SARS-CoV-2 Outbreak on a Spanish Mink Farm: Epidemiological, Molecular, and Pathological Studies

Abstract

Farmed minks have been reported to be highly susceptible to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and may represent a risk to humans. In this study, we describe the first outbreak of SARS-CoV-2 occurred on a mink farm in Spain, between June and July 2020, involving 92,700 animals. The outbreak started shortly after some farm workers became seropositive for SARS-CoV-2. Minks showed no clinical signs compatible with SARS-CoV-2 infection throughout the outbreak. Samples from 98 minks were collected for histopathological, serological, and molecular studies. Twenty out of 98 (20.4%) minks were positive by RT-qPCR and 82 out 92 (89%) seroconverted. This finding may reflect a rapid spread of the virus at the farm with most of the animals overcoming the infection. Additionally, SARS-CoV-2 was detected by RT-qPCR in 30% of brain samples from positive minks. Sequencing analysis showed that the mink sequences were not closely related with the other mink SARS-CoV-2 sequences available, and that this mink outbreak has its probable origin in one of the genetic variants that were prevalent in Spain during the first COVID-19 epidemic wave. Histological studies revealed bronchointerstitial pneumonia in some animals. Immunostaining of viral nucleocapsid was also observed in nasal turbinate tissue. Farmed minks could therefore constitute an important SARS-CoV-2 reservoir, contributing to virus spread among minks and humans. Consequently, continuous surveillance of mink farms is needed.

No Evidence for the Presence of SARS-CoV-2 in Bank Voles and Other Rodents in Germany, 2020–2022

“…However, ever since the beginning of the pandemic the role of animals as potential intermediate or reservoir hosts has been discussed. When the virus was introduced into mink ( Neovison vison ) farms and caused local epidemics in these highly susceptible animal species [ 22 , 23 , 24 , 25 ], evidence for mink-to-human spillback infections was reported [ 26 ], resulting in concerns about viral maintenance and evolution/adaptation in animals. Aside from these mink-to-human and the likely initial animal-to-human transmissions, suspicions of zooanthroponotic SARS-CoV-2 transmissions were reported from a cat ( Felis catus ) and pet hamsters [ 17 , 18 , 27 ], expanding the species potentially representing a risk for infections of humans to companion animals and rodents in particular.…”

No Evidence of SARS-CoV-2 Infection in Wild Mink (Mustela lutreola and Neogale vison) from Northern Spain during the First Two Years of Pandemic

“…American mink are highly susceptible to SARS-CoV-2, and this virus spreads efficiently within mink farms once introduced by direct and indirect contact [ 36 ]. The SARS-CoV-2 virus has been detected in more than 400 mink farms in eight countries in the European Union, including Spain and North America [ 19 , 20 , 37 ], and reinfections have been demonstrated [ 38 ]. The transfer of variants between humans and mink has been reported in Denmark, The Netherlands and Poland [ 18 , 23 , 39 , 40 ].…”

Nanomaterials to combat SARS-CoV-2: Strategies to prevent, diagnose and treat COVID-19

“…WGS provides a deep insight into the DNA sequence of the viral genome and, when combined with metadata analysis at the individual or community level, it has allowed to analyze the origins of the COVID-19 pandemic (Al Kaabi et al, 2021;Singh et al, 2021;Costa et al, 2022), and to characterize outbreaks in a community or region (Alcoba-Florez et al, 2021;Aggarwal et al, 2022;Ciuffreda et al, 2022), hospitals (Rivett et al, 2020), farms (Badiola et al, 2021;Oude Munnink et al, 2021), schools (Huang et al, 2022) and homes (Ladhani et al, 2022), among other social or industrial entities (Bartik et al, 2020;Murti et al, 2021) (Figure 4A). Moreover, public health responses to the COVID-19 pandemic are supported by sequencing WGS from circulating SARS-CoV-2 VOCs and analyzing the risk host factors.…”