A Vietnamese man is fanned by his wife in the post-operative ward at Hanoi's Institute of Tuberculosis, where more and more people with TB cannot be cured due to antibiotic resistance. STR New/Reuters

Misuse of antibiotics has made drug resistance more severe and undermined treatments for diseases such as tuberculosis, malaria and gonorrhea, the World Health Organization warns.

The UN health agency marked World Health Day on Thursday to launch its "Combat Drug Resistance" campaign to limit the impact of resistance and preserve medical advances.

"In the absence of urgent corrective and protective actions, the world is heading towards a post-antibiotic era, in which many common infections will no longer have a cure and, once again, kill unabated," WHO director-general Margaret Chan said in a statement.

The group is calling on its 193 member states to:

• Develop and implement a comprehensive, financed national plan.
• Strengthen surveillance and laboratory capacity.
• Ensure uninterrupted access to essential medicines of assured quality.
• Regulate and promote rational use of medicines.
• Enhance infection prevention and control.
• Foster innovation and research and development for new tools.

Last year, at least 444,000 new cases of multidrug-resistant tuberculosis were detected, WHO said. Also, the malaria parasite is acquiring resistance to the latest generation of drugs and some hospital-acquired infections are becoming more difficult to treat worldwide.

Action is needed now because new drugs cannot be developed fast enough to replace drugs that have lost their effectiveness, said Dr. Michael O'Leary, the WHO's representative in China.

"Infections caused by resistant microorganisms often fail to respond to conventional treatment, resulting in prolonged illness and greater risk of death," O'Leary said.