It was a great day for fieldwork on the shores of the Delaware Bay. The late afternoon sun casts a warm glow on the gently sloping beach. When the tide went out, we could see little shells. The dune grass rustled in the wind. The beach vines were blooming. And the bird droppings were fresh and plentiful.
“Here’s one,” said Pamela McKenzie, a researcher at St. Jude Children’s Research Hospital in Memphis, pointing with her gloved finger at one small white speck, then another. “There is one, there is one, there is one.”
For the next two hours, Dr. Mackenzie and colleagues crawled along the beach, scooping up bird droppings. Their goal is to stay one step ahead of bird flu. Bird flu, a group of viruses adapted to birds, have evolved to spread easily among humans and have long worried experts that they could trigger the next pandemic.
Every spring, this area of southern New Jersey becomes a hotspot for bird flu. Flying northward, shorebirds descend to local shores to rest and reenergize, excreting virus along the way. And every year for the past 40 years, St. Jude scientists have followed them into town.
This task requires patience to wait for the movement of the birds to match the movement of the tide. You need keen eyes and knees strong enough to endure hours of limping and squatting along sometimes rugged coastlines. “The sand isn’t very nice,” said Lisa Kercher, a member of the St. Jude team. “It’s a thick, muddy, nasty beach full of bird droppings.”
But these dung-covered shores are helping scientists understand how bird flu evolves, how it behaves in the wild, and how these bird viruses become a global public health threat. It helps me learn more about what I need. These scientific questions have led St. Jude’s research team for decades as the United States grapples with the largest bird flu epidemic in history, caused by a highly pathogenic new virus known as H5N1. The urgency has increased even further.
“The Delaware Bay has become a flu gold mine,” said Robert Webster, a St. Jude flu expert who first discovered the hotspot in 1985. Since then, he or his colleagues have returned every year. “And we’ll keep digging that gold mine until we find the answer.”
beach with birds
In June, the southern New Jersey coast fills with vacationing families, with colorful beach umbrellas stretching out onto the sand.
But the beach in May belongs to birds. Hundreds of thousands of migratory birds and seagulls stop here on their way to their summer breeding grounds, some of whom travel several days from South America to arrive limping and exhausted. There is also “They are in dire need of replenishing their weight.” Wildlife biologist Lawrence Niles, who leads a local sandpiper conservation project through his company, said: wildlife restoration project.
Luckily, the birds arrived just as the large shoals of horseshoe crabs were pulling ashore and laying thousands of eggs. Dr. Niles says the birds can continue to eat the gelatinous, green eggs for two weeks, “almost doubling their weight.” All the while, they cover the beach, mingle with local birds, and pass the flu on to each other, just like kids in a packed classroom.
Wild waterfowl such as ducks, seagulls, and shorebirds are natural carriers of influenza A viruses of various subtypes. Wild birds generally carry relatively benign versions of these viruses and pose little immediate threat to birds or humans. However, influenza viruses can change rapidly, accumulate new mutations, and exchange genetic material. These changes can, and sometimes do, turn a terrible virus, like his H5N1 strain currently circulating, into a deadly virus.
Influenza is often transmitted at low levels among sandpipers and gulls, and is often less than 1 percent sample. However, the Delaware Bay sees an explosion of easy bird-to-bird migration from May to early June. Over the years, St. Jude’s team found it in an average of 12 percent of samples, but that figure climbed to his 33 percent. They found almost every subtype of influenza A, along with new remixes that can emerge when animals are infected with multiple versions of the virus at once.
St. Jude scientists are working closely with Dr. Niles and others to monitor what’s going on, and the shorebirds face threats ranging from climate change to climate change during their spring sojourn. assessing the health status of Overfishing of horseshoe crabs. Dr. Niles and his team are usually the first to go to the beach to count, catch, inspect and tag birds. They then provide the bird’s whereabouts to the Flu Hunting Squad. “Then we go outside and pick up poop,” said Dr. Kercher.
