SARS-CoV-2 mink-associated variant strain – Denmark

Since June 2020, Danish authorities have reported an intensive unfold of SARS-CoV-2, the virus that causes COVID-19, on mink farms in Denmark. On 5 November, the Danish public well being authorities reported
the detection of a mink-associated SARS-CoV-2 variant with a combination of mutations not previously observed (referred to as “Cluster 5”) in 12 human cases in North Jutland, detected from August to September 2020.

So far, Statens Serum Institut (SSI) in Denmark has recognized seven distinctive mutations within the spike protein of SARS-CoV-2 amongst variants co-circulating in mink and people. SSI cultured the “Cluster 5” variant with 4 amino acid modifications within the spike protein, which was recognized in mink and remoted from the 12 human instances reported in North Jutland. Preliminary findings steered that there was a decrease functionality of antibodies to neutralize the Cluster 5 pressure, which requires additional investigation.

Following public well being measures applied by Danish authorities, the incidence of COVID-19 in North Jutland decreased from 100 per 100,000 inhabitants within the week starting 2 November (week 45) to 60 per 100,000 inhabitants within the week starting 16 November (week 47). Over the previous weeks, Danish authorities have performed mass testing of 111 447 people in North Jutland utilizing reverse transcriptase polymerase chain response (RT-PCR) and are planning to conduct genetic sequencing for all optimistic samples.

In November 2020, 349 instances had been reported amongst individuals related to mink farming, a rise from 200 instances in October 2020. Since June 2020, a complete of 644 individuals related to mink farming have examined optimistic. Moreover, there have been at the very least 338 instances reported amongst individuals working with mink pelting, in six factories and two small amenities, which suggests that there’s an elevated danger of COVID-19 an infection in people who find themselves concerned in farming, culling and pelting of mink. As of 1 December 2020, a complete of 289 mink farms have been affected, which accounts for about 20% of all mink farms in Denmark.

From the week starting 6 June 2020 (week 24) to the week starting 16 November 2020 (week 47), 10 386 COVID-19 optimistic samples from distinctive people underwent complete genome sequencing, which accounted for 17.6% of all optimistic samples within the corresponding time interval. Of those sequenced samples, 750 had been virus variants related to contaminated mink. As well as, at the very least two new SARS-CoV-2 variants had been just lately detected in Southern Denmark which weren’t genetically associated to the unique Danish mink-associated variant pressure.

In North Denmark, the proportion of SARS-CoV-2 mink-associated variant strains amongst all sequenced samples decreased from 60% and 51% in weeks 41 and 42, respectively, to 26% and 31% in weeks 46 and 47; in Central Denmark, the proportion elevated from ~three% in weeks 41 and 42 to over 30% in weeks 46 and 47; in South Denmark, the proportion elevated from zero% in weeks 41 and 42 to 11% and 21% in weeks 46 and 47, respectively, whereas noting that there are variations in sequencing frequency and practices amongst numerous areas. In areas with no affected mink farms, human instances contaminated with the mink-associated variant have occurred sporadically. As of 20 November, no new human instances of the Cluster 5 pressure have been detected by genetic sequencing, and authorities assessed that the Cluster 5 variant is not circulating in people.

Mink have beforehand been reported to be contaminated with SARS-CoV-2, together with in two outbreaks on massive mink farms within the Netherlands in April 2020. Moreover, the Netherlands have reported human infections with mink-associated SARS-CoV-2 strains which weren’t Cluster 5 strains. So far, eight international locations, specifically Denmark, Lithuania, Netherlands, Spain, Sweden, Italy, and Greece and america of America have reported COVID-19 in farmed mink to the World Organisation for Animal Well being (OIE).

