America's pandemic seems to be entering a new phase, with national rates falling from September's peak and vaccines being given to children, but there is a new concern: wildlife spreading the virus.
New research has shown that coronavirus can be transmitted from deer to humans. This is the first evidence of wild animals carrying the virus. This could lead to similar transmission and spillover in some animal populations, which could have serious implications for the elimination of the virus or the possible emergence of new variants.
A preprint study found that one-third of Iowa deer tested positive for active infections over nine months. The peak was 80% between November and January.
This report builds upon previous research that showed one-third of American deer were exposed to the virus, and developed antibodies. However, it shows a high rate of active infections which last for a shorter time.
According to the analysis, it is very likely that the virus spread from humans to deer via multiple interactions.
The scientists were shocked by almost everything in their study. They were aware that deer could have the coronavirus. They were shocked by the results - four of five deer tested positive for the coronavirus at their highest peak, as well as viral loads that were "truly jaw-dropping", Suresh Kuchipudi (clinical professor of virology at Penn State) told The Guardian. The genetic analysis showed clear connections between human transmission and animals, as well as the rapid transmission to other deer.
Vivek Kapur (Penn State microbiology professor and coauthor of this study) said, "If there's spillover into free-living Deer, it'll rip through like wildfire." Although the study was limited to Iowa only, researchers believe widespread infection could be found in deer in other states.
The deer, which are plentiful in North America, are a popular hunting target. They are susceptible to SARS-CoV-2 because they may eat contaminated food, drink contaminated water, or look undergrowth for signs of spit and relieve themselves.
Kuchipudi stated that animals will become infected if they come into contact with the virus through any source. It is very likely that an animal will contract the virus even if they have never met face-to-face.
These findings have implications for wildlife in general. There is a possibility that other animals may also be infected with the coronavirus. This would make it more difficult to eradicate the virus or prevent new mutations.
SARS-CoV-2 has been confirmed in dogs, cats, ferrets and lions around the globe. The first confirmed cases of SARS-CoV-2 in these animals was recently detected in Hyenas at Denver Zoo.
Investigators discovered active infections and antibodies in wild mink in Utah after an outbreak occurred at a Utah mink farm in August 2020.
Denmark killed 17 million mink in November 2020 after the virus spread from humans to mink, and then back to people. This is the only known case of coronavirus being passed to animals. Although the virus did mutate, none of these changes were considered dangerous.
Before the Covid-19 pandemic in 2004, coronaviruses infected animals. In the US, vaccinations against common coronaviruses were a standard practice for pets.
A coronavirus that causes mild cold symptoms may have caused the 1889 pandemic which claimed 1,000,000 lives. Notably, cattle have passed coronaviruses on to deer. This raises concerns that SARS-CoV-2 may also move between cattle, deer and humans to potentially catastrophic results.
It is difficult to eradicate a virus that can spread between animals and people.
Professor of microbiology, immunology, and the University of Iowa, Stanley Perlman said, "It's harder to get rid of virus if it has reservoir." Although fatalities decrease as people become immune to viruses, the virus doesn't disappear. The 1918 flu pandemic is still circulating today.
"It will always be with us. Perlman did not know what form it was in. But, I do hope it will be an attenuated or weakened form.
Mutations can occur from cross-species contagion. It's difficult to predict if these mutations will be more severe or milder. Perlman stated that there has been no evidence of animal spillback into humans.
Ellen Carlin, an assistant researcher at Georgetown University's Center for Global Health Science and Security said that "the more any virus circulates and travels around, the greater chance it has to mutate."
"Just because a virus mutation occurs, it doesn't necessarily mean that it is a problem for animal or human health." It could, so we need be on the lookout for that," Carlin stated. "Anything is possible at the moment."
Carlin stated that the evidence on animal reservoirs is increasingly pointing to the need to make long-term efforts in order to stop the spread of the virus. For example, vaccines for humans can only prevent cases where the virus is spreading among animals.
We need to do better at detecting viruses in animals and preventing them from reaching people. Carlin stated that this requires us to address some of the most difficult challenges such as climate change, land use change, deforestation, and climate change. Experts say it also requires investments in monitoring and health care systems.
Carlin stated that the deer study is a "really hard reminder" that funding wildlife research for SARS-CoV-2 and other infectious diseases needs to be improved. While we have scientists who can go out and figure out the cause of SARS-CoV-2, there is no system to support that.
Further research is needed to determine if and how the virus spreads from one species to another, including humans.
Kuchipudi stated that if research like this had not been done, outbreaks among Iowa deer wouldn't have been discovered. He said, "There was a silent disease, if you will," that occurred in the deer. "We wouldn't have known this if we hadn't tested the samples."
