Adaptation, spread and transmission of SARS-CoV-2 in farmed minks and associated humans in the Netherlands

In the first wave of the COVID-19 pandemic (April 2020), SARS-CoV-2 was detected in farmed minks and genomic sequencing was performed on mink farms and farm personnel in the Netherlands. Using sequence data and Bayesian phylodynamic methods, the study explored transmission in minks and humans on farms. A high number of farm infections (68/126) and infections among farm workers (>50% of farms) were detected, with limited community spread. Three of five initial introductions led to onward spread between mink farms until November 2020. Viruses in the largest cluster acquired an amino acid substitution in Spike RBD (position 486), evolved faster, and spread longer and more widely. Movement of people between farms and geographic distance were significant predictors of virus dispersal. The study highlights the importance of integrating genetic and epidemiological data to investigate outbreaks at the animal–human interface.