Occupational and environmental exposure to SARS-CoV-2 in and around infected mink farms

de Rooij, M. M. T.; Hakze-Van der Honing, R.; Hulst, M.; Harders, F.; Engelsma, M.; van de Hoef, W.; Meliefste, K.; Nieuwenweg, S.; Oude Munnink, B.; van Schothorst, I.; Sikkema, R.; van der Spek, A.; Spierenburg, M.; Spithoven, J.; Bouwstra, R.; Molenaar, R.-J.; Koopmans, M.; Stegeman, A.; Van der Poel, W. H. M.; Smit, L. A. M.

Uncontrolled SARS-CoV-2 infections in farmed minks raised immediate concerns regarding human health which initiated intensive environmental investigations. Air sampling was performed in infected mink farms, at farm premises and at residential sites. A range of other environmental samples were collected from minks' housing units. Inside the farms, high levels of SARS-CoV-2 RNA were found in airborne dust, on surfaces, and on various other environmental matrices. This warns for occupational exposure which was substantiated by considerable SARS-CoV-2 RNA concentrations in personal air samples. Dispersion of SARS-CoV-2 to outdoor air was found to be limited and SARS-CoV-2 RNA was not detected in air samples collected beyond farm premises, implying a negligible environmental exposure risk for nearby communities. Our occupational and environmental risk assessment is in line with whole genome sequences analyses showing mink-to-human transmission in farm workers, but no indications for direct zoonotic transmission events to nearby communities.