Finding new diseases is difficult and dangerous work. In the middle of the night, the researchers would get dressed in protective gear. They would wear suits that covered them from head to toe, goggles, two pairs of gloves, and boots. Then they would go to caves and set up nets to capture bats and tarps to collect their droppings. There would be so many bats that it would take the team just a few minutes to have hundreds to sample.
Studying these bats, researchers from the Smithsonian’s Global Health Program discovered six new coronaviruses, the same family of viruses as the one that causes COVID-19, which, as of April 11, has infected more than 1.5 million people globally, including more than 459,000 in the United States. They published their results Thursday in the journal PLOS ONE. While they do not suspect the new viruses are harmful to humans or closely related to COVID-19, the finding takes on new relevance as the world grapples with the ongoing pandemic.
“The goal is to prevent the virus from getting into the humans in the first place,” says Marc Valitutto, lead author of the study and a former wildlife veterinarian with the Global Health Program.
Searching for new viruses is “a grueling job,” he adds, “but this is what’s required if you want to prevent 90,000 deaths, which is what we’re seeing today. So, it’s a small investment monetarily compared to what we’re spending now.”
Suzan Murray, a zoo veterinarian and director of the Global Health Program, and co-author of Thursday’s study, agrees. “It really makes sense to go upstream and try and identify and prevent some of this first,” she says. “We need to be building the wildlife resources and the capacity to do wildlife testing and wildlife surveillance ahead of the curve.”
Zoonotic pathogens, which spread between animals and humans, have caused almost three quarters of infectious diseases in humans this century. This interaction happens because of changes in land use and other human behavior.
A major source of zoonotic diseases are bats. Bats have strong immune systems that enable them to host pathogens without being infected. That resistance to infections combined with their ability to travel far distances make them prime vehicles for carrying and transmitting viruses. They sometimes carry coronaviruses, a family of viruses that can cause respiratory and gastrointestinal infections in birds and mammals. Research shows that bats were the original hosts of SARS and MERS, both respiratory illnesses caused by coronaviruses; according to the National Institutes of Health, “it is likely” that SARS-CoV-2, the virus that causes COVID-19 infections, also originated in bats. Bats can also carry filoviruses, such as Ebola.
Zoonotic pathogens can also go from humans to animals, and there is a concern that people might transmit COVID-19 to bats. This could endanger bat populations and also cause bats to further spread the disease. For this reason, the U.S. Fish and Wildlife Service issued an advisory to bat biologists in late March suggesting they temporarily stop working with bats in North America, The Washington Post reported.
The Global Health Program behind the Myanmar research is part of the Smithsonian Conservation Biology Institute. The research also came out of PREDICT, a U.S. Agency for International Development-funded initiative to monitor and discover viruses. Researchers from the University of California, Davis also participated.
For the new findings, the researchers collected samples and data between May 2016 and August 2018 from three sites in Myanmar.
One cave that the researchers studied in Myanmar, Linno Cave, had more than half a million bats. Tourists would visit the area to watch the bats leave the cave each night. Caves in Myanmar also serve as religious sites, and local people go there to collect bat droppings for fertilizer.
Working with local scientists and government representatives, the Smithsonian team took oral and rectal swabs from the bats. They also set up plastic tarps to collect guano, the droppings. Capturing samples from each bat took less than five minutes. A team then analyzed the samples at a lab in Myanmar.
They tested 464 bats from at least 11 species and collected 759 samples. Forty-eight of the samples contained coronaviruses. They found seven coronaviruses, six of which were previously unknown to researchers. Most of these were in the guano, not from the swabs, which suggested that the droppings could be a major source of viral transmission.
The discovery of six novel coronaviruses did not surprise the researchers, given that PREDICT has found more than 150 coronaviruses around the world. And bats are thought to carry thousands of coronaviruses, the majority of which researchers have yet to discover. “We know that these exist,” Valitutto says. “It’s just a matter of finding them.” There are an estimated 1.6 million unknown viral species in birds and mammals.
Smithsonian researchers have worked with the Myanmar government for more than two decades. In 2018, they announced the discovery of a new coronavirus in bats there and a second coronavirus that scientists had previously detected only in Thailand.
The researchers now find themselves studying coronaviruses at a time when the whole world is focused on that viral family. And they believe that the current pandemic demonstrates why their work is so important.
“You go out and you do these presentations associated with your work and in some respects it seems a little bit inflated, where you’re an alarmist and you’re trying to say, ‘The sky is falling, the sky is falling, you’ve got to protect yourself, it’s only a matter of time,’” Valitutto says. “But here it is, here is the time…. This is a prime example to show you, ‘Hey, this is why we need to do this work.’” Valitutto was in China for another project when the current pandemic began.
“We have been saying within the medical community, ‘An epidemic is coming, it’s coming soon, it’s likely to be one of these three or four viral families, it has the potential to kill a lot of people,’” Murray says. “Until it really touches people, it’s hard to recognize how connected we are. And as long as something’s happening across an ocean and far away, sometimes it’s hard to really feel the relevance of it.” People now realize, she says, that “we’re more connected than we think we are.”
Murray has been involved in COVID-19 modelling as the Smithsonian liaison to the Foreign Animal Disease Threat and Pandemic Preparedness subcommittees of the Office of Science and Technology Policy at the White House.
“When people look at the COVID response right now they’re saying, ‘Oh my goodness, too bad we weren’t prepared,’” Murray says. “This is what it looks like when we were pretty well prepared.”