SARS-CoV-2 in Danish Mink Farms: Course of the Epidemic and a Descriptive Analysis of the Outbreaks in 2020.
Authors: Boklund Anette, Hammer Anne Sofie, Quaade Michelle Lauge, Rasmussen Thomas Bruun, Lohse Louise, Strandbygaard Bertel, Jørgensen Charlotte Sværke, Olesen Ann Sofie, Hjerpe Freja Broe, Petersen Heidi Huus, Jensen Tim Kåre, Mortensen Sten, Calvo-Artavia Francisco F, Lefèvre Stine Kjær, Nielsen Søren Saxmose, Halasa Tariq, Belsham Graham J, Bøtner Anette
Journal: Animals : an open access journal from MDPI
Summary
# SARS-CoV-2 in Farmed Mink: Understanding an Emerging Zoonotic Risk Between June and December 2020, Danish researchers analysed outbreak data from 215 mink farms to characterise how SARS-CoV-2 spreads in intensive mink production and what clinical and epidemiological patterns emerge during infection. Using prevalence surveys, virological testing (including air, fur, water and environmental samples) and serological assessment across affected farms, the team documented infection dynamics, shedding routes, and cross-species transmission potential. Clinical disease was notably variable—roughly a third of infected farms showed no overt signs—but where clinical illness occurred, farmers observed typical markers: reduced feed intake, increased mortality and respiratory symptoms that generally resolved within a median of 11 days. Approximately two-thirds of farms showed 100% virus detection and sero-conversion in sampled animals at initial testing, whilst the virus was recovered at low levels from air samples, mink fur, flies, gutter water and even a seagull's foot, though notably absent from feed. Companion animals (dogs and cats) on affected farms occasionally tested positive, but other species monitored (chickens, rabbits, horses and local wildlife) did not. For equine and farm animal professionals, this research underscores mink's exceptional susceptibility to SARS-CoV-2 and highlights that whilst human contact likely drives farm-to-farm transmission, environmental persistence and fomite routes warrant caution when working across multiple livestock facilities or in mixed farming environments.
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Practical Takeaways
- •Not applicable - this study concerns farmed mink epidemiology and zoonotic disease transmission, not equine medicine or husbandry
- •Equine practitioners should note that contact with infected animals and contaminated environments poses minimal documented risk, as horses tested negative in this study
- •This research is relevant primarily to livestock disease management and public health epidemiology, not to equine-specific clinical practice
Key Findings
- •SARS-CoV-2 infection was detected in 215 Danish mink farms with rapid spread from June to September 2020, with steep increases from September onwards
- •One-third of infected farms showed no clinical signs; in affected farms, decreased feed intake, increased mortality, and respiratory symptoms were most common over a median of 11 days
- •In 65% and 69% of farms, 100% of sampled animals tested positive for virus and sero-conversion respectively at first sampling
- •SARS-CoV-2 was detected at low levels in air samples, mink fur, flies, and gutter water near infected farms, but transmission routes between farms remain unclear