Bird flu is a huge problem now – but we’re just one mutation away from it getting much worse | Devi Sridhar

If the H5N1 virus jumps into the human population and more dangerous strains emerge, it could set off a new pandemic

Lockdowns are a horrible experience, but fortunately one that is in the past now. Unless, that is, you're a domestic bird in Britain. Since 7 November, a UK directive has instructed all farmers to keep their birds indoors as part of a stringent measure to stop the spread of avian flu, or the H5N1 virus. This measure is intended to avoid infection of domestic birds from wild birds, and will result in tens of millions of chickens, ducks, geese and turkeys being brought inside for the foreseeable future. We've also seen island birds affected, resulting in the shutdown of human visitors to the Isle of May in Scotland for five weeks, among other measures.

Avian flu is known as one of the most infectious diseases: the R number, which was often discussed for the spread of Covid-19, can be as high as 100 for avian flu, meaning one bird can infect as many as 100 others. And the past few months have seen exponential spread of the virus, with Britain and Europe hit especially hard. A lab in Surrey that tests samples says it has seen a 600% increase in cases in the past three months.

Prof Devi Sridhar is chair of global public health at the University of Edinburgh