‘We don’t know exactly why’

Photo Credit: Getty Images

Every spring, Delaware Bay draws thousands of migratory birds and horseshoe crabs, creating a natural spectacle. For nearly 40 years, scientists have gathered here to track flu viruses in the bird population, hoping to catch early signs of potentially dangerous outbreaks. 

This year, however, researchers noticed something surprising. Despite the growing threat of H5N1, they didn’t find the virus in the bird droppings they collected, and “we don’t know exactly why,” said Dr. Lisa Kercher, director of St. Jude Children’s Research Hospital laboratory operations.

This unexpected finding has raised hopes that scientists may have more time to prevent future flu outbreaks, offering new insights into how viruses spread and potentially easing fears of a new pandemic.

For over two decades, H5N1 has been closely monitored, as it’s one of the deadliest flu viruses known to infect birds. The virus spreads through birds but also mutates quickly, which raises concerns about its ability to infect humans in the future. As a result, H5N1’s ability to infect a wide variety of species has made it a focus of global health experts.

However, recent surveillance has revealed some interesting findings. The virus appears to be evolving through a process called reassortment, where two different viruses infect the same animal and swap genes, leading to bigger genetic changes. Researchers are investigating how this may affect the spread of the virus in the coming years.

By analyzing previous surveillance data gathered by Dr. Robert Webster and Dr. Richard Webby, Dr. Louise Moncla from the University of Pennsylvania conducted a new study. The study revealed that the 2021 H5N1 outbreak in North America was driven by eight separate introductions of the virus by migrating waterfowl and shorebirds along the Atlantic and Pacific flyways. 

Unlike the outbreak in 2014, when aggressive culling stopped the virus from spreading, the new strain from 2021 has continued to circulate because wild birds have continued to introduce the virus into both farmed and backyard poultry populations.

Moncla and her team concluded that wild birds are emerging as a key “reservoir” for H5N1 in North America and that monitoring migrating birds is crucial to prevent future outbreaks.

Despite these challenges, researchers remain hopeful. Webby’s team plans to continue their surveillance, knowing that their data could offer an early warning for future outbreaks.

“[The birds] stop in Delaware Bay to refuel, and then the viruses get moved around while they’re stopped over, and then they carry it off again,” Kercher said.

“To predict the bad things — whether it’s a tornado, whether a pandemic — you’ve got to understand normal now,” Webby said. “From there, we can detect when things are different, when it changes hosts, and what drives those transitions.”

Join our free newsletter for weekly updates on the latest innovations improving our lives and shaping our future, and don’t miss this cool list of easy ways to help yourself while helping the planet.

_{Images are for reference only.Images and contents gathered automatic from google or 3rd party sources.All rights on the images and contents are with their legal original owners.}