“Unique year”
But when the team spent the first full day on-site this spring, the tide had turned again by the time the conservationists had finished their work. So the St. Jude scientists spent hours waiting for the water to recede. I hope you can still find the herd. “We’re at the mercy of the birds, but they don’t tell us what they’re doing,” Dr. Kercher says.
At about 4pm, we finally trudged down a gravel road, past pine forests and marshes, to the local beach where shorebirds had been sighted earlier.
Dressed in black joggers and a gray waffle-knit top with a hood, Dr. Mackenzie got out of the car and looked out at the beach. The horseshoe crab was growing along the high tide line. A flock of birds was flying in the water in the distance. Dr. Mackenzie raised his binoculars. Bingo: They were ruddy turnstones, sandpipers whose tricolor markings are sometimes compared to the spots of a calico cat. The St. Jude researchers found that these birds were particularly likely to carry the flu virus.
The scientists wore gloves and masks as a recent added safety measure. “This is not what we have done in the past,” Dr. Mackenzie said. “But this year is a unique year.”
The new H5N1 strain first appeared in North America in late 2021 and has spread rapidly across the continent.that led to death almost 60 million farmed birds killed lots of wild things And they even felled unfortunate mammals, from red foxes to gray seals.
The St. Jude team found no trace of H5N1 in Delaware Bay last spring. At that point, however, the virus had not yet reached South America, the wintering ground for shorebirds. By this spring, that means the birds can take it home. “We are absolutely worried that it will show up,” said Dr. Kercher.
So the scientists stepped up surveillance and set a goal of collecting 1,000 stool samples instead of the usual 600. They began to move toward the beach, looking down for the correct white spot. Any poop is fine. It had to be fresh excrement, ideally excrement from bloody turnstone and another species of sandpiper, red cob. Scientists have become good at distinguishing between the two types of feces. “Turning stones are mostly logs,” says Dr. Mackenzie. “The red knot feels a little splattered.”
When the scientists found a suitable spot, they knelt down and unsheathed a swab with a blunt tip. In some cases it took several attempts to successfully collect the sample. “Using these tools is by no means an easy technique.” Research team member Patrick Seiler said: “I was trying to scoop poop into a small vial while the wind was blowing.”
flu clues
They packed the samples in small plastic coolers like the ones that vacationers bring to the same beach. The samples are then shipped back to our Memphis lab for testing and analysis.
Typically, researchers sequence the viruses they discover, look for notable mutations, chart evolution over time, and then select subsets for study in different cell types and animal models. increase. Over the past few decades, this research has led scientists to understand what “common” bird flu viruses look like and how they behave, according to St. Jude team flu expert Richard Webby. It has helped me learn more.
It also helped identify outliers. “And that brings us to the chase,” said Dr. Webby, who said it could ultimately reveal “something about the basic biology of these viruses.” . In 2009, some of the viruses they found turned out to be surprisingly well transmitted among ferrets.Further study of these viruses was useful to researchers Identify genetic mutations It may facilitate airborne transmission of influenza among mammals.
If the team finds H5N1 this year, Dr. Webby and colleagues are wondering what changes the virus may have acquired as it travels between shorebirds, what might make the virus more dangerous to humans, and what vaccines and treatments might be affected. You’ll look for changes that might increase tolerance.
Dr. Webby and his colleagues reported that the virus has already evolved significantly since reaching North America. in a recent paperIt is based on analysis of virus samples isolated from birds outside the Delaware Bay area. The new mutants they discovered do not have the ability to spread easily between mammals, but some can cause severe neurological symptoms in infected mammals.
The detection of the virus in this year’s Delaware Bay samples would be another sign that the H5N1 virus is becoming increasingly established in North America. It could also be a problem for some shorebirds, especially the magnolia, whose numbers have plummeted in recent decades. Dr. Niles said H5N1 is a “big unknown threat” to these birds.
So while the excreta collection process remains humble, the dangers feel greater as scientists work their way toward the coast.
All they can say is that they have yet to discover a new H5N1 virus. “But that doesn’t mean we won’t do it,” Dr. Mackenzie said. I carefully scooped up the scatology clues left by the birds. “I’m sure you’ll understand.”
