Experts have issued a warning about the rapidly changing virus responsible for the unprecedented surge in avian influenza cases worldwide. Amid mounting calls for countries to vaccinate their poultry, specialists underscored that the risk to humans remains low.
However, they expressed concern over the escalating number of bird flu cases in mammals. Previously limited to seasonal outbreaks, the H5N1 avian influenza virus underwent a significant transformation in mid-2021, rendering it considerably more infectious.
Richard Webby, head of a World Health Organization collaborating center dedicated to studying animal influenza, revealed that something pivotal occurred, leading to year-round outbreaks, geographic expansion, and extensive mortality among wild birds and millions of culled poultry. Webby, a researcher at St Jude Children’s Research Hospital in Memphis, confirmed that this is unequivocally the largest avian influenza outbreak ever recorded.
Webby’s team recently published a study in Nature Communications detailing the virus’s rapid evolution as it spread from Europe to North America. The research indicated that the virus became more virulent upon reaching North American soil, causing more severe diseases.
To further investigate, the researchers deliberately infected a ferret with one of the novel bird flu strains. The astonishingly high viral load detected in the ferret’s brain indicated a greater pathogenicity compared to previous strains.
While emphasizing the ongoing low risk to humans, Webby stressed that the virus is far from static—it is actively changing. This dynamic nature raises concerns about the potential for the virus to acquire genetic traits that could enable it to infect humans more efficiently.
Although human infections are rare and typically occur through close contact with infected birds, the ever-changing nature of the virus presents a constant monitoring challenge for global health authorities.
