Genetic changes power H5N1 virus spread, severity in animals

Subject : Science and technology

Section: Biotechnology

Concept :

Jude Children’s Research Hospital scientists discovered how the current epizootic H5N1 avian influenza virus (bird flu) gained new genes and greater virulence as it spread west.
Researchers showed that the avian virus could severely infect the brains of mammalian research models, a notable departure from previous related strains of the virus.
The researchers genetically traced the virus’ expansion across the continent and its establishment in wild waterfowl populations to understand what makes it so different.

A low risk to humans

While the newer strains of this H5N1 influenza show a greater ability to cause disease in mammals than earlier viruses, the scientists found it to be low-risk to humans.
This is because the virus appears well-adapted to transmit between birds rather than between mammals.

Genetic change supercharges spread and severity

In the past, similar strains of influenza viruses have not caused similarly severe diseases, nor have they become far-flung in wild bird populations.
Since the new strains have done so much more damage, the scientists looked for what was different.
The group identified the direct ancestor to the current strains, which spread from Europe to the Americas after gaining a different version of the viral protein, neuraminidase.
This new protein increased the virus’s ability to transmit between birds. Then it arrived on the East Coast of Canada and traveled to the United States.
As the researchers studied the virus further, they pinpointed which viruses — distinct from previous ones — caused the current outbreaks. They found that after reaching North America, the virus rapidly changed again to become more virulent.
It mixed with flu viruses in North American wild birds, swapping several genes. This reassortment of genes had two effects.
One, the virus seemed to become even more adapted to the bird population, infecting many different types of birds. This included atypical hosts, such as buzzards and eagles, which typically do not get the flu.
Second, the virus gained its severe disease-causing properties.

For further reference on H5N1 Virus, refer – https://optimizeias.com/avian-flu/