“We actually know through previous studies along with also through what’s happened inside past in which most viruses come through mammals … not birds along with also not reptiles or additional species,” said Kevin Olival, lead author of the study along with also an associate vice president for research at EcoHealth Alliance, a global environmental health nonprofit.
To understand what might create an unexpected pandemic risk, Olival along with also his colleagues tried to address several pieces of This particular puzzle.
“So the first piece is usually, truly: What makes some species inside planet better hosts for viruses or zoonotic viruses than additional species?” he said. Some animals are better reservoirs — or sources — of viruses than others.
Pieces of the puzzle
He along with also his colleagues created a database in which included 754 mammal species — 14% of the mammal diversity on the planet — along with also 586 unique viral species, every recognized virus found in mammals.
Next, they analyzed 2,805 mammal-virus associations. For instance, about 45% of the total 586 viral species have been detected in humans, along with also of those, nearly 72% have been detected at least once in a human along with also at least once in another species.
Applying mathematical types to the database, the researchers discovered in which the risk of a virus leaping through a mammal to a human varied based on how related the animal species was to humans as well as the frequency of contact with humans.
Yet there was also an entirely independent variable. Simply belonging to one category of animals as opposed to another made This particular much more likely in which a particular creature might be a source of zoonotic viruses. For example, bats may not be closely related to humans, although they carry a “significantly greater proportion of zoonotic viruses than any additional mammals,” said Olival.
The researchers also used the database along with also mathematical tools to predict the number of viruses each specific animal might carry.
The second piece of the puzzle was geography: Where might unknown zoonotic diseases be hiding? Naturally, the location of each zoonotic virus’ animal host answered This particular question. Zoonotic viruses arising through bats could cluster in South along with also Central America along with also parts of Asia, while primate viruses could be found in Africa, Central America along with also Southeast Asia. Zoonotic viruses carried by rodents could mostly be found in North along with also South America along with also Central Africa. Olival along with also his colleagues mapped This particular information.
The third along with also final piece of the puzzle was “what makes some viruses more likely to jump into people than others,” Olival said. “I think in which’s a truly important piece, along with also there’s a lot more work in which can be done, although we truly provided a framework to move in which predictive field forward.”
Overall, Olival said, the brand-new study, which took about six years to complete, “provides a roadmap for where inside planet we should prioritize for finding along with also stopping the next emerging virus, along with also in which road map includes what species we should focus on along with also what locations are most important along with also what viruses should we be looking out for.”
Amesh Adalja, a spokesman for the Infectious Disease Society of America, said the research is usually “very important.”
“We are going to continue to have infectious disease threats, along with also This particular’s basically one of the great scientific along with also medical challenges to keep pace with in which,” said Adalja, also a senior associate at the Johns Hopkins Center for Health Security who was not involved inside study.
Not everyone risks catching a zoonotic infection. Some people — including hunters, people who work in slaughterhouses along with also those who work in agricultural settings — are “basically at the leading edge of the human-animal interface,” Adalja said, along with also so are more likely to become infected using a zoonotic virus.
with This particular reason, there’s a lot of interest in doing active surveillance of these populations, he said.
Generally, the brand-new study tries to develop “some type of analytical way of assessing the risk of these types of infections,” he added, along with also “does, hopefully, make This particular a much easier prospect.”
“As human beings expand their reach along with also live in many different areas where they traditionally haven’t lived in, you will see more opportunities for novel viruses to appear,” Adalja said.
“You can think about Lyme disease as a zoonotic infection,” he said, observing in which Lyme became a big health issue only when people started out to live in places “in which are more wooded.”
Olival said human behaviors are a key factor inside emergence of these zoonotic infectious diseases.
“Anything in which puts us into contact with these mammal species in which most people have never heard of, right, in which might be living deep inside forest,” he said. “So things like deforestation along with also road building along with also hunting — all those factors are Great examples of interactions in which can actually cause diseases to come out of their natural habitat along with also jump into the human population.”
Though contact makes a difference, so too does temperature. Certain viruses, such as flu, are more likely to spread in cold conditions as opposed to hot, Adalja said.
“We know, for example, in which diseases like yellow fever, which people currently, in today’s world, think of as a tropical disease, used to occur in Boston,” he said, explaining in which This particular is usually also known in which “mosquitoes have thrived in areas in which aren’t traditionally associated with mosquitoes.”
along with also while This particular’s true there’s a lot more diversity of animal species in jungle or rain forest areas, there’s a danger in believing in which emerging diseases could happen in only some parts of the planet. “Flu viruses might do better in colder temperatures, although additional viruses might do better in tropical climates,” Adalja said.
“the planet is usually a very, very smaller place,” he said. “This particular’s very easy to be in a jungle in Africa or South America or the Indian subcontinent one day along with also in a Western city the next day.”
This particular speed of travel allows an infection through one side of the globe to appear on another side when, inside past, This particular could not have been possible for an infected person traveling in which far to make the trip, Olival noted.
“My biggest fear is usually in which a disease may emerge anywhere inside planet, even inside most remote region of the planet, along with also can arrive to a major US city in less than 24 hours,” Olival said.
The best way to handle This particular potential infectious threat is usually to truly home in on the viruses in which are at the highest threat level along with also then try to intervene once you’ve identified in which, Adalja said.
“We have to continue to refine the way we basically sift through all these viruses on This particular planet along with also understand which are most likely to cause” emerging infectious diseases, he said. “So you can be much better prepared for infectious diseases along with also maybe even prevent them through occurring.”