Warnings over the spread of bird flu come after the World Health Organization said people should not assume the risk to humans will always remain low. Countries have suffered huge numbers of bird deaths since an outbreak of H5N1 began in late 2021, and it has spread to mammals.
An outbreak of bird flu spreading across the US is “wiping out everything in numbers we’ve never seen before”, scientists have warned.
The country has suffered before from the H5N8 strain, which saw 50 million poultry birds culled in 2015.
But the more contagious H5N1 strain is causing different problems, as it spreads through the wild bird population.
Between late 2021 and October last year, it had resulted in the deaths of tens of thousands of wild birds – notably colonial nesting birds, seabirds, and raptors.
As a result, more than 58 million poultry were either infected or had to be culled throughout the US – and more than seven million in Canada.
Professor Jennifer Mullinax, of the University of Maryland, said the outbreak was “unprecedented”.
She described her university’s findings, based on data regarding the current US outbreak and global incidence from 2014 until early 2023, as a “call to arms” for government agencies and the agriculture sector to act.
“We are all going to have to deal with this together, because we can’t afford not to,” she said.