Design, Science and Technology

 

Genetic changes to avian influenza viruses have led to spread among many wild species, creating an uncontrollable global outbreak. Researchers studying the evolution of the bird flu virus over the past 18 years have shown how the strain currently circulating worldwide, an extremely deadly form of the H5N1 subtype, has become increasingly infectious to wild birds. The strain emerged in Europe in 2020, and has spread to an unprecedented number of countries. The study, published in Nature on the 18th October 2023 looked at changes to the virus’s genome over time and used data on reported outbreaks to track how it spread. In 2020, the rate of spread among wild birds was three times faster than that in farmed poultry, because of mutations that allowed the virus to adapt to diverse species. “What was once very clearly a poultry pathogen has now become an animal-health issue much more broadly,” says Andy Ramey, a wildlife geneticist at the US Geological Survey Alaska Science Center in Anchorage. “That has implications for wildlife and domestic poultry as well as us humans that rely upon these resources.”

 

Research Cited published in Nature (Oct. 18, 2023):

 https://doi.org/10.1038/s41586-023-06631-2 

Read the full article at: www.nature.com

 

A new study highlights both the promise and the limitations of gene editing, as a highly lethal form of avian influenza continues to spread around the world.

 

Scientists have used the gene-editing technology known as CRISPR to create chickens that have some resistance to avian influenza, according to a new study that was published in the journal Nature Communications on Tuesday. The study suggests that genetic engineering could potentially be one tool for reducing the toll of bird flu, a group of viruses that pose grave dangers to both animals and humans. But the study also highlights the limitations and potential risks of the approach, scientists said. Some breakthrough infections still occurred, especially when gene-edited chickens were exposed to very high doses of the virus, the researchers found. And when the scientists edited just one chicken gene, the virus quickly adapted.

 

The findings suggest that creating flu-resistant chickens will require editing multiple genes and that scientists will need to proceed carefully to avoid driving further evolution of the virus, the study’s authors said. The research is “proof of concept that we can move toward making chickens resistant to the virus,” Wendy Barclay, a virologist at Imperial College London and an author of the study, said at a news briefing. “But we’re not there yet.” Some scientists who were not involved in the research had a different takeaway. “It’s an excellent study,” said Dr. Carol Cardona, an expert on bird flu and avian health at the University of Minnesota. But to Dr. Cardona, the results illustrate how difficult it will be to engineer a chicken that can stay a step ahead of the flu, a virus known for its ability to evolve swiftly. “There’s no such thing as an easy button for influenza,” Dr. Cardona said. “It replicates quickly, and it adapts quickly.”

What to Know About Avian Flu

The spread of H5N1. A new variant of this strain of the avian flu has spread widely through bird populations in recent years. It has taken an unusually heavy toll on wild birds and repeatedly spilled over into mammals, including minks, foxes and bears.

 

 

Research cited published in Nature Comm. (Oct. 10, 2023):

https://doi.org/10.1038/s41467-023-41476-3 

Read the full article at: www.nytimes.com