BREAKING! Swedish Researchers Discover New Fast Evolving Betacoronavirus Called The Grimso Virus In Rodents And Warn That The Virus Could Be A Threat To Humans!

Contrary to perceptions that most human coronaviruses originated from bats or other exotic wild animals, past history and scientific studies have proven that most actually originated from rodents.


 
Worryingly, a new study led by researchers from Uppsala University-Sweden along with scientists from the University of Oxford-UK, University of Sydney-Australia and the International Livestock Research Institute-Kenya has discovered a new strain of fast evolving betacoronaviruses that can be a threat to humans should it acquire the relevant mutations to jump to humans or participates in a recombinant event with the hundreds of SARS-CoV-2 coronavirus variants currently circulating around the world. The new betacoronavirus currently being temporarily called the Grimso virus as it has been found in a type of rodents found not only in Sweden but also other parts of Europe known as bank voles (Myodes glareolus). These rodents are however most predominantly found in a county called Grimso in Sweden, hence the temporary name for the new betacoronavirus.
 
The ongoing unprecedented COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), with bats as original reservoirs, has once again highlighted the importance of exploring the interface of wildlife diseases and human health.
 
Interestingly, in this new research, the study team identified a novel Betacoronavirus from bank voles (Myodes glareolus) in Grimsö, Sweden that can be a potential threat to humans.
 
Constant and repeated detection over three years and an overall prevalence of 3.4% suggest that the virus commonly occurs in bank voles. Furthermore, phylogenetic analyses indicate that the Grimso virus belongs to a highly divergent Embecovirus lineage predominantly associated with bank voles. Given that bank voles are one of the most common rodent species in Sweden and Europe, the tsuy findings our indicate that Grimso virus might be circulating widely in bank voles and further point out the importance of sentinel surveillance of coronaviruses in wild small mammalian animals, especially in wild rodents.

The study findings were published in the peer reviewed journal: Viruses. https://www.mdpi.com/1999-4915/14/6/1205/htm
 
The study led by researchers from the Zoonosis Science Center at Uppsala University involved the study of approximately 260 bank voles caught around Grimsö, örebro County, shows that the virus is well established in Sweden's red-backed voles.
 
Lead researcher, Dr Åke Lundkvist, Professor in virology and head of the Zoonosis Science Center at Uppsala University told Thailand Medical News, "Between 2015 and 2017, we consistently found what we have called the 'Grimsö Virus' in 3.4 per cent of these voles, which would suggest that the virus is widespread and common in Sweden's bank voles."
 
The study was co-lead by first authors Dr Jiaxin Ling and Dr Anishia Wasberg, a doctoral student.
 
The study team mapped zoonotic viruses to increase the understanding of the interaction between viruses and h ost animals. Unlike the SARS-CoV and MERS coronaviruses that originate in bats, seasonal coronaviruses, such as HCoV-OC43 and HCoV-HKU1, appear to have spread to humans from rodents like rats, mice and voles.
 
The key objective of the study was to increase knowledge and develop methods that can effectively limit major virus outbreaks and avoid infection spreading from animals to humans.
 
The study team using an RNA sequencing method, identified the new coronavirus known as the 'Grimsö Virus' belonging to the betacoronavirus family that also includes SARS-CoV, MERS and SARS-CoV-2 in the rodents that they studied from Grimso.
 
It is already known that rodents also carry several zoonotic microorganisms, such as Hantaviruses and Tularemia, meaning they play a key role in how infectious diseases are spread.
 
Importantly, in recent years, there has been a dramatic increase in infectious diseases that can be linked to small mammals, like rodents, and research around the ecology of these host animals is an essential component in the work to prevent future outbreaks.
 
It should be noted that the bank vole (Myodes glareolus) is one of Europe's most common rodents.
 
Past studies have found several coronaviruses circulating amongst animals in countries like the United Kingdom, Poland, France and Germany.
 
Professor Lundkvist added, “We still do not know what potential threats the Grimsö Virus may pose to public health. However, based on our observations and previous coronaviruses identified among bank voles voles, there is good reason to continue monitoring the coronavirus amongst wild rodents."
 
Past studies have shown that rodents are the primordial hosts of coronaviruses, and rodent coronaviruses constitute at least two subgenera, Luchacovirus and Embecovirus from genera Alphacoronavirus and Betacoronavirus, respectively. https://www.mdpi.com/1999-4915/11/2/125
 
https://pubmed.ncbi.nlm.nih.gov/33318860/
 
The study team discovered the new highly divergent betacoronavirus (Grimso virus) in the Swedish bank voles and based on their knowledge, this study is the first to identify full-genome features of Grimso virus, together with the prevalence and diversity of this rodent coronavirus in Sweden.
 
This new Grimso virus is highly divergent and genetically distinct from earlier described rodent CoVs based on the RNA-sequencing results, which also explains that many reserachers failed to detect any CoVs by using a published pan-coronavirus RT-PCR.
 
By utilizing the specific primers targeted to the spike gene, the study team have discovered nine samples which were positive in the PCR screening, with a continuous positivity for three years, which are 2/48 in 2015, 1/61 in 2016, and 6/157 in 2017.
 
The study team recovered two genome sequences from two strains of Grismo virus. The genomes of strains Grimso215 and Grimso2306 shared 95.6% sequence identity at the nucleotide level, with 1338 site differences. This divergence is notably higher than the expected differences based on a typical substitution rate for coronaviruses of 0.001 substitutions per site per year, which under Poisson distribution predicts an accumulation of 61–121 substitutions over three years. https://pubmed.ncbi.nlm.nih.gov/34518866/
 
https://www.sciencedirect.com/science/article/pii/S1567134812001839
 
This worrying observation suggests that either multiple strains of Grimso-like viruses are co-circulating in bank voles in Grimsö or that these viruses are transmitted regularly to bank voles from other species.
 
One could also contemplate that the observed divergence could be associated with the temporal fluctuations in bank vole population density, leaving room for an increased viral transmission in a cyclic peak preceded by population turnover, similarly as previously described for Puumla Hantavirus dynamics in bank voles. https://www.nature.com/articles/srep21323
 
With a prevalence of around 3.4% (9/266), the study team hypothesize that Swedish bank voles are competent hosts for the Grimso virus.
 
Such wild animals provide pools of divergent virus species for interspecies transmission. The studies on the discovery of animal CoVs have been especially important since the emergence of human coronaviruses. The hidden diversity of CoVs has been explored in at least 37 rodent species distributed in Asia and Europe.
 
Alarmingly, these studies point out that rodent CoVs have undergone frequent recombination and cross-species transmission events.
https://pubmed.ncbi.nlm.nih.gov/33318860/
 
https://pubmed.ncbi.nlm.nih.gov/30285857/
 
Past studies found distinct CoVs in bank voles based on the partial sequences of the RdRp gene in the UK, Poland, Germany, and France. https://pubmed.ncbi.nlm.nih.gov/27102167/
 
https://pubmed.ncbi.nlm.nih.gov/29186061/
 
The study team’s phylogenetic analyses based on complete sequences of ORF1b, S, and N genes, as well as a partial RdRp gene, all suggested that bank voles carry one more divergent CoV, Grimso virus.
 
All these findings suggest a relatively broad geographic distribution of CoVs in bank voles in Europe, which is indicative of possible long-term host–virus association. Furthermore, as coronaviruses closely related to the Grimso virus have been detected in bank voles elsewhere in Europe, it further supports that this divergent coronavirus infects and circulates in Swedish bank voles.
 
In order to understand the zoonotic risks of Grismo virus, the study team analyzed the protein domain of the spike protein and hemagglutinin esterase. Due to the high divergence and the lack of isolated live virus, the team could not yet identify the host receptor usage for this novel rodent CoV. However, the study team warned that scientists cannot neglect the zoonotic potential of Grimso virus to livestock or humans. Together with mapping and continuous monitoring of the Grimso virus, further studies will aim to isolate the virus and assess the pathogenic profile.
 
The study team concluded, “We identified a highly divergent Embecovirus, named the Grimso virus, in Swedish bank voles. Our analyses suggest that multiple distinct viral strains co-circulate in this population, although further investigation will be necessary to fully understand the transmission ecology. Furthermore, we found that closely related coronaviruses are broadly distributed across Europe and exclusively associated with bank voles and other vole species, indicating that bank voles are likely natural reservoirs of the Grimso virus. While the potential threat posed by the virus to human and animal health is unknown, our study findings underscore the importance of longitudinal surveillance of CoVs in wild rodents in advancing current knowledge on the ecology of CoVs in reservoir populations.”

With numerous SARS-CoV-2 variants now in circulation in Europe and the present of another betacoronavirus that itself is fast evolving, the chances of a recombinant event taking place and leading to the emergenc of a lethal human coronavirus is very high. It will indeed be fun if such a scenario materializes soon in Europe, preferably in the United Kingdom that now already has  a variety of surges by various pathogens including monkeypox. With many bogus yet arrogant and rude experts there, such an emergence of new lethal pathogens will be interesting.
 
For more on the Grimso Virus, keep on logging to Thailand Medical News.