Occupational class difference in COVID-19 symptoms in France: contribution of work-related exposures

Abstract Background The association between socio-occupational class and SARS-CoV-2 infection remains inconclusive and may depend on the setting and the pandemic stage. Our study aims to quantify self-reported COVID-19 symptoms by occupational class (OC) in spring 2020 in France and explain observed differences using work-related risk factors. Methods We analyzed data from the EpiCoV population-based cohort, comprising 46,849 active workers aged 18-64 in metropolitan France. COVID-19 symptoms were sudden loss of taste/smell, fever with cough, fever with shortness of breath, or fever with chest oppression. Separating regions highly affected by COVID-19 from other regions, we related OC with reporting of COVID-19 symptoms and assessed the mediation effect of work-related SARS-CoV-2 exposures (contact with the public, using public transportation, self-perceived exposure) using the Karlson-Holm-Breen mediation analysis method. Results During the study period, 7.1% of the workers reported COVID-19 symptoms. In both regions, work-related SARS-CoV-2 exposures were related to higher reporting of symptoms, and those exposures were more prevalent in the lowest than in the highest OCs. However, the association of OC with reporting symptoms was not the same in the two regions. In less affected regions, the lowest OC reported COVID-19 symptoms less often than the highest OC, whereas in highly affected regions, symptoms were more frequent in middle OCs, and this was partly explained by work-related SARS-CoV-2 exposures. Conclusions Different socio-occupational patterns of symptoms were observed in the two groups of regions. The situation in the less affected regions, with more reporting in the highest relative to the lowest classes, may be attributable to exposure factors playing a role opposite to that of work-related exposures. Further studies on OC disparities in COVID-19 severity are needed based on hospitalization and mortality. Key messages • During the early pandemic, in regions less affected by COVID-19, the upper occupational class reported more COVID-19 symptoms, whereas the middle class did so in highly affected regions. • Work-related exposure to SARS-CoV-2 mediates the association between occupational class and reporting COVID-19 symptoms to some extent, even when the occupational gradient is reversed.