Bats and pangolins are not the only wild animals that possess new coronaviruses. Rodents like rats, mice, and voles can also carry viruses that are sometimes capable of jumping over to our own species.
Researchers have identified a widespread and common coronavirus called the Grimso virus after discovering it among Sweden''s red-backed bank voles (Myodes glareolus).
We don''t know whether the newly discovered virus is in any way dangerous to humans; however, the findings provide a good example of why we must monitor wildlife viruses, particularly those carried by animals who live in close proximity to us.
"We do not know what potential threats the Grimso virus may pose to public health," says virologist Ake Lundkvist of Uppsala University in Sweden.
Bank voles are among the most common rodents in Europe. Their paths often cross with our own species, and they are known hosts of the Puumala virus, which causes a hemorrhagic illness known as nephropathia epidemica in humans.
Voles are well-known to shelter in human buildings when looking for refuge from bad weather conditions, and this increases the risk of us developing a virus they carry into our households.
Even before the COVID-19 epidemic began, Lundkvist and his colleagues have tried to monitor wildlife disease among voles, to better anticipate when their viruses might spill over. There''s a lot of possibility that interactions with voles will only increase in the future.
Between 2015 and 2017, uppsala researchers examined 450 wild bank voles from a site west of Stockholm called Grimso. Using coronaviruses, the group determined that a new betacoronavirus was circulating in 3.4 percent of the sample.
Betacoronaviruses are commonly found among bats and rodents, and when they jump over to humans, they are responsible for causing the common cold and respiratory diseases like SARS-CoV-2.
The new vole virus hasn''t been seen jumping over to humans yet, but if COVID-19 has taught us anything, it''s important to maintain ongoing surveillance of wildlife disease to prevent further outbreaks.
Researchers in Sweden discovered several distinct viral strains of theGrimso virus that circulated among bank vole populations in the course of three years.
Other closely related coronaviruses were generally distributed among voles in other parts of Europe, such as France, Germany, and Poland, suggesting that these animals are natural resurgences for the disease.
The extreme divergent nature of the Grimsovirus is a bad sign. It indicates the virus is easily adapted to new hosts and habitats.
The various strains found in circulation might have originated from bank voles, or they might have jumped over from another species.
"We believe that bank voles are among the most common rodent species in Sweden and Europe. We believe that the Grimso virus may circulate widely in bank voles, and that sentinel surveillance of coronaviruses may be beneficial for wild small mammals, particularly in wild rodents," the authors say.
Human exploitation of wild spaces has recently increased the risk of animal disease spreading to humans. This risk was particularly common among animals such as bats, rodents, and primates, who have abundant populations and have quickly adapted to human environments.
While rodents and bats have long been considered vectors of human disease, they aren''t the only animals infectious disease specialists to have their eyes on.
Larger mammals, like wild deer, are in close contact with human civilization, and in the northeast of the United States, about 40 percent of deer have been exposed to SARS-CoV-2.
Livestock, like mink, have been included in the COVID-19 epidemic, and researchers are concerned that the virus might mutate among these animal hosts and reinfect us with a different version of the disease down the road.
Increasing biodiversity will only result in increased visibility, putting more animals to restraints. Improved surveillance will also be critical.
If bad weather and habitat damage diminish in the future, we might be bringing new coronaviruses to our homes.
Viruses have been published in this paper.