Public well being response

On four November 2020, Denmark determined to cull all farmed mink in Denmark. This resolution was made following data that it had not been attainable to stop the unfold of an infection from farm to farm, or from animals to people, and mink are performing as a reservoir and contributing to the continuing transmission in Denmark. On 5 November, motion restrictions had been launched within the affected areas in North Jutland. On 6 November, Denmark shared the complete genome sequences of SARS-CoV-2 obtained from people to the World Initiative on Sharing Avian Influenza Information (GISAID) platform, and 133 sequences from mink on 18 November. On 19 November 2020, restrictions had been lifted in North Jutland because of decreased incidence and the absence of latest instances of the Cluster 5 variant recognized within the affected areas.

By 25 November, mink on all 289 affected mink farms, and farms inside an assigned zone, had been culled. Moreover, mink farming has been banned in Denmark till 31 December 2021, together with import and export of stay mink. Financial help packages have been established for these affected.

Danish authorities have continued to work with the WHO SARS-CoV-2 Virus Evolution Working Group and have agreed to share the Cluster 5 variant SARS-CoV-2 with the COVID-19 Reference Laboratory Community for additional research and testing.

WHO danger evaluation

It’s anticipated that every one viruses, together with SARS-CoV-2 change over time. SARS-CoV-2 strains that are infecting mink and subsequently transmitted again to people, could have acquired distinctive mutations to adapt to the mink host. Superior laboratory research are required to completely perceive the impression of novel variants of SARS-CoV-2 on viral properties similar to transmissibility, medical presentation and effectiveness of diagnostics, therapeutics and vaccines. These research are lengthy, complicated and are accomplished in shut collaboration with numerous analysis teams.

Whereas public well being and social measures applied by Denmark have led to optimistic developments, latest findings of different mink-associated variants amongst human instances in mid-Jutland and the detection of some 200 human instances amongst staff are of concern.

WHO recommendation

This occasion highlights the vital function that farmed mink populations can play within the on-going transmission of SARS-CoV-2 and the essential significance of strong surveillance, sampling and sequencing of those viruses by using a One Well being method, particularly round areas the place such animal reservoirs are recognized. The worldwide relevance of the preliminary findings by Denmark is probably important, and WHO acknowledges the significance of immediate sharing of epidemiological, virological, and full genome sequence data with different international locations and analysis groups, together with by open-source platforms similar to GISAID.

WHO advises the next measures:

• Conduct additional virological research to know the particular mutations described by Denmark and to research any modifications in transmissibility and pathogenicity of the virus;
• Nations, notably these with mink and different fur farming, to extend the sequencing of SARS-CoV-2 from human and animal samples the place attainable and share sequence information, together with if the identical mutations are discovered;
• Nations to extend surveillance for COVID-19 on the animal-human interface the place prone animal reservoirs are recognized, together with on mink and different fur farms;
• Nations to strengthen farming biosafety and biosecurity measures round recognized animal reservoirs, notably on mink farms, to restrict the danger of zoonotic occasions related to SARS-CoV-2. This contains an infection prevention and management measures for animal staff, farm guests and people concerned in animal husbandry or culling;
• Remind communities and well being staff of the essential ideas to scale back the danger of transmission of acute respiratory infections by:
• Avoiding shut contact with individuals affected by acute respiratory infections;
• Washing arms ceaselessly, particularly after direct contact with ailing individuals or their surroundings;
• Avoiding unprotected contact with farm or wild animals;
• Training cough etiquette, similar to sustaining distance, protecting coughs and sneezes with disposable tissues or clothes, and washing arms, if experiencing signs of acute respiratory an infection;
• Enhancing commonplace an infection prevention and management practices in well being care amenities, particularly in emergency departments of hospitals.

WHO recommends the well being measures listed above for all vacationers. In case of signs suggestive of acute respiratory sickness both throughout or after journey, vacationers are inspired to hunt medical consideration and share their journey historical past with their well being care supplier. Well being authorities ought to work with journey, transport and tourism sectors to offer vacationers with data to scale back the overall danger of acute respiratory infections through journey well being clinics, journey businesses, conveyance operators and at factors of entry.

WHO advises in opposition to the appliance of any journey or commerce restrictions for Denmark primarily based on data at the moment accessible in relation to this occasion.

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