Mammalian spread of H5N1 and its pandemic potential

Subject : Science and technology

Section: Health

Concept :

Avian influenza (bird flu) is a highly contagious viral infection that impacts birds. However, rarely it can infect mammals through a phenomenon called spillover, and spread among them.
There are various subtypes of avian influenza viruses that range from low pathogenic to highly pathogenic types. One of the highly pathogenic subtypes is H5N1.
Apart from causing severe disease and death in birds, H5N1 has also caused human infections through close contact with infected birds or contaminated environments. It is often fatal.
Several instances of the spread of H5N1 among mammals have been reported. Concerns are raised about its spillover among humans and the risks of the human pandemic.

Associated concerns of H5N1 Spread

The H5N1 can potentially impact mammals like ferrets, minks, seals, and domestic cats when during their contact with infected birds or their feces or while consuming the infected carcasses.
They can further serve as reservoirs. Moreover, the virus could evolve to adapt to new hosts and might lead to further outbreaks.
Along Russia’s Caspian Sea coast there was a mass mortality event that killed nearly 700 seals. Scientists are investigating the potential mammalian spillover as an H5N1 variant was detected in wild birds of the region a few months ago.
Similarly, in February 2023, Peru registered cases of H5N1 in sea lions and a dolphin. Additionally, a lion in a zoo also died from H5N1.
The U.K. communicated the cases of otters’ and foxes’ death due to H5N1 infection.
Notably, wildlife ranging from foxes, coyotes, and raccoons scavenge on infected birds or bird carcasses.
It was found that the only recorded incidents of intra-mammal transmission of the virus were among mink in captivity at a farm in Spain (in 2022).

H5N1 outbreaks cause severe economic impacts such as: