Key TakeawaysA new online assessment tool may help researchers predict which viruses that originate in wildlife couldcause pandemicslike COVID-19.Zoonotic viruses, those that spill over from animals into humans, are an increasing threat as humans move into areas that were once isolated.The online risk assessment tool is open source, which means that epidemiologists, veterinarians, and infectious disease specialists around the world can add information and check the risk of new viruses as they are discovered.
Key Takeaways
A new online assessment tool may help researchers predict which viruses that originate in wildlife couldcause pandemicslike COVID-19.Zoonotic viruses, those that spill over from animals into humans, are an increasing threat as humans move into areas that were once isolated.The online risk assessment tool is open source, which means that epidemiologists, veterinarians, and infectious disease specialists around the world can add information and check the risk of new viruses as they are discovered.
You’ve probably heard about outbreaks of Ebola, Lassa fever, and Zika virus around the world in recent years. Before producing epidemics or pandemics, the pathogens that caused the diseases had to “spillover” from wildlife to humans.
When a virus or another infectious agent makes the jump from animals to humans, it’s called a zoonotic disease or zoonosis. A zoonotic disease you’ve probably heard about recently isSARS-CoV-2, the virus that causes COVID-19.
Although they can be bacterial, fungal, or parasitic, viral zoonotic diseases are the most serious threat.
Assessing New Viruses
COVID-19 has put infectious disease experts around the world on an even higher alert for the potentialnextpandemic. To aid in making predictions, researchers have created an online tool that can help others evaluate the risk of a new virus jumping (or “spilling over”) from animals into humans.
Jonna Mazet, DVM, PhDWe need to know: how and why does a wildlife virus become zoonotic? Which viruses pose the greatest threat?
Jonna Mazet, DVM, PhD
We need to know: how and why does a wildlife virus become zoonotic? Which viruses pose the greatest threat?
The online application is meant to help researchers and governments assess the risk of new viruses as they are discovered and communicate that risk to ensure that disease prioritization, prevention, and control actions are taken.
How the Tool Works
The tool evaluates a newly-discovered virus and based on the findings, creates a list of other viruses that policymakers and public health officials might want to keep an eye on.
SpillOver is open-source, which means that it will be able to grow and become more robust as new information about emerging viruses is added.
Identifying Risk Factors
To create the SpillOver application, the authors identified risk factors of the viruses, hosts, and the environment that would be most relevant to animal viruses spilling over into humans.
Sarah Olson, PhDScientists have only cataloged about 0.2% of global virus diversity in mammals and birds.
Sarah Olson, PhD
Scientists have only cataloged about 0.2% of global virus diversity in mammals and birds.
The risk factors included in the assessment tool were the number of animal hosts, where they are found geographically, and the types of environments in which they live.
The top 12 viruses on the list were already known to be human pathogens—a finding that was expected and showed that the assessment tool works.
The Lassa virus took first place, with SARS-CoV-2 coming in second. Even though it caused a pandemic, SARS-CoV-2 did not make first place because not much was known about its animal hosts.
The larger list of viruses included several newly-discovered coronaviruses that are considered high risk for moving from wildlife to humans.
What Is Lassa Fever?
Why Do Viruses Make the Jump?
Mazet says that viruses are jumping between wildlife and humans at a faster rate because humans are moving into wilderness areas at a faster rate. Usually, when humans move into wilderness areas and other isolated locations, it’s because they are looking for raw materials like the rare metals needed for technology such as cell phones or to open up more land for agriculture.
“It’s not the wildlife, or even the viruses, that are jumping out and attacking or infecting us—it’s our behavior that puts us at risk. And that’s sometimes a bitter pill to take to recognize that,” Mazet says. “But on the other hand, that means it is within our capacity to adjust our behavior so that we reduce our risk.”
As people move into areas that were once isolated, they often bring domesticated animals with them. Viruses are then able to jump to livestock and eventually move to humans. “That provides for another opportunity for a pathogen to change and become a bit more virulent before it spills over into people,” Mazet says.
An Overview of Zika Virus
Although the SpillOver tool is for assessing viral zoonoses, there is also a risk of disease and epidemics from bacteria that can spread from animals to humans. In bacteria, Mazet says that the risk is not so much from a bacterium jumping from animal to human as it is from the genes for antimicrobial resistance spreading.
Watching For the Next Virus
“This tool is very much about understanding a yet-unknown virus—aka virus X—that can crop up at any time," saysSarah Olson, PhD, an author of the study and the associate director of epidemiology at the Wildlife Conservation Society in the Bronx, tells Verywell. “The tool is useful to rank viruses ‘known to science’ but its other value is pointing out a list of information that is needed to improve our assessment of risk.”
Jonna Mazet, DVM, PhDIt’s not the wildlife, or even the viruses, that are jumping out and attacking or infecting us—it’s our behavior that puts us at risk. And that’s sometimes a bitter pill to take.
It’s not the wildlife, or even the viruses, that are jumping out and attacking or infecting us—it’s our behavior that puts us at risk. And that’s sometimes a bitter pill to take.
According to Olsen, there are an estimated 1.67 million undescribed viruses in mammals and birds. About half of those are thought to be capable of spilling over into humans. “To put it another way, scientists have only cataloged about 0.2% of global virus diversity in mammals and birds,” Olson says.
Mazet says that “we need to know: how and why does a wildlife virus become zoonotic? Which viruses pose the greatest threat?”
The Threat of Coronaviruses
According to Mazet, the journal article on the SpillOver tool was mostly written before SARS-CoV-2 was fully recognized. Olson points out that the virus was not detected in wildlife before the pandemic and was already spreading globally before the threat was fully recognized.
The study authors noted that many coronaviruses may spill over into humans but go unrecognized. A lack of diagnostic capabilities and poor reporting contribute to them being overlooked. Additionally, the viruses usually only cause mild symptoms—or no symptoms at all—making them even harder to spot.
Will COVID-19 Be Around Forever?
The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit ourcoronavirus news page.
1 SourceVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Grange ZL, Goldstein T, Johnson CK, et al.Ranking the risk of animal-to-human spillover for newly discovered viruses.Proc Nat Acad Sci. 2021 Apr;118(15):e2002324118. doi:10.1073/pnas.2002324118
1 Source
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Grange ZL, Goldstein T, Johnson CK, et al.Ranking the risk of animal-to-human spillover for newly discovered viruses.Proc Nat Acad Sci. 2021 Apr;118(15):e2002324118. doi:10.1073/pnas.2002324118
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Grange ZL, Goldstein T, Johnson CK, et al.Ranking the risk of animal-to-human spillover for newly discovered viruses.Proc Nat Acad Sci. 2021 Apr;118(15):e2002324118. doi:10.1073/pnas.2002324118
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