Rassegna Stampa

26 maggio 2022

Why unprecedented bird flu outbreaks sweeping the world are concerning scientists

Fonte: nature.com

Mass infections in wild birds pose a significant risk to vulnerable species, are hard to contain and increase the opportunity for the virus to spill over into people.

A highly infectious and deadly strain of avian influenza virus has infected tens of millions of poultry birds across Europe, Asia, Africa and North America. But scientists are particularly concerned about the unprecedented spread in wild birds — outbreaks pose a significant risk to vulnerable species, are hard to contain and increase the opportunity for the virus to spill over into people.

Since October, the H5N1 strain has caused nearly 3,000 outbreaks in poultry in dozens of countries. More than 77 million birds have been culled to curb the spread of the virus, which almost always causes severe disease or death in chickens. Another 400,000 non-poultry birds, such as wild birds, have also died in 2,600 outbreaks — twice the number reported during the last major wave, in 2016–17.

Researchers say that the virus seems to be spreading in wild birds more easily than ever before, making outbreaks particularly hard to contain. Wild birds help to transport the virus around the world, with their migration patterns determining when and where it will spread next. Regions in Asia and Europe will probably continue to see large outbreaks, and infections could creep into currently unaffected continents such as South America and Australia.