#Replication and #Transmission of #Influenza A Virus in Farmed #Mink

 

Abstract

Farmed mink are frequently exposed to circulating influenza A viruses (IAVs), as confirmed by viral isolation and serological evidence. Previous work reveals that naïve mink serve as susceptible hosts for both avian and human influenza strains, highlighting their potential role in influenza ecology. In this study, we investigated whether farmed mink naturally pre-exposed to H9 retain the capacity to serve as “mixing vessels” for reassorting human and avian IAVs. Our results demonstrate that they remain fully susceptible and permissive to infection by both avian H6N6 and human H1N1 influenza strains. Notably, efficient transmission of these viruses occurred among farmed mink, confirming their potential to sustain viral exchange. These findings indicate that farmed mink represent highly permissive hosts capable of facilitating reassortment between circulating human and avian IAVs. Given this risk, current mink farming practices may substantially increase the likelihood of a pandemic emergence. We therefore urge immediate revision, stringent enhancement, and rigorous enforcement of biosecurity protocols and active surveillance systems in fur farming operations.

Source: 

Link: https://www.mdpi.com/1999-4915/18/1/9

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Anthropozoonotic #spillovers reveal sustained long-term cryptic #circulation of #SARS-CoV-2 within and between #Lithuanian #mink farms

Abstract

Several studies have documented reverse zoonotic transmission of SARS-CoV-2, including in farmed mink which are susceptible to human respiratory viruses and are known for serving as a reservoir capable of generating new virus variants in densely populated farms. Here, we present the results of a genomic investigation launched in response to detected human infections with mink-origin SARS-CoV-2 lineages, and show evidence of at least 14 high-confidence introductions of SARS-CoV-2 from humans into farmed mink in Lithuania where sustained transmission in farmed mink lasted up to a year. We estimated the most likely timeframes for these introductions encompassing at least six SARS-CoV-2 lineages, some of which were already extinct in humans, with Bayesian phylogenetic and molecular clock analyses. This study highlights the public health risks posed by fur farms and underscores that passive genomic surveillance systems are ineffective without the active involvement and expertise of responsible institutions.

Competing Interest Statement

The authors have declared no competing interest.

Funding Statement

Gytis Dudas was supported by EMBO installation grant EMBO-IG-5305-2023.

Source: MedRxIV, https://www.medrxiv.org/content/10.1101/2025.07.15.25331253v1

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First #human #infection and management of #Versteria rafei infection restricted to #liver with phylogenetic analysis in the context of known cases

Summary

A recently described cestode genus, Versteria, has been implicated in disseminated human disease in North America. We report the first known case of infection with a recently reported species, Versteria rafei, localised to the liver with attempted surgical resection. Through review of other patients known to be infected with this parasite, we established that this is a rare zoonotic infection involving contact with minks and mustelids. Although Versteria belongs to the same family as Echinococcus, there are several important differences. Known Versteria infections in humans typically are symptomatic, quickly involve multiple organs without treatment, and occur in immunosuppressed hosts. Furthermore, albendazole appears to be at least parasitostatic, with a reduction but not a resolution of the lesions under treatment and development of calcifications analogous to changes seen with treatment for alveolar echinococcosis.

Source: Lancet Infectious Diseases, https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(25)00281-6/abstract?rss=yes

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A #MERS-CoV-like #mink #coronavirus uses #ACE2 as entry receptor

Abstract

Despite accumulating evidence that bat-derived coronaviruses often require intermediate hosts to facilitate transmission to humans1, the potential role of fur animals in zoonotic coronavirus spillovers has largely been overlooked2. Here we report the isolation and characterization of a novel mink respiratory coronavirus (MRCoV) from farmed minks with pneumonia. Notably, MRCoV uses angiotensin-converting enzyme 2 (ACE2) as a receptor and can infect mink, bat, monkey, and human cells. Cryo-electron microscopy analysis revealed that the MRCoV receptor-binding domain (RBD) binds to the same interface on ACE2 receptors as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RBD, despite exhibiting notable structural differences. We identify the key determinants on ACE2 and MRCoV RBD that confer efficient binding. HKU5-33S, a bat coronavirus closely related to MRCoV, utilizes ACE2 of bat Pipistrellus abramus and requires only two amino acid substitutions to adapt to mink ACE2. Furthermore, SARS-CoV-2 protease and polymerase inhibitors potently block MRCoV infection, indicating a potential therapeutic strategy. Collectively, these findings enhance the understanding of coronavirus receptor dynamics and highlight their zoonotic potential. Given the risks posed by fur farms as reservoirs for emerging pathogens, our study underscores the urgent need for enhanced surveillance to mitigate future coronavirus outbreaks.

Source: Nature, https://www.nature.com/articles/s41586-025-09007-w

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#Italy - #SARS-CoV-2 in #animals (Inf. with) - Immediate notification

A mink farm in Lombardy Region.

The minks were controlled in the framework of a national surveillance plan.

Source: WOAH, https://wahis.woah.org/#/in-review/6367?reportId=173318&fromPage=event-dashboard-url

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Highly Pathogenic Avian #Influenza (HPAI) #H5N1 virus in #Finland in 2021-2023 – Genetic diversity of the viruses and infection kinetics in #human dendritic cells

Abstract

Highly pathogenic avian influenza (HPAI) H5N1 is known for its virulence and zoonotic potential, infecting birds and mammals, thus raising public health concerns. Since 2021 its spread among birds has led to cross-species transmission causing epizootics among mammals, eventually impacting fur animal farms in Finland in 2023. To analyze the infectivity of the Finnish H5N1 isolates in human cells, representatives of diverse H5N1 isolates were selected based on the genetic differences, host animal species, and the year of occurrence. The infection kinetics of the selected H5N1 isolates from wild pheasant and fox, and fur animals blue fox and white mink were examined in human monocyte-derived dendritic cells (moDCs) with H5N1 human isolate as a control. Although the isolate from pheasant (a wild bird) showed weakly reduced replication and viral protein expression in human cells compared to mammalian isolates, no discernible differences in virus replication in moDCs was observed. This study revealed similar infectivity in human moDCs for all five H5N1 isolates, regardless of the observed genetic differences. While H5N1 human infections remain rare, the virus poses a risk for widespread epizootics in mammals such as fur animal farms and, more recently, dairy cattle.

Source: Emerging Microbes & Infections, https://www.tandfonline.com/doi/full/10.1080/22221751.2024.2447618

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