stewards, childcare workers, preschool and primary school teachers had ca 1.25-2 times the odds of infection. Bus, tram and taxi drivers had an increased odds of infection in both waves (odds ratio: 1.2-2.1). Occupation was of limited relevance for the odds of severe infection, here studied as hospitalisation with the disease. Conclusion: Our findings from the entire Norwegian population may be of relevance to national and regional authorities in handling the epidemic. Also, we provide a knowledge foundation for more targeted future studies of lockdowns and disease control measures.