Antibiotic resistance happens when bugs become immune to existing drugs, allowing minor injuries and common infections to become deadly.
This happens naturally, but overuse and misuse of the drugs dramatically speeds up resistance, WHO said, voicing alarm at the results of a worldwide study showing that misconceptions about the threat are widespread, prompting dangerous behaviours.
"The rise of antibiotic resistance is a global health crisis. More and more governments recognise (it is) one of the greatest threats to health today," WHO chief Margaret Chan told reporters, stressing that worldwide, resistance was "reaching dangerously high levels."
Working antibiotics are also vital to protect babies born prematurely, people going through cancer treatments or undergoing routine surgery, she said, warning that if left unchecked drug resistance "will mean the end of modern medicine as we know it."
More From This Section
WHO's 12-country survey published today found that nearly two thirds of all those questioned (64 per cent) believe wrongly that antibiotics can be used to treat colds and flu, despite the fact that the drugs have no impact on viruses.
And nearly half thought antibiotic resistance was only a problem for people who take the drugs regularly, when in fact, anyone, of any age and anywhere, can get an antibiotic-resistant infection.
Around a third meanwhile believed it was best to stop an antibiotic treatment as soon as they felt better, rather than completing the prescribed course of treatment, the survey showed.