The front of a bus.
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Severe COVID-19 twice as common among bus drivers


Bus drivers were at double the risk of being hospitalised for severe COVID-19 in the later stages of the pandemic, and several occupations in education and healthcare were also at risk of serious illness. This has been shown by a study at the University of Gothenburg.

The study is based on large amounts of data from several different registers, totalling 552,562 cases of confirmed COVID-19 infection and 5,985 cases of severe COVID-19 infection. These cases, based on hospitalisations from October 2020 to December 2021, were then cross-referenced with the person’s occupation in November of the previous year. The study compared occupations that involved working closely with other people and occupations that had little or no close contact with colleagues or the public.

While the risk of hospitalisation for severe COVID-19 was found to be particularly elevated among bus and tram drivers (98% increased risk), the study also highlights staff at after-school clubs (72% increased risk), registered nurses (68% increased risk), compulsory school teachers (60% increased risk) and preschool child minders (60% increased risk).  

Low risk for the individual

The researchers stress that the individual risk of workers in a given profession being hospitalised for COVID-19 has remained very low, as the number of affected people in the occupational groups is small.

Maria Åberg
Photo: Johan Wingborg

The results also indicate certain differences between men and women in several occupations. For example, there was a 53% increased risk of hospitalisation with COVID-19 among specialist doctors of both genders, but narrowing the focus solely to female specialists, the increase in risk was significantly higher, at 105%.

“When looking at specific occupations, interesting gender differences emerge. Among women, there are increased risks for specialist doctors, nurses, midwives and preschool staff. Male occupations that carry higher risk include bus and tram drivers and security guards. This also reflects the fact that we have a gender-segregated labour market,” says Maria Åberg, Professor of General Medicine at Sahlgrenska Academy, the Faculty of Medicine at the University of Gothenburg.

Focus on the workplace

Above all, the researchers hope that the results of the study will be an eye-opener for employers. The results clearly show a work-related contagion in several different types of contact professions, not only in health care. It highlights the need for improved risk assessment and preventive measures in these sectors.

Kjell Torén
Photo: Elin Lindström

“The workplace is also an important arena for informing about and carrying out vaccination. Over the course of our research, we have come to the strong conclusion that workplaces or employers need to be involved in getting these high-risk occupations access to vaccination, for example by allowing them to be vaccinated during working hours or by organising vaccination sessions at their place of work. And occupational healthcare has an important role to play in making this happen,” says Kjell Torén, Senior Professor of Occupational and Environmental Medicine at Sahlgrenska Academy at the University of Gothenburg.

“We know that vaccination protects against severe COVID-19 and we believe that vaccination in high-risk workplaces during working hours would further reduce the risks. This applies in particular to bus and tram drivers and preschool staff. Healthcare workers were usually offered vaccination during working hours, but perhaps additional measures could have increased vaccination uptake,” says Maria Åberg.

Published in the Scandinavian Journal of Work, Environment & Health, the study was conducted in collaboration with Karolinska Institutet.

The study does not take into account vaccination levels among the cases included in the large dataset, which the researchers plan to pursue in a later study.

Title: Occupational risks associated with severe COVID-19 disease and SARS-CoV-2 infection – a Swedish national case-control study conducted from October 2020 to December 2021;

Increased risk - but still unusual with severe covid

Although the risk of becoming seriously ill was higher for occupations with close and frequent contact with people who were infected with covid-19, in real terms there are relatively few cases. With regard to drivers in public transport, 13,404 people with the profession of bus driver or tram driver were included, of which 92 needed hospital treatment for covid during the studied period (about 0.7 percent). There are a total of 27,200 bus and tram drivers in Sweden.