Research published on May 29 revealed the “rapid evolution” of the highly pathogenic avian influenza virus.
Since 1996, avian flu (H5N1) has led to enormous economic losses and the mass depopulation of billions of poultry, the study authors noted in their research. In the less than 30 years since its first identification, H5N1 has spread rapidly throughout the world, and has evolved in a series of transient, phylogenetically distinct clades. So rapid is the spread that nations are now calling for the full vaccination of all poultry, according to MedicalXpress.
While the threat of H5N1 to humans is relatively low at present, the impact on birds and mammals is a cause for concern. According to the researchers “something happened” in 2021 that led the family of bird flu viruses to become significantly more infectious, and caused outbreaks to last all year, instead of just popping up sporadically.
Richard Webby, the World Health Organization’s head of the center studying influenza in animals, said the most recent outbreak is “absolutely” the largest the world has ever seen.
— Raquel Ramirez Hernandez, PhD(c), MPH (@RaquelaHernand) June 4, 2023
“That does increase the potential that even just by chance [the virus could] pick up genetic traits that allow it to be more of a human virus,” Webby noted, according to MedicalXpress. Webby also led the research published in the journal “Nature.”
In Chile, some 9,000 sea lions, penguins, otters, porpoises and dolphins have died of bird flu since the start of 2023, the outlet noted, though this figure has been called into question.
Webby said that one of the things that “scares us the most” is indications that the virus is now spreading within mammal populations. It would only take “two or three minor changes in one protein of the viruses” for it to become highly adapted to human hosts, Webby added. (RELATED: ‘It’s Just A Matter Of Time’: Scientists Issue Warning As Deadly, Ebola-Like Virus Spreads)
Another type of bird flu, H3N8, killed its first ever human in April 2023. The patient is believed to have contracted the virus due to close proximity and exposure to live poultry and wet markets in China.