H5N1 kills 50 million birds, spreads to mammals Premium

Learn about the spread of H5N1, which has caused 50 million bird deaths and has now spread to mammals. Read more on The Hindu.

This year, the world has been witnessing one of the worst-ever documented outbreak of the highly pathogenic avian influenza H5N1 killing millions of birds. The virus, which is known to cause severe disease and death in birds, has also been detected in mammalian species and also in humans.

This has put health authorities on high alert regarding the implications of the large outbreak on public health.

Although avian influenza has different subtypes, H5N1 is a highly pathogenic subtype that causes mortality in birds. Since 2022, the virus has infected over 100 million birds across the globe, resulting in the deaths of over 50 million and culling of millions of poultry. Unlike previous outbreaks of highly pathogenic subtypes of avian influenza, H5N1 is heavily impacting wild bird species, including many which were on the verge of extinction.

While it is difficult to ascertain how many wild birds have been affected by the virus, a significant impact has been seen in eagles, pelicans, geese, waterfowl, gulls, falcons and shorebirds, in addition to the highest possible impact on poultry seen till date, at least in the U.S. 

The impact of H5N1 on wild bird populations has varied depending on several factors, such as level of exposure, geographical locations and migratory patterns of the affected species.

High mortality in wild birds due to the virus could lead to significant ecological consequences, including vulnerability of predators and alterations in species composition in affected ecosystems, and therefore a possible impact on biodiversity not just limited to avian species.

It has raised concerns regarding the spread of the virus among critically endangered avian populations.