Bugs that are resistant to antibiotics could pose more of a risk to humanity than climate change, England’s chief medical officer has warned.
Professor Dame Sally Davies said antimicrobial resistance could soon kill at least 10 million people per year and wipe out humanity "before climate change does".
The over-use of antibiotics in medicine and agriculture can lead to the bugs they are designed to kill becoming resistant.
If antibiotics stop working, something as small as a minor infection could prove fatal, Dame Sally warned.
“We humans are doing it to ourselves, but it could kill us before climate change does,” she told Sky News.
“It is a very important area and we are under-investing in sorting it out.
“Antibiotics underpin modern medicine - you can't have gut surgery, replacement hips, all sorts of surgery without risking infection.
“At least 10 million could die every year if we don't get on top of this.”
According to Government data, since 2014 the UK has cut the amount of antibiotics it uses by more than 7% and sales of antibiotics for use in food-producing animals has dropped by 40%.
But the number of drug-resistant bloodstream infections rose by 35% between 2013 and 2017.
Professor Dame Sally Davies cautioned the post-Brexit UK against importing meat or fish from countries that "misuse" antibiotics while rearing livestock.
She said the UK "should not be importing beef or other animals where antibiotics have been misused and growth promotion is a misuse, in my book, because it leads to problems across the world."
Some strains of bugs including tuberculosis, MRSA and Clostridium difficile no longer respond to antibiotics that used to be effective against them.
There has also been a rise in so-called superbugs, which are resistant to not just one antibiotic but several or all of them.