Finding the next deadly virus and preventing a rat, bat or monkey from spreading it to people should be the primary focus of the world’s efforts to stop the next pandemic, a group of international researchers pleads in a study published Friday.
Preventing diseases from skipping from wildlife to people would save lives and billions in costs, the researchers said, and should be prioritized ahead of detecting and treating viruses after people get sick.
Disease experts and wildlife biologists had warned of the deadly risks of pathogens spreading from animals to people before COVID-19 arrived. The long list of such previous viruses include HIV, ebola and chikungunya.
Now, two years of fighting a virus that may have jumped from an unknown animal in Wuhan, China, has magnified that threat and the urgency of preventing the next exotic disease from circling the globe, said Aaron Bernstein, interim director of The Center for Climate, Health and the Global Environment at Harvard University and a pediatrician at Boston Children’s Hospital.
Hammering on the need to invest in diagnosis, treatment and vaccinations after a disease emerges – without addressing how these pathogens get transferred to people – kind of misses the point, said Bernstein, a lead author on the paper, published Friday in the journal “Science Advances” by a group of 20 researchers across five continents.
It’s not that vaccines, pharmaceuticals and diagnostic tests aren’t needed, it’s that addressing future pandemics should start before the virus arrives, he said. “Vaccines aren’t primary prevention.”
The researchers estimate it would cost $20 billion a year to focus preventive efforts in locations with the greatest risk — only a tenth of the estimated annual economic losses from emerging viral diseases and a small price beside the estimated 3.3 million lives lost each year from emerging infectious diseases.
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The study showed novel viral outbreaks are occurring at an increasing rate and expected to become even more frequent.
They point to diseases already being tracked in animals, like a swine disease underway in China and the chronic wasting disease in deer in the U.S. The study stated each “may be only a handful of mutations away from triggering a human pandemic.”
Such diseases can be transmitted not only directly from animals to people, but also through insects such as ticks, mosquitoes and even garden slugs and snails.
Most diseases spill out of bats, rats and monkeys, which are diverse in the wet tropics of the world, said Stuart Pimm, a conservation ecology professor at the Duke Nicholas School for the Environment at Harvard.
“We know which countries they’re in,” Pimm said. “It would just seem to be very prudent for us to know what’s in tropical bats.”
And those animals shouldn’t be imported “without finding out what sort of diseases they’re carrying,” he added. “We ought to be paying a lot of attention to what might be out there, what’s infecting animals, and what’s infecting animals that we’re importing, either for the pet trade or for bushmeat or some sort of luxury item.”
The study lists three main drivers of new pathogens: the wildlife trade and hunting; agricultural intensification and expansion; and the destruction of tropical forests. Deforestation, especially in the tropics, brings people into greater contact with animals as they clear land for farming, timber and road-building.
The pandemic prevention study was one of at least two articles on similar topics published in journals over the past week. The second was from a group of Florida researchers at the University of Florida and Stetson University, who say they are the first to document larvae of the rat lungworm parasite living inside the invasive Cuban tree frog.
As adults, the lungworm larvae live in rat lungs, said Terry Farrell, a biology professor at Stetson. Humans could get the lungworms by accidentally ingesting snails or slugs that feed on produce.
Increasing awareness of the potential for emerging parasites should be a priority, Farrell said.
“It’s amazing and horrifying how rapidly we are spreading diseases across the globe,” he said. “Almost all of these parasitic diseases that we are concerned about are transmitted through the food chain.”
It’s of particular concern in Florida because it’s “the epicenter” of the importation of reptiles, amphibians and fishes, he said.
Pimm noted that a key area of concern with mass clearing in the Amazon is a mere four-hour flight to Miami.
The pandemic prevention study recommended three actions: better surveillance of potential pathogens, better management of the world’s wildlife trade; and substantial reduction of deforestation.
The measures also could have other benefits, Bernstein said, such as protecting wildlife habitat and removing carbon from the atmosphere.
A few small centers try to monitor pathogens, said Marcia Castro, chairman of the global health and population department at Harvard’s T.H. Chan School of Public Health. “But one of the challenges is to have a real network across the world.”
What can individuals do to help prevent the spread of disease?
Bernstein suggests eating locally or regionally grown foods where possible, buying products from companies that disclose where their products come from and avoiding products that rely on materials from rainforests. He also advises against buying exotic pets from tropical waters or forests, or buying clothes made from wild or farmed animals.