GENEVA (AFP) - Antibiotic resistance, which can turn common ailments into killers, has reached dangerous levels worldwide, the World Health Organization warned on Monday (Nov 16), saying users still know too little about how antibiotics work.

Antibiotic resistance happens when bugs become immune to existing drugs, allowing minor injuries and common infections to become deadly.

Overuse and misuse of the drugs increases this resistance, but WHO also published a survey of 10,000 people worldwide showing a range of dangerous misconceptions about the threat, which are allowing it to prosper.

"The rise of antibiotic resistance is a global health crisis, and governments now recognise it as one of the greatest challenges for public health today," WHO chief Margaret Chan said in a statement, stressing that resistance was "reaching dangerously high levels in all parts of the world."

"Antibiotic resistance is compromising our ability to treat infectious diseases and undermining many advances in medicine," she warned.

WHO's 12-country survey published on Monday 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.

The survey, conducted in Barbados, China, Egypt, India, Indonesia, Mexico, Nigeria, Russia, Serbia, South Africa, Sudan and Vietnam, also showed that 66 per cent believe that there is no risk of antibiotic resistance for people who take their antibiotics as prescribed.

And nearly half (44 per cent) 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.

"The findings of this survey point to the urgent need to improve understanding around antibiotic resistance," Keiji Fukuda, the UN chief's special representative on antimicrobial resistance, said in the statement.

Along with its survey, WHO launched a campaign on Monday called "Antibiotics: Handle with care", aimed at raising awareness about the problem, and correcting such misconceptions.

"This campaign is just one of the ways we are working with governments, health authorities and other partners to reduce antibiotic resistance," Fukuda said.

"One of the biggest health challenges of the 21st century will require global behaviour change by individuals and societies," he added.

A WHO report in April showed there were "major gaps" in all regions of the world in addressing the problem and reining in overuse and misuse of antibiotics.

The UN health agency has warned that without urgent action, the world could be headed for "a post-antibiotic era" in which common infections and minor injuries that have long been treatable once again become killers.

The survey published on Monday showed a dire lack of understanding of the problem and widespread dangerous behaviour.

Broken down by country, the survey for instance showed that 5 per cent of Chinese respondents who had taken antibiotics in the past six months had purchased them on the Internet, while the same percentage in Nigeria had bought them from a stall or hawker.

In Russia, only 56 per cent of those who had taken antibiotics in the past year had them prescribed by a doctor or nurse.