A newly-identified coronavirus is "well established" in voles in Sweden, according to Swedish researchers.
The virus comes from the same family of beta coronaviruses as SARS-CoV-2, the virus which causes COVID-19.
While the disease poses no immediate threat, the researchers at Uppsala University say there is "good reason" to continue to monitor it.
Rodents already carry several microorganisms, such as hantaviruses and tularemia, and play a key role in how infectious diseases are spread.
In recent years, there has been a dramatic increase in infectious diseases that can be linked to small mammals, like rodents.
The Zoonosis Science Center (ZSC) at Uppsala University studied 260 bank voles caught around Grimsö, Örebro County.
Åke Lundkvist, professor in virology and head of the ZSC, said: "Between 2015 and 2017, we consistently found what we have called the 'Grimsö virus' in 3.4% of these voles, which would suggest that the virus is widespread and common in Sweden's bank voles.”
Researchers map zoonotic viruses to increase the understanding of the interaction between viruses and host animals.
Seasonal coronaviruses, such as HCoV-OC43 and HCoV-HKU1, appear to have spread to humans from rodents like rats, mice and voles.
The researchers hope to develop methods that can effectively limit major virus outbreaks and avoid infection spreading from animals to humans.
Researchers examined red-backed voles caught around Grimsö between 2015 and 2017 and tested them for coronavirus.
Using an RNA sequencing method, they identified a new coronavirus known as the 'Grimsö virus' belonging to the betacoronavirus family that also includes SARS-CoV, MERS and SARS-CoV-2.
The bank vole (Myodes glareolus) is one of Europe's most common rodents. Previous studies have found several coronaviruses circulating amongst animals in countries including the UK, Poland, France and Germany.
Professor Lundkvist said: "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, there is good reason to continue monitoring the coronavirus amongst wild rodents.”
In 2020, new research suggested that destruction of the natural environment by farming and deforestation is making future pandemics more likely, new research has suggested.
The research by the University of the West of England and the Greenpeace Research Laboratories at the University of Exeter, suggested disease risks are "ultimately interlinked" with biodiversity and natural processes such as the water cycle.
Diseases from animals, or ‘zoonotic’ diseases, often begin due to changes in land use, the researchers wrote.
Previous research by the EcoHealth Alliance suggests that 31% of outbreaks of emerging infectious diseases are linked to changes in land use, including HIV, Ebola and the Zika virus.
The researchers analysed the relationship between societies and the environment using a computer framework, and concluded that maintaining intact ecosystems will help prevent the emergence of new pandemics.
Deforestation and other land use change undermines resources including water which are key to reducing disease transmission, the study found.
Lead author Dr Mark Everard, of the University of the West of England (UWE Bristol), said: "Ecosystems naturally restrain the transfer of diseases from animals to humans, but this service declines as ecosystems become degraded.
"At the same time, ecosystem degradation undermines water security, limiting availability of adequate water for good hand hygiene, sanitation and disease treatment.
"Disease risk cannot be dissociated from ecosystem conservation and natural resource security."